Juan Carlos Fernandez-Miranda

All Publications

• Lateral compartment of the cavernous sinus from the endoscopic endonasal approach: anatomical considerations and surgical relevance to adenoma surgery. Journal of neurosurgery Xu, Y., Asmaro, K., Lee, C. K., Vigo, V., Mohyeldin, A., Nunez, M. A., Cohen-Gadol, A. A., Fernandez-Miranda, J. C. 2024: 1-13

  Abstract

  OBJECTIVE: The cavernous sinus (CS) has 4 compartments: superior, inferior, posterior, and lateral. Among these, the lateral compartment is the most common location for residual tumor, given the risk of neurovascular injury. The authors' study aimed to delineate the anatomical landmarks in this area and illustrate the technical nuances of the lateral transcavernous approach.METHODS: Twenty-two colored silicone-injected specimens were dissected via an endoscopic endonasal approach to the lateral compartment of the CS. The anatomical landmarks and the internal carotid artery (ICA) mobilization technique were investigated. Two illustrative cases are provided.RESULTS: The lateral compartment of the CS is bounded by the carotid-oculomotor membrane (COM) and optic strut as the roof and the petrolingual ligament and lingual process as the floor. It is divided into 2 asymmetrical subcompartments: the upper, larger subcompartment, located superior to the abducens nerve, accommodates the lateral parasellar ligament (LPL), inferolateral trunk (ILT), and branches of the tentorial artery; and the lower, smaller subcompartment, inferior to the abducens nerve, accommodates only the sympathetic nerve branches as they join the abducens nerve. The LPL is a well-defined ligamentous band and was identified in 38 (86%) hemispheres with 2 distinct configurations: 1) robust LPL (59%), with highly compacted ligamentous bands tightly adherent to the ICA; and 2) dispersed LPL (27%), with less compaction and adherence to ICA. The main attachment of the LPL to the cavernous ICA was most commonly observed at the horizontal ICA segment (55%), followed by the anterior (18%) and posterior (14%) genua. The ILT, as the main vessel in the lateral compartment, was identified in 41 (93%) hemispheres and originated from the horizontal ICA segment (80%) or the anterior genu (14%), from either the lateral (52%) or inferior (41%) aspect of the cross-section of the ICA. In 64% of hemispheres, the LPL wrapped the ILT, abducens nerve, and sympathetic nerve to form a broad and firm neurovascular-ligamental complex. Transection of the LPL, ILT, and COM enables medial ICA mobilization and enhances access to the lateral compartment of the CS, potentially increasing the exposure width by 6 ± 1 mm.CONCLUSIONS: This study provides valuable insights into the anatomical intricacies of the lateral compartment of the CS and underscores the potential benefits of the endoscopic endonasal lateral transcavernous approach. Further clinical applications are essential for validating these findings and optimizing surgical outcomes.

  View details for DOI 10.3171/2024.4.JNS232662

  View details for PubMedID 39126713

• Resection of corticotroph microadenomas invading the medial wall of the cavernous sinus in two cases of a primary and recurrent case of Cushing's disease. Neurosurgical focus: Video Mohyeldin, A., Nunez, M. A., Xu, Y., Fernandez-Miranda, J. C. 2023; 9 (1): V2

  Abstract

  Emerging evidence from multiple highly specialized groups continues to support a role for resection of the medial wall of the cavernous sinus when it is invaded by functional pituitary adenomas, to offer durable biochemical remission. The authors present two cases of Cushing's disease that underscore the power of this surgical technique in achieving remission in microadenomas that ectopically present in the cavernous sinus or have invaded the medial wall of the sinus. This video demonstrates key steps in the safe removal of the medial wall of the cavernous sinus and successful resection of tumor burden in the cavernous sinus for sustained postoperative remission. The video can be found here: https://stream.cadmore.media/r10.3171/2023.4.FOCVID2323.

  View details for DOI 10.3171/2023.4.FOCVID2323

  View details for PubMedID 37416808

• Supramarginal resection of skull base chordomas: proof of concept and preliminary outcomes NEUROSURGICAL FOCUS Rychen, J., Constanzo, F., Xu, Y., Johnstone, T. M., Bex, A., Rinaldi, M., Lee, C. K., Fernandez-Miranda, J. C. 2023; 56 (5): E3

  Abstract

  The mainstay of treatment for skull base chordoma (SBC) is maximal safe resection followed by radiotherapy. However, even after gross-total resection (GTR), the recurrence rate is high due to microscopic disease in the resection margins. Therefore, supramarginal resection (SMR) could be beneficial, as has been shown for sacral chordoma. The paradigm of postoperative radiation therapy for every patient has also begun to change, as molecular profiling has shown variability in the risk of recurrence. The aim of this study was to present the concept of SMR applied to SBC, along with an individualized decision for postoperative radiation therapy.This is a retrospective analysis of all SBCs operated on by the senior author between 2018 and 2023. SMR was defined as negative histological margins of bone and/or dura mater, along with evidence of bone resection beyond the tumor margins in the craniocaudal and lateral planes on postoperative imaging. Tumors were classified into 3 molecular recurrence risk groups (group A, low risk; group B, intermediate risk; and group C, high risk). Postoperative radiation therapy was indicated in group C tumors, in group B chordomas without SMR, or in cases of patient preference.Twenty-two cases of SBC fulfilled the inclusion criteria. SMR was achieved in 12 (55%) cases, with a mean (range) amount of bone resection beyond the tumor margins of 10 (2-20) mm (+40%) in the craniocaudal axis and 6 (1-15) mm (+31%) in the lateral plane. GTR and near-total resection were each achieved in 5 (23%) cases. Three (19%) tumors were classified as group A, 12 (75%) as group B, and 1 (6%) as group C. Although nonsignificant due to the small sample size, the trends showed that patients in the SMR group had smaller tumor volumes (13.9 vs 19.6 cm3, p = 0.35), fewer previous treatments (33% vs 60% of patients, p = 0.39), and less use of postoperative radiotherapy (25% vs 60%, p = 0.19) compared to patients in the non-SMR group. There were no significant differences in postoperative CSF leak (0% vs 10%, p = 0.45), persistent cranial nerve palsy (8% vs 20%, p = 0.57), and tumor recurrence (8% vs 10%, p = 0.99; mean follow-up 15 months) rates between the SMR and non-SMR groups.In select cases, SMR of SBC appears to be feasible and safe. Larger cohorts and longer follow-up evaluations are necessary to explore the benefit of SMR and individualized postoperative radiation therapy on progression-free survival.

  View details for DOI 10.3171/2024.2.FOCUS23909

  View details for Web of Science ID 001224534800001

  View details for PubMedID 38691859

• Cytodifferentiation of pituitary tumors influences pathogenesis and cavernous sinus invasion. Journal of neurosurgery Asmaro, K., Zhang, M., Rodrigues, A. J., Mohyeldin, A., Vigo, V., Nernekli, K., Vogel, H., Born, D. E., Katznelson, L., Fernandez-Miranda, J. C. 2023: 1-9

  Abstract

  Pituitary tumors (PTs) continue to present unique challenges given their proximity to the cavernous sinus, whereby invasive behavior can limit the extent of resection and surgical outcome, especially in functional tumors. The aim of this study was to elucidate patterns of cavernoinvasive behavior by PT subtype.A total of 169 consecutive first-time surgeries for PTs were analyzed; 45% of the tumors were functional. There were 64 pituitary transcription factor-1 (PIT-1)-expressing, 62 steroidogenic factor-1 (SF-1)-expressing, 38 T-box transcription factor (TPIT)-expressing, and 5 nonstaining PTs. The gold standard for cavernous sinus invasion (CSI) was based on histopathological examination of the cavernous sinus medial wall and intraoperative exploration.Cavernous sinus disease was present in 33% of patients. Of the Knosp grade 3 and 4 tumors, 12 (19%) expressed PIT-1, 7 (11%) expressed SF-1, 8 (21%) expressed TPIT, and 2 (40%), were nonstaining (p = 0.36). PIT-1 tumors had a significantly higher predilection for CSI: 53% versus 24% and 18% for TPIT and SF-1 tumors, respectively (OR 6.08, 95% CI 2.86-13.55; p < 0.001). Microscopic CSI-defined as Knosp grade 0-2 tumors with confirmed invasion-was present in 44% of PIT-1 tumors compared with 7% and 13% of TPIT and SF-1 tumors, respectively (OR 11.72, 95% CI 4.35-35.50; p < 0.001). Using the transcavernous approach to excise cavernous sinus disease, surgical biochemical remission rates for patients with acromegaly, prolactinoma, and Cushing disease were 88%, 87%, and 100%, respectively. The granule density of PIT-1 tumors and corticotroph functional status did not influence CSI.The likelihood of CSI differed by transcription factor expression; PIT-1-expressing tumors had a higher predilection for invading the cavernous sinus, particularly microscopically, compared with the other tumor subtypes. This elucidates a unique cavernoinvasive behavior absent in cells from other lineages. Innovative surgical techniques, however, can mitigate tumor behavior and achieve robust, reproducible biochemical remission and gross-total resection rates. These findings can have considerable implications on the surgical management and study of PT biology and behavior.

  View details for DOI 10.3171/2023.3.JNS221949

  View details for PubMedID 37119095

• The Pterygosphenoidal Triangle: Surgical Anatomy and Case Series in Endoscopic Endonasal Skull Base Surgery. Operative neurosurgery (Hagerstown, Md.) Xu, Y., Asmaro, K., Mohyeldin, A., Zhang, M., Nunez, M. A., Mao, Y., Cohen-Gadol, A. A., Fernandez-Miranda, J. C. 2023

  Abstract

  BACKGROUND: Safe exposure of the lacerum segment of the carotid artery remains a challenge in endoscopic endonasal surgery.OBJECTIVE: To introduce the pterygosphenoidal triangle as a novel and reliable landmark for facilitating access to the foramen lacerum.METHODS: Fifteen colored silicone-injected anatomic specimens were dissected using an endoscopic endonasal approach to the foramen lacerum region in a stepwise manner. Twelve dried skulls were studied and 30 high-resolution computed tomography scans were analyzed to measure the borders and angles of the pterygosphenoidal triangle. Surgical cases incorporating the foramen lacerum exposure between July 2018 and December 2021 were reviewed to provide surgical outcomes of the proposed surgical technique.RESULTS: The pterygosphenoidal triangle is delineated by the pterygosphenoidal fissure medially and the vidian nerve laterally. The palatovaginal artery is located at the base of the triangle anteriorly, while the apex is formed by the pterygoid tubercle posteriorly, which leads to the anterior wall of the foramen lacerum and lacerum internal carotid artery. In the reviewed surgical cases, 39 patients underwent 46 foramen lacerum approaches for resection of pituitary adenoma (12 patients), meningioma (6 patients), chondrosarcoma (5 patients), chordoma (5 patients), or other lesions (11 patients). There were no carotid injuries or ischemic events. Near-total resection was achieved in 33 (85%) of 39 patients (gross-total in 20 [51%]).CONCLUSION: This study details the pterygosphenoidal triangle as a novel and practical anatomic surgical landmark for safe and effective exposure of the foramen lacerum in endoscopic endonasal surgery.

  View details for DOI 10.1227/ons.0000000000000627

  View details for PubMedID 37071748

• Prospective intraoperative and histologic evaluation of cavernous sinus medial wall invasion by pituitary adenomas and its implications for acromegaly remission outcomes. Scientific reports Mohyeldin, A., Katznelson, L. J., Hoffman, A. R., Asmaro, K., Ahmadian, S. S., Eltobgy, M. M., Nayak, J. V., Patel, Z. M., Hwang, P. H., Fernandez-Miranda, J. C. 2022; 12 (1): 9919

  Abstract

  Recurrence and biochemical remission rates vary widely among different histological subtypes of pituitary adenoma. In this prospective study, we evaluated 107 consecutive primary pituitary adenomas operated on by a single neurosurgeon including 28 corticotroph, 27 gonadotroph, 24 somatotroph, 17 lactotroph, 5 null-cell and 6 plurihormonal. In each case, we performed direct endoscopic intraoperative inspection of the medial wall of the cavernous sinus, which was surgically removed when invasion was visualized. This was performed irrespective of tumor functional status. Medial wall resection was performed in 47% of pituitary adenomas, and 39/50 walls confirmed pathologic evidence of invasion, rendering a positive predictive value of intraoperative evaluation of medial wall invasion of 78%. We show for the first-time dramatic disparities in the frequency of medial wall invasion among pathological subtypes. Somatotroph tumors invaded the medial wall much more often than other adenoma subtypes, 81% intraoperatively and 69% histologically, followed by plurihormonal tumors (40%) and gonadotroph cell tumors (33%), both with intraoperative positive predictive value of 100%. The least likely to invade were corticotroph adenomas, at a rate of 32% intraoperatively and 21% histologically, and null-cell adenomas at 0%. Removal of the cavernous sinus medial wall was not associated with permanent cranial nerve morbidity nor carotid artery injury, although 4 patients (all Knosp 3-4) experienced transient diplopia. Medial wall resection in acromegaly resulted in the highest potential for biochemical remission ever reported, with an average postoperative day 1 GH levels of 0.96 ug/L and surgical remission rates of 92% based on normalization of IGF-1 levels after surgery (mean = 15.56 months; range 3-30 months). Our findings suggest that tumor invasion of the medial wall of the cavernous sinus may explain the relatively low biochemical remission rates currently seen for acromegaly and illustrate the relevance of advanced intradural surgical approaches for successful and durable outcomes in endonasal pituitary surgery for functional adenomas.

  View details for DOI 10.1038/s41598-022-12980-1

  View details for PubMedID 35705579

• Microsurgical anatomy of the dorsal clinoidal space: implications for endoscopic endonasal parasellar surgery. Journal of neurosurgery Xu, Y., Nunez, M. A., Mohyeldin, A., Vigo, V., Mao, Y., Cohen-Gadol, A. A., Fernandez-Miranda, J. C. 2022: 1-13

  Abstract

  OBJECTIVE: The clinoidal venous space dorsal to the internal carotid artery (ICA) has not been well studied given its inaccessibility due to obstruction by the ICA during transcranial surgery. The evolution of endoscopic endonasal surgery has provided a new perspective into the clinoidal space and a new route for paraclinoidal lesions. Understanding the dorsal clinoidal space (DCS) is vital in planning and performing endoscopic endonasal surgery in the parasellar region. A detailed and precise description of the DCS from the endonasal perspective has not yet been provided. The authors' goal in this study was to delineate the microsurgical anatomy of the DCS from an endoscopic endonasal perspective, emphasizing its surgical implications when treating invasive pituitary adenomas and other parasellar lesions.METHODS: An endoscopic endonasal transsellar approach was performed in 15 silicone-injected postmortem heads. Afterward, the sellar region was dissected through a transcranial approach using magnification *3 to *40 microscopy. The osseous, dural, and arterial relationships of the DCS and its architecture were investigated. The DCS's length, width, and depth were measured and its anatomical variations recorded.RESULTS: The DCS was identified in 90% of the specimens, and in most cases, its shape was a narrow rectangular pyramid, with its base oriented toward the sphenoid sinus and its apex toward the posterior clinoid process. It is delimited superiorly by the distal ring, inferiorly by the medial aspect of the proximal dural ring or caroticoclinoid ligament, laterally by the clinoidal ICA, and medially by the superior continuation of the medial wall of the cavernous sinus. The width, height, and length of the DCS were 4 ± 1, 4.5 ± 1.5, and 7 ± 2 mm, respectively. A fenestrated caroticoclinoid ligament is a potential route for tumor invasion from the cavernous sinus into the DCS.CONCLUSIONS: This report provides important anatomical descriptions of the DCS from endoscopic endonasal and transcranial perspectives that may facilitate the space's safe exposure for the removal of invasive adenomas, increasing total resection rates and minimizing the risk of injury to neurovascular structures.

  View details for DOI 10.3171/2021.12.JNS211974

  View details for PubMedID 35120312

• Microsurgical anatomy and the importance of the petrosal process of the sphenoid bone in endonasal surgery JOURNAL OF NEUROSURGERY Doniz-Gonzalez, A., Vigo, V., Nunez, M., Xu, Y., Mohyeldin, A., Cohen-Gadol, A. A., Fernandez-Miranda, J. C. 2021; 137 (5): 1431-1442

  View details for DOI 10.3171/2021.12.JNS212024.

  View details for Web of Science ID 000891788200002

• Proximal Branches of the Anterior Cerebral Artery: Anatomic Study and Applications to Endoscopic Endonasal Surgery. Operative neurosurgery (Hagerstown, Md.) Najera, E., Truong, H. Q., Belo, J. T., Borghei-Razavi, H., Gardner, P. A., Fernandez-Miranda, J. 2019

  Abstract

  BACKGROUND: The endoscopic endonasal approach is a surgical alternative for midline anterior skull base tumors. A detailed understanding of the proximal anterior cerebral artery (ACA) branches' anatomy from an endonasal perspective is essential for avoiding vascular complications.OBJECTIVE: To evaluate, from an endonasal perspective, the anatomic variations of the ACA and its proximal branches, specifically the recurrent artery of Heubner (RAH), and the fronto-orbital (FOA) and frontopolar (FPA) arteries.METHODS: We study the origin, course, branching pattern, diameter, and relationship between the proximal ACA branches and the optic apparatus and olfactory tract in 25 head specimens.RESULTS: The RAH was present in all hemispheres and originated within 3±1.5 mm of the AcomA, with a 0.4±0.1 mm diameter. Based on its relationship with the A1 segment, we observed three RAH courses: anterior (40%), superior (22%), and posterior (38%). The FOA was present in all cases, a mean of 6±4 mm from the AcomA, with a 0.7±0.4 mm diameter. The FOA arose mainly from the A2 (70%), with three courses in relation to the olfactory tract: crossing its proximal third (54%), crossing its middle third (31%), and running parallel to it along the gyrus rectus (15%). The FPA was present in 92% of the hemispheres, a mean of 10±5 mm from the AcomA, always arising from the A2 and coursing anteriorly within the interhemispheric fissure towards the frontal pole.CONCLUSION: The RAH, FOA, and FPA can be differentiated by origin, course, and destination using the A1 segment, olfactory tract, and interhemispheric fissure, respectively, as surgical landmarks.

  View details for PubMedID 30649510

• Proposal and Validation of a Simple Grading Scale (TRANSSPHER Grade) for Predicting Gross Total Resection of Nonfunctioning Pituitary Macroadenomas After Transsphenoidal Surgery. Operative neurosurgery (Hagerstown, Md.) Mooney, M. A., Sarris, C. E., Zhou, J. J., Barkhoudarian, G., Chicoine, M. R., Fernandez-Miranda, J. C., Gardner, P. A., Hardesty, D. A., Jahnke, H., Kelly, D. F., Liebelt, B. D., Mayberg, M. R., Prevedello, D. M., Sfondouris, J., Sheehy, J. P., Chandler, J. P., Yuen, K. C., White, W. L., Little, A. S., TRANSSPHER Study Group 2019

  Abstract

  BACKGROUND: A simple, reliable grading scale to better characterize nonfunctioning pituitary adenomas (NFPAs) preoperatively has potential for research and clinical applications.OBJECTIVE: To develop a grading scale from a prospective multicenter cohort of patients that accurately and reliably predicts the likelihood of gross total resection (GTR) after transsphenoidal NFPA surgery.METHODS: Extent-of-resection (EOR) data from a prospective multicenter study in transsphenoidal NFPA surgery were analyzed (TRANSSPHER study; ClinicalTrials.gov NCT02357498). Sixteen preoperative radiographic magnetic resonance imaging (MRI) tumor characteristics (eg, tumor size, invasion measures, tumor signal characteristics, and parameters impacting surgical access) were evaluated to determine EOR predictors, to calculate receiver-operating characteristic curves, and to develop a grading scale. A separate validation cohort (n=165) was examined to assess the scale's performance and inter-rater reliability.RESULTS: Data for 222 patients from 7 centers treated by 15 surgeons were analyzed. Approximately one-fifth of patients (18.5%; 41 of 222) underwent subtotal resection (STR). Maximum tumor diameter>40 mm; nodular tumor extension through the diaphragma into the frontal lobe, temporal lobe, posterior fossa, or ventricle; and Knosp grades 3 to 4 were identified as independent STR predictors. A grading scale (TRANSSPHER grade) based on a combination of these 3 features outperformed individual variables in predicting GTR (AUC, 0.732). In a validation cohort, the scale exhibited high sensitivity and specificity (AUC, 0.779) and strong inter-rater reliability (kappa coefficient, 0.617).CONCLUSION: This simple, reliable grading scale based on preoperative MRI characteristics can be used to better characterize NFPAs for clinical and research purposes and to predict the likelihood of achieving GTR.

  View details for PubMedID 30649445

• Left Pan-Hippocampal Low Grade Glioma-2-Stage Transsylvian Transventricular and Paramedian Supracerebellar Transtentorial Approaches: 2-Dimensional Operative Video. Operative neurosurgery (Hagerstown, Md.) Fernandez-Miranda, J. C. 2018

  Abstract

  The surgical goal for low-grade gliomas (LGGs) is to maximize resection while minimizing morbidity. Pan-hippocampal LGGs extend from the hippocampal head to the hippocampal tail, and involve the parahippocampal gyrus and uncus. Given their anteroposterior extension, they cannot be completely removed with 1 single approach, requiring a 2-stage front-to-back operation.In this video, we present the case of a 52-yr-old man with new onset of generalized seizures and a dominant-side, nonenhancing, pan-hippocampal infiltrative lesion compatible with a low-grade glioma. Preoperative high-definition fiber tractography (HDFT) showed the spatial relationship of the tumor with surrounding fiber tracts, such as the arcuate, inferior fronto-occipital, and middle longitudinal fascicles, and optic radiations.Surgical resection was planned in 2 separate stages. The first stage consisted of a transsylvian transinferior insular sulcus approach to the extra- and intraventricular aspects of the uncohippocampal region. The entire anterior and middle portions of the tumor were successfully removed with minimal morbidity, including transient naming difficulties and permanent superior quadrantanopia. Postoperative HDFT showed preservation of all fiber tracts, except for a portion of Meyer's loop and the inferior-most aspect of the inferior fronto-occipital fascicle. The second stage was completed 8 wk later and consisted of a paramedian supracerebellar-transtentorial approach on sitting position. The posterior portion of the tumor was entirely removed to achieve a complete macroscopic tumor resection. The final diagnosis was IDH1-positive LGG.Pan-hippocampal tumors remain a surgical challenge but accurate knowledge of surgical neuroanatomy and surgical approaches facilitates their safe and effective treatment.The patient signed an informed consent including the use of photographic and video material for educational or academic purposes.

  View details for PubMedID 30295907

• Paramedian Supracerebellar Approach in Semi-Sitting Position for Endoscopic Resection of Pineal Cyst: 2-Dimensional Operative Video. Operative neurosurgery (Hagerstown, Md.) Fernandez-Miranda, J. C. 2018

  Abstract

  In this video, we present the case of a 41-yr-old female with new onset of recurrent syncopal episodes. She underwent extensive evaluations and diagnostic work-up by cardiology and neurology, excluding any other cause than a large pineal cyst that was found on magnetic resonance imaging.Surgical indications for pineal cyst resection are very limited as most pineal cyst can be treated conservatively. Recurrent drop-attacks (without loss of consciousness) or syncopal episodes (with brief loss of consciousness) have been associated with pineal cysts secondary to a possible ball valve effect with shift of position causing sudden obstruction of the ventricular system followed by rapid rising of intracranial pressure.Several approaches, different positions, and alternative surgical techniques (microscopic vs endoscopic) have been proposed for resection of pineal region lesions. The semi-sitting position provides excellent exposure of the pineal region secondary to gravity-based retraction of the cerebellum, and carries minimal risk of air venous embolism when head elevation is reduced to 30° and lower extremities are elevated. The paramedian supracerebellar approach is less invasive and faster than midline supracerebellar approach, because it requires exposure of just 1 transverse sinus (nondominant for centered lesions) and avoids exposure of the torcula. The endoscopic technique greatly improves the ergonomics of the approach when compared to the microscope based technique, and provides excellent visualization of all the neurovascular structures in the pineal region.Surgical resection was successfully performed with no complications and complete cyst resection. Patient was discharged on postoperative day 1 and remains free of syncopal episodes.The patient signed informed consent including the use of photographic and video material for educational or academic purposes.

  View details for PubMedID 30295900

• The medial wall of the cavernous sinus. Part 1: Surgical anatomy, ligaments, and surgical technique for its mobilization and/or resection. Journal of neurosurgery Truong, H. Q., Lieber, S., Najera, E., Alves-Belo, J. T., Gardner, P. A., Fernandez-Miranda, J. C. 2018: 1–9

  Abstract

  OBJECTIVE The medial wall of the cavernous sinus (CS) is often invaded by pituitary adenomas. Surgical mobilization and/or removal of the medial wall remains a challenge. METHODS Endoscopic endonasal dissection was performed in 20 human cadaver heads. The configuration of the medial wall, its relationship to the internal carotid artery (ICA), and the ligamentous connections in between them were investigated in 40 CSs. RESULTS The medial wall of the CS was confirmed to be an intact single layer of dura that is distinct from the capsule of the pituitary gland and the periosteal layer that forms the anterior wall of the CS. In 32.5% of hemispheres, the medial wall was indented by and/or well adhered to the cavernous ICA. The authors identified multiple ligamentous fibers that anchored the medial wall to other walls of the CS and/or to specific ICA segments. These parasellar ligaments were classified into 4 groups: 1) caroticoclinoid ligament, spanning from the medial wall and the middle clinoid toward the clinoid ICA segment and anterior clinoid process; 2) superior parasellar ligament, connecting the medial wall to the horizontal cavernous ICA and/or lateral wall of the CS; 3) inferior parasellar ligament, bridging the medial wall to the anterior wall of the CS or anterior surface of the short vertical segment of the cavernous ICA; and 4) posterior parasellar ligament, which anchors the medial wall to the short vertical segment of the cavernous ICA and/or the posterior carotid sulcus. The caroticoclinoid ligament and inferior parasellar ligament were present in most CSs (97.7% and 95%, respectively), while the superior and posterior parasellar ligaments were identified in approximately half of the CSs (57.5% and 45%, respectively). The caroticoclinoid ligament was the strongest and largest ligament, and it was typically assembled as a group of ligaments with a fan-like arrangement. The inferior parasellar ligament was the first to be encountered after opening the anterior wall of the CS during an interdural transcavernous approach. CONCLUSIONS The authors introduce a classification of the parasellar ligaments and their role in anchoring the medial wall of the CS. These ligaments should be identified and transected to safely mobilize the medial wall away from the cavernous ICA during a transcavernous approach and for safe and complete resection of adenomas that selectively invade the medial wall.

  View details for DOI 10.3171/2018.3.JNS18596

  View details for PubMedID 30192192

• Supratotal Resection of Residual Clival Chordoma With Combined Endoscopic Endonasal and Contralateral Transmaxillary Approaches: 2-Dimensional Operative Video. Operative neurosurgery (Hagerstown, Md.) Lavigne, P., Wang, E. W., Fernandez-Miranda, J. C. 2018

  Abstract

  The optimal treatment for skull base chordomas is gross total resection followed by radiotherapy and not radiation of partially resected tumors. Supratotal resection, defined as removal beyond all involved bone and dura, is ideal but difficult to achieve.In this video, we present the case of a 37-yr-old man with new onset of progressive cranial nerve sixth palsy and a skull base lesion compatible with clival chordoma. He underwent partial surgical resection at an outside institution via transcranial approach, with significant tumor residual at the clivus, dorsum sella, posterior clinoids, and petrous apex, extensive dural invasion, and intradural extension with attachment to the basilar artery and its long perforating branches.Supratotal surgical resection was achieved using an endoscopic endonasal transclival approach, ipsilateral transpteryoid approach to the foramen lacerum for carotid artery mobilization, bilateral interdural transcavernous approach with posterior clinoidectomies, and con-tralateral transmaxillary approach to the petrous apex. Reconstruction was performed in a multilayer fashion with fascia lata and fat grafts, extended nasoseptal flap, a lumbar drainage for 3 d. No cerebrospinal fluid leak occurred, and the abducens nerve palsy significantly improved at 3-mo follow-up. Proton therapy is planned.Recent advances in endoscopic endonasal surgery allow for very high rates of complete and even supratotal resection despite the challenging location. A long learning curve to acquire the technical skills and complex surgical anatomy is required to decrease complication rates and achieve maximal resection in chordomas. Reoperations are more challenging and risky; therefore, first attempt should have curative intent.The patient signed informed consent including the use of photographic and video material for educational or academic purposes.

  View details for PubMedID 30189024

• Bilateral coagulation of inferior hypophyseal artery and pituitary transposition during endoscopic endonasal interdural posterior clinoidectomy: do they affect pituitary function? Journal of neurosurgery Truong, H. Q., Borghei-Razavi, H., Najera, E., Igami Nakassa, A. C., Wang, E. W., Snyderman, C. H., Gardner, P. A., Fernandez-Miranda, J. C. 2018: 1–6

  Abstract

  OBJECTIVE The endoscopic endonasal transcavernous approach with interdural pituitary transposition provides surgical access to the posterior clinoids and interpeduncular cistern. Prior to posterior clinoidectomy, selective coagulation and transection of the inferior hypophyseal artery (IHA) is recommended to prevent uncontrolled tearing of the artery and its avulsion from the wall of the cavernous carotid artery. The authors' preliminary experience has shown that unilateral sacrifice of the IHA caused no permanent endocrine dysfunction. In this study, they investigated the pituitary function in the setting of bilateral sacrifice of IHAs and pituitary transposition. METHODS All patients with normal preoperative pituitary function who underwent endoscopic endonasal bilateral posterior clinoidectomy with bilateral IHA sacrifice between March 2010 and December 2016 were included and retrospectively evaluated. All data regarding pituitary function were collected. The degree of pituitary gland manipulation was estimated based on tumor size on preoperative MRI. An angle between a line from the point where the gland meets the floor of the sella to the highest point of the tumor and the horizontal plane of the sellar floor, or access angle, was also measured. Posterior pituitary bright spots on pre- and postoperative T1-weighted MRI were also reported. RESULTS Twenty patients had bilateral transcavernous posterior clinoidectomies with coagulation of both IHAs. There were 13 chordomas, 3 epidermoid cysts, 2 chondrosarcomas, 1 meningioma, and 1 hemangiopericytoma. The mean follow-up was 19 months (range 13-84 months). Two patients experienced transient diabetes insipidus (DI) requiring desmopressin, which resolved before hospital discharge. One patient (with chordoma) developed delayed permanent DI, and a second patient (with hemangiopericytoma) developed permanent DI and panhypopituitarism. The access angle was higher in the group with pituitary dysfunction (47.25° compared to 33.81°; p = 0.07). Posterior pituitary bright spots were preserved in 75% of cases with normal postoperative endocrine function. CONCLUSIONS The endoscopic endonasal transcavernous approach to the interpeduncular cistern with pituitary transposition and bilateral sacrifice of the IHAs does not cause pituitary dysfunction in a majority of patients. When endocrine deficit occurs, it appears to be more likely to have been caused by surgical manipulation than loss of blood supply. This finding confirms clinically the crucial concept of interarterial anastomosis of pituitary vasculature proposed by anatomists.

  View details for PubMedID 30074461

• Cavernous sinus compartments from the endoscopic endonasal approach: anatomical considerations and surgical relevance to adenoma surgery JOURNAL OF NEUROSURGERY Fernandez-Miranda, J. C., Zwagerman, N. T., Abhinav, K., Lieber, S., Wang, E. W., Snyderman, C. H., Gardner, P. A. 2018; 129 (2): 430-441

  View details for DOI 10.3171/2017.2.JNS162214

  View details for Web of Science ID 000440659400017

• Contralateral transmaxillary corridor: an augmented endoscopic approach to the petrous apex JOURNAL OF NEUROSURGERY Patel, C. R., Wang, E. W., Fernandez-Miranda, J. C., Gardner, P. A., Snyderman, C. H. 2018; 129 (1): 211–19

  Abstract

  OBJECTIVE The endoscopic endonasal approach (EEA) has been shown to be an effective means of accessing lesions of the petrous apex. Lesions that are lateral to the paraclival segment of the internal carotid artery (ICA) require lateralization of the paraclival segment of the ICA or a transpterygoid infrapetrous approach. In this study the authors studied the feasibility of adding a contralateral transmaxillary (CTM) corridor to provide greater access to the petrous apex with decreased need for manipulation of the ICA. METHODS Using image guidance, EEA and CTM extension were performed bilaterally on 5 cadavers. The anterior wall of the sphenoid sinus and rostrum were removed. The angle of the surgical approach from the axis of the petrous segment of the ICA was measured. Five illustrative clinical cases are presented. RESULTS The CTM corridor required a partial medial maxillectomy. When measured from the axis of the petrous ICA, the CTM corridor decreased the angle from 44.8° ± 2.78° to 20.1° ± 4.31°, a decrease of 24.7° ± 2.58°. Drilling through the CTM corridor allowed the drill to reach lateral aspects of the petrous apex that would have required lateralization of the ICA or would not have been accessible via EEA. The CTM corridor allowed us to achieve gross-total resection of the petrous apex region in 5 clinical cases with significant paraclival extension. CONCLUSIONS The CTM corridor is a feasible extension to the standard EEA to the petrous apex that offers a more lateral trajectory with improved access. This approach may reduce the risk and morbidity associated with manipulation of the paraclival ICA.

  View details for PubMedID 29053078

• Cavernous sinus compartments from the endoscopic endonasal approach: anatomical considerations and surgical relevance to adenoma surgery. Journal of neurosurgery Fernandez-Miranda, J. C., Zwagerman, N. T., Abhinav, K., Lieber, S., Wang, E. W., Snyderman, C. H., Gardner, P. A. 2017: 1–12

  Abstract

  OBJECTIVE Tumors with cavernous sinus (CS) invasion represent a neurosurgical challenge. Increasing application of the endoscopic endonasal approach (EEA) requires a thorough understanding of the CS anatomy from an endonasal perspective. In this study, the authors aimed to develop a surgical anatomy-based classification of the CS and establish its utility for preoperative surgical planning and intraoperative guidance in adenoma surgery. METHODS Twenty-five colored silicon-injected human head specimens were used for endonasal and transcranial dissections of the CS. Pre- and postoperative MRI studies of 98 patients with pituitary adenoma with intraoperatively confirmed CS invasion were analyzed. RESULTS Four CS compartments are described based on their spatial relationship with the cavernous ICA: superior, posterior, inferior, and lateral. Each compartment has distinct boundaries and dural and neurovascular relationships: the superior compartment relates to the interclinoidal ligament and oculomotor nerve, the posterior compartment bears the gulfar segment of the abducens nerve and inferior hypophyseal artery, the inferior compartment contains the sympathetic nerve and distal cavernous abducens nerve, and the lateral compartment includes all cavernous cranial nerves and the inferolateral arterial trunk. Twenty-nine patients had a single compartment invaded, and 69 had multiple compartments involved. The most commonly invaded compartment was the superior (79 patients), followed by the posterior (n = 64), inferior (n = 45), and lateral (n = 23) compartments. Residual tumor rates by compartment were 79% in lateral, 17% in posterior, 14% in superior, and 11% in inferior. CONCLUSIONS The anatomy-based classification presented here complements current imaging-based classifications and may help to identify involved compartments both preoperatively and intraoperatively.

  View details for PubMedID 28862552

• Extended Middle Fossa Approach With Anterior Petrosectomy and Anterior Clinoidectomy for Resection of Spheno-Cavernous-Tentorial Meningioma: The Hakuba-Kawase-Dolenc Approach: 3-Dimensional Operative Video OPERATIVE NEUROSURGERY Fernandez-Miranda, J. C. 2017; 13 (2): 281

  View details for Web of Science ID 000404126300037

  View details for PubMedID 28927221

• Prof. Albert L. Rhoton, Jr.: His Life and Legacy WORLD NEUROSURGERY Fernandez-Miranda, J. C. 2016; 92: 590–96

  View details for PubMedID 27318315

• Endoscopic Endonasal Transclival Transcondylar Approach for Foramen Magnum Meningiomas: Surgical Anatomy and Technical Note OPERATIVE NEUROSURGERY Wang, W., Abhinav, K., Wang, E., Snyderman, C., Gardner, P. A., Fernandez-Miranda, J. C. 2016; 12 (2): 153–61

  Abstract

  The endoscopic endonasal approach provides a direct route to ventral foramen magnum (FM) lesions like meningiomas, which are difficult to access. Endonasal access at the FM is limited laterally by the occipital condyles and inferiorly by the C1 anterior arch and the odontoid process, which may need partial resection.We investigated the surgical anatomy and technical nuances for endonasally increasing the surgical corridor at the FM region both laterally and inferiorly. Unique to our report, we quantified the amount of required medial condyle resection to obtain exposure of the lateral aspects of the FM.Five fresh human head silicone-injected specimens underwent endonasal inferior transclival, transcondylar approaches. The lateral limit of medial condyle resection was defined using a vertical line extending inferiorly from foramen lacerum and its intersection with the occipital condyle. The condylectomy was limited posteriorly by the cortical bone surrounding the hypoglossal canal. The volume of the resected condyle (cubic centimeters) for 10 sides was measured using the pre- and postdissection computed tomography-volumetric analysis.The mean percentage condylar volume resected during a unilateral medial condylectomy was 18% (9.7%-28.3%). The surgical corridor was extended inferiorly in all specimens without violating the transverse ligament by drilling the superior aspects of C1 anterior arch and the exposed odontoid tip. These operative nuances were successfully applied in the operating room.Anatomical landmarks can reliably guide an endonasal anteromedial condyle resection. Minimal condyle resection is required to widen lateral access at the FM, which minimizes the risk of craniocervical instability.

  View details for PubMedID 29506094

• Subcomponents and connectivity of the superior longitudinal fasciculus in the human brain BRAIN STRUCTURE & FUNCTION Wang, X., Pathak, S., Stefaneanu, L., Yeh, F., Li, S., Fernandez-Miranda, J. C. 2016; 221 (4): 2075–92

  Abstract

  The subcomponents of the human superior longitudinal fasciculus (SLF) are disputed. The objective of this study was to investigate the segments, connectivity and asymmetry of the SLF. We performed high angular diffusion spectrum imaging (DSI) analysis on ten healthy adults. We also conducted fiber tracking on a 30-subject DSI template (CMU-30) and 488-subject template from the Human Connectome Project (HCP-488). In addition, five normal brains obtained at autopsy were microdissected. Based on tractography and microdissection results, we show that the human SLF differs significantly from that of monkey. The fibers corresponding to SLF-I found in 6 out of 20 hemispheres proved to be part of the cingulum fiber system in all cases and confirmed on both DSI and HCP-488 template. The most common patterns of connectivity bilaterally were as follows: from angular gyrus to caudal middle frontal gyrus and dorsal precentral gyrus representing SLF-II (or dorsal SLF), and from supramarginal gyrus to ventral precentral gyrus and pars opercularis to form SLF-III (or ventral SLF). Some connectivity features were, however, clearly asymmetric. Thus, we identified a strong asymmetry of the dorsal SLF (SLF-II), where the connectivity between the supramarginal gyrus with the dorsal precentral gyrus and the caudal middle frontal gyrus was only present in the left hemisphere. Contrarily, the ventral SLF (SLF-III) showed fairly constant connectivity with pars triangularis only in the right hemisphere. The results provide a novel neuroanatomy of the SLF that may help to better understand its functional role in the human brain.

  View details for PubMedID 25782434

• Anterior Transpetrosal Approach for Resection of Recurrent Skull Base Chordoma: 3-Dimensional Operative Video OPERATIVE NEUROSURGERY Chabot, J. D., Gardner, P., Fernandez-Miranda, J. C. 2015; 11 (3): 464

  View details for PubMedID 26083158

• Endoscopic Endonasal Approach to the Optic Canal: Anatomic Considerations and Surgical Relevance OPERATIVE NEUROSURGERY Abhinav, K., Acosta, Y., Wang, W., Bonilla, L. R., Koutourousiou, M., Wang, E., Synderman, C., Gardner, P., Fernandez-Miranda, J. C. 2015; 11 (3): 431–45

  Abstract

  Increasing use of endoscopic endonasal surgery for suprasellar lesions with extension into the optic canal (OC) has necessitated a better endonasal description of the OC.To identify the osseous OC transcranially and then investigate its anatomic relationship to the key endonasal intrasphenoidal landmarks. We also aimed to determine and describe the technical nuances for safely opening the falciform ligament and intracanalicular dura (surrounding the optic nerve [ON]) endonasally.Ten fresh human head silicon-injected specimens underwent an endoscopic transtuberculum/transplanum approach followed by 2-piece orbitozygomatic craniotomy to allow identification of 20 OCs. After completing up to 270° of endonasal bony decompression of the OC, a dural incision started at the sella and continued superiorly across the superior intercavernous sinus. Subsequently the dural opening was extended anterolaterally across the dura of the prechiasmatic sulcus, limbus sphenoidale, and planum.Endonasally, the length of the osseous OC was approximately 6 mm and equivalent to the length of the lateral opticocarotid recess, as measured anteroposteriorly. The ophthalmic artery arose from the supraclinoidal carotid artery at approximately 2.5 mm from the medial osseous OC entrance. Transcranial correlation of the endonasal dural incision confirmed medial detachment of the falciform ligament and exposure of the preforaminal ON.The lateral opticocarotid recess allows distinction of the preforaminal ON, roofed by the falciform ligament from the intracanalicular segment in the osseous OC. This facilitates the preoperative surgical strategy regarding the extent of OC decompression and dural opening. Extensive endonasal decompression of the OC and division of the falciform ligament is feasible.

  View details for PubMedID 26177488

• High-definition fiber tractography for the evaluation of perilesional white matter tracts in high-grade glioma surgery NEURO-ONCOLOGY Abhinav, K., Yeh, F., Mansouri, A., Zadeh, G., Fernandez-Miranda, J. C. 2015; 17 (9): 1199–1209

  Abstract

  Conventional white matter (WM) imaging approaches, such as diffusion tensor imaging (DTI), have been used to preoperatively identify the location of affected WM tracts in patients with intracranial tumors in order to maximize the extent of resection and potentially reduce postoperative morbidity. DTI, however, has limitations that include its inability to resolve multiple crossing fibers and its susceptibility to partial volume effects. Therefore, recent focus has shifted to more advanced WM imaging techniques such as high-definition fiber tractography (HDFT). In this paper, we illustrate the application of HDFT, which in our preliminary experience has enabled accurate depiction of perilesional tracts in a 3-dimensional manner in multiple anatomical compartments including edematous zones around high-grade gliomas. This has facilitated accurate surgical planning. This is illustrated by using case examples of patients with glioblastoma multiforme. We also discuss future directions in the role of these techniques in surgery for gliomas.

  View details for PubMedID 26117712

  View details for PubMedCentralID PMC4588761

• Asymmetry, connectivity, and segmentation of the arcuate fascicle in the human brain BRAIN STRUCTURE & FUNCTION Fernandez-Miranda, J. C., Wang, Y., Pathak, S., Stefaneau, L., Verstynen, T., Yeh, F. 2015; 220 (3): 1665–80

  Abstract

  The structure and function of the arcuate fascicle is still controversial. The goal of this study was to investigate the asymmetry, connectivity, and segmentation patterns of the arcuate fascicle. We employed diffusion spectrum imaging reconstructed by generalized q-sampling and we applied both a subject-specific approach (10 subjects) and a template approach (q-space diffeomorphic reconstruction of 30 subjects). We complemented our imaging investigation with fiber microdissection of five post-mortem human brains. Our results confirmed the highly leftward asymmetry of the arcuate fascicle. In the template, the left arcuate had a volume twice as large as the right one, and the left superior temporal gyrus provided five times more volume of fibers than its counterpart. We identified four cortical frontal areas of termination: pars opercularis, pars triangularis, ventral precentral gyrus, and caudal middle frontal gyrus. We found clear asymmetry of the frontal terminations at pars opercularis and ventral precentral gyrus. The analysis of patterns of connectivity revealed the existence of a strong structural segmentation in the left arcuate, but not in the right one. The left arcuate fascicle is formed by an inner or ventral pathway, which interconnects pars opercularis with superior and rostral middle temporal gyri; and an outer or dorsal pathway, which interconnects ventral precentral and caudal middle frontal gyri with caudal middle and inferior temporal gyri. The fiber microdissection results provided further support to our tractography studies. We propose the existence of primary and supplementary language pathways within the dominant arcuate fascicle with potentially distinct functional and lesional features.

  View details for PubMedID 24633827

• Endoscopic endonasal transcavernous posterior clinoidectomy with interdural pituitary transposition JOURNAL OF NEUROSURGERY Fernandez-Miranda, J. C., Gardner, P. A., Rastelli, M. M., Peris-Celda, M., Koutourousiou, M., Peace, D., Snyderman, C. H., Rhoton, A. L. 2014; 121 (1): 91–99

  Abstract

  OBJECT.: The object of this paper was to describe the surgical anatomy and technical nuances of the endonasal transcavernous posterior clinoidectomy approach with interdural pituitary transposition and to report the clinical outcome of this technical modification.The surgical anatomy of the proposed approach was studied in 10 colored silicon-injected anatomical specimens. The medical records of 12 patients that underwent removal of the posterior clinoid(s) with this technique were reviewed.The natural anatomical corridor provided by the cavernous sinus is used to get access to the posterior clinoid by mobilizing the pituitary gland in an interdural fashion. The medial wall of the cavernous sinus is preserved intact and attached to the gland during its medial and superior mobilization. This provides protection to the gland, allowing for preservation of its venous drainage pathways. The inferior hypophyseal artery is transected to facilitate the manipulation of the medial wall of the cavernous sinus and pituitary gland. This approach was successfully performed in all patients, including 6 with chordomas, 5 with petroclival meningiomas, and 1 with an epidermoid tumor. No patient in this series had neurovascular injury related to the posterior clinoidectomy. There were no instances of permanent hypopituitarism or diabetes insipidus.The authors introduce a surgical variant of the endoscopic endonasal posterior clinoidectomy approach that does not require intradural pituitary transposition and is more effective than the purely extradural approach. The endoscopic endonasal transcavernous approach facilitates the removal of prominent posterior clinoids increasing the working space at the lateral recess of the interpeduncular cistern, while preserving the pituitary function.

  View details for DOI 10.3171/2014.3.JNS131865

  View details for Web of Science ID 000337935300014

  View details for PubMedID 24816325

• Clival chordomas: A pathological, surgical, and radiotherapeutic review HEAD AND NECK-JOURNAL FOR THE SCIENCES AND SPECIALTIES OF THE HEAD AND NECK Fernandez-Miranda, J. C., Gardner, P. A., Snyderman, C. H., Devaney, K. O., Mendenhall, W. M., Suarez, C., Rinaldo, A., Ferlito, A. 2014; 36 (6): 892–906

  Abstract

  The purpose of this study was to discuss the optimal management of patients with clival chordomas and provide an up-to-date review of the field.A schematic description of the anatomy of the clivus and its surrounding structures is provided based on the modular classification of the surgical corridors used in endoscopic skull base surgery. Postoperative radiotherapy (RT) techniques are described.The optimal treatment is gross total resection. Recent advances in endoscopic endonasal skull base surgery have allowed very high rates of macroscopic and radiographic complete tumor resection in spite of the challenging location of these lesions. When the tumor location or extension is too lateral or inferior to be effectively resected with an endoscopic approach, an open approach or a combination of endoscopic and open approaches in stages should be considered. Postoperative RT is usually indicated because the likelihood of recurrence is high in spite of complete surgical resection. The main site of recurrence is local and late recurrences are relatively common. The probability of cure is approximately 50% at 10 years and significantly increases when complete tumor resection has been achieved.The preferred treatment for patients with clival chordoma is gross total resection (via endoscopic endonasal surgery when possible) followed by postoperative RT. Treatment at experienced multidisciplinary cranial base centers is key to minimize complications and to enhance the probability of total removal of the tumors.

  View details for PubMedID 23804541

• Endoscopic endonasal surgery for suprasellar meningiomas: experience with 75 patients Clinical article JOURNAL OF NEUROSURGERY Koutourousiou, M., Fernandez-Miranda, J. C., Stefko, S., Wang, E. W., Snyderman, C. H., Gardner, P. A. 2014; 120 (6): 1326–39

  Abstract

  Following the introduction of the neurosurgical microscope, the outcomes in suprasellar meningioma surgery were dramatically improved. More recently, the neurosurgical endoscope has been introduced as a visualization option during removal of skull base tumors, both transcranially and endonasally. The authors retrospectively reviewed the effectiveness of endoscopic endonasal surgery (EES) in the management of suprasellar meningiomas.Between 2002 and 2011, 75 patients (81.3% female) with suprasellar meningiomas underwent EES at the University of Pittsburgh Medical Center. The authors present the results of EES and analyze the resection rates, visual outcome, and complications.Seventy-one patients presented with primary tumors, whereas 4 were previously treated elsewhere. Their mean age was 57.3 years (range 36-88 years), and most patients presented with visual loss (81.3%). Tumors occupied the tuberculum sellae (86.7%) and planum sphenoidale (50.7%), with extension into the optic canals in 26.7% (unilateral in 21.3% and bilateral in 5.3%) and the pituitary fossa (9.3%). Gross-total tumor resection (Simpson Grade I) was achieved in 76% of the cases in the whole cohort and in 81.4% of the patients in whom it was the goal of surgery. Tumor location and extension into the optic canals was not a limitation for total resection. Tumor size, configuration, and vascular encasement were significant factors that influenced the degree of resection (p < 0.0001). Vision was improved or normalized in 85.7% of the cases. Visual deterioration following EES occurred in 2 patients (3.6%). Complications included postoperative CSF leaks (25.3% overall, 16.1% in recent years) resulting in meningitis in 4 cases. One patient had an intraoperative injury of the artery of Heubner resulting in associated neurological deficit. Another elderly patient died within 1 month after EES due to cerebral vasospasm and multisystem impairment. No patient developed postoperative cerebral contusions, hemorrhage, or seizures. During a mean follow-up period of 29 months (range 1-98 months), 4 patients have shown recurrence, but only 1 required repeat EES.With the goal of gross-total tumor resection and visual improvement, EES can achieve very good results, (comparable to microscopic approaches) for the treatment of suprasellar meningiomas. Avoidance of brain and optic nerve retraction, preservation of the vascularization of the optic apparatus, and wide decompression of the optic canals are the main advantages of EES for the treatment of suprasellar meningiomas, while CSF leaks remain a disadvantage.

  View details for DOI 10.3171/2014.2.JNS13767

  View details for Web of Science ID 000336352700009

  View details for PubMedID 24678782

• Endoscopic endonasal approach for growth hormone secreting pituitary adenomas: outcomes in 53 patients using 2010 consensus criteria for remission PITUITARY Shin, S. S., Tormenti, M. J., Paluzzi, A., Rothfus, W. E., Chang, Y., Zainah, H., Fernandez-Miranda, J. C., Snyderman, C. H., Challinor, S. M., Gardner, P. A. 2013; 16 (4): 435–44

  Abstract

  We report the outcomes of the endoscopic endonasal approach (EEA) for resection of growth hormone secreting pituitary adenomas using 2010 consensus criteria. We also assess outcomes with additional medical therapy and radiosurgery (RS) for patients not achieving remission with EEA alone. A retrospective review of 53 patients who had follow up endocrinologic data at least 3 months post-surgery was performed among patients who were treated by EEA between 1998 and 2012. Data were analyzed for remission using GH and IGF-I levels based on 2010 consensus criteria. We also analyzed the outcomes using 2000 consensus criteria for ease in comparison to prior studies of outcomes of surgery for acromegaly. In this series of mostly large (88.2% macroadenomas), invasive (46.9% Hardy-Wilson C, D, E) adenomas, there were 27 patients (50.9%) who achieved remission after EEA only. For patients who had no remission with EEA alone, RS and/or medical therapy were used and 37 patients (69.8 %) achieved remission overall. Statistical analysis showed larger tumor size, Hardy Stages C, D, E and Knosp Scores 3, 4 to be predictive against remission for EEA only and EEA with other modalities. The volume of residual tumor after EEA was not found to be predictive of remission with additional therapies. We used stringent consensus criteria from 2010 in a series which included a high proportion of invasive GH secreting adenomas to show that EEA alone or combined with other modalities results in comparable remission rates to earlier studies which used less strict criteria, while retaining low complication rates.

  View details for PubMedID 23179961

• Deterministic Diffusion Fiber Tracking Improved by Quantitative Anisotropy PLOS ONE Yeh, F., Verstynen, T. D., Wang, Y., Fernandez-Miranda, J. C., Tseng, W. 2013; 8 (11): e80713

  Abstract

  Diffusion MRI tractography has emerged as a useful and popular tool for mapping connections between brain regions. In this study, we examined the performance of quantitative anisotropy (QA) in facilitating deterministic fiber tracking. Two phantom studies were conducted. The first phantom study examined the susceptibility of fractional anisotropy (FA), generalized factional anisotropy (GFA), and QA to various partial volume effects. The second phantom study examined the spatial resolution of the FA-aided, GFA-aided, and QA-aided tractographies. An in vivo study was conducted to track the arcuate fasciculus, and two neurosurgeons blind to the acquisition and analysis settings were invited to identify false tracks. The performance of QA in assisting fiber tracking was compared with FA, GFA, and anatomical information from T1-weighted images. Our first phantom study showed that QA is less sensitive to the partial volume effects of crossing fibers and free water, suggesting that it is a robust index. The second phantom study showed that the QA-aided tractography has better resolution than the FA-aided and GFA-aided tractography. Our in vivo study further showed that the QA-aided tractography outperforms the FA-aided, GFA-aided, and anatomy-aided tractographies. In the shell scheme (HARDI), the FA-aided, GFA-aided, and anatomy-aided tractographies have 30.7%, 32.6%, and 24.45% of the false tracks, respectively, while the QA-aided tractography has 16.2%. In the grid scheme (DSI), the FA-aided, GFA-aided, and anatomy-aided tractographies have 12.3%, 9.0%, and 10.93% of the false tracks, respectively, while the QA-aided tractography has 4.43%. The QA-aided deterministic fiber tracking may assist fiber tracking studies and facilitate the advancement of human connectomics.

  View details for PubMedID 24348913

• Endoscopic endonasal surgery for craniopharyngiomas: surgical outcome in 64 patients Clinical article JOURNAL OF NEUROSURGERY Koutourousiou, M., Gardner, P. A., Fernandez-Miranda, J. C., Tyler-Kabara, E. C., Wang, E. W., Snyderman, C. H. 2013; 119 (5): 1194–1207

  Abstract

  The proximity of craniopharyngiomas to vital neurovascular structures and their high recurrence rates make them one of the most challenging and controversial management dilemmas in neurosurgery. Endoscopic endonasal surgery (EES) has recently been introduced as a treatment option for both pediatric and adult craniopharyngiomas. The object of the present study was to present the results of EES and analyze outcome in both the pediatric and the adult age groups.The authors retrospectively reviewed the records of patients with craniopharyngioma who had undergone EES in the period from June 1999 to April 2011.Sixty-four patients, 47 adults and 17 children, were eligible for this study. Forty-seven patients had presented with primary craniopharyngiomas and 17 with recurrent tumors. The mean age in the adult group was 51 years (range 28-82 years); in the pediatric group, 9 years (range 4-18 years). Overall, the gross-total resection rate was 37.5% (24 patients); near-total resection (> 95% of tumor removed) was 34.4% (22 patients); subtotal resection (≥ 80% of tumor removed) 21.9% (14 patients); and partial resection (< 80% of tumor removed) 6.2% (4 patients). In 9 patients, EES had been combined with radiation therapy (with radiosurgery in 6 cases) as the initial treatment. Among the 40 patients (62.5%) who had presented with pituitary insufficiency, pituitary function remained unchanged in 19 (47.5%), improved or normalized in 8 (20%), and worsened in 13 (32.5%). In the 24 patients who had presented with normal pituitary function, new pituitary deficit occurred in 14 (58.3%). Nineteen patients (29.7%) suffered from diabetes insipidus at presentation, and the condition developed in 21 patients (46.7%) after treatment. Forty-four patients (68.8%) had presented with impaired vision. In 38 (86.4%) of them, vision improved or even normalized after surgery; in 5, it remained unchanged; and in 1, it temporarily worsened. One patient without preoperative visual problems showed temporary visual deterioration after treatment. Permanent visual deterioration occurred in no one after surgery. The mean follow-up was 38 months (range 1-135 months). Tumor recurrence after EES was discovered in 22 patients (34.4%) and was treated with repeat surgery (6 patients), radiosurgery (1 patient), combined repeat surgery and radiation therapy (8 patients), interferon (1 patient), or observation (6 patients). Surgical complications included 15 cases (23.4%) with CSF leakage that was treated with surgical reexploration (13 patients) and/or lumbar drain placement (9 patients). This leak rate was decreased to 10.6% in recent years after the introduction of the vascularized nasoseptal flap. Five cases (7.8%) of meningitis were found and treated with antibiotics without further complications. Postoperative hydrocephalus occurred in 7 patients (12.7%) and was treated with ventriculoperitoneal shunt placement. Five patients experienced transient cranial nerve palsies. There was no operative mortality.With the goal of gross-total or maximum possible safe resection, EES can be used for the treatment of every craniopharyngioma, regardless of its location, size, and extension (excluding purely intraventricular tumors), and can provide acceptable results comparable to those for traditional craniotomies. Endoscopic endonasal surgery is not limited to adults and actually shows higher resection rates in the pediatric population.

  View details for DOI 10.3171/2013.6.JNS122259

  View details for Web of Science ID 000325956200020

  View details for PubMedID 23909243

• Rethinking the Role of the Middle Longitudinal Fascicle in Language and Auditory Pathways CEREBRAL CORTEX Wang, Y., Fernandez-Miranda, J. C., Verstynen, T., Pathak, S., Schneider, W., Yeh, F. 2013; 23 (10): 2347–56

  Abstract

  The middle longitudinal fascicle (MdLF) was originally described in the monkey brain as a pathway that interconnects the superior temporal and angular gyri. Only recently have diffusion tensor imaging studies provided some evidence of its existence in humans, with a connectivity pattern similar to that in monkeys and a potential role in the language system. In this study, we combine high-angular-resolution fiber tractography and fiber microdissection techniques to determine the trajectory, cortical connectivity, and a quantitative analysis of the MdLF. Here, we analyze diffusion spectrum imaging (DSI) studies in 6 subjects (subject-specific approach) and in a template of 90 DSI studies (NTU-90 Atlas). Our tractography and microdissection results show that the human MdLF differs significantly from the monkey. Indeed, the human MdLF interconnects the superior temporal gyrus with the superior parietal lobule and parietooccipital region, and has only minor connections with the angular gyrus. On the basis of the roles of these interconnected cortical regions, we hypothesize that, rather than a language-related tract, the MdLF may contribute to the dorsal "where" pathway of the auditory system.

  View details for PubMedID 22875865

• Endoscopic endonasal surgery for skull base chordomas: experience with 84 patients Koutourousiou, M., Gardner, P. A., Fernandez-Miranda, J. C., Henry, S. L., Wang, E. W., Snyderman, C. H. ELSEVIER SCIENCE INC. 2013: S68

  View details for DOI 10.1016/j.jamcollsurg.2013.07.144

  View details for Web of Science ID 000325577900126

• Endoscopic endonasal surgery for giant pituitary adenomas: advantages and limitations Clinical article JOURNAL OF NEUROSURGERY Koutourousiou, M., Gardner, P. A., Fernandez-Miranda, J. C., Paluzzi, A., Wang, E. W., Snyderman, C. H. 2013; 118 (3): 621–31

  Abstract

  Giant pituitary adenomas (> 4 cm in maximum diameter) represent a significant surgical challenge. Endoscopic endonasal surgery (EES) has recently been introduced as a treatment option for these tumors. The authors present the results of EES for giant adenomas and analyze the advantages and limitations of this technique.The authors retrospectively reviewed the medical files and imaging studies of 54 patients with giant pituitary adenomas who underwent EES and studied the factors affecting surgical outcome.Preoperative visual impairment was present in 45 patients (83%) and partial or complete pituitary deficiency in 28 cases (52%), and 7 patients (13%) presented with apoplexy. Near-total resection (> 90%) was achieved in 36 patients (66.7%). Vision was improved or normalized in 36 cases (80%) and worsened in 2 cases due to apoplexy of residual tumor. Significant factors that limited the degree of resection were a multilobular configuration of the adenoma (p = 0.002) and extension to the middle fossa (p = 0.045). Cavernous sinus invasion, tumor size, and intraventricular or posterior fossa extension did not influence the surgical outcome. Complications included apoplexy of residual adenoma (3.7%), permanent diabetes insipidus (9.6%), new pituitary insufficiency (16.7%), and CSF leak (16.7%, which was reduced to 7.4% in recent years). Fourteen patients underwent radiation therapy after EES for residual mass or, in a later stage, for recurrence, and 10 with functional pituitary adenomas received medical treatment. During a mean follow-up of 37.9 months (range 1-114 months), 7 patients were reoperated on for tumor recurrence. Three patients were lost to follow-up.Endoscopic endonasal surgery provides effective initial management of giant pituitary adenomas with favorable results compared with traditional microscopic transsphenoidal and transcranial approaches.

  View details for PubMedID 23289816

• Endoscopic endonasal middle clinoidectomy: anatomic, radiological, and technical note. Neurosurgery Fernandez-Miranda, J. C., Tormenti, M., Latorre, F., Gardner, P., Snyderman, C. 2012; 71 (2 Suppl Operative): ons233–ons239

  Abstract

  BACKGROUND: The middle clinoid is an osseous prominence that arises from the body of the sphenoid bone at the anterolateral margin of the sella.OBJECTIVE: To illustrate the radiological and surgical anatomy of the middle clinoid and describe the technical nuances for endonasal endoscopic middle clinoid removal.METHODS: The fine-cut head CT-angiogram scans of 100 patients and 50 anatomic specimens were examined. The middle clinoid was categorized as: absent, small, prominent, or caroticoclinoidal ring. Ten colored silicon-injected anatomic specimens were used to study the surgical anatomy for the endonasal middle clinoidectomy. Extensive surgical experience allowed for intraoperative observations regarding the surgical anatomy of the middle clinoid and the technical nuances for its removal.RESULTS: The middle clinoid was identifiable in 60% of scans (bilateral in 35%), and 20% had at least one caroticoclinoidal ring (bilateral in 6%). When present, the middle clinoid is located at the transition between the intracavernous internal carotid artery (ICA) and paraclinoidal ICA, and covers the anteromedial roof of the cavernous sinus. Endonasal removal of the middle clinoid improves access to the parasellar region. The middle clinoidectomy is completed exposing the following structures sequentially: sellar dura, anterior wall of the cavernous sinus, dura of the lateral tuberculum sella, and paraclinoidal ICA. When a caroticoclinoidal ring is identified, progressive reduction of the middle clinoid can be achieved without fracturing the ring.CONCLUSION: Recognition of the middle clinoid and caroticoclinoidal ring on preoperative imaging is critical for surgical planning and middle clinoid removal in endonasal skull base surgery.

  View details for PubMedID 22806082

• Endoscopic Endonasal Transclival Approach to the Jugular Tubercle NEUROSURGERY Fernandez-Miranda, J. C., Morera, V. A., Snyderman, C. H., Gardner, P. 2012; 71: 146–58

  Abstract

  The jugular tubercle is a rounded bony prominence that arises from the inferolateral margin of the clivus. In a previous publication, we described the surgical anatomy of the expanded endonasal approach to the jugular tubercle.To illustrate the translation of laboratory work to the operating room describing the anatomic and technical nuances of the endonasal approach to the jugular tubercle.We review the relevant surgical anatomy needed to perform an endonasal approach to the jugular tubercle, and we select 4 different lesions to illustrate the application of our laboratory findings.In the first case, exposure and partial drilling of the jugular tubercle was critical to gain an adequate corridor to the meningioma, particularly to its inferolateral margin. This allowed for early devascularization, safe extracapsular dissection, and preservation of surrounding neurovascular structures. In addition, the jugular tubercle was hyperostotic and its resection, along with generous dural removal, provided a grade I Simpson tumor resection. In the second (chondrosarcoma) and third (chordoma) cases, the jugular tubercle was infiltrated by tumor, and consequently its complete resection was essential to achieve total tumor removal. In the last case, an unusual adrenocorticotropic hormone-secreting adenoma recurrence at the jugular tubercle region, the technical modification of the transclival approach presented here was successfully applied to achieve complete resection and Cushing disease remission.The transjugular tubercle variant of the expanded endonasal transclival approach allows for direct access to ventrolateral lesions in the inferior clival/petroclival region with no cerebral or cerebellar retraction, or cranial nerve manipulation during the approach.

  View details for PubMedID 22127047

• High-Definition Fiber Tractography of the Human Brain: Neuroanatomical Validation and Neurosurgical Applications NEUROSURGERY Fernandez-Miranda, J. C., Pathak, S., Engh, J., Jarbo, K., Verstynen, T., Yeh, F., Wang, Y., Mintz, A., Boada, F., Schneider, W., Friedlander, R. 2012; 71 (2): 430–53

  Abstract

  High-definition fiber tracking (HDFT) is a novel combination of processing, reconstruction, and tractography methods that can track white matter fibers from cortex, through complex fiber crossings, to cortical and subcortical targets with subvoxel resolution.To perform neuroanatomical validation of HDFT and to investigate its neurosurgical applications.Six neurologically healthy adults and 36 patients with brain lesions were studied. Diffusion spectrum imaging data were reconstructed with a Generalized Q-Ball Imaging approach. Fiber dissection studies were performed in 20 human brains, and selected dissection results were compared with tractography.HDFT provides accurate replication of known neuroanatomical features such as the gyral and sulcal folding patterns, the characteristic shape of the claustrum, the segmentation of the thalamic nuclei, the decussation of the superior cerebellar peduncle, the multiple fiber crossing at the centrum semiovale, the complex angulation of the optic radiations, the terminal arborization of the arcuate tract, and the cortical segmentation of the dorsal Broca area. From a clinical perspective, we show that HDFT provides accurate structural connectivity studies in patients with intracerebral lesions, allowing qualitative and quantitative white matter damage assessment, aiding in understanding lesional patterns of white matter structural injury, and facilitating innovative neurosurgical applications. High-grade gliomas produce significant disruption of fibers, and low-grade gliomas cause fiber displacement. Cavernomas cause both displacement and disruption of fibers.Our HDFT approach provides an accurate reconstruction of white matter fiber tracts with unprecedented detail in both the normal and pathological human brain. Further studies to validate the clinical findings are needed.

  View details for PubMedID 22513841

• Craniopharyngioma: A pathologic, clinical, and surgical review HEAD AND NECK-JOURNAL FOR THE SCIENCES AND SPECIALTIES OF THE HEAD AND NECK Fernandez-Miranda, J. C., Gardner, P. A., Snyderman, C. H., Devaney, K. O., Strojan, P., Suarez, C., Genden, E. M., Rinaldo, A., Ferlito, A. 2012; 34 (7): 1036–44

  Abstract

  Craniopharyngioma is a rare and mostly benign epithelial tumor of the sellar and suprasellar region. Two principal patterns of craniopharyngioma are recognized: papillary and adamantinomatous. Papillary craniopharyngiomas are encountered in adults and may lack the cystic spaces filled with "motor oil" as well as the palisading peripheral rows of epithelial cells, keratinization, or calcification typical of pediatric adamantinomatous craniopharyngioma. Secondary to their anatomic location, craniopharyngiomas may present with endocrinologic dysfunction and visual disturbances. Differential diagnosis includes Rathke's cleft cyst, pituitary adenoma, dermoid/epidermoid cysts, and other rare sellar/suprasellar lesions as pituicytomas. Many controversies exist concerning the preferred surgical approach for these tumors. Endoscopic endonasal surgery is no longer reserved only for sellar or small cystic suprasellar lesions. Prechiasmatic/preinfundibular lesions are effectively removed using an endonasal transtuberculum/transplanum approach; subchiasmatic/transinfundibular tumors require the addition of a transellar approach with inferior pituitary transposition; and retrochiasmatic/retroinfundibular lesions are better accessed performing an endonasal superior pituitary transposition. Compared with well-established trancranial approaches (pterional, subfrontal, presigmoid), endoscopic endonasal surgery combines the virtues of the caudocranial and midline approaches, allowing for appropriate infrachiasmatic exposure without the need for manipulation of surrounding neurovascular structures to access the tumor. This anatomic advantage, combined with high-definition wide-angle visualization, exquisite endonasal microsurgical techniques, and devoted instrumentation facilitates a high rate of endocrine function preservation and visual improvement, while concurrently achieving comparable resections. Endoscopic skull base reconstruction with the vascularized nasoseptal flap has dramatically reduced the incidence of cerebrospinal fluid leak, consolidating endoscopic endonasal surgery as an effective and safe alternative for the treatment of these challenging tumors.

  View details for PubMedID 21584897

• Endoscopic endonasal approach to cholesterol granulomas of the petrous apex: a series of 17 patients Clinical article JOURNAL OF NEUROSURGERY Paluzzi, A., Gardner, P., Fernandez-Miranda, J. C., Pinheiro-Neto, C. D., Scopel, T., Koutourousiou, M., Snyderman, C. H. 2012; 116 (4): 792–98

  Abstract

  The aim of this study was to report the results in a consecutive series of patients who had undergone an endoscopic endonasal approach (EEA) for drainage of a petrous apex cholesterol granuloma (CG).Seventeen cases with a confirmed diagnosis of petrous apex CG were identified from a database of more than 1600 patients who had undergone an EEA to skull base lesions at the authors' institution in the period from 1998 to 2011. Clinical outcomes were reviewed and compared with those in previous studies of open approaches.Nine patients underwent a transclival approach and 8 patients underwent a combined transclival and infrapetrous approach. A Silastic stent was used in 11 patients (65%), a miniflap in 4 (24%), and a simple marsupialization of the cyst in 3 (18%). All symptomatic patients had partial or complete improvement of their symptoms postoperatively and at the follow-up (mean follow-up 20 months, range 3-67 months). Complications developed in 3 patients (18%) including epistaxis, chronic serous otitis media, eye dryness, and a transient sixth cranial nerve palsy. Two patients (12%) had a symptomatic recurrence of the cyst requiring repeat endoscopic endonasal drainage. There were no instances of internal carotid artery injuries, CSF leaks, or new hearing loss. The mean postoperative hospital stay was 2 days (range 0.7-4.6 days). These results were comparable with those in previous studies of open approaches to petrous apex CGs. There was a strong correlation between the size of the cyst and the type of approach chosen (Rpb [point biserial correlation coefficient] = +0.67, p = 0.003359) and a very strong correlation between the degree of medial extension (defined by the V-angle) and the choice of approach (Rpb = +0.81, p < 0.0001). Based on these observations, the authors developed an algorithm for guiding the choice of the most appropriate route of drainage.The EEA is a safe and effective alternative to traditional open approaches to petrous apex CGs.

  View details for PubMedID 22224788

• Microvascular Anatomy of the Medial Temporal Region: Part 1: Its Application to Arteriovenous Malformation Surgery NEUROSURGERY Fernandez-Miranda, J. C., de Oliveira, E., Rubino, P. A., Wen, H., Rhoton, A. L. 2010; 67 (3): 237–76

  Abstract

  The medial temporal region (also called the temporomesial or mediobasal temporal region) is the site of the most complex cortical anatomy.To investigate the anatomic variability of the arterial supply and venous drainage of each segment of the medial temporal region (MTR), and to discuss and illustrate the implications of the findings for surgery of arteriovenous malformations (AVM) of the MTR.Forty-seven cerebral hemispheres and 10 silicon-injected cadaveric heads were examined using x3 to x40 magnification. Illustrative surgical cases of MTR AVMs were selected.The anterior choroidal artery (AChA) gave rise to an anterior uncal artery in 83% of hemispheres and a posterior uncal or unco-hippocampal artery in 98%. The plexal segment of the AChA gave off neural branches in 38%. The MCA was the site of origin of anterior uncal, unco-parahippocampal, or anterior parahippocampal arteries in 94% of hemispheres. An anterior uncal artery arose from the internal carotid artery (ICA) in 45% of hemispheres. The posterior cerebral artery (PCA) irrigated the entorhinal area through its anterior parahippocampal or hippocampo-parahippocampal branches in every case. A PCA bifurcation was identified in 89% of hemispheres, typically at the middle segment of the MTR. The most common pattern of bifurcation was by division into posteroinferior temporal and parieto-occipital arterial trunks. The anterior segment of the basal vein had a predominant anterior drainage in 35% of hemispheres, and the middle segment had a predominant inferior drainage in 16%.An understanding of the vascular variability of the MTR is essential for accurate microsurgical resection of MTR AVMs.

  View details for PubMedID 20679924

• "Far-Medial" Expanded Endonasal Approach to the Inferior Third of the Clivus: The Transcondylar and Transjugular Tubercle Approaches NEUROSURGERY Morera, V. A., Fernandez-Miranda, J. C., Prevedello, D. M., Madhok, R., Barges-Coll, J., Gardner, P., Carrau, R., Snyderman, C. H., Rhoton, A. L., Kassam, A. B. 2010; 66 (6): ONS211–ONS219

  Abstract

  The endoscopic endonasal transclival approach is a valid alternative for treatment of lesions in the clivus. The major limitation of this approach is a significant lateral extension of the tumor. We aim to identify a safe corridor through the occipital condyle to provide more lateral exposure of the foramen magnum.Sixteen parameters were measured in 25 adult skulls to analyze the exact extension of a safe corridor through the condyle. Endonasal endoscopic anatomic dissections were carried out in nine colored latex-injected heads.Drilling at the lateral inferior clival area exposed two compartments divided by the hypoglossal canal: the jugular tubercle (superior) and the condylar (inferior). Completion of a unilateral ventromedial condyle resection opens a 3.5 mm (transverse length) * 10 mm (vertical length) lateral surgical corridor, facilitating direct access to the vertebral artery at its dural entry point into the posterior fossa. The supracondylar groove is a reliable landmark for locating the hypoglossal canal in relation to the condyle. The hypoglossal canal is used as the posterior limit of the condyle removal to preserve more than half of the condylar mass. The transjugular tubercle approach is accomplished by drilling above the hypoglossal canal, and increases the vertical length of the lateral surgical corridor by 8 mm, allowing for visualization of the distal cisternal segment of the lower cranial nerves.The transcondylar and transjugular tubercle "far medial" expansions of the endoscopic endonasal approach to the inferior third of the clivus provide a unique surgical corridor to the ventrolateral surface of the ponto- and cervicomedullary junctions.

  View details for PubMedID 20489508

• Three-dimensional microsurgical and tractographic anatomy of the white matter of the human brain NEUROSURGERY Fernandez-Miranda, J. C., Rhoton, A. L., Alvarez-Linera, J., Kakizawa, Y., Choi, C., de Oliveira, E. P. 2008; 62 (6): 989–1026

  View details for DOI 10.1227/01.NEU.0000297076.98175.67

  View details for Web of Science ID 000258226600015

• Multicenter Registry of Adenomas of the Pituitary and Related Disorders: Initial Description of Cushing Disease Cohort, Surgical Outcomes, and Surgeon Characteristics. Neurosurgery Little, A. S., Karsy, M., Evans, J. J., Kim, W., Pacione, D. R., Kim, A. H., Gardner, P. A., Hendricks, B. K., Sarris, C. E., Torok, I. E., Low, T. M., Crocker, T. A., Valappil, B., Kanga, M., Abdallah, H., Collopy, S., Fernandez-Miranda, J. C., Vigo, V., Ljubimov, V. A., Zada, G., Garrett, N. E., Delery, W., Yuen, K. C., Rennert, R. C., Couldwell, W. T., Silverstein, J. M., Kshettry, V. R., Chicoine, M. R. 2024; 95 (2): 372-379

  Abstract

  To address the lack of a multicenter pituitary surgery research consortium in the United States, we established the Registry of Adenomas of the Pituitary and Related Disorders (RAPID). The goals of RAPID are to examine surgical outcomes, improve patient care, disseminate best practices, and facilitate multicenter surgery research at scale. Our initial focus is Cushing disease (CD). This study aims to describe the current RAPID patient cohort, explore surgical outcomes, and lay the foundation for future studies addressing the limitations of previous studies.Prospectively and retrospectively obtained data from participating sites were aggregated using a cloud-based registry and analyzed retrospectively. Standard preoperative variables and outcome measures included length of stay, unplanned readmission, and remission.By July 2023, 528 patients with CD had been treated by 26 neurosurgeons with varying levels of experience at 9 academic pituitary centers. No surgeon treated more than 81 of 528 (15.3%) patients. The mean ± SD patient age was 43.8 ± 13.9 years, and most patients were female (82.2%, 433/527). The mean tumor diameter was 0.8 ± 2.7 cm. Most patients (76.6%, 354/462) had no prior treatment. The most common pathology was corticotroph tumor (76.8%, 381/496). The mean length of stay was 3.8 ± 2.5 days. The most common discharge destination was home (97.2%, 513/528). Two patients (0.4%, 2/528) died perioperatively. A total of 57 patients (11.0%, 57/519) required an unplanned hospital readmission within 90 days of surgery. The median actuarial disease-free survival after index surgery was 8.5 years.This study examined an evolving multicenter collaboration on patient outcomes after surgery for CD. Our results provide novel insights on surgical outcomes not possible in prior single-center studies or with national administrative data sets. This collaboration will power future studies to better advance the standard of care for patients with CD.

  View details for DOI 10.1227/neu.0000000000002888

  View details for PubMedID 39008545

• A phenomenon not to be missed: delayed postoperative cerebrospinal fluid rhinorrhea following no identifiable intraoperative leak in sellar surgery. Rhinology Kshirsagar, R. S., Eide, J. G., Abiri, A., Asmaro, K. P., Filip, P., Pangal, D., Ruzevick, J., Adappa, N. D., Batra, P. S., Bergsneider, M. S., Craig, J. R., Fernandez-Miranda, J. C., Gardner, P. A., Grady, M. S., Halderman, A. A., Hsu, F. P., Mohyeldin, A., Palmer, J. N., Papagiannopoulos, P., Snyderman, C. H., Tajudeen, B. A., Wang, E. W., Wang, M. B., Zada, G., Zenonos, G. A., Kuan, E. C. 2024

  View details for DOI 10.4193/Rhin24.175

  View details for PubMedID 39018522

• Impact of Frailty on Surgical Outcomes of Patients With Cushing Disease Using the Multicenter Registry of Adenomas of the Pituitary and Related Disorders Registry. Neurosurgery Findlay, M. C., Rennert, R. C., Lucke-Wold, B., Couldwell, W. T., Evans, J. J., Collopy, S., Kim, W., Delery, W., Pacione, D. R., Kim, A. H., Silverstein, J. M., Kanga, M., Chicoine, M. R., Gardner, P. A., Valappil, B., Abdallah, H., Sarris, C. E., Hendricks, B. K., Torok, I. E., Low, T. M., Crocker, T. A., Yuen, K. C., Vigo, V., Fernandez-Miranda, J. C., Kshettry, V. R., Little, A. S., Karsy, M. 2024

  Abstract

  Despite growing interest in how patient frailty affects outcomes (eg, in neuro-oncology), its role after transsphenoidal surgery for Cushing disease (CD) remains unclear. We evaluated the effect of frailty on CD outcomes using the Registry of Adenomas of the Pituitary and Related Disorders (RAPID) data set from a collaboration of US academic pituitary centers.Data on consecutive surgically treated patients with CD (2011-2023) were compiled using the 11-factor modified frailty index. Patients were classified as fit (score, 0-1), managing well (score, 2-3), and mildly frail (score, 4-5). Univariable and multivariable analyses were conducted to examine outcomes.Data were analyzed for 318 patients (193 fit, 113 managing well, 12 mildly frail). Compared with fit and managing well patients, mildly frail patients were older (mean ± SD 39.7 ± 14.2 and 48.9 ± 12.2 vs 49.4 ± 8.9 years, P < .001) but did not different by sex, race, and other factors. They had significantly longer hospitalizations (3.7 ± 2.0 and 4.5 ± 3.5 vs 5.3 ± 3.5 days, P = .02), even after multivariable analysis (β = 1.01, P = .007) adjusted for known predictors of prolonged hospitalization (age, Knosp grade, surgeon experience, American Society of Anesthesiologists grade, complications, frailty). Patients with mild frailty were more commonly discharged to skilled nursing facilities (0.5% [1/192] and 4.5% [5/112] vs 25% [3/12], P < .001). Most patients underwent gross total resection (84.4% [163/193] and 79.6% [90/113] vs 83% [10/12]). No difference in overall complications was observed; however, venous thromboembolism was more common in mildly frail (8%, 1/12) than in fit (0.5%, 1/193) and managing well (2.7%, 3/113) patients (P = .04). No difference was found in 90-day readmission rates.These results demonstrate that mild frailty predicts CD surgical outcomes and may inform preoperative risk stratification. Frailty-influenced outcomes other than age and tumor characteristics may be useful for prognostication. Future studies can help identify strategies to reduce disease burden for frail patients with hypercortisolemia.

  View details for DOI 10.1227/neu.0000000000003090

  View details for PubMedID 38985563

• Management of recurrent cerebrospinal fluid rhinorrhea caused by sequential, anatomically separated skull base defects - A case-based systematic review. World neurosurgery Hallenberger, T. J., Rychen, J., Soleman, J., Fernandez-Miranda, J. C., Brand, Y., Mariani, L., Roethlisberger, M. 2024

  Abstract

  Recurrent cerebrospinal fluid (CSF) rhinorrhea caused by sequential, anatomically separated skull base defects are rarely reported in the literature. Neither management nor etiology are sufficiently investigated. We herein present an illustrative case and a systematic review of the literature regarding etiology, diagnostics, and management of this rare phenomenon.A systematic literature search looking for articles reporting sequential CSF-leaks with multiple skull base defects was performed. Data from included articles was descriptively reported, the quality of the included studies was assessed with GRADE.A 71-year-old female patient with posttraumatic rhino- and left-sided otorrhea due to a left-sided longitudinal fracture of the petrous bone presented at our institution. After initial surgical repair and a ten-week symptom-free interval, CSF-rhinorrhea reoccurred. Imaging review revealed a pre-existing contralateral meningoencephalocele of the lateral sphenoid recess causing recurrent CSF-rhinorrhea most likely after initial traumatic laceration. The defect was successfully treated. Literature search identified 366 reports, six of which were included in the systematic review with a total of ten cases. Quality was deemed good in 8/10 cases. The most common location for primary and sequential CSF-leaks was along the sphenoid bone (4/10 and 5/10 patients, respectively). All publications except one reported the presence of a meningo(encephalo)cele as cause of the sequential CSF-leak.Occurrence of recurrent CSF-rhinorrhea due to an anatomically separated sequential skull base lesion remains a rare yet described phenomenon. Reassessment of imaging studies and a structured diagnostic work-up to detect sequential CSF-leaks independent of the primary lesion should therefore be considered.

  View details for DOI 10.1016/j.wneu.2024.07.013

  View details for PubMedID 38986941

• Predictors of Durable Remission After Successful Surgery for Cushing Disease: Results From the Multicenter RAPID Registry. Neurosurgery Findlay, M. C., Tenhoeve, S., Alt, J., Rennert, R. C., Couldwell, W. T., Evans, J., Collopy, S., Kim, W., Delery, W., Pacione, D., Kim, A., Silverstein, J. M., Chicoine, M. R., Gardner, P., Rotman, L., Yuen, K. C., Barkhoudarian, G., Fernandez-Miranda, J., Benjamin, C., Kshettry, V. R., Zada, G., Van Gompel, J., Catalino, M. H., Little, A. S., Karsy, M. 2024

  Abstract

  Cushing disease (CD) affects mortality and quality of life along with limited long-term remission, underscoring the need to better identify recurrence risk. The identification of surgical or imaging predictors for CD remission after transsphenoidal surgery has yielded some inconsistent results and has been limited by single-center, single-surgeon, or meta-analyses studies. We sought to evaluate the multicenter Registry of Adenomas of the Pituitary and Related Disorders (RAPID) database of academic US pituitary centers to assess whether robust nonhormonal recurrence predictors could be elucidated.Patients with treated CD from 2011 to 2023 were included. The perioperative and long-term characteristics of CD patients with and without recurrence were assessed using univariable and multivariable analyses.Of 383 patients with CD from 26 surgeons achieving postoperative remission, 288 (75.2%) maintained remission at last follow-up while 95 (24.8%) showed recurrence (median time to recurrence 9.99 ± 1.34 years). Patients with recurrence required longer postoperative hospital stays (5 ± 3 vs 4 ± 2 days, P = .002), had larger average tumor volumes (1.76 ± 2.53 cm3 vs 0.49 ± 1.17 cm3, P = .0001), and more often previously failed prior treatment (31.1% vs 14.9%, P = .001) mostly being prior surgery. Multivariable hazard prediction models for tumor recurrence found younger age (odds ratio [OR] = 0.95, P = .002) and Knosp grade of 0 (OR = 0.09, reference Knosp grade 4, P = .03) to be protective against recurrence. Comparison of Knosp grade 0 to 2 vs 3 to 4 showed that lower grades had reduced risk of recurrence (OR = 0.27, P = .04). Other factors such as length of stay, surgeon experience, prior tumor treatment, and Knosp grades 1, 2, or 3 failed to reach levels of statistical significance in multivariable analysis.This multicenter study centers suggests that the strongest predictors of recurrence include tumor size/invasion and age. This insight can help with patient counseling and prognostication. Long-term follow-up is necessary for patients, and early treatment of small tumors may improve outcomes.

  View details for DOI 10.1227/neu.0000000000003042

  View details for PubMedID 38905223

• Endoscopic Endonasal Resection of a Thyroid-Stimulating Hormone-Secreting Pituitary Adenoma With Invasion of the Medial Wall of the Cavernous Sinus. Operative neurosurgery (Hagerstown, Md.) Ljubimov, V. A., Rychen, J., Lee, C. K., Cobos Sillero, M. I., Xu, Y., Fernandez-Miranda, J. C. 2024

  Abstract

  Thyroid-stimulating hormone-secreting adenomas (TSH-oma) are exceptionally rare.1 The primary treatment is surgical resection with radiation and pharmacotherapy postoperatively if subtotal resection, especially with cavernous sinus invasion.2 We present the case of a 29-year-old man with TSH-oma with cavernous sinus medial wall invasion. This is the first documented case with selective resection of the cavernous sinus medial wall to achieve a complete resection and biochemical remission in TSH-oma through endoscopic endonasal approach. The patient had elevated TSH and thyroid hormones with symptoms of weight loss, palpitations, excess sweating, and decreased endurance. MRI revealed a 1.3 × 2.1 × 1.2 cm contrast-enhancing sellar mass with rightward pituitary gland displacement without evidence of cavernous sinus invasion (Knosp 2). The patient consented to procedure/publication. No institutional review board approval needed per institution. We performed standard resection of the firm sellar tumor portion and noted that there was tumor invasion into the left cavernous sinus medial wall dura. The bony opening was expanded to expose the anterior wall of the cavernous sinus, which was opened to identify the cavernous internal carotid artery and the medial wall attachments. The thickened medial wall was completely resected. We achieved a complete tumor resection, and the patient's TSH and thyroid hormone dropped to a desired threshold.3 Tumor stained for GATA3 and PIT1, characterizing the TSH-oma.4,5 Understanding cavernous sinus vascular and ligamentous anatomy allows for safe separation of invaded medial wall dura from the cavernous internal carotid artery,6 allowing for a more complete tumor resection, improving surgical cure rates, and sparing the patient from future radiation and pharmacotherapy.

  View details for DOI 10.1227/ons.0000000000001240

  View details for PubMedID 38888332

• The Utility of a "Second-Look" Debridement Following Endonasal Skull Base Surgery in the Pediatric Population. Journal of neurological surgery. Part B, Skull base Chang, M. T., Huang, A. E., Quon, J. L., Fernandez-Miranda, J. C., Wen, C. Z., Eide, J. G., Kshirsagar, R. S., Qian, Z. J., Nayak, J. V., Hwang, P. H., Adappa, N. D., Patel, Z. M. 2024; 85 (3): 313-317

  Abstract

  Background  Sinonasal debridement is typically performed in the weeks following endonasal skull base surgery (ESBS). In the pediatric population, this second-look procedure may require general anesthesia; however, there is currently little evidence assessing the benefit of this practice. Methods  This was a multicenter retrospective study of pediatric patients (age <18 years) undergoing a planned second-look debridement under general anesthesia following ESBS. Intraoperative findings, interventions performed, and perioperative complications were reviewed. Multivariate regression analysis was performed to identify associations between intraoperative findings and clinical factors. Results  We reviewed 69 cases of second-look debridements (age mean 8.6 ± 4.2 years, range: 2-18 years), occurring a mean of 18.3 ± 10.3 days following ESBS. All abnormal findings were noted in patients age ≤12 years. Synechiae were noted in 8.7% of cases, bacterial rhinosinusitis in 2.9%, and failed reconstruction with cerebrospinal fluid leak in 4.5% (two cases of flap malposition and one case of flap necrosis). All failed reconstructions were noted following expanded endonasal cases for craniopharyngioma, and in each case, a revision reconstruction was performed during the second-look surgery. Synechiae were not significantly associated with younger age, revision cases, or cases with reconstructive flaps. There were no perioperative complications. Conclusion  Second-look debridement under general anesthesia may be useful in the identification and intervention of sinonasal pathology following endoscopic skull base surgery, particularly in children ≤12 years old or those with pedicled flap reconstructions. Larger controlled studies are warranted to validate this practice and refine indications and timing of this second procedure.

  View details for DOI 10.1055/a-2048-7564

  View details for PubMedID 38721369

  View details for PubMedCentralID PMC11076083

• Purely endoscopic subtemporal keyhole anterior transpetrosal approach to access the petrous apex region: surgical techniques and early results. Journal of neurosurgery Morisako, H., Sasaki, T., Ikegami, M., Tanoue, Y., Ohata, H., Goudihalli, S. R., Fernandez-Miranda, J. C., Ohata, K., Goto, T. 2024: 1-10

  Abstract

  The anterior transpetrosal approach using a microscope to provide wider access to the petrous apex region has been described for radical resection of lesions of the middle and posterior skull base. The microscopic anterior transpetrosal approach (mATPA) requires a wide craniotomy and meticulous epidural procedures to minimize temporal lobe retraction. Recently, the clinical application of transcranial endoscopic keyhole approaches for minimally invasive surgery has been steadily expanding. In this study, the details of the purely endoscopic subtemporal keyhole ATPA (eATPA) for petrous apex lesions are described and its initial results are reported.Between May 2022 and May 2023, the authors performed eATPA in 10 patients with petrous apex lesions, of which 6 were meningiomas, 3 were trigeminal schwannomas, and 1 was epidermoid cyst. The surgical procedure of the purely eATPA is as follows. After a small temporal craniotomy, the endoscopic procedure is started. The anterior rim of the petrous bone and Meckel's cave are exposed via an intradural subtemporal approach. The lesion is removed with additional drilling of Kawase's triangle, cutting the superior petrosal sinus, opening Meckel's cave, and cutting the tentorium. The authors also compared the outcomes of mATPA versus eATPA for consecutive cases of petrous apex lesions.Gross-total resection was achieved in 8 of the 10 patients. The average operative time was 4 hours 13 minutes. There were 3 cases of transient abducens nerve palsy and 1 case of trochlear nerve palsy in the postoperative period. No new-onset motor deficits or CSF leakage was noted in any of these patients. Only 1 patient exhibited postoperative asymptomatic temporal lobe edema. The Karnofsky Performance Scale (KPS) scores remained unchanged or improved for all patients postoperatively. Compared with mATPA, eATPA achieved a similar extent of resection and comparable postoperative KPS scores with a significantly shorter mean operative time, much smaller temporal craniotomy, and thus less mean blood loss during surgery with lower rates of new-onset temporal lobe edema in the postoperative period.An eATPA allows a direct route to access Meckel's cave and posterior cranial fossa lesions similar to conventional mATPA, with shortening the operative time and reducing the risk of postoperative temporal lobe edema. This eATPA is considered one of the new surgical techniques that can be expected to develop in the future.

  View details for DOI 10.3171/2024.1.JNS231774

  View details for PubMedID 38579340

• Recurrence morbidity of olfactory neuroblastoma. International forum of allergy & rhinology Melder, K., Mace, J. C., Choby, G., Almeida, J. P., Champagne, P., Chan, E., Ciporen, J., Chaskes, M. B., Fernandez-Miranda, J., Fung, N. K., Gardner, P., Hwang, P., Ji, K. S., Kalyvas, A., Kong, K. A., Patel, C., Patel, Z., Celda, M. P., Pinheiro-Neto, C. D., Snyderman, C., Thorp, B. D., Van Gompel, J. J., Zenonos, G., Zwagerman, N. T., Sanusi, O., Wang, E. W., Geltzeiler, M. 2024

  Abstract

  BACKGROUND: With modern treatment paradigms, olfactory neuroblastoma (ONB) has favorable overall survival (OS); however, the incidence of recurrence remains high. The primary aims of this study were to delineate the prognosis of recurrence of ONB and explore how recurrence subsites are associated with OS, disease-specific survival (DSS), and further recurrence.METHODS: A retrospective chart review of ONB cases from nine academic centers between 2005 and 2021 was completed. Tumor characteristics, recurrence subsites, timelines to recurrence, additional recurrences, and survival estimates were determined using descriptive and time-to-event analyses.RESULTS: A final cohort of 233 patients was identified, with 70 (30.0%) patients recurring within 50.4 (standard deviation±40.9) months of diagnosis on average, consisting of local (50%), neck (36%), intracranial (9%), and distant (6%) recurrence. Compared with subjects without recurrence, patients with recurrence had significantly different primary American Joint Committee on Cancer T stage (p<0.001), overall stage (p<0.001), and modified Kadish scores (p<0.001). Histopathology identified that dural involvement and positive margins were significantly greater in recurrent cases. First recurrence was significantly associated with worse 5-year DSS (hazard ratio=5.62; p=0.003), and subjects with neck or local recurrence had a significantly better DSS compared to intracranial or distant recurrence.CONCLUSIONS: Recurrent cases of ONB have significantly different stages and preoperative imaging factors. Patients with local or neck recurrence, however, have better DSS than those with intracranial or distant recurrence, independent of initial tumor stage or Hyams grade. Identifying specific factors that confer an increased risk of recurrence and DSS is important for patient counseling in addition to surveillance planning.

  View details for DOI 10.1002/alr.23351

  View details for PubMedID 38567900

• Multicenter Registry of Adenomas of the Pituitary and Related Disorders: Initial Description of Cushing Disease Cohort, Surgical Outcomes, and Surgeon Characteristics. Neurosurgery Little, A. S., Karsy, M., Evans, J. J., Kim, W., Pacione, D. R., Kim, A. H., Gardner, P. A., Hendricks, B. K., Sarris, C. E., Torok, I. E., Low, T. M., Crocker, T. A., Valappil, B., Kanga, M., Abdallah, H., Collopy, S., Fernandez-Miranda, J. C., Vigo, V., Ljubimov, V. A., Zada, G., Garrett, N. E., Delery, W., Yuen, K. C., Rennert, R. C., Couldwell, W. T., Silverstein, J. M., Kshettry, V. R., Chicoine, M. R. 2024

  Abstract

  To address the lack of a multicenter pituitary surgery research consortium in the United States, we established the Registry of Adenomas of the Pituitary and Related Disorders (RAPID). The goals of RAPID are to examine surgical outcomes, improve patient care, disseminate best practices, and facilitate multicenter surgery research at scale. Our initial focus is Cushing disease (CD). This study aims to describe the current RAPID patient cohort, explore surgical outcomes, and lay the foundation for future studies addressing the limitations of previous studies.Prospectively and retrospectively obtained data from participating sites were aggregated using a cloud-based registry and analyzed retrospectively. Standard preoperative variables and outcome measures included length of stay, unplanned readmission, and remission.By July 2023, 528 patients with CD had been treated by 26 neurosurgeons with varying levels of experience at 9 academic pituitary centers. No surgeon treated more than 81 of 528 (15.3%) patients. The mean ± SD patient age was 43.8 ± 13.9 years, and most patients were female (82.2%, 433/527). The mean tumor diameter was 0.8 ± 2.7 cm. Most patients (76.6%, 354/462) had no prior treatment. The most common pathology was corticotroph tumor (76.8%, 381/496). The mean length of stay was 3.8 ± 2.5 days. The most common discharge destination was home (97.2%, 513/528). Two patients (0.4%, 2/528) died perioperatively. A total of 57 patients (11.0%, 57/519) required an unplanned hospital readmission within 90 days of surgery. The median actuarial disease-free survival after index surgery was 8.5 years.This study examined an evolving multicenter collaboration on patient outcomes after surgery for CD. Our results provide novel insights on surgical outcomes not possible in prior single-center studies or with national administrative data sets. This collaboration will power future studies to better advance the standard of care for patients with CD.

  View details for DOI 10.1227/neu.0000000000002888

  View details for PubMedID 38441527

• Patient and caregiver perspectives of fluid discharge protocols following pituitary surgery. Journal of clinical & translational endocrinology Chang, J. J., Amano, A., Brown-Johnson, C., Chu, O., Gates-Bazarbay, V., Wipff, E., Kling, S. M., Alhadha, M., Carlos Fernandez-Miranda, J., Vilendrer, S. 2024; 35: 100336

  Abstract

  Post-operative fluid restriction after transsphenoidal surgery (TSS) for pituitary tumors may effectively prevent delayed hyponatremia, the most common cause of readmission. However, implementation of individualized fluid restriction interventions after discharge is often complex and poses challenges for provider and patient. The purpose of this study was to understand the factors necessary for successful implementation of fluid restriction and discharge care protocols following TSS.Semi-structured interviews with fifteen patients and four caregivers on fluid discharge protocols were conducted following TSS. Patients and caregivers who had surgery before and after the implementation of updated discharge protocols were interviewed. Data were analyzed inductively using a procedure informed by rapid and thematic analysis.Most patients and caregivers perceived fluid restriction protocols as acceptable and feasible when indicated. Facilitators to the protocols included clear communication about the purpose of and strategies for fluid restriction, access to the care team, and involvement of patients' caregivers in care discussions. Barriers included patient confusion about differences in the care plan between teams, physical discomfort of fluid restriction, increased burden of tracking fluids during recovery, and lack of clarity surrounding desmopressin prescriptions.Outpatient fluid restriction protocols are a feasible intervention following pituitary surgery but requires frequent patient communication and education. This evaluation highlights the importance of patient engagement and feedback to effectively develop and implement complex clinical interventions.

  View details for DOI 10.1016/j.jcte.2024.100336

  View details for PubMedID 38545460

  View details for PubMedCentralID PMC10965805

• Complications of Endonasal Odontoidectomy in Pediatric versus Adult Populations: A Systematic Review and Meta-Analysis JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Kosaraju, N., Lee, C. K., Qian, Z., Fernandez-Miranda, J. C., Nayak, J. V., Chang, M. T. 2024

  View details for DOI 10.1055/a-2257-5439

  View details for Web of Science ID 001178879200003

• Educational stereoscopic representation of a step-by-step brain white fiber dissection according to Klingler's method. Surgical and radiologic anatomy : SRA Jacquesson, T., Djarouf, I., Simon, É., Haegelen, C., Mertens, P., Picart, T., Fernandez-Miranda, J. 2024

  Abstract

  Understanding and teaching the three-dimensional architecture of the brain remains difficult because of the intricate arrangement of grey nuclei within white matter tracts. Although cortical area functions have been well studied, educational and three-dimensional descriptions of the organization of deep nuclei and white matter tracts are still missing.We propose herein a detailed step-by-step dissection of the lateral aspect of a left hemisphere using the Klingler method and provide high-quality stereoscopic views with the aim to help teach medical students or surgeons the three-dimensional anatomy of the brain.Three left hemispheres were extracted and prepared. Then, according to the Klingler method, dissections were carried out from the lateral aspect. Photographs were taken at each step and were modified to provide stereoscopic three-dimensional views.Gray and white structures were described: cortex, claustrum, putamen, pallidum, caudate nucleus, amygdala; U-fibers, external and internal capsules, superior longitudinal fasciculus, frontal aslant fasciculus, uncinate fasciculus, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, corticospinal fasciculus, corona radiata, anterior commissure, and optic radiations.This educational stereoscopic presentation of an expert dissection of brain white fibers and basal ganglia would be of value for theoretical or hands-on teaching of brain anatomy; labeling and stereoscopy could, moreover, improve the teaching, understanding, and memorizing of brain anatomy. In addition, this could be also used for the creation of a mental map by neurosurgeons for the preoperative planning of brain tumor surgery.

  View details for DOI 10.1007/s00276-024-03305-0

  View details for PubMedID 38376527

  View details for PubMedCentralID 3798102

• Probabilistic coverage of the frontal aslant tract in young adults: Insights into individual variability, lateralization, and language functions. Human brain mapping Linn, W. J., Barrios-Martinez, J., Fernandes-Cabral, D., Jacquesson, T., Nuñez, M., Gomez, R., Anania, Y., Fernandez-Miranda, J., Yeh, F. C. 2024; 45 (3): e26630

  Abstract

  The frontal aslant tract (FAT) is a crucial neural pathway of language and speech, but little is known about its connectivity and segmentation differences across populations. In this study, we investigate the probabilistic coverage of the FAT in a large sample of 1065 young adults. Our primary goal was to reveal individual variability and lateralization of FAT and its structure-function correlations in language processing. The study utilized diffusion MRI data from 1065 subjects obtained from the Human Connectome Project. Automated tractography using DSI Studio software was employed to map white matter bundles, and the results were examined to study the population variation of the FAT. Additionally, anatomical dissections were performed to validate the fiber tracking results. The tract-to-region connectome, based on Human Connectome Project-MMP parcellations, was utilized to provide population probability of the tract-to-region connections. Our results showed that the left anterior FAT exhibited the most substantial individual differences, particularly in the superior and middle frontal gyrus, with greater variability in the superior than the inferior region. Furthermore, we found left lateralization in FAT, with a greater difference in coverage in the inferior and posterior portions. Additionally, our analysis revealed a significant positive correlation between the left FAT inferior coverage area and the performance on the oral reading recognition (p = .016) and picture vocabulary (p = .0026) tests. In comparison, fractional anisotropy of the right FAT exhibited marginal significance in its correlation (p = .056) with Picture Vocabulary Test. Our findings, combined with the connectivity patterns of the FAT, allowed us to segment its structure into anterior and posterior segments. We found significant variability in FAT coverage among individuals, with left lateralization observed in both macroscopic shape measures and microscopic diffusion metrics. Our findings also suggested a potential link between the size of the left FAT's inferior coverage area and language function tests. These results enhance our understanding of the FAT's role in brain connectivity and its potential implications for language and executive functions.

  View details for DOI 10.1002/hbm.26630

  View details for PubMedID 38376145

  View details for PubMedCentralID PMC10878181

• The RAPID Consortium: A Platform for Clinical and Translational Pituitary Tumor Research. Journal of neurological surgery. Part B, Skull base Karsy, M., Kshettry, V., Gardner, P., Chicoine, M., Fernandez-Miranda, J. C., Evans, J. J., Barkhoudarian, G., Hardesty, D., Kim, W., Zada, G., Crocker, T., Torok, I., Little, A. 2024; 85 (1): 1-8

  Abstract

  Objectives  Pituitary tumor treatment is hampered by the relative rarity of the disease, absence of a multicenter collaborative platform, and limited translational-clinical research partnerships. Prior studies offer limited insight into the formation of a multicenter consortium. Design  The authors describe the establishment of a multicenter research initiative, Registry of Adenomas of the Pituitary and Related Disorders (RAPID), to encourage quality improvement and research, promote scholarship, and apply innovative solutions in outcomes research. Methods  The challenges encountered during the formation of other research registries were reviewed with those lessons applied to the development of RAPID. Setting/Participants  RAPID was formed by 11 academic U.S. pituitary centers. Results  A Steering Committee, bylaws, data coordination center, and leadership team have been established. Clinical modules with standardized data fields for nonfunctioning adenoma, prolactinoma, acromegaly, Cushing's disease, craniopharyngioma, and Rathke's cleft cyst were created using a Health Insurance Portability and Accountability Act-compliant cloud-based platform. Currently, RAPID has received institutional review board approval at all centers, compiled retrospective data and agreements from most centers, and begun prospective data collection at one site. Existing institutional databases are being mapped to one central repository. Conclusion  The RAPID consortium has laid the foundation for a multicenter collaboration to facilitate pituitary tumor and surgical research. We sought to share our experiences so that other groups also contemplating this approach may benefit. Future studies may include outcomes benchmarking, clinically annotated biobank tissue, multicenter outcomes studies, prospective intervention studies, translational research, and health economics studies focused on value-based care questions.

  View details for DOI 10.1055/a-1978-9380

  View details for PubMedID 38274483

  View details for PubMedCentralID PMC10807961

• Ipsilateral Nasoseptal Flaps in a Transpterygoid Approach: Technical Pearls and Reconstruction Outcomes JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Chang, M. T., Grimm, D., Asmaro, K., Yong, M., Low, C., Lee, C. K., Nayak, J. V., Hwang, P. H., Fernandez-Miranda, J. C., Patel, Z. M. 2024

  View details for DOI 10.1055/s-0043-1778662

  View details for Web of Science ID 001147729300003

• Anatomic and Surgical Considerations in the Management of a Sellar and Suprasellar Arachnoid Cyst: 2-Dimensional Operative Video. Operative neurosurgery (Hagerstown, Md.) Rychen, J., Constanzo, F., Chan, D., Kossler, A. L., Fernandez-Miranda, J. C. 2024

  View details for DOI 10.1227/ons.0000000000001061

  View details for PubMedID 38198191

• The Temporoparietal Fascia Flap Transposition Technique for Ventral Skull Base Reconstruction: Anatomic Analysis and Surgical Application. Operative neurosurgery (Hagerstown, Md.) Xu, Y., Asmaro, K., Mohyeldin, A., Nunez, M. A., Mao, Y., Cohen-Gadol, A. A., Nayak, J., Fernandez-Miranda, J. C. 2024

  Abstract

  BACKGROUND AND OBJECTIVES: The temporoparietal fascia (TPF) flap is an alternative for revision endoscopic skull base reconstruction in the absence of the nasoseptal flap, and we aimed to investigate the anatomy and surgical application of TPF flap transposition in endoscopic endonasal surgery.METHODS: Six lightly embalmed postmortem human heads and 30 computed tomography angiography imaging scans were used to analyze the anatomic features of the TPF flap transposition technique. Three cases selected from a 512 endoscopic endonasal cases database were presented for the clinical application of the TPF flap.RESULTS: The TPF flap, composed by the deepest 3 scalp layers (galea aponeurotica, loose areolar connective tissue, and pericranium), can be harvested and then transposed through the infratemporal-maxillary-pterygoid tunnel to the ventral skull base. The superficial temporal artery as its feeding artery, gives frontal and parietal branches with similar diameter (1.5 ± 0.3 mm) at its bifurcation. The typical bifurcation was present in 50 sides (83.3%), with single (frontal) branch in 5 sides (8.3%), single (parietal) branch in 2 sides (3.3%), and multiple branches (>2) in 3 sides (5%). The transposed TPF flap was divided into 3 parts according to its anatomic location: (1) infratemporal part with an area of 19.5 ± 2.5 cm2, (2) maxillary part with an area of 23.7 ± 2.8 cm2, and (3) skull base part with an area of 44.2 ± 4 cm2. Compared with the nasoseptal flap, nasal floor flap, inferior turbinate flap, and extended septal flap, the coverage area of the skull base part of the TPF flap was significantly larger than any of them (P < .0001).CONCLUSION: The TPF flap technique is an effective alternative for endoscopic endonasal skull base reconstruction. The TPF flap could successfully cover large skull base defects through the infratemporal-maxillary-pterygoid tunnel.

  View details for DOI 10.1227/ons.0000000000001048

  View details for PubMedID 38189439

• Spontaneous Otogenic Pneumocephalus Triggered by Air Travel. Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology Aaron, K. A., Eltawil, Y., Fernandez-Miranda, J. C., Jackler, R. K. 2024; 45 (1): e68-e70

  View details for DOI 10.1097/MAO.0000000000004054

  View details for PubMedID 38085769

• Association of Decreased Enhancement of Nasoseptal Flap on Postoperative Magnetic Resonance Imaging with the Risk of Complication JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Wingrove, P. M., Arani, K. N., Snyderman, C. H., Gardner, P. A., Cabral, D., Zenonos, G. A., Wang, E. W., Chabot, J., Fernandez-Miranda, J. C., Chang, Y., Hughes, M. A. 2023

  View details for DOI 10.1055/s-0043-1776007

  View details for Web of Science ID 001105208300001

• In Reply: Refining the Anatomy of Percutaneous Trigeminal Rhizotomy: A Cadaveric, Radiologic, and Surgical Study. Operative neurosurgery (Hagerstown, Md.) Xu, Y., Fernandez-Miranda, J. C., Cohen-Gadol, A. A. 2023

  View details for DOI 10.1227/ons.0000000000000986

  View details for PubMedID 37916824

• Intraoperative augmented reality fiber tractography complements cortical and subcortical mapping. World neurosurgery: X Chidambaram, S., Anthony, D., Jansen, T., Vigo, V., Fernandez Miranda, J. C. 2023; 20: 100226

  Abstract

  Augmented reality (AR) has been found to be advantageous in enhancing visualization of complex neuroanatomy intraoperatively and in neurosurgical education. Another key tool that allows neurosurgeons to have enhanced visualization, namely of white matter tracts, is diffusion tensor imaging (DTI) that is processed with high-definition fiber tractography (HDFT). There remains an enduring challenge in the structural-functional correlation of white matter tracts that centers on the difficulty in clearly assigning function to any given fiber tract when evaluating them through separated as opposed to integrated modalities. Combining the technologies of AR with fiber tractography shows promise in helping to fill in this gap between structural-functional correlation of white matter tracts. This novel study demonstrates through a series of three cases of awake craniotomies for glioma resections a technique that allows the first and most direct evidence of fiber tract stimulation and assignment of function or deficit in vivo through the intraoperative, real-time fusion of electrical cortical stimulation, AR, and HDFT. This novel technique has qualitatively shown to be helpful in guiding intraoperative decision making on extent of resection of gliomas. Future studies could focus on larger, prospective cohorts of glioma patients who undergo this methodology and further correlate the post-operative imaging results to patient functional outcomes.

  View details for DOI 10.1016/j.wnsx.2023.100226

  View details for PubMedID 37456694

  View details for PubMedCentralID PMC10344792

• Eustachian tube dysfunction symptoms after endonasal skull base surgery. International forum of allergy & rhinology Grimm, D., Daum, R., Castro Silva, B. R., Lee, C. K., Fernandez-Miranda, J. C., Nayak, J. V., Patel, Z. M., Hwang, P. H., Chang, M. T. 2023

  Abstract

  ETD symptoms are present in 16% patients with underlying skull base pathology. Preoperative ETD symptoms improve following surgical treatment of skull base pathology. ETD symptoms may worsen in patients with central, posterior, or malignant skull base pathology.

  View details for DOI 10.1002/alr.23266

  View details for PubMedID 37694445

• Multicenter Survival Analysis and Application of an Olfactory Neuroblastoma Staging Modification Incorporating Hyams Grade. JAMA otolaryngology-- head & neck surgery Choby, G., Geltzeiler, M., Almeida, J. P., Champagne, P. O., Chan, E., Ciporen, J., Chaskes, M. B., Fernandez-Miranda, J., Gardner, P., Hwang, P., Ji, K. S., Kalyvas, A., Kong, K. A., McMillan, R., Nayak, J., O'Byrne, J., Patel, C., Patel, Z., Peris Celda, M., Pinheiro-Neto, C., Sanusi, O., Snyderman, C., Thorp, B. D., Van Gompel, J. J., Young, S. C., Zenonos, G., Zwagerman, N. T., Wang, E. W. 2023

  Abstract

  Current olfactory neuroblastoma (ONB) staging systems inadequately delineate locally advanced tumors, do not incorporate tumor grade, and poorly estimate survival and recurrence.The primary aims of this study were to (1) examine the clinical covariates associated with survival and recurrence of ONB in a modern-era multicenter cohort and (2) incorporate Hyams tumor grade into existing staging systems to assess its ability to estimate survival and recurrence.This retrospective, multicenter, case-control study included patients with ONB who underwent treatment between January 1, 2005, and December 31, 2021, at 9 North American academic medical centers.Standard-of-care ONB treatment.The main outcomes were overall survival (OS), disease-free survival (DFS), and disease-specific survival (DSS) as C statistics for model prediction.A total of 256 patients with ONB (mean [SD] age, 52.0 [15.6] years; 115 female [44.9%]; 141 male [55.1%]) were included. The 5-year rate for OS was 83.5% (95% CI, 78.3%-89.1%); for DFS, 70.8% (95% CI, 64.3%-78.0%); and for DSS, 94.1% (95% CI, 90.5%-97.8%). On multivariable analysis, age, American Joint Committee on Cancer (AJCC) stage, involvement of bilateral maxillary sinuses, and positive margins were associated with OS. Only AJCC stage was associated with DFS. Only N stage was associated with DSS. When assessing the ability of staging systems to estimate OS, the best-performing model was the novel modification of the Dulguerov system (C statistic, 0.66; 95% CI, 0.59-0.76), and the Kadish system performed most poorly (C statistic, 0.57; 95% CI, 0.50-0.63). Regarding estimation of DFS, the modified Kadish system performed most poorly (C statistic, 0.55; 95% CI, 0.51-0.66), while the novel modification of the AJCC system performed the best (C statistic, 0.70; 95% CI, 0.66-0.80). Regarding estimation of DSS, the modified Kadish system was the best-performing model (C statistic, 0.79; 95% CI, 0.70-0.94), and the unmodified Kadish performed the worst (C statistic, 0.56; 95% CI, 0.51-0.68). The ability for novel ONB staging systems to estimate disease progression across stages was also assessed. In the novel Kadish staging system, patients with stage VI disease were approximately 7 times as likely to experience disease progression as patients with stage I disease (hazard ratio [HR], 6.84; 95% CI, 1.60-29.20). Results were similar for the novel modified Kadish system (HR, 8.99; 95% CI, 1.62-49.85) and the novel Dulguerov system (HR, 6.86; 95% CI, 2.74-17.18).The study findings indicate that 5-year OS for ONB is favorable and that incorporation of Hyams grade into traditional ONB staging systems is associated with improved estimation of disease progression.

  View details for DOI 10.1001/jamaoto.2023.1939

  View details for PubMedID 37535372

• Endoscopic Endonasal Transtuberculum Approach for Pediatric Tuberoinfundibular Craniopharyngioma: 2-Dimensional Operative Video. Operative neurosurgery (Hagerstown, Md.) Vigo, V., Chang, J. E., Nunez, M. A., Prolo, L. M., Hwang, P. H., Fernandez-Miranda, J. C. 2023

  Abstract

  INDICATIONS CORRIDOR AND LIMITS OF EXPOSURE: The endoscopic endonasal transtuberculum approach grants access to suprasellar and retrochiasmatic lesions with hypothalamic involvement. Here, we present a case of a 13-year-old boy with a history of stunted growth, decreased vision, headaches, and low energy with a tuberoinfundibular craniopharyngioma. The patient consented to the procedure.ANATOMIC ESSENTIALS NEED FOR PREOPERATIVE PLANNING AND ASSESSMENT: Evaluation of the sphenoid sinus pneumatization, internal carotid artery disposition, presence of clinoidal rings, variations of the infrachiasmatic corridor (optic chiasm location, height of dorsum sella), and location of the pituitary stalk are crucial for surgical strategy.ESSENTIALS STEPS OF THE PROCEDURE: Harvesting of nasoseptal flap and access to the sphenoid sinus; drilling the sella, tuberculum, and chiasmatic sulcus up to the limbus sphenoidalis and laterally exposing the clinoidal carotid artery segment; wide dural opening to the level of distal rings inferolaterally and falciform ligaments superolaterally; identification and coagulation of superior hypophyseal branches providing tumor supply; intracapsular dissection and debulking and subpial sharp dissection at the hypothalamic tumor interface to achieve complete removal; and reconstruction with inlay collagen, fascia lata, and nasoseptal flap.PITFALLS/AVOIDANCE OF COMPLICATIONS: Preservation of the superior hypophyseal arteries and stalk is essential for preventing pituitary dysfunction. Preoperative reckoning of hypothalamic invasion and identification of adequate interface aids in avoiding complications. To reduce CSF leak risk, multilayer reconstruction was performed and lumbar drain placed postoperatively.VARIANTS AND INDICATIONS FOR THEIR USE: For retroclival extension, intradural pituitary transposition should be considered to expand the corridor; in patients with preoperative hypopituitarism, pituitary sacrifice is most effective to increase retroclival access.

  View details for DOI 10.1227/ons.0000000000000726

  View details for PubMedID 37350589

• Endoscopic Endonasal Approach to the Ventral Petroclival Fissure: Anatomical Findings and Surgical Techniques JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Xu, Y., Mohyeldin, A., Lee, C. K., Nunez, M., Mao, Y., Cohen-Gadol, A. A., Fernandez-Miranda, J. C. 2023

  View details for DOI 10.1055/a-2088-3086

  View details for Web of Science ID 001006994800006

• Nerve to the zygomaticus major muscle: An anatomical study and surgical application to smile reconstruction. Clinical anatomy (New York, N.Y.) Yoshioka, N., Fernandez-Miranda, J. C. 2023

  Abstract

  Smile reconstruction using the branches that supply the zygomaticus major muscle as a motor source is an established procedure in facial reanimation surgery for facial paralysis. However, the anatomy of the nerve to the muscle remains unclear. Therefore, we herein examined the topographical anatomy of the nerve to the zygomaticus major muscle to obtain more detailed information on donor nerve anatomy. Preserved cadaver dissection was performed under a microscope on 13 hemifaces of 8 specimens. The branches that innervate the zygomaticus major muscle and their peripheral routes medial to the muscle were traced and examined. A median of four (ranges 2-4) branches innervated the zygomaticus major muscle. The proximal two branches (near the muscle origin) arose from the zygomatic branch, the second of which was the major branch. The distal branches (near the oral commissure) arose from the buccal branch or zygomaticobuccal plexus. The vertical distance from the caudal margin of the zygomatic arch to the major branch intersecting point was 19±4.0mm, while the horizontal distance parallel to the Frankfort plane was 29±5.2mm. The proximal two branches innervating the zygomaticus major muscle were detected in the majority of specimens. The anatomical findings obtained herein on the nerve to the zygomaticus major muscle will allow for more reliable donor selection in facial reanimation surgery.

  View details for DOI 10.1002/ca.24079

  View details for PubMedID 37283304

• Pursuing perfect 2D and 3D photography in neuroanatomy: a new paradigm for staying up to date with digital technology JOURNAL OF NEUROSURGERY Xu, Y., Vigo, V., Klein, J., Nunez, M., Fernandez-Miranda, J. C., Cohen-Gadol, A. A., Mao, Y. 2023; 138 (6): 1766-1772

  View details for DOI 10.3171/2022.9.JNS221988.

  View details for Web of Science ID 001018876000031

• Fronto-Orbitozygomatic Approach for Cavernous Sinus Hemangioma: 3-Dimensional Operative Video. Operative neurosurgery (Hagerstown, Md.) Vigo, V., Asmaro, K. P., Nunez, M. A., Fernandez-Miranda, J. C. 2023

  View details for DOI 10.1227/ons.0000000000000744

  View details for PubMedID 37167004

• In Reply to the Letter to the Editor Regarding: "Endoscopic Contralateral Interhemispheric Transfalcine Keyhole Approach for Large Falcine Meningiomas". World neurosurgery Sakaeyama, Y., Morisako, H., Ohata, H., Nakajo, K., Valenzuela, J. C., Fernandez-Miranda, J. C., Goto, T. 2023; 173: 292-293

  View details for DOI 10.1016/j.wneu.2023.01.099

  View details for PubMedID 37189314

• An algorithm for the use of free tissue graft reconstruction in the endoscopic endonasal approach for pituitary tumors. World neurosurgery Hebert, A. M., Kuan, E. C., Wang, M. B., Snyderman, C. H., Gardner, P. A., Bergsneider, M., Fernandez-Miranda, J. C., Wang, E. W. 2023

  Abstract

  OBJECTIVE: To identify factors associated with successful use of free tissue grafting versus vascularized reconstruction after resection of pituitary tumors.METHODS: A retrospective chart review of two tertiary academic medical centers over 3.5 years was conducted. Variables assessed included age, sex, body mass index (BMI), pathology, extent of surgical exposure, cavernous sinus or suprasellar extension, intraoperative cerebrospinal fluid (CSF) leak, grade of leak, previous radiation, and prior surgery. Reconstructive techniques were divided into no reconstruction, free tissue grafts, and vascularized flaps.RESULTS: 485 patients were included. Free grafts were used in 299/485 cases (61.6%) and were more commonly used with smaller approaches (p<0.001). Larger exposure size and CSF leak grades 2 and 3 were associated with vascularized flap use (p<0.001 and p=0.012, respectively). Using multivariate regression, type of reconstruction could be predicted by increasing extent of approach, intraoperative CSF leak grade, and suprasellar extension (OR 2.014, p <0.001, 95% CI 1.335-3.039; OR 1.636, p=0.025, 95% CI 1.064-2.517; OR 1.975, p<0.001, 95% CI 1.554-2.510, respectively). Postoperative CSF leak occurred in 9 out of 173 (5.2%) patients with intraoperative leak and was not associated with any factors on analysis.CONCLUSION: We propose an algorithm whereby grade 1 CSF leaks in sellar and parasellar resections can be successfully reconstructed with a free graft. Vascularized flaps may be reserved for grade 2 or 3 intraoperative CSF leaks, extended approaches, or tumors with suprasellar extension.

  View details for DOI 10.1016/j.wneu.2023.03.125

  View details for PubMedID 37024082

• The Utility of a "Second-Look" Debridement Following Endonasal Skull Base Surgery in the Pediatric Population JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Chang, M. T., Huang, A. E., Quon, J. L., Fernandez-Miranda, J. C., Wen, C. Z., Eide, J. G., Kshirsagar, R. S., Qian, Z., Nayak, J. V., Hwang, P. H., Adappa, N. D., Patel, Z. M. 2023

  View details for DOI 10.1055/a-2048-7564

  View details for Web of Science ID 000960953100002

• Endoscopic supraorbital eyebrow approach for medium-size tuberculum sellae meningiomas; a cadaveric stepwise dissection, technical nuances and surgical outcomes. World neurosurgery Sasaki, T., Morisako, H., Ikegami, M., Wardhana, D. W., Fernandez-Miranda, J. C., Goto, T. 2023

  Abstract

  Tuberculum sellae meningiomas (TSMs) have traditionally been removed using a transcranial approach. In recent years, endoscopic surgeries for TSMs have been reported with an expansion of indications.We have performed a fully endoscopic supraorbital keyhole approach for small to medium size TSMs, and performed radical tumor removal similar to conventional transcranial procedure. We report the details of this surgical procedure including cadaveric stepwise dissection and initial surgical results for small to medium size TSMs.We used an endoscopic supraorbital eyebrow approach for 6 patients with TSMs between September 2020 and September 2022. Mean tumor diameter was 16.0 mm (range, 10-20 mm). The surgical approach included an eyebrow skin incision ipsilateral to the lesion, a small frontal craniotomy, subfrontal exposure of the lesion, removal of the tuberculum sellae, unroofing of the optic canal and resection of the tumor. The extent of resection, pre- and postoperative visual function, complications, and operative time were evaluated.Optic canal involvement was observed in all patients. Two patients (33%) showed visual dysfunction before surgery. Simpson grade 1 tumor resection was achieved in all cases. Visual function was improved in 2 cases, and remained unchanged in 4 cases. Postoperative pituitary function was preserved in all cases, with no decreases in olfaction.The endoscopic supraorbital eyebrow approach for TSMs allowed resection of the lesion, including tumor extending to the optic canal, with a good surgical view. This technique is minimally invasive for patients and may represent a good surgical option for medium size TSMs.

  View details for DOI 10.1016/j.wneu.2023.03.063

  View details for PubMedID 36940807

• Reappraisal of the anatomy of the frontotemporal branches of the facial nerve. Journal of neurosurgery Nunez, M. A., Mohyeldin, A., Marotta, D. A., Vigo, V., Asmaro, K., Xu, Y., Cohen-Gadol, A. A., Fernandez-Miranda, J. C. 2023: 1-9

  Abstract

  OBJECTIVE: The anatomy of the temporal branches of the facial nerve (FN) has been widely described in the neurosurgical literature because of its relevance in anterolateral approaches to the skull base and implication in frontalis palsies from these approaches. In this study, the authors attempted to describe the anatomy of the temporal branches of the FN and identify whether there are any FN branches that cross the interfascial space of the superficial and deep leaflets of the temporalis fascia.METHODS: The surgical anatomy of the temporal branches of the FN was studied bilaterally in 5 embalmed heads (n = 10 extracranial FNs). Exquisite dissections were performed to preserve the relationships of the branches of the FN and their relationship to the surrounding fascia of the temporalis muscle, the interfascial fat pad, the surrounding nerve branches, and their final terminal endpoints near the frontalis and temporalis muscles. The authors correlated their findings intraoperatively with 6 consecutive patients with interfascial dissection in which neuromonitoring was performed to stimulate the FN and associated twigs that were observed to be interfascial in 2 of them.RESULTS: The temporal branches of the FN stay predominantly superficial to the superficial leaflet of the temporal fascia in the loose areolar tissue near the superficial fat pad. As they course over the frontotemporal region, they give off a twig that anastomoses with the zygomaticotemporal branch of the trigeminal nerve, which crosses the superficial layer of the temporalis muscle, spanning the interfascial fat pad, and then pierces the deep temporalis fascial layer. This anatomy was observed in 10 of the 10 FNs dissected. Intraoperatively, stimulation of this interfascial segment yielded no facial muscle response up to 1 mA in any of the patients.CONCLUSIONS: The temporal branch of the FN gives off a twig that anastomoses with the zygomaticotemporal nerve, which crosses the superficial and deep leaflets of the temporal fascia. Interfascial surgical techniques aimed at protecting the frontalis branch of the FN are safe in their efforts to protect against frontalis palsy with no clinical sequelae when executed properly.

  View details for DOI 10.3171/2023.1.JNS222027

  View details for PubMedID 36905660

• Radiographic predictors of occult intracranial involvement in olfactory neuroblastoma patients. International forum of allergy & rhinology Geltzeiler, M., Choby, G. W., Ji, K. S., Mace, J. C., Almeida, J. P., de Almeida, J., Champagne, P., Chan, E., Ciporen, J. N., Chaskes, M. B., Cornell, S., Drozdowski, V., Fernandez-Miranda, J., Gardner, P. A., Hwang, P. H., Kalyvas, A., Kong, K. A., McMillan, R. A., Nayak, J. V., Patel, C., Patel, Z. M., Celda, M. P., Pinheiro-Neto, C., Sanusi, O. R., Snyderman, C. H., Thorp, B. D., Van Gompel, J. J., Zadeh, G., Zenonos, G., Zwagerman, N. T., Wang, E. W. 2023

  Abstract

  BACKGROUND: Traditional management of olfactory neuroblastoma (ONB) includes margin negative resection with removal of cribriform plate, dura, and olfactory bulb, regardless of intracranial disease. This approach may be over-treating certain patients. Our investigation examines risk factors associated with occult intracranial disease to optimize therapeutic outcomes.METHODS: This retrospective, multi-institutional cohort study examined clinical covariates associated with occult intracranial involvement. Patient demographics, staging, Hyam's grade and pathologic involvement of dura, olfactory bulb/tract and brain were collected. Diagnostic imaging was reviewed. Positive and negative predictive value (NPV) were estimated along with effect size estimates. Cox hazard regression examined associations with overall (OS) and disease-free survival (DFS).RESULTS: 224 subjects with new diagnoses of ONB (2005-2021) were identified. Skull base bone involvement on computed tomography (CT) had the highest NPV for pathologic dura (88.0%), olfactory bulb (88%), and brain involvement (97.3%). Hyam's grade category was significantly associated with dural involvement (phiC = 0.26; 95% CI: 0.16, 0.42). Subjects without radiologic skull base involvement (n = 66) had pathologic positivity of 12.1%. Within this subgroup, Hyam's grade was clinically significant for dural positivity (phi = 0.34; 95% CI: -0.12, 0.71) with 28.6% involvement in high grade tumors. Neither clinical nor pathologic positivity of intracranial structures were associated with significantly different OS or DFS.CONCLUSIONS: Both CT and MRI had reasonably good NPV for involvement of dura and olfactory bulb. Higher Hyam's grade was associated with dural involvement. Patients with low-grade tumors not involving the skull base may be suitable for avoiding skull base resection, however further investigation is warranted. This article is protected by copyright. All rights reserved.

  View details for DOI 10.1002/alr.23145

  View details for PubMedID 36841933

• Orbital Resection by Intranasal Technique (ORBIT): A new classification system for reporting endoscopically resectable primary benign orbital tumors. International forum of allergy & rhinology Jafari, A., Adappa, N. D., Anagnos, V. J., Campbell, R. G., Castelnuovo, P., Chalian, A., Chambers, C. B., Chitguppi, C., Dallan, I., Rassi, E. E., Freitag, S. K., Fernandez Miranda, J. C., Ferreira, M. J., Gardner, P. A., Gudis, D. A., Harvey, R. J., Huang, Q., Humphreys, I. M., Kennedy, D. W., Lee, J. Y., Lehmann, A. E., Locatelli, D., McKinney, K. A., Moreau, A., Nyquist, G., Palmer, J. N., Prepageran, N., Pribitkin, E. A., Rabinowitz, M. R., Rosen, M. R., Sacks, R., Sharma, D., Snyderman, C. H., Tonya Stefko, S., Stokken, J. K., Wang, E. W., Workman, A. D., Wu, A. W., Yu, J. Y., Zhang, M. M., Zhou, B., Bleier, B. S. 2023

  Abstract

  INTRODUCTION: The CHEER staging system has become the gold standard for outcomes reporting in endoscopic orbital surgery for orbital cavernous hemangiomas (OCHs). A recent systematic review demonstrated similar outcomes between OCHs and other primary benign orbital tumors (PBOTs). Therefore, we hypothesized that a simplified and more comprehensive classification system could be developed to predict surgical outcomes of other PBOTs.METHODS: Patient and tumor characteristics as well as surgical outcomes from 11 international centers were recorded. All tumors were retrospectively assigned an Orbital Resection by Intranasal Technique (ORBIT) class and stratified based on surgical approach as either exclusively endoscopic or combined (endoscopic and open). Outcomes based on approach were compared using chi-squared or Fisher's exact tests. The Cochrane-Armitage test for trend was used to analyze outcomes by class.RESULTS: Findings from 110 PBOTs from 110 patients (age 49.0 ± 15.0 years, 51.9% female) were included in the analysis. Higher ORBIT class was associated with a lower likelihood of gross total resection (GTR). GTR was more likely to be achieved when an exclusively endoscopic approach was utilized (p<0.05). Tumors resected using a combined approach tended to be larger, to present with diplopia, and to have an immediate post-operative cranial nerve palsy (p<0.05).CONCLUSION: Endoscopic treatment of PBOTs is an effective approach, with favorable short- and long-term post-operative outcomes as well as low rate of adverse events. The ORBIT classification system is an anatomic-based framework that effectively facilitates high-quality outcomes reporting for all PBOTs. This article is protected by copyright. All rights reserved.

  View details for DOI 10.1002/alr.23141

  View details for PubMedID 36808854

• Subtemporal Approach and Its Infratentorial Extension: Review and a Comparative Analysis of Different Techniques. Journal of neurological surgery. Part B, Skull base Dziedzic, T. A., Abhinav, K., Fernandez-Miranda, J. C. 2023; 84 (1): 89-97

  Abstract

  Introduction  Surgical resection of lesions occupying the incisural space is challenging. In a comparative fashion, we aimed to describe the anatomy and surgical approaches to the tentorial incisura and to the rostral brainstem via the intradural subtemporal approach and its infratentorial extensions. Methods  Six fresh human head specimens (12 sides) were prepared for the microscopic dissection of the tentorial incisura using the intradural subtemporal approach and its infratentorial extensions. Endoscope was used to examine the anatomy of the region inadequately exposed with the microscope. Image-guided navigation was used to confirm bony structures visualized around the petrous apex. Results  Standard subtemporal approach provides surgical access to the supratentorial brainstem above the pontomesencephalic sulcus and to the lateral surface of the cerebral peduncle. The linear or triangular tentorial divisions can provide access to the infratentorial space below the pontomesencephalic sulcus. The triangular tentorial flap in comparison with the linear incision obstructs the exposure of anterior incisural space and of the prepontine cistern. Visualization of the brainstem below the trigeminal nerve can be achieved by the anterior petrosectomy. Conclusion  Infratentorial extension of the intradural subtemporal approach is technically demanding due to critical neurovascular structures and a relatively narrow corridor. In-depth anatomical knowledge is essential for the selection of the appropriate operative approach and safe surgical resections of lesions.

  View details for DOI 10.1055/s-0041-1741566

  View details for PubMedID 36743711

  View details for PubMedCentralID PMC9897897

• Refining the Anatomy of Percutaneous Trigeminal Rhizotomy: A Cadaveric, Radiological, and Surgical Study. Operative neurosurgery (Hagerstown, Md.) Xu, Y., El Ahmadieh, T. Y., Nunez, M. A., Zhang, Q., Liu, Y., Fernandez-Miranda, J. C., Cohen-Gadol, A. A., Mao, Y. 2023

  Abstract

  BACKGROUND: Percutaneous trigeminal rhizotomy (PTR) is a widely used procedure for trigeminal neuralgia. However, comprehensive analyses that combine anatomic, radiological, and surgical considerations are rare.OBJECTIVE: To present high-quality anatomic dissections and radiological studies that highlight the technical nuances of this procedure.METHODS: Six silicon-injected postmortem heads underwent PTR. The surgical corridors were dissected, and the neurovascular relationships were studied. In addition, 20 dried human skulls and 50 computed tomography angiography and MRI scans were collected to study the anatomic relationships for a customized puncture corridor.RESULTS: The PTR corridor was divided into 3 segments: the buccal segment (length, 34.76 ± 7.20 mm), the inferior temporal fossa segment (length, 42.06 ± 6.92 mm), and the Meckel cave segment (length, 24.75 ± 3.34 mm). The puncture sagittal (alpha) and axial (beta) angles measured in this study were 38.32° ± 4.62° and 19.13° ± 2.82°, respectively. The precondylar reference line coincided with the foramen ovale in 75% of the computed tomography angiography scans, and the postcondylar line coincided with the carotid canal in 70% of the computed tomography angiography scans; these lines serve as the intraoperative landmarks for PTR. The ovale-carotid-pterygoid triangle, delineated by drawing a line from the foramen ovale to the carotid canal and the lateral pterygoid plate, is a distinguished landmark to use for avoiding neurovascular injury during fluoroscopy.CONCLUSION: Knowledge of the anatomic and radiological features of PTR is essential for a successful surgery, and a customized technical flow is a safe and effective way to access the foramen ovale.

  View details for DOI 10.1227/ons.0000000000000590

  View details for PubMedID 36716051

• Extreme Far-Lateral Approach for Recurrent Chordoma: 3-Dimensional Operative Video. Operative neurosurgery (Hagerstown, Md.) Vigo, V., Asmaro, K. P., Nunez, M. A., Bobrow, A., Dodd, R. L., Desai, A., Fernandez-Miranda, J. C. 2023

  View details for DOI 10.1227/ons.0000000000000584

  View details for PubMedID 36719953

• A simple technique for generating 3D endoscopic images. Surgical neurology international Campero, A., Baldoncini, M., Villalonga, J. F., Nernekli, K., Pipolo, D. O., Forlizzi, V., Fernandez-Miranda, J. C. 2023; 14: 54

  Abstract

  Background: Most neurosurgical photographs are limited to two-dimensional (2D), in this sense, most teaching and learning of neuroanatomical structures occur without an appreciation of depth. The objective of this article is to describe a simple technique for obtaining right and left 2D endoscopic images with manual angulation of the optic.Methods: The implementation of a three-dimensional (3D) endoscopic image technique is reported. We first describe the background and core principles related to the methods employed. Photographs are taken demonstrating the principles and also during an endoscopic endonasal approach, illustrating the technique. Later, we divide our process into two sections containing explanations, illustrations, and descriptions.Results: The results of taking a photograph with an endoscope and its assembly to a 3D image has been divided into two parts: Photo acquisition and image processing.Conclusion: We conclude that the proposed method is successful in producing 3D endoscopic images.

  View details for DOI 10.25259/SNI_1106_2022

  View details for PubMedID 36895218

• The RAPID Consortium: A Platform for Clinical and Translational Pituitary Tumor Research JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Karsy, M., Kshettry, V., Gardner, P., Chicoine, M., Fernandez-Miranda, J. C., Evans, J. J., Barkhoudarian, G., Hardesty, D., Kim, W., Zada, G., Crocker, T., Torok, I., Little, A. 2022

  View details for DOI 10.1055/a-1978-9380

  View details for Web of Science ID 000906049500002

• Endoscopic Endonasal Transpterygoid Approach for Resection of Carotid Sympathetic Plexus Schwannomas: a cadaveric stepwise dissection, technical nuances and surgical outcomes. World neurosurgery Wardhana, D. W., Morisako, H., Sasaki, T., Ikegami, M., Teranishi, Y., Fernandez-Miranda, J. C., Goto, T. 2022

  Abstract

  Carotid sympathetic plexus (CSP) schwannomas are rare brain tumors located in a complex site around the cavernous sinus (CS) and carotid canal in the petrous bone. This study describes three cases of CSP schwannomas that underwent surgical removal of the tumor through an endoscopic endonasal transpterygoid approach.Between 2016 and 2021, three cases of CSP schwannomas were treated using an endoscopic endonasal transpterygoid approach. Preoperative tumor size, preoperative and postoperative symptoms, internal carotid artery (ICA) displacement, extent of tumor resection, intraoperative findings showing tumor origin, and surgical complications were evaluated in all patients.Two tumors were in the petrous region, and the other one was in both the petrous and cavernous regions. The median tumor diameter was 41.3 mm. In the three cases, the ICA was displaced to the superolateral side, the anterolateral side, and the posterior side, respectively. Near-total resection was achieved in all three cases via an endoscopic endonasal transpterygoid approach. There were no endonasal postoperative complications, and the cranial nerve disability improved in all three patients at one-year follow-up.The surgical technique for CPS schwannoma using an endoscopic endonasal transpterygoid approach may be a viable option because endoscopy has been proven to offer better intraoperative visualization and reduce postoperative discomfort for patients. Tumors located medial and inferior to the ICA pars CS or anterior, inferior, and medial to the paraclival ICA are ideal candidates for surgery using this endoscopic approach.

  View details for DOI 10.1016/j.wneu.2022.10.118

  View details for PubMedID 36332778

• Pursuing perfect 2D and 3D photography in neuroanatomy: a new paradigm for staying up to date with digital technology. Journal of neurosurgery Xu, Y., Vigo, V., Klein, J., Nunez, M. A., Fernandez-Miranda, J. C., Cohen-Gadol, A. A., Mao, Y. 2022: 1-7

  View details for DOI 10.3171/2022.9.JNS221988

  View details for PubMedID 36308484

• Frontotemporal-Orbitozygomatic Approach and Its Variants: Technical Nuances and Video Illustration. Operative neurosurgery (Hagerstown, Md.) El Ahmadieh, T. Y., Nunez, M., Vigo, V., Abou-Al-Shaar, H., Fernandez-Miranda, J. C., Cohen-Gadol, A. A. 2022

  Abstract

  The frontotemporal-orbitozygomatic (FTOz) approach is an extension of the traditional pterional approach. It provides the neurosurgeon with a wide access to the skull base with minimal or no brain retraction needed; it also offers a panoramic view that enables various trajectories toward the anterior, middle, and central cranial fossae as well as the upper segment of the posterior cranial fossa. Intracranial lesions that can be addressed using the FTOz approach include large medial sphenoid wing and spheno-orbital meningiomas; suprasellar and parasellar tumors; lesions of the orbital apex, interpeduncular cistern, third ventricle, and upper paraclival regions; and anterior communicating artery and basilar-tip aneurysms. In this article, we discuss the advantages and disadvantages of the FTOz approach and describe related technical nuances and common pitfalls. Our goal was to provide an up-to-date report of this time-tested surgical approach using original high-quality dissections, 3-dimensional models, and 2-dimensional 4K videos to serve as a reliable and practical educational resource for neurosurgery trainees and junior neurosurgeons. A case example is also provided to show the 1-piece orbitozygomatic approach.

  View details for DOI 10.1227/ons.0000000000000370

  View details for PubMedID 36318722

• Surgical Limitations of the Microscopic Transciliary Supraorbital Keyhole Approach to the Anterior and Middle Skull Base. World neurosurgery Borghei-Razavi, H., Eguiluz-Melendez, A., Wenping, X., Truong, H. Q., Fernandes-Cabral, D., Najera, E., Stefko, T., Fernandez-Miranda, J. C., Gardner, P. A. 2022

  Abstract

  BACKGROUND: The microscopic transciliary SupraOrbital keyhole (mtSO) approach has been used for a wide variety of anterior and middle fossa pathologies, including aneurysms, meningiomas, craniopharyngiomas, and other skull-base tumors. Several clinical series have proven its efficacy and safety, but detailed anatomical demarcations of the anterior and middle cranial base exposure are lacking. Our aim was to define the surgical limitations of the mtSO approach to the ipsilateral and contralateral anterior and middle skull base.METHODS: Five cadaveric specimens (10 sides) were studied with image guidance to illustrate the limits of the surgical exposure. In addition, 30 dry skulls were used to measure the working distances between the craniotomy and key bony landmarks of the mtSO approach.RESULTS: Surgical exposure at the anterior skull base covered the area between the medial half of the contra- and the medial two-thirds of the ipsilateral sphenoid wing including both optic nerves and interoptic space. The anterior limit at the midline was the sphenoethmoidal suture. Ipsilateral anterior clinoidectomy permitted exposure of the superior orbital fissure, which defined the anteromedial limit at the middle fossa, whereas the anterolateral limit was defined by the ophthalmic branch of the trigeminal nerve. Moreover, the posteromedial and posterolateral limits were the posterior clinoid process and the petrous ridge, respectively.CONCLUSIONS: Our findings define the surgical limitations of the mtSO approach for the treatment of anterior and middle cranial base pathologies. These limits can be reliably identified on imaging studies allowing assessment of exposure to guide preoperative case selection.

  View details for DOI 10.1016/j.wneu.2022.09.071

  View details for PubMedID 36210606

• Magnetic Resonance Diffusion Tractography of Brain White Matter tracts-An Educational 3-Dimensional Stereoscopic Overview for Operative Planning and Mapping in Brain Tumor Surgery: 3-Dimensional Operative Video. Operative neurosurgery (Hagerstown, Md.) Ng, S., Lima Maldonado, I., Destrieux, C., Yeh, F., Fernandez-Miranda, J., Duffau, H., Jacquesson, T. 2022; 23 (3): e177

  View details for DOI 10.1227/ons.0000000000000306

  View details for PubMedID 35972103

• Intracranial Breakthrough Through Cavernous Sinus Compartments: Anatomic Study and Implications for Pituitary Adenoma Surgery. Operative neurosurgery (Hagerstown, Md.) Xu, Y., Mohyeldin, A., Asmaro, K. P., Nunez, M. A., Doniz-Gonzalez, A., Vigo, V., Cohen-Gadol, A. A., Fernandez-Miranda, J. C. 2022; 23 (2): 115-124

  Abstract

  BACKGROUND: Pituitary adenomas (PAs) with cavernous sinus (CS) invasion can extend into the intradural space by breaking through the CS walls.OBJECTIVE: To elaborate on the potential breakthrough route through CS compartments for invasive PAs and describe relevant surgical anatomy and technical nuances, with an aim to improve resection rates.METHODS: Twelve colored silicon-injected human head specimens were used for endonasal and transcranial dissection of the CS walls; ligaments, dural folds, and cranial nerves on each compartment were inspected. Two illustrative cases of invasive PA are also presented.RESULTS: The potential breakthrough routes through the CS compartments had unique anatomic features. The superior compartment breakthrough was delimited by the anterior petroclinoidal ligament laterally, posterior petroclinoidal ligament posteriorly, and interclinoidal ligament medially; tumor extended into the parapeduncular space with an intimate spatial relationship with the oculomotor nerve and posterior communicating artery. The lateral compartment breakthrough was limited by the anterior petroclinoidal ligament superiorly and ophthalmic nerve inferiorly; tumor extended into the middle fossa, displacing the trochlear nerve and inferolateral trunk to reach the medial temporal lobe. The posterior compartment breakthrough delineated by the Gruber ligament, petrosal process of the sphenoid bone, and petrous apex inferiorly, posterior petroclinoidal ligament superiorly, and dorsum sellae medially; tumor displaced or encased the abducens nerve and inferior hypophyseal artery and compressed the cerebral peduncle.CONCLUSION: The superior lateral and posterior components of the CS are potential routes for invasion by PAs. Better identification of CS breakthrough patterns is crucial for achieving higher gross total resection and remission rates.

  View details for DOI 10.1227/ons.0000000000000291

  View details for PubMedID 35838451

• Endoscopic contralateral interhemispheric transfalcine keyhole approach for large falcine meningioma. World neurosurgery Sakaeyama, Y., Morisako, H., Ohata, H., Nakajo, K., Valenzuela, J. C., Fernandez-Miranda, J. C., Goto, T. 2022

  Abstract

  OBJECTIVE: Falcine meningioma is usually approached from ipsilaterally and the technique for tumor removal has traditionally been performed under microscopy. We report a surgical procedure for large falcine meningioma by an endoscopic contralateral interhemispheric transfalcine keyhole approach.METHODS: The study period was from September 2019 to March 2021. Study participants were patients with World Health Organization grade I meningioma showing falx attachment, excluding neurofibromatosis, who underwent initial surgery at our institution. The surgical procedure begins with a small contralateral craniotomy of about 3 cm, followed by insertion of an endoscope. The tumor attachment to the falx is excised, exposing the tumor. Internal decompression is performed, and the lesion is dissected from the surrounding brain before removal through the falx.RESULTS: An endoscopic contralateral interhemispheric transfalcine keyhole approach was used to resect four cases of large falcine meningioma. Mean operation time was 265 min (range: 216-294 min), achieving Simpson grade I removal in all cases. No evidence of cerebral infarction, cerebral edema, or new neurological complaints related to impaired venous return were seen using this surgical method.CONCLUSIONS: In the case of falcine meningioma, the endoscopic keyhole contralateral technique allows detachment of the tumor from the falx and safe manipulation in a minor field of view. In addition, because the craniotomy is smaller and the operation time is shorter, this procedure offers a less-invasive approach for the patient. This technique is thus, in our opinion, quite advantageous.

  View details for DOI 10.1016/j.wneu.2022.06.148

  View details for PubMedID 35809843

• Primary central nervous system amyloidoma involving cranial nerves V and VII: A case report and literature review INTERDISCIPLINARY NEUROSURGERY-ADVANCED TECHNIQUES AND CASE MANAGEMENT Son, E., Mohyeldin, A., Men, C., Pendharkar, A., Fernandez-Miranda, J. C., Kossler, A. L. 2022; 28

  View details for DOI 10.1016/j.inat.2022.101519

  View details for Web of Science ID 000777777000003

• Comparison of Endoscopic Endonasal Approach and Lateral Microsurgical Infratemporal Fossa Approach to the Jugular Foramen: An Anatomical Study. Journal of neurological surgery. Part B, Skull base Liu, J., Pinheiro-Neto, C. D., Yang, D., Wang, E., Gardner, P. A., Hirsch, B. E., Snyderman, C. H., Fernandez-Miranda, J. C. 2022; 83 (Suppl 2): e474-e483

  Abstract

  Objective  The jugular foramen is one of the most challenging surgical regions in skull base surgery. With the development of endoscopic techniques, the endoscopic endonasal approach (EEA) has been undertaken to treat some lesions in this area independently or combined with open approaches. The purpose of the current study is to describe the anatomical steps and landmarks for the EEA to the jugular foramen and to compare it with the degree of exposure obtained with the lateral infratemporal fossa approach. Materials and Methods  A total of 15 osseous structures related to the jugular foramen were measured in 33 adult dry skulls. Three silicone-injected adult cadaveric heads (six sides) were dissected for EEA and three heads (six sides) were used for a lateral infratemporal fossa approach (Fisch type A). The jugular foramen was exposed, relevant landmarks were demonstrated, and the distances between relevant landmarks and the jugular foramen were obtained. High-quality pictures were obtained. Results  The jugular foramen was accessed in all dissections by using either approach. Important anatomical landmarks for EEA include internal carotid artery (ICA), petroclival fissure, inferior petrosal sinus, jugular tubercle, and hypoglossal canal. The EEA exposed the anterior and medial parts of the jugular foramen, while the lateral infratemporal fossa approach (Fisch type A) exposed the lateral and posterior parts of the jugular foramen. With EEA, dissection and transposition of the facial nerve was avoided, but the upper parapharyngeal and paraclival ICA may need to be mobilized to adequately expose the jugular foramen. Conclusion  The EEA to the jugular foramen is anatomically feasible but requires mobilization of the ICA to provide access to the anterior and medial aspects of the jugular foramen. The lateral infratemporal approach requires facial nerve transposition to provide access to the lateral and posterior parts of the jugular foramen. A deep understanding of the complex anatomy of this region is paramount for safe and effective surgery of the jugular foramen. Both techniques may be complementary considering the different regions of the jugular foramen accessed with each approach.

  View details for DOI 10.1055/s-0041-1731034

  View details for PubMedID 35832999

  View details for PubMedCentralID PMC9272292

• Differential tractography as a dynamic imaging biomarker: A methodological pilot study for Huntington's disease. NeuroImage. Clinical Barrios-Martinez, J. V., Fernandes-Cabral, D. T., Abhinav, K., Fernandez-Miranda, J. C., Chang, Y., Suski, V., Yeh, F., Friedlander, R. M. 2022; 35: 103062

  Abstract

  Huntington's disease (HD) is a neurodegenerative disorder characterized by motor, psychiatric, and cognitive symptoms. Due to its diverse manifestations, the scientific community has long recognized the need for sensitive, objective, individualized, and dynamic disease assessment tools. We examined the feasibility of Differential Tractography as a biomarker to evaluate correlation of symptom severity and of HD progression at the individual level. Differential tractography is a novel tractography modality that maps pathways with axonal injury characterized by a decrease of anisotropic diffusion pattern. We recruited sixteen patients scanned at 0-, 6-, and 12-month intervals by diffusion MRI scans for differential tractography assessment and correlated its volumetric findings with the Unified Huntington's Disease Rating Scale (UHDRS). Deterministic fiber tracking algorithm was applied. Longitudinal data was modeled using the generalized estimating equation (GEE) model and correlated with UHDRS scores, in addition to Spearman correlation for cross-sectional data. Our results show that volumes of affected pathways revealed by differential tractography significantly correlated with UHDRS scores in longitudinal data (p-value<0.001), and chronological changes in differential tractography also correlated with the changes in UHDRS (p-value<0.001). This technique opens new clinical avenues as a clinical translational tool to evaluate presymptomatic and symptomatic gene positive individuals. Our results provide support that differential tractography has the potential to be used as a dynamic imaging biomarker to assess at the individual level in a non-invasive manner, disease progression in HD. Critically important, differential tractography proves to be a quantitative tool for following degeneration in presymptomatic patients, with potential applications in clinical trials.

  View details for DOI 10.1016/j.nicl.2022.103062

  View details for PubMedID 35671556

• Ideal trajectory for frontal ventriculostomy: Radiological study and anatomical study. Clinical neurology and neurosurgery Vigo, V., Tassinari, A., Scerrati, A., Cavallo, M. A., Rodriguez-Rubio, R., Fernandez-Miranda, J. C., De Bonis, P. 2022; 217: 107264

  Abstract

  OBJECTIVE: Several techniques have been described to improve the accuracy of the freehand procedure for frontal ventriculostomy and reduce complications due to suboptimal placement or misplacement of the catheter tip. To date, none of the available studies have found a reliable, low cost and consistent technique. We aimed to provide a standardized protocol for freehand frontal ventriculostomy.METHODS: In the first part of the radiological study, 125 CT scans were used to measure the length of the catheter using 2 right-sided entry points. In the second part, a grid of 24 entry points on the frontal bone was used in 50 CT scans to record the distance from the cranial surface to the Foramen of Monro (FM). Ventriculostomy was performed on six cadaveric heads using a grid of 9 entry points, comparing a 5ml syringe with the freehand technique to reach the target.RESULTS: The first part of the radiological study showed a length from the cranial surface to the FM was overall 67,38±1,03mm. For the second part, the mean length of the 24 selected points was 68,54±2,73mm without statistical difference. In the anatomical study, the FM was reached 8 times (14.8%) with the syringe vs 31 times (57.4%) with the freehand technique, and the ventricles 43 (79.6%) vs 37 (68.5%). The mean lengths from the skull to the FM were 71.33±4.21mm.CONCLUSIONS: In this study, we showed the optimal length of a frontal ventricular catheter. We have also demonstrated that the portion of the frontal bone above the superior temporal lines matches a sphere in which the center is the FM.

  View details for DOI 10.1016/j.clineuro.2022.107264

  View details for PubMedID 35526512

• The role of endoscopic endonasal surgery in the management of prolactinomas based on their invasiveness into the cavernous sinus. Pituitary Abou-Al-Shaar, H., Mallela, A. N., Patel, A., Shariff, R. K., Shin, S. S., Choi, P. A., Faraji, A. H., Fazeli, P. K., Costacou, T., Wang, E. W., Fernandez-Miranda, J. C., Snyderman, C. H., Gardner, P. A., Zenonos, G. A. 2022

  Abstract

  PURPOSE: To review our institutional experience with thesurgical management of prolactinomas through the endoscopic endonasal approach with specific focus on cavernous sinus invasion.METHODS: Clinical and radiographic data were collected retrospectively from the electronic medical record of 78 consecutive patients with prolactinomas undergoing endoscopic endonasal resection from 2002 to 2019. Immediate and late post-operative remission were defined as prolactin<20ng/mL within 14days and 1-year of surgery without adjuvant therapy, respectively. Cavernous sinus invasion was quantified by Knosp score.RESULTS: A total of 78 patients with prolactinoma, 59% being male, underwent surgical resection with a mean age of 37±13years. Indications for surgery were medication resistance in 38 patients (48.7%), medication intolerance in 11 (14.1%), and patient preference in 29 (37.2%). Patients with Knosp 0-2 achieved higher immediate remission rates (83.8%) compared to patients with Knosp 3 (58.8%) and Knosp 4 (41.7%) patients (p=0.003). Long-term remission rates were 48.7% and increased to 71.8% when combined with adjuvant treatments. Knosp 4 prolactinomas had significantly higher tumor volumes, higher preoperative prolactin levels, higher recurrence rates, higher rates of adjuvant therapy utilization, and were more likely to have failed dopamine agonist therapy compared to other tumor grades (p<0.05). We encountered 18 complications in our series, and no cerebrospinal fluid leaks.CONCLUSION: The endoscopic endonasal approach is a safe and effective modality that can be employed in properly selected patients with invasive prolactinomas. It is associatedwith improved control and remission rates despite cavernous sinus invasion, though at a lower rate than without invasion.

  View details for DOI 10.1007/s11102-022-01221-3

  View details for PubMedID 35467273

• Endoscopic Endonasal Approach for Suprasellar Mature Teratoma in Growing Teratoma Syndrome: 2-Dimensional Operative Video. Operative neurosurgery (Hagerstown, Md.) Vigo, V., Prolo, L. M., Nunez, M. A., Nayak, J. V., Fernandez-Miranda, J. C. 2022

  Abstract

  Intracranial growing teratoma syndrome is a rare phenomenon characterized by enlargement of a germ cell tumor during or after adjuvant therapy despite normalization of tumor markers.1,2 It has been suggested that chemotherapy acts on the nonteratomatous components or induces differentiation of the immature germ cells to mature teratomatous phenotype.3 An 8-year-old boy presented with headache, emesis, and blurry vision. Neuroimaging revealed hydrocephalus with multiple central nervous system masses: pineal gland, suprasellar region, and spine (T8). Elevated serum and cerebrospinal fluid levels of alpha-fetoprotein and beta-human chorionic gonadotropin were found. A ventriculoperitoneal shunt was placed. Despite chemotherapy and decreasing tumor markers, the pineal mass rapidly enlarged, and the patient became somnolent. He underwent microsurgical resection with the diagnosis of mixed germ cell tumor. During his second chemotherapy cycle, the patient endorsed worsening vision and panhypopituitarism. Imaging demonstrated enlargement and honeycomb appearance of the suprasellar mass. The patient and family consented to the procedure, and an endoscopic endonasal approach was performed to access the retroinfundibular region. Removal of the nonfunctional pituitary gland and dorsum sellae was performed. Careful dissection of the tumor from the optic apparatus, hypothalamus, and perforating arteries allowed total resection. Reconstruction with fascia lata and nasoseptal flap was performed. Mature teratoma was found histologically. Postoperative course was complicated by flap hemorrhage resolved by surgical revision. Postoperative imaging showed complete resection. The patient was discharged without other complications and was making excellent recovery. To the best of our knowledge, this is the first reported case of hypothalamic intracranial growing teratoma syndrome successfully treated using an endoscopic endonasal approach.

  View details for DOI 10.1227/ons.0000000000000166

  View details for PubMedID 35383719

• Combined transpetrosal approach for giant petroclival meningioma: 2-dimensional operative video. Neurosurgical focus: Video Vigo, V., Asmaro, K., Nunez, M. A., Moyheldin, A., Jackler, R. K., Fernandez-Miranda, J. C. 2022; 6 (2): V8

  Abstract

  Petroclival meningiomas are extremally challenging lesions due to their deep location and close relation to critical neurovascular structures. Several approaches have been described to achieve gross-total resection with low morbidity and mortality. In this 2-dimensional operative video, the authors show a simultaneous combined transpetrosal approach. The patient is a 44-year-old woman with an 8-month history of gait imbalance with evidence of a giant petroclival meningioma on neuroimaging. She underwent a combined middle fossa approach with anterior petrosectomy and retrosigmoid/retrolabyrinthine approach to achieve gross-total tumor resection. The postoperative course was characterized by trigeminal neuralgia, and neuroimaging showed gross-total resection of the tumor. The video can be found here: https://stream.cadmore.media/r10.3171/2022.1.FOCVID21248.

  View details for DOI 10.3171/2022.1.FOCVID21248

  View details for PubMedID 36284994

• Microsurgical anatomy and the importance of the petrosal process of the sphenoid bone in endonasal surgery. Journal of neurosurgery Doniz-Gonzalez, A., Vigo, V., Nunez, M. A., Xu, Y., Mohyeldin, A., Cohen-Gadol, A. A., Fernandez-Miranda, J. C. 2022: 1-12

  Abstract

  OBJECTIVE: The petrosal process of the sphenoid bone (PPsb) is a relevant skull base osseous prominence present bilaterally that can be used as a key surgical landmark, especially for identifying the abducens nerve. The authors investigated the surgical anatomy of the PPsb, its relationship with adjacent neurovascular structures, and its practical application in endoscopic endonasal surgery.METHODS: Twenty-one dried skulls were used to analyze the osseous anatomy of the PPsb. A total of 16 fixed silicone-injected postmortem heads were used to expose the PPsb through both endonasal and transcranial approaches. Dimensions and distances of the PPsb from the foramen lacerum (inferiorly) and top of the posterior clinoid process (PCP; superiorly) were measured. Moreover, anatomical variations and the relationship of the PPsb with the surrounding crucial structures were recorded. Three representative cases were selected to illustrate the clinical applications of the findings.RESULTS: The PPsb presented as a triangular bony prominence, with its base medially adjacent to the dorsum sellae and its apex pointing posterolaterally toward the petrous apex. The mean width of the PPsb was 3.5 ± 1 mm, and the mean distances from the PPsb to the foramen lacerum and the PCP were 5 ± 1 and 11 ± 2.5 mm, respectively. The PPsb is anterior to the petroclival venous confluence, superomedial to the inferior petrosal sinus, and inferomedial to the superior petrosal sinus; constitutes the inferomedial limit of the cavernous sinus; and delimits the upper limit of the paraclival internal carotid artery (ICA) before the artery enters the cavernous sinus. The PPsb is anterior and medial to and below the sixth cranial nerve, forming the floor of Dorello's canal. During surgery, gentle mobilization of the paraclival ICA reveals the petrosal process, serving as an accurate landmark for the location of the abducens nerve.CONCLUSIONS: This investigation revealed details of the microsurgical anatomy of the PPsb, its anatomical relationships, and its application as a surgical landmark for identifying the abducens nerve. This novel landmark may help in minimizing the risk of abducens nerve injury during transclival approaches, which extend laterally toward the petrous apex and cavernous sinus region.

  View details for DOI 10.3171/2021.12.JNS212024

  View details for PubMedID 35276642

• Anatomic Considerations in Endoscopic Pituitary Surgery. Otolaryngologic clinics of North America Low, C. M., Vigo, V., Nunez, M., Fernandez-Miranda, J. C., Patel, Z. M. 2022

  Abstract

  The pituitary gland is a small gland at the base of the skull controlling many physiologic processes through its regulation of primary endocrine glands. Pathologies of the pituitary gland and sellar space are wide ranging and most commonly include pituitary adenomas but can also encompass pituitary hyperplasia, other benign nonadenomatous tumors, cysts, and primary and metastatic malignancy. At present, the endoscopic approach has been established as a safe and effective approach to surgical management of pituitary pathology. A detailed understanding of the sella and parasellar anatomy from an endoscopic approach is imperative to performing safe endoscopic surgery in this area.

  View details for DOI 10.1016/j.otc.2021.12.014

  View details for PubMedID 35256171

• Anatomical Limits of the Endoscopic Contralateral Transmaxillary Approach to the Petrous Apex and Petroclival Region. Journal of neurological surgery. Part B, Skull base Mangussi-Gomes, J., Alves-Belo, J. T., Truong, H. Q., Nogueira, G. F., Wang, E. W., Fernandez-Miranda, J. C., Gardner, P. A., Snyderman, C. H. 2022; 83 (1): 44-52

  Abstract

  Objectives  This study aimed to establish the anatomical landmarks for performing a contralateral transmaxillary approach (CTM) to the petrous apex (PA) and petroclival region (PCR), and to compare CTM with a purely endoscopic endonasal approach (EEA). Design  EEA and CTM to the PA and PCR were performed bilaterally in eight human anatomical specimens. Surgical techniques and anatomical landmarks were described, and EEA was compared with CTM with respect to ability to reach the contralateral internal acoustic canal (IAC). Computed tomographic scans of 25 cadaveric heads were analyzed and the "angle" and "reach" of CTM and EEA were measured. Results  Entry to the PA via a medial approach was limited by (1) abducens nerve superiorly, (2) internal carotid artery (ICA) laterally, and (3) petroclival synchondrosis inferiorly (Gardner's triangle). With CTM, it was possible to reach the contralateral IAC bilaterally in all specimens dissected, without dissection of the ipsilateral ICAs, pterygopalatine fossae, and Eustachian tubes. Without CTM, reaching the contralateral IAC was possible only if: (1) angled endoscopes and instruments were employed or (2) the pterygopalatine fossa was dissected with mobilization of the ICA and resection of the Eustachian tube. The average "angle" and "reach" advantages for CTM were 25.6-degree greater angle of approach behind the petrous ICA and 1.4-cm more lateral reach. Conclusion  The techniques and anatomical landmarks for CTM to the PA and PCR are described. Compared with a purely EEA, the CTM provides significant "angle" and "reach" advantages for the PA and PCR.

  View details for DOI 10.1055/s-0040-1716693

  View details for PubMedID 35155069

  View details for PubMedCentralID PMC8824622

• Microsurgical Anatomy of the Dorsal Clinoidal Space: Implications for Endoscopic Endonasal Parasellar Surgery Abstracts JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Xu, Y., Nunez, M. A., Mohyeldin, A., Vigo, V., Mao, Y., Cohen-Gadol, A. A., Fernandez-Miranda, J. 2022; 83

  View details for Web of Science ID 000762759700001

• Subtemporal Approach and Its Infratentorial Extension: Review and a Comparative Analysis of Different Techniques JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Dziedzic, T., Abhinav, K., Fernandez-Miranda, J. C. 2022

  View details for DOI 10.1055/s-0041-1741566

  View details for Web of Science ID 000741101100001

• Cranial and Cerebral Anatomic Key Points for Neurosurgery: A New Educational Insight. Operative neurosurgery (Hagerstown, Md.) Simon, E., Beuriat, P. A., Delabar, V., Jouanneau, E., Fernandez-Miranda, J., Jacquesson, T. 2022; 22 (1): e18-e27

  Abstract

  The anatomy of both the skull and the brain offers many landmarks that could lead surgery. Cranial "craniometric" key points were described many years ago, and then, cerebral key points-along sulci and gyri-were detailed more recently for microneurosurgical approaches that can reach deep structures while sparing the brain. Nonetheless, this anatomic knowledge is progressively competed by new digital devices, such as imaging guidance systems, although they can be misleading.To summarize cranial and sulcal key points and their related anatomic structures to renew their interest in modern neurosurgery and help surgical anatomy teaching.After a literature review collecting anatomic key points of skull and brain, specimens were prepared and images were taken to expose skull and brain from lateral, superior, posterior, and oblique views. A high-definition camera was used, and images obtained were modified, superimposing both key points and underlying anatomic structures.From 4 views, 16 cranial key points were depicted: anterior and superior squamous point, precoronal and retrocoronal point, superior sagittal point, intraparietal point, temporoparietal point, preauricular point, nasion, bregma, stephanion, euryon, lambda, asterion, opisthocranion, and inion. These corresponded to underlying cerebral key points and relative brain parts: anterior and posterior sylvian point, superior and inferior rolandic point, supramarginal and angular gyri, parieto-occipital sulcus, and various meeting points between identifiable sulci. Stereoscopic views were also provided to help learning these key points.This comprehensive overview of the cranial and sulcal key points could be a useful tool for any neurosurgeon who wants to check her/his surgical route and make the surgery more "gentle, safe, and accurate."

  View details for DOI 10.1227/ONS.0000000000000016

  View details for PubMedID 34982906

• Update in Cushing disease: What the neurosurgeon has to KNOW, on behalf of the EANS skull base section. Brain & spine Eulate-Beramendi, S., Casajus, A., Ollero, L., Niemann, L. K., Fernandez-Miranda, J. C., Bruneau, M., Berhouma, M., Cavallo, L. M., Cornelius, J. F., Daniel, R. T., Froelich, S., Jouanneau, E., Kasper, E., Mazzatenta, D., Meling, T. R., Messerer, M., Schroeder, H. W., Tatagiba, M., Visocchi, M., Voormolen, E. H., Zazpe, I. 2022; 2: 100917

  Abstract

  Introduction: Cushing's disease is a state of chronic and excessive cortisol levels caused by a pituitary adenoma.Research question: CD is a complex entity and often entails difficulties in its diagnosis and management. For that reason, there are still controversial points to that respect. The aim of this consensus paper of the skull base section of the EANS is to review the main aspects of the disease a neurosurgeon has to know and also to offer updated recommendations on the controversial aspects of its management.Material and methods: PUBMED database was used to search the most pertinent articles published on the last 5 years related with the management of CD. A summary of literature evidence was proposed for discussion within the EANS skull base section and other international experts.Results: This article represents the consensual opinion of the task force regarding optimal management and surgical strategy in CD.Discussion and conclusion: After discussion in the group several recommendations and suggestions were elaborated. Patients should be treated by an experienced multidisciplinary team. Accurate clinical, biochemical and radiological diagnosis is mandatory. The goal of treatment is the complete adenoma resection to achieve permanent remission. If this is not possible, the treatment aims to achieving eucortisolism. Radiation therapy is recommended to patients with CD when surgical options have been exhausted. All patients in remission should be tested all life-long.

  View details for DOI 10.1016/j.bas.2022.100917

  View details for PubMedID 36248125

• Full cervical cord tractography: A new method for clinical use. Frontiers in neuroanatomy Dauleac, C., Frindel, C., Pelissou-Guyotat, I., Nicolas, C., Yeh, F., Fernandez-Miranda, J., Cotton, F., Jacquesson, T. 2022; 16: 993464

  Abstract

  Despite recent improvements in diffusion-weighted imaging, spinal cord tractography is not used in routine clinical practice because of difficulties in reconstructing tractograms, with a pertinent tri-dimensional-rendering, in a long post-processing time. We propose a new full tractography approach to the cervical spinal cord without extensive manual filtering or multiple regions of interest seeding that could help neurosurgeons manage various spinal cord disorders. Four healthy volunteers and two patients with either cervical intramedullary tumors or spinal cord injuries were included. Diffusion-weighted images of the cervical spinal cord were acquired using a Philips 3 Tesla machine, 32 diffusion directions, 1,000 s/mm2 b-value, 2 * 2 * 2 mm voxel size, reduced field-of-view (ZOOM), with two opposing phase-encoding directions. Distortion corrections were then achieved using the FSL software package, and tracking of the full cervical spinal cord was performed using the DSI Studio software (quantitative anisotropy-based deterministic algorithm). A unique region of avoidance was used to exclude everything that is not of the nervous system. Fiber tracking parameters used adaptative fractional anisotropy from 0.015 to 0.045, fiber length from 10 to 1,000 mm, and angular threshold of 90°. In all participants, a full cervical cord tractography was performed from the medulla to the C7 spine level. On a ventral view, the junction between the medulla and spinal cord was identified with its pyramidal bulging, and by an invagination corresponding to the median ventral sulcus. On a dorsal view, the fourth ventricle-superior, middle, and inferior cerebellar peduncles-was seen, as well as its floor and the obex; and gracile and cuneate tracts were recognized on each side of the dorsal median sulcus. In the case of the intramedullary tumor or spinal cord injury, the spinal tracts were seen to be displaced, and this helped to adjust the neurosurgical strategy. This new full tractography approach simplifies the tractography pipeline and provides a reliable 3D-rendering of the spinal cord that could help to adjust the neurosurgical strategy.

  View details for DOI 10.3389/fnana.2022.993464

  View details for PubMedID 36237419

• Clinical outcomes, Kadish-INSICA staging and therapeutic targeting of somatostatin receptor 2 in olfactory neuroblastoma. European journal of cancer (Oxford, England : 1990) Lechner, M., Takahashi, Y., Turri-Zanoni, M., Liu, J., Counsell, N., Hermsen, M., Kaur, R. P., Zhao, T., Ramanathan, M. J., Schartinger, V. H., Emanuel, O., Helman, S., Varghese, J., Dudas, J., Riechelmann, H., Sprung, S., Haybaeck, J., Howard, D., Engel, N. W., Stewart, S., Brooks, L., Pickles, J. C., Jacques, T. S., Fenton, T. R., Williams, L., Vaz, F. M., O'Flynn, P., Stimpson, P., Wang, S., Hannan, S. A., Unadkat, S., Hughes, J., Dwivedi, R., Forde, C. T., Randhawa, P., Gane, S., Joseph, J., Andrews, P. J., Royle, G., Franchi, A., Maragliano, R., Battocchio, S., Bewicke-Copley, H., Pipinikas, C., Webster, A., Thirlwell, C., Ho, D., Teschendorff, A., Zhu, T., Steele, C. D., Pillay, N., Vanhaesebroeck, B., Mohyeldin, A., Fernandez-Miranda, J., Park, K. W., Le, Q., West, R. B., Saade, R., Manes, R. P., Omay, S. B., Vining, E. M., Judson, B. L., Yarbrough, W. G., Sansovini, M., Silvia, N., Grassi, I., Bongiovanni, A., Capper, D., Schuller, U., Thavaraj, S., Sandison, A., Surda, P., Hopkins, C., Ferrari, M., Mattavelli, D., Rampinelli, V., Facchetti, F., Nicolai, P., Bossi, P., Henriquez, O. A., Magliocca, K., Solares, C. A., Wise, S. K., Llorente, J. L., Patel, Z. M., Nayak, J. V., Hwang, P. H., Lacy, P. D., Woods, R., O'Neill, J. P., Jay, A., Carnell, D., Forster, M. D., Ishii, M., London, N. R., Bell, D. M., Gallia, G. L., Castelnuovo, P., Severi, S., Lund, V. J., Hanna, E. Y. 1800

  Abstract

  INTRODUCTION: Olfactory neuroblastoma (ONB) is a rare cancer of the sinonasal region. We provide a comprehensive analysis of this malignancy with molecular and clinical trial data on a subset of our cohort to report on the potential efficacy of somatostatin receptor 2 (SSTR2)-targeting imaging and therapy.METHODS: We conducted a retrospective analysis of 404 primary, locally recurrent, and metastatic olfactory neuroblastoma (ONB) patients from 12 institutions in the United States of America, United Kingdom and Europe. Clinicopathological characteristics and treatment approach were evaluated. SSTR2 expression, SSTR2-targeted imaging and the efficacy of peptide receptor radionuclide therapy [PRRT](177Lu-DOTATATE) were reported in a subset of our cohort (LUTHREE trial; NCT03454763).RESULTS: Dural infiltration at presentation was a significant predictor of overall survival (OS) and disease-free survival (DFS) in primary cases (n=278). Kadish-Morita staging and Dulguerov T-stage both had limitations regarding their prognostic value. Multivariable survival analysis demonstrated improved outcomes with lower stage and receipt of adjuvant radiotherapy. Prophylactic neck irradiation significantly reduces the rate of nodal recurrence. 82.4% of the cohort were positive for SSTR2; treatment of three metastatic cases with SSTR2-targeted peptide-radionuclide receptor therapy (PRRT) in the LUTHREE trial was well-tolerated and resulted in stable disease (SD).CONCLUSIONS: This study presents pertinent clinical data from the largest dataset, to date, on ONB. We identify key prognostic markers and integrate these into an updated staging system, highlight the importance of adjuvant radiotherapy across all disease stages, the utility of prophylactic neck irradiation and the potential efficacy of targeting SSTR2 to manage disease.

  View details for DOI 10.1016/j.ejca.2021.09.046

  View details for PubMedID 34980502

• Microvascular anatomy of the medial temporal region. Journal of neurosurgery Xu, Y., Mohyeldin, A., Nunez, M. A., Doniz-Gonzalez, A., Vigo, V., Cohen-Gadol, A. A., Fernandez-Miranda, J. C. 1800: 1-13

  Abstract

  OBJECTIVE: The authors investigated the microvascular anatomy of the hippocampus and its implications for medial temporal tumor surgery. They aimed to reveal the anatomical variability of the arterial supply and venous drainage of the hippocampus, emphasizing its clinical implications for the removal of associated tumors.METHODS: Forty-seven silicon-injected cerebral hemispheres were examined using microscopy. The origin, course, irrigation territory, spatial relationships, and anastomosis of the hippocampal arteries and veins were investigated. Illustrative cases of hippocampectomy for medial temporal tumor surgery are also provided.RESULTS: The hippocampal arteries can be divided into 3 segments, the anterior (AHA), middle (MHA), and posterior (PHA) hippocampal artery complexes, which correspond to irrigation of the hippocampal head, body, and tail, respectively. The uncal hippocampal and anterior hippocampal-parahippocampal arteries contribute to the AHA complex, the posterior hippocampal-parahippocampal arteries serve as the MHA complex, and the PHA and splenial artery compose the PHA complex. Rich anastomoses between hippocampal arteries were observed, and in 11 (23%) hemispheres, anastomoses between each segment formed a complete vascular arcade at the hippocampal sulcus. Three veins were involved in hippocampal drainage-the anterior hippocampal, anterior longitudinal hippocampal, and posterior longitudinal hippocampal veins-which drain the hippocampal head, body, and tail, respectively, into the basal and internal cerebral veins.CONCLUSIONS: An understanding of the vascular variability and network of the hippocampus is essential for medial temporal tumor surgery via anterior temporal lobectomy with amygdalohippocampectomy and transsylvian selective amygdalohippocampectomy. Stereotactic procedures in this region should also consider the anatomy of the vascular arcade at the hippocampal sulcus.

  View details for DOI 10.3171/2021.9.JNS21390

  View details for PubMedID 34952521

• Endoscopic Anatomy of the Zygomatic Nerve: Implications for the Endoscopic Transmaxillary Approach JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Xu, Y., Nunez, M., Mohyeldin, A., Fernandez-Miranda, J. C., Cohen-Gadol, A. A. 2021

  View details for DOI 10.1055/s-0041-1739237

  View details for Web of Science ID 000729958200001

• Venous thromboembolism rates and risk factors following endoscopic skull base surgery. International forum of allergy & rhinology Chang, M. T., Jitaroon, K., Song, S., Roozdar, P., Wangworat, Y., Ibrahim, N., Ma, Y., Rao, V. K., Chang, S. D., Fernandez-Miranda, J. C., Patel, Z. M., Dodd, R. L., Hwang, P. H., Harsh, G. R., Nayak, J. V. 2021

  Abstract

  BACKGROUND: Venous thromboembolism (VTE) is a potentially fatal perioperative complication. The objective of this study was to assess the rate and risk factors for VTE in endoscopic skull base surgery (ESBS).METHODS: This was a retrospective review of adults undergoing ESBS at a tertiary academic center. Incidence of VTE in the 30-day postoperative period was recorded. Logistic regression analyses identified factors associated with VTE.RESULTS: 1122 ESBS cases between 2009 and 2019 were studied. Almost no cases (96.1%) employed perioperative VTE chemoprophylaxis. The overall incidence of VTE was 2.3% (26/1122). Malignant pathologies had a higher rate of VTE compared to nonmalignant pathologies (4.5% vs 2.0%, OR 2.85, 95%CI 1.22-6.66). Factors associated with an increased risk of VTE included a Caprini score greater than 5 (OR 1.53, 95% CI 1.28-1.83); multiple preoperative endocrinopathies such as the syndrome of inappropriate antidiuretic hormone secretion (SIADH) (OR 22.48, 95% CI 3.93-128.70), adrenal insufficiency (OR 5.24, 95% CI 1.82-15.03), hypercortisolism (OR 4.46, 95% CI 1.47-13.56), and hypothyroidism (OR 3.69, 95% CI 1.66-8.20), each 10-hour increment of lumbar drain duration (OR 1.16, 95%CI 1.08-1.25), and each 10-hour increment for duration of hospitalization (OR 1.05, 95% CI 1.03-1.06).CONCLUSIONS: The incidence of VTE following ESBS is relatively low. Factors with a higher association with VTE include malignancy, preoperative endocrinopathies, higher Caprini score, prolonged lumbar drain duration, and prolonged hospitalization. Further study is needed to validate these findings and to refine clinical decision making around perioperative VTE prophylaxis. This article is protected by copyright. All rights reserved.

  View details for DOI 10.1002/alr.22943

  View details for PubMedID 34894093

• In Reply: Residual and Recurrent Disease Following Endoscopic Endonasal Approach as a Reflection of Anatomic Limitation for the Resection of Midline Anterior Skull Base Meningiomas. Operative neurosurgery (Hagerstown, Md.) Setty, P., Fernandez-Miranda, J. C., Wang, E. W., Snyderman, C. H., Gardner, P. A. 2021

  View details for DOI 10.1093/ons/opab366

  View details for PubMedID 34634118

• The Modular Concept in Skull Base Surgery: Anatomical Basis of the Median, Paramedian and Lateral Corridors. Acta bio-medica : Atenei Parmensis Giotta Lucifero, A., Fernandez-Miranda, J. C., Nunez, M., Bruno, N., Tartaglia, N., Ambrosi, A., Marseglia, G. L., Galzio, R., Luzzi, S. 2021; 92 (S4): e2021411

  Abstract

  Introduction A thorough understanding of skull base anatomy is imperative to perform safely and effectively any skull base approach.In this article, we examine the microsurgical anatomy of the skull base by proposing a modular topographic organization in the median, paramedian, and lateral surgical corridors in relation to transcranial and endoscopic approaches. Methods Five dry skulls were studied focusing on the intracranial and exocranial skull base. Two lines were drawn parallel to the lateral border of the cribriform plate of the ethmoid bone and foramen lacerum, respectively. Lines 1 and 2 delimited the median, paramedian and lateral corridors of the skull base. The bony structures that formed each corridor were carefully reviewed in relation to the planning and execution of the skull base transcranial and endoscopic approaches. Results The midline corridor involves the crista galli, cribriform plate, planum and jugum sphenoidale, chiasmatic sulcus, tuberculum sellae, sellar region, dorsum sellae, clivus, and foramen magnum. The paramedian corridor includes the fovea ethmoidalis, the root of the lesser and greater sphenoid wing, anterior clinoid process, foramen lacerum, the upper half of the petro-occipital suture, and jugular tubercle. The lateral corridors include the orbital plates, sphenoid wings, squamosal and petrous parts of the temporal bone, caudal aspect of the petro-occipital suture, internal auditory canal, jugular foramen, the sulcus of the sigmoid sinus. Conclusion In-depth three-dimensional knowledge of skull base anatomy based on the modular concept of the surgical corridors is critical for the planning and execution of the transcranial and endoscopic approaches.

  View details for DOI 10.23750/abm.v92iS4.12115

  View details for PubMedID 34437364

• Residual and Recurrent Disease Following Endoscopic Endonasal Approach as a Reflection of Anatomic Limitation for the Resection of Midline Anterior Skull Base Meningiomas. Operative neurosurgery (Hagerstown, Md.) Setty, P., Fernandez-Miranda, J. C., Wang, E. W., Snyderman, C. H., Gardner, P. A. 2021

  Abstract

  BACKGROUND: Endoscopic endonasal approaches (EEAs) to anterior skull base meningiomas have grown in popularity, though anatomic limitations remain unclear.OBJECTIVE: To show the anatomic limits of EEA for meningiomas.METHODS: Retrospective chart review for all patients that underwent EEA for anterior skull base meningiomas from 2005 to 2014.RESULTS: A total of 100 patients averaged follow-up of 46.9 mo (24-100 mo). A total of 35 patients (35%) had olfactory groove, 33 planum sphenoidale (33%), and 32 tuberculum sella (32%) meningiomas. The average diameter was 2.9 cm (0.5-8.1 cm). Vascular encasement was seen in 11 patients (11%) and calcification in 20 (20%). Simpson Grade 1 (SG1) resection was achieved in 64 patients (64%). Only calcification impacted degree of resection (40% SG1, P=.012). The most common residual was on the anterior clinoid dura (11 patients [11%]). Six (6%) had residual superior/lateral to the optic nerve. Residual tumor was adherent to the optic apparatus or arteries in 5 patients (5%) each, and 3 patients (3%) had residual lateral to the mid-orbit. Rates of residual decreased over time. A total of 11 patients (11%) had tumor recurrence (mean of 40 mo): 4 (4%) on the anterior clinoid, 2 (2%) each on the lateral orbital roof, adherent to optic apparatus and superolateral to the optic nerve, and 1 (1%) was at the anterior falx.CONCLUSION: Anterior skull base meningiomas can effectively be approached via EEA in most patients; tumors extending to the anterior clinoid, anterior falx, or superolateral to the optic nerve or orbital roof, especially if calcified, may be difficult to reach via EEA.

  View details for DOI 10.1093/ons/opab244

  View details for PubMedID 34245152

• Comparison of Endoscopic Endonasal Approach and Lateral Microsurgical Infratemporal Fossa Approach to the Jugular Foramen: An Anatomical Study JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Liu, J., Pinheiro-Neto, C. D., Yang, D., Wang, E., Gardner, P. A., Hirsch, B. E., Snyderman, C. H., Fernandez-Miranda, J. C. 2021

  View details for DOI 10.1055/s-0041-1731034

  View details for Web of Science ID 000669648400001

• Microsurgical Anatomy of the Endoscopy-Assisted Retrosigmoid Intradural Suprameatal Approach to the Meckel's Cave. Operative neurosurgery (Hagerstown, Md.) Xu, Y., Hendricks, B. K., Nunez, M. A., Mohyeldin, A., Fernandez-Miranda, J. C., Cohen-Gadol, A. A. 2021

  Abstract

  BACKGROUND: Understanding the microsurgical anatomical features of the endoscopy-assisted retrosigmoid intradural suprameatal approach (RISA) is critical for surgeons treating petroclival tumors or lesions in the cerebellopontine region that extend into Meckel's cave.OBJECTIVE: To evaluate increased exposure for Meckel's cave in the RISA and assess the surgical landmarks for this approach.METHODS: A standard retrosigmoid craniotomy to the cerebellopontine region was performed in 4 cadaveric specimens (8 hemispheres) with microscope-assisted endoscopy. The length and depth of the drilling region from the suprameatal tubercle to the petrous apex were analyzed. After opening Meckel's cave and mobilizing the trigeminal root completely, the landmarks for this approach were investigated.RESULTS: The endoscopy-assisted RISA facilitates mobilization of the trigeminal root and enhances surgical exposure in the region of Meckel's cave and the petrous apex with increases of 10.1±1.3 mm in depth, 21.4±3.2 mm in length, and 6.4±0.6 mm in height. The posterior and superior semicircular canals, internal auditory canal, superior petrous sinus, and internal carotid artery (petrous segment) served as important landmarks for this approach. One case illustration is presented to describe the application of this approach.CONCLUSION: The RISA is suitable mainly for lesions in the posterior fossa that extend into Meckel's cave. The endoscopy-assisted reach optimizes accessibility to the petrous apex region, obviates the need for extensive drilling, and decreases the risk of internal carotid artery injury. Better realization and recognition of microsurgical landmarks and parameters of this approach are crucial for successful outcomes.

  View details for DOI 10.1093/ons/opab096

  View details for PubMedID 33930162

• Microsurgical anatomy of the lateral posterior choroidal artery: implications for intraventricular surgery involving the choroid plexus. Journal of neurosurgery Xu, Y., Mohyeldin, A., Doniz-Gonzalez, A., Vigo, V., Pastor-Escartin, F., Meng, L., Cohen-Gadol, A. A., Fernandez-Miranda, J. C. 2021: 1–16

  Abstract

  OBJECTIVE: The lateral posterior choroidal artery (LPChA) should be a major surgical consideration in the microsurgical management of lateral ventricular tumors. Here the authors aim to delineate the microsurgical anatomy of the LPChA by using anatomical microdissections. They describe the trajectory, segments, and variations of the LPChA and discuss the surgical implications when approaching the choroid plexus using different routes.METHODS: Twelve colored silicone-injected, lightly fixed, postmortem human head specimens were prepared for dissection. The origin, diameter, trunk, course, segment, length, spatial relationships, and anastomosis of the LPChA were investigated. The surgical landmarks of 4 different approaches to the LPChA were also examined thoroughly.RESULTS: The LPChA was present in 23 hemispheres (96%), and in 14 (61%) it originated from the posterior segment of the P2 (i.e., P2P); most commonly (61%) the LPChA had 2 trunks, and in 17 hemispheres (74%) it had a C-shaped trajectory. According to its course, the authors divided the LPChA into 3 segments: 1) cisternal, from PCA to choroidal fissure (length 10.6 ± 2.5 mm); 2) forniceal, starting at the choroidal fissure, 8.2 ± 5.7 mm posterior to the inferior choroidal point, and terminating at the posterior level of the choroidal fissure (length 28.7 ± 6.8 mm); and 3) pulvinar, starting at the posterior choroidal fissure and terminating in the pulvinar (length 5.9 ± 2.2 mm). The LPChA was divided into 3 patterns according to its entrance into the choroidal fissure: A (anterior) 78%; B (posterior) 13%; and C (mixed) 9%. The transsylvian trans-limen insulae approach provided the best exposure for cisternal and proximal forniceal segments; the lateral transtemporal approach facilitated a more direct approach to the forniceal segment, including cases with posterior entrance; the transparietal transcortical and contralateral posterior interhemispheric transfalcine transprecuneus approaches provided direct access to the pulvinar segment of the LPChA and to the posterior forniceal segment, including cases with posterior choroidal entrance.CONCLUSIONS: The LPChA typically runs in the medial border of the choroid plexus, which may facilitate its recognition during surgery. The distance between the AChA at the inferior choroidal point and the LPChA is a valuable reference during surgery, but there are cases of posterior choroidal entrance. Most frequently, there are 2 or more LPChA trunks, which makes possible the sacrifice of one trunk feeding the tumor while preserving the other that provides supply to relevant structures. The intraventricular approaches can be selected based on the tumor location and the LPChA anatomy.

  View details for DOI 10.3171/2020.8.JNS202230

  View details for PubMedID 33836500

• Multi-compartment skull base orbital cavernous venous malformation: A rare presentation of a common orbital mass. American journal of ophthalmology case reports Azad, A. D., Sears, C. M., Hwang, P. H., Mohyeldin, A., Fernandez-Miranda, J., Kossler, A. L. 2021; 21: 101020

  Abstract

  Purpose: We present a unique case of an orbital intraconal cavernous venous malformation that extended along the trigeminal nerve to the pterygopalatine and middle cranial fossa. Our aim is to describe an atypical presentation of this common orbital vascular mass.Observations: A 57-year-old female presented with right eye proptosis. Orbital magnetic resonance imaging demonstrated a lobulated contrast-enhancing mass involving the right intraconal orbital space, pterygopalatine fossa, and right middle cranial fossa, radiographically presumed to be a schwannoma. Intraoperative and histopathologic evaluation confirmed a cavernous venous malformation that extended along the trigeminal nerve. The mass, including its attachments to the cranial nerves and dura, was successfully removed via a combined transorbital and endoscopic endonasal approach. The patient recovered well with 20/20 vision, full extraocular movements, and resolution of proptosis.Conclusions: This a rare presentation of an orbital cavernous venous malformation not previously described. Cavernous venous malformations typically present as ovoid well-circumscribed lesions; however, they can also extend outside the orbit along the path of cranial nerves, as was observed in this case. These types of lesions should be included in the differential diagnosis of masses arising from or extending along cranial nerves, even when involving the orbit.

  View details for DOI 10.1016/j.ajoc.2021.101020

  View details for PubMedID 33598587

• Mucosal Grafting Reduces Recurrence After Endonasal Surgery of Petrous Apex Cholesterol Granulomas. The Laryngoscope Patel, C. R., Snyderman, C. H., Fernandez-Miranda, J. C., Gardner, P. A., Wang, E. W. 2021

  Abstract

  OBJECTIVES/HYPOTHESIS: The endoscopic endonasal approach (EEA) is increasingly utilized for management of petrous apex cholesterol granuloma (PACG). Surgical goals include drainage and marsupialization of the cyst. Various techniques have been described to try to reduce the rates of recurrence. We studied the effect of mucosal grafting on recurrence.STUDY DESIGN: Retrospective Cohort study.METHODS: Patients who underwent EEA for PACG at two tertiary care centers between 1999 and 2018 were identified and divided into two cohorts: Mucosal versus no mucosal reconstruction. Surgical approach, reconstructive method, and recurrence were recorded. Primary endpoint was symptomatic or radiographic recurrence.RESULTS: Thirty-four patients were identified undergoing 37 surgeries. Four patients developed recurrences of which three elected to undergo revision. Some form of mucosa was used to line the drainage tract in 20 cases. A free mucosal graft was used in 8, and a small customized nasal septal flap (miniflap) in 12. All four recurrences occurred in cases where no mucosa was used, demonstrating decreased recurrences with mucosal reconstruction (P <.05). There was no difference found between free mucosal grafts and miniflaps.CONCLUSIONS: Utilization of mucosa to partially line a circumferentially de-epithelialized drainage pathway after EEA for PACG reduce recurrence rates.LEVEL OF EVIDENCE: 3 Laryngoscope, 2021.

  View details for DOI 10.1002/lary.29432

  View details for PubMedID 33559896

• Interhemispheric Precuneus Retrosplenial Transfalcine Approach for Falcotentorial Meningiomas: Anatomic Study and Clinical Series. Operative neurosurgery (Hagerstown, Md.) Celtikci, E. n., Nunez, M. n., Liu, J. K., Gardner, P. A., Cohen-Gadol, A. A., Fernandez-Miranda, J. C. 2021

  Abstract

  Falcotentorial meningiomas are surgically challenging. Currently accepted approaches include occipital interhemispheric and supracerebellar infratentorial approaches, which have documented drawbacks.To propose an alternative approach to the posterior tentorial incisural space, the interhemispheric precuneus retrosplenial transfalcine approach (IPRTA).A total of 6 colored-silicone-injected adult cadaveric heads were dissected. We measured the interval between bridging veins and studied computed tomography venography scans of 20 subjects to confirm the feasibility of the IPRTA. Bony landmarks, the region's bridging veins, and the anterior and posterior borders of the approach were identified. The surgical corridor widths (veins' interval) and lengths were compared between alternative midline approaches. We also reviewed 4 consecutive clinical cases using this approach.The IPRTA provides the shortest distance to the anterior and posterior limits of the posterior tentorial incisura. Moreover, it is the only approach that provides direct visualization of the anterior and posterior limits of falcotentorial junction meningiomas. In all specimens and patients, a minimum 30-mm interval between the anterior and posterior parietal veins was found in at least one of the hemispheres. Tumor removal was successful in all 4 patients but resulted in mild paresthesia in the lower extremities of 2 patients and temporary foot drop in 1 patient.The IPRTA offers the shortest and most direct corridor for falcotentorial meningiomas and provides excellent visualization of most of the critical structures in the region. Detailed preoperative evaluation of the deep and superficial venous structures is recommended.

  View details for DOI 10.1093/ons/opab095

  View details for PubMedID 33930163

• Contralateral Interhemispheric Transfalcine Transprecuneus Approach: Advancing Operative Angles to Deep-Seated Lesions. World neurosurgery Fernandez-Miranda, J. C., Xu, Y., Hendricks, B. K., Cohen-Gadol, A. 2020; 144: 341–50

  Abstract

  The reach to expose the peritrigonal/atrial territories poses special challenges. The highly functional overlying cortices and white matter tracts, such as the optic radiations lateral to the ventricle, postcentral gyrus laterally and more superficially, and the thalamus anteroinferiorly, constrain the surgical corridors to the atrium. Standard interhemispheric or transcortical approaches involve significant retraction and resection of the normal parenchyma. In this offering, the authors describe the contralateral posterior interhemispheric transfalcine transprecuneus approach (PITTA), which provides flexible working angles while protecting the functional brain tissues. In summary, the PITTA is founded on the concept of using a contralateral operative trajectory to augment a more tangential working angle to the more difficult-to-reach lateral target through a midline route. The PITTA emphasizes the importance of operative working angles (versus necessary operative space) through less disruptive exposures as a more viable parameter for achieving desirable results.

  View details for DOI 10.1016/j.wneu.2020.08.150

  View details for PubMedID 33227880

• Anatomy of the Orbit JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Lieber, S., Fernandez-Miranda, J. C. 2020

  View details for DOI 10.1055/s-0040-1715096

  View details for Web of Science ID 000570189100001

• The Effect of Nasoseptal Flap Elevation on Post-Operative Olfaction and Sinonasal Quality of Life: A Prospective Double-Blinded Randomized Controlled Trial. American journal of rhinology & allergy Chou, C. T., Valappil, B., Mattos, J. L., Snyderman, C. H., Gardner, P. A., Fernandez-Miranda, J. C., Wang, E. W. 2020: 1945892420957505

  Abstract

  BACKGROUND: The use of nasoseptal flaps (NSF) for defect reconstruction in endoscopic endonasal approaches (EEA) to cranial base pathology has markedly reduced rates of cerebrospinal fluid leak. However, the effect of NSF use on post-operative olfaction remains unclear.OBJECTIVE: To evaluate the impact of NSF use during EEA on binarial and uninarial olfaction, and sinonasal quality of life (QOL).METHODS: This was a prospective double-blinded randomized controlled trial. Patients undergoing EEA for sellar pathology were recruited from the University of Pittsburgh Medical Center from December 2014 to May 2017. Subjects were randomized pre-operatively to a side of NSF harvest. Olfaction and QOL were assessed pre-operatively and 6 to 12months post-operatively using the University of Pennsylvania Smell Identification Test, "Sniffin' Sticks," and Sinonasal Outcomes Test 22. The side of dominant uninarial olfaction was determined using "Sniffin' Sticks."RESULTS: Thirty-one patients were enrolled. Sixteen underwent EEA without NSF (control group) and 15 with NSF. A dominant side of olfaction was identified in 14 patients with NSF; 8 patients were randomized to NSF harvest on the dominant side and the remaining 6 on the non-dominant side. NSF elevation resulted in a 4% decrease in University of Pennsylvania Smell Identification Test scores, but was not statistically significant compared to controls. Similarly, NSF elevation on the side of dominant olfaction resulted in a 6% decrease, but was not statistically significant when compared to the non-dominant elevation group. Change in rhinologic QOL as determined by the Sinonasal Outcomes Test 22 was not significantly different between any of the groups.CONCLUSIONS: The use of NSF during EEA for sellar pathology does not have a significant effect on olfaction or rhinologic QOL. The presence of a dominant side of olfaction is not a primary consideration when deciding the side of NSF harvest.

  View details for DOI 10.1177/1945892420957505

  View details for PubMedID 32921136

• Anatomical Limits of the Endoscopic Contralateral Transmaxillary Approach to the Petrous Apex and Petroclival Region JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Mangussi-Gomes, J., Alves-Belo, J. T., Truong, H. Q., Nogueira, G. F., Wang, E. W., Fernandez-Miranda, J. C., Gardner, P. A., Snyderman, C. H. 2020

  View details for DOI 10.1055/s-0040-1716693

  View details for Web of Science ID 000567827000007

• Managing complications of endoscopic transsphenoidal surgery in pituitary adenomas. Expert review of endocrinology & metabolism Abhinav, K., Tyler, M., Dale, O. T., Mohyeldin, A., Fernandez-Miranda, J. C., Katznelson, L. 2020: 1–9

  Abstract

  INTRODUCTION: Over the last two decades there has been a gradual shift from the traditional microscopic approach toward the use of endoscopic endonasal approach for resection of pituitary adenomas. Multiple medical and surgical complications can occur following endoscopic transsphenoidal resection of adenomas.AREAS COVERED: We discuss the evolution of the surgical practice from the use of the 'microscope' to the 'endoscope' in the resection of pituitary adenomas. We present a comprehensive review of the medical and surgical complications following surgery with particular emphasis on both the prevention and management of electrolyte disturbance, cerebrospinal fluid leak and the rare but dreaded complication of internal carotid injury (ICA). We also searched the PubMed database to identify relevant literature between 1984 and 2019.EXPERT OPINION: Use of endoscope compared with microscope may be associated with better preservation of pituitary gland function with similar extent of resection. Overall medical and surgical complications can be safely managed in high volume centers in association with endocrinologists and skull base trained otolaryngologists. Understanding of anatomico-technical nuances and meticulous surgical technique are important toward preventing ICA injury. Ongoing surgical and technical developments coupled with imaging advances will likely lead to better future outcomes for patients with functioning and nonfunctioning adenomas.

  View details for DOI 10.1080/17446651.2020.1800452

  View details for PubMedID 32744080

• In Reply: Precautions for Endoscopic Transnasal Skull Base Surgery During the COVID-19 Pandemic NEUROSURGERY Patel, Z. M., Fernandez-Miranda, J., Hwang, P. H., Nayak, J. V., Dodd, R. L., Sajjadi, H., Jackler, R. K. 2020; 87 (2): E162–E163

  View details for Web of Science ID 000593120500027

• Anatomy of the Orbit. Journal of neurological surgery. Part B, Skull base Lieber, S., Fernandez-Miranda, J. C. 2020; 81 (4): 319-332

  Abstract

  The orbit is a paired, transversely oval, and cone-shaped osseous cavity bounded and formed by the anterior and middle cranial base as well as the viscerocranium. Its main contents are the anterior part of the visual system, globe and optic nerve, and the associated neural, vascular, muscular, glandular, and ligamentous structures required for oculomotion, lacrimation, accommodation, and sensation. A complex stream of afferent and efferent information passes through the orbit, which necessitates a direct communication with the anterior and middle cranial fossae, the pterygopalatine and infratemporal fossae, as well as the aerated adjacent frontal, sphenoidal, and maxillary sinuses and the nasal cavity. This article provides a detailed illustration and description of the microsurgical anatomy of the orbit, with a focus on the intrinsically complex spatial relationships around the annular tendon and the superior orbital fissure, the transition from cavernous sinus to the orbital apex. Sparse reference will be made to surgical approaches, their indications or limitations, since they are addressed elsewhere in this special issue. Instead, an attempt has been made to highlight anatomical structures and elucidate concepts most relevant to safe and effective transcranial, transfacial, transorbital, or transnasal surgery of orbital, periorbital, and skull base pathologies.

  View details for DOI 10.1055/s-0040-1715096

  View details for PubMedID 33072474

  View details for PubMedCentralID PMC7561454

• Structural white matter connectometry of word production in aphasia: an observational study. Brain : a journal of neurology Hula, W. D., Panesar, S., Gravier, M. L., Yeh, F., Dresang, H. C., Dickey, M. W., Fernandez-Miranda, J. C. 2020

  Abstract

  While current dual-steam neurocognitive models of language function have coalesced around the view that distinct neuroanatomical networks subserve semantic and phonological processing, respectively, the specific white matter components of these networks remain a matter of debate. To inform this debate, we investigated relationships between structural white matter connectivity and word production in a cross-sectional study of 42 participants with aphasia due to unilateral left hemisphere stroke. Specifically, we reconstructed a local connectome matrix for each participant from diffusion spectrum imaging data and regressed these matrices on indices of semantic and phonological ability derived from their responses to a picture-naming test and a computational model of word production. These connectometry analyses indicated that both dorsally located (arcuate fasciculus) and ventrally located (inferior frontal-occipital, uncinate, and middle longitudinal fasciculi) tracts were associated with semantic ability, while associations with phonological ability were more dorsally situated, including the arcuate and middle longitudinal fasciculi. Associations with limbic pathways including the posterior cingulum bundle and the fornix were also found. All analyses controlled for total lesion volume and all results showing positive associations obtained false discovery rates < 0.05. These results challenge dual-stream accounts that deny a role for the arcuate fasciculus in semantic processing, and for ventral-stream pathways in language production. They also illuminate limbic contributions to both semantic and phonological processing for word production.

  View details for DOI 10.1093/brain/awaa193

  View details for PubMedID 32705146

• Big Data, Big Impact: The Potential for Data Science in Neurosurgery. World neurosurgery Panesar, S. S., Fernandez-Miranda, J. 2020; 138: 558–59

  View details for DOI 10.1016/j.wneu.2020.03.182

  View details for PubMedID 32544994

• Full tractography for detecting the position of cranial nerves in preoperative planning for skull base surgery: technical note JOURNAL OF NEUROSURGERY Jacquesson, T., Yeh, F., Panesar, S., Barrios, J., Attye, A., Frindel, C., Cotton, F., Gardner, P., Jouanneau, E., Fernandez-Miranda, J. C. 2020; 132 (5): 1642–52

  View details for DOI 10.3171/2019.1.JNS182638

  View details for Web of Science ID 000530830500039

• In Reply: Precautions for Endoscopic Transnasal Skull Base Surgery During the COVID-19 Pandemic. Neurosurgery Patel, Z. M., Fernandez-Miranda, J., Hwang, P. H., Nayak, J. V., Dodd, R. L., Sajjadi, H., Jackler, R. K. 2020

  View details for DOI 10.1093/neuros/nyaa156

  View details for PubMedID 32323725

• Results of a prospective multicenter controlled study comparing surgical outcomes of microscopic versus fully endoscopic transsphenoidal surgery for nonfunctioning pituitary adenomas: the Transsphenoidal Extent of Resection (TRANSSPHER) Study JOURNAL OF NEUROSURGERY Little, A. S., Kelly, D. F., White, W. L., Gardner, P. A., Fernandez-Miranda, J. C., Chicoine, M. R., Barkhoudarian, G., Chandler, J. P., Prevedello, D. M., Liebelt, B. D., Sfondouris, J., Mayberg, M. R., TRANSSPHER Study Grp 2020; 132 (4): 1043–53

  View details for DOI 10.3171/2018.11.JNS181238

  View details for Web of Science ID 000523185100258

• Endoscopic endonasal resection of a large tuberculum sella meningioma. Neurosurgical focus: Video Mohyeldin, A., Nayak, J. V., Fernandez-Miranda, J. C. 2020; 2 (2): V3

  Abstract

  Over the past three decades, endoscopic endonasal surgery has unlocked new corridors to treat a wide spectrum of ventral skull base lesions. Tuberculum sella meningiomas represent one of the most ideal pathologies for ventral skull base access. Traditionally, these lesions were approached primarily through various subfrontal and frontal-lateral transcranial approaches that have unfortunately been shown to be associated with worsening visual decline postoperatively. The endoscopic endonasal approach is now being attempted by more surgeons and leverages an infrachiasmatic trajectory that provides direct access to the tuberculum sella where most of the vascular supply for these lesions can be taken early, facilitating more efficient surgical resection and mitigating the risk of optic nerve injury. Here we review a challenging case of a large (∼3 cm) tuberculum sella meningioma, encasing critical vessels off the circle of Willis and resected via an endoscopic endonasal approach. We discuss the technical nuances and relevant surgical anatomy of this approach and highlight important considerations in the safe and successful removal of these meningiomas. We show that certain tumors that appear to encase the supraclinoidal carotid artery can be fully resected via an endonasal approach with precise surgical technique and adequate exposure. Furthermore, this case illustrates the risk of injuring a key perforating vessel from the anterior communicating artery complex, called the subcallosal artery. Injury to this vessel is highly associated with tumors like the one presented here that extend into the suprachiasmatic space between the optic chiasm and the anterior communicating complex. Meticulous surgical dissection is required to preserve this perforating vessel as well as branches from the superior hypophyseal artery. Finally, we review our current closure techniques for these challenging approaches and discuss the use of a lumbar drain for 3 days to lower CSF leak rates. The video can be found here: https://youtu.be/mafyXi5B0MA.

  View details for DOI 10.3171/2020.4.FocusVid.19981

  View details for PubMedID 36284775

  View details for PubMedCentralID PMC9542388

• Endoscopic endonasal surgery for giant pediatric craniopharyngioma. Neurosurgical focus: Video Mohyeldin, A., Hwang, P., Grant, G. A., Fernandez-Miranda, J. C. 2020; 2 (2): V8

  Abstract

  Pediatric craniopharyngiomas that were once thought to be inoperable or considered only for salvage medical therapy are now being reconsidered for aggressive surgical resection via endoscopic endonasal approaches. Here we review the operative video case of an 11-year-old with a giant complex craniopharyngioma that was resected via an endoscopic endonasal approach. Due to the extent of tumor burden near the basilar apex, a transclival approach was necessary. To accomplish this, a wide sphenoidotomy, posterior ethmoidectomy, and resection of the middle turbinate were necessary to create enough working space for the resection. We also highlight several key innovations in pediatric endoscopic endonasal surgery management and underscore a multidisciplinary approach that allows for the safe and successful treatment of these lesions. Our multidisciplinary team involves an experienced fellowship-trained endoscopic skull base surgeon and otolaryngologist, as well as a pediatric neurosurgeon, pediatric endocrinologist, pediatric anesthesiologist, and pediatric intensivists who play important roles in the preoperative, intraoperative, and postoperative phases of care of the patient. Finally, we discuss critical surgical decision points including pituitary transposition, which has a lot of conceptual appeal when it is anatomically feasible but unfortunately, in our experience, has low functional preservation rates. Initially, we always aim to utilize pituitary transposition for tuberoinfundibular craniopharyngiomas, and once the relationship between the tumor and the stalk is determined, a decision on whether to preserve or sacrifice the stalk and pituitary gland is made. In this particular case, there was a salvageable stalk and the transposition was performed knowing that the chances for functional preservation were low. The video can be found here: https://youtu.be/ClL73FU5QIU.

  View details for DOI 10.3171/2020.4.FocusVid.19983

  View details for PubMedID 36284783

  View details for PubMedCentralID PMC9542483

• Neurosurgery and Manned Spaceflight NEUROSURGERY Panesar, S. S., Fernandez-Miranda, J. C., Kliot, M., Ashkan, K. 2020; 86 (3): 317–24

  View details for DOI 10.1093/neuros/nyy531

  View details for Web of Science ID 000536463300012

• Reduced Tearing With Stable Quality of Life After Vidian Neurectomy: A Prospective Controlled Trial. The Laryngoscope Wang, E. W., Gardner, P. A., Fraser, S. n., Stefko, S. T., Fernandez-Miranda, J. C., Snyderman, C. H. 2020

  Abstract

  Although vidian neurectomy (VN) is associated with decreased lacrimation, its impact on dry eye quality-of-life is not well-defined. Endoscopic endonasal transpterygoid approaches (EETA) may require vidian nerve sacrifice.A prospective cohort trial.A prospective trial evaluating VN during EETA on lacrimation by phenol red thread testing and dry eye severity by the five-item Dry Eye Questionnaire (DEQ-5) was performed. Preservation of the contralateral vidian nerve allowed comparison between the eye subjected to VN and the control eye postoperatively.Twenty-one subjects were enrolled with no preoperative difference in lacrimation between eyes (P = .617) and overall mild dry eye severity. Although the control eye had no difference in lacrimation pre- and postoperatively, decreased tearing was noted in the VN eye at 1 month (20.8 mm vs. 15.8 mm, P = .015) and at 3 months (23.2 mm vs. 15.8 mm, P = .0051) postoperatively. Overall, no difference was noted in the DEQ-5 score for dry eye severity between the pre- and postoperative measures. However, six patients were noted to have moderate to severe dry eye severity postoperatively and five of these six had decreased lacrimation (<20 mm) preoperatively. Patients with decreased tearing preoperatively demonstrated significantly worse postoperative DEQ-5 scores when compared to patients with normal tearing (P < .0056).VN during EETA results in decreased tearing but is not associated with increased dry eye severity overall. However, patients with decreased tearing preoperatively are at risk for increased dry eye severity and should be counseled for this risk.2 Laryngoscope, 2020.

  View details for DOI 10.1002/lary.29287

  View details for PubMedID 33247625

• Seizure Risk following Open and Expanded Endoscopic Endonasal Approaches for Intradural Skull Base Tumors. Journal of neurological surgery. Part B, Skull base Goldschmidt, E. n., Chabot, J. D., Algattas, H. n., Lieber, S. n., Khattar, N. n., Nakassa, A. C., Angriman, F. n., Snyderman, C. H., Wang, E. W., Fernandez-Miranda, J. C., Gardner, P. A. 2020; 81 (6): 673–79

  Abstract

  Objectives  The incidence of seizures following a craniotomy for tumor removal varies between 15 and 20%. There has been increased use of endoscopic endonasal approaches (EEAs) for a variety of intracranial lesions due to its more direct approach to these pathologies. However, the incidence of postoperative seizures in this population is not well described. Methods  This is a single-center, retrospective review of consecutive patients undergoing EEA or open craniotomy for resection of a cranial base tumor between July 2007 and June 2014. Patients were included if they underwent an EEA for an intradural skull base lesion. Positive cases were defined by electroencephalograms and clinical findings. Patients who underwent a craniotomy to remove extra-axial skull base tumors were analyzed in the same fashion. Results  Of the 577 patients treated with an EEA for intradural tumors, 4 experienced a postoperative seizure (incidence 0.7%, 95% confidence interval [CI]: 0.002-0.02). Over the same period, 481 patients underwent a craniotomy for a skull base lesion of which 27 (5.3%, 95% CI: 0.03-0.08) experienced a seizure after surgery. The odds ratio for EEA was 0.13 (95% CI: 0.05-0.35). Both populations were different in terms of age, gender, tumor histology, and location. Conclusion  This study is the largest series looking at seizure incidence after EEA for intracranial lesions. Seizures are a rare occurrence following uncomplicated endonasal approaches. This must be tempered by selection bias, as there are inherent differences in which patients are treated with either approach that influence the likelihood of seizures.

  View details for DOI 10.1055/s-0039-1694968

  View details for PubMedID 33381372

  View details for PubMedCentralID PMC7755514

• The Smith-Robinson Approach to the Subaxial Cervical Spine: A Stepwise Microsurgical Technique Using Volumetric Models From Anatomic Dissections. Operative neurosurgery (Hagerstown, Md.) Vigo, V. n., Pastor-Escartín, F. n., Doniz-Gonzalez, A. n., Quilis-Quesada, V. n., Capilla-Guasch, P. n., González-Darder, J. M., De Bonis, P. n., Fernandez-Miranda, J. C. 2020

  Abstract

  The Smith-Robinson1 approach (SRA) is the most widely used route to access the anterior cervical spine. Although several authors have described this approach, there is a lack of the stepwise anatomic description of this operative technique. With the advent of new technologies in neuroanatomy education, such as volumetric models (VMs), the understanding of the spatial relation of the different neurovascular structures can be simplified.To describe the anatomy of the SRA through the creation of VMs of anatomic dissections.A total of 4 postmortem heads and a cervical replica were used to perform and record the SRA approach to the C4-C5 level. The most relevant steps and anatomy of the SRA were recorded using photogrammetry to construct VM.The SRA was divided into 6 major steps: positioning, incision of the skin, platysma, and muscle dissection with and without submandibular gland eversion and after microdiscectomy with cage positioning. Anatomic model of the cervical spine and anterior neck multilayer dissection was also integrated to improve the spatial relation of the different structures.In this study, we review the different steps of the classic SRA and its variations to different cervical levels. The VMs presented allow clear visualization of the 360-degree anatomy of this approach. This new way of representing surgical anatomy can be valuable resources for education and surgical planning.

  View details for DOI 10.1093/ons/opaa265

  View details for PubMedID 32864701

• Endoscopic Endonasal Approach for Resection of Suprasellar Hemangioblastoma: Selective Pituitary Sacrifice and Use of Indocyanine Dye: 2-Dimensional Operative Video. Operative neurosurgery (Hagerstown, Md.) Abhinav, K. n., Gimenez, P. n., Tyler, M. n., Patel, Z. M., Fernandez-Miranda, J. C. 2020

  Abstract

  Suprasellar hemangioblastomas are rare lesions occurring sporadically or more commonly with von Hippel Lindau disease (VHLD).1,2 A 27-yr-old female presented with amenorrhea, mildly raised prolactin levels and otherwise normal pituitary function, homonymous hemianopia, and mild cognitive decline. Imaging revealed a large suprasellar lesion arising from the infundibulum, causing compression of optic chiasm with edema in the visual pathways. Lesion appeared hypervascular with prominent feeding vessels from the internal carotid arteries bilaterally. To access these vessels derived from the superior hypophyseal arteries and allow early devascularization, endoscopic endonasal approach was performed.3 Stalk preservation was deemed unlikely. After opening of the suprasellar dura, indocyanine dye allowed early identification of the feeding vessels. They were sequentially sacrificed, allowing early devascularization while preserving the normal blood supply to the optic chiasm from the superior hypophyseal arteries. Pituitary gland and stalk were removed with the latter being completely involved by tumor to provide access to the retroclival region and posterior circulation. After opening of the dura underlying the dorsum sella, inferior pole of the tumor was exposed with blood supply identified from the posterior communicating arteries but not the basilar or posterior cerebral arteries. Devascularized lesion was safely removed from the optic apparatus, hypothalamus, and the third ventricle. Histology was consistent with hemangoblastoma (VHLD negative). Patient's cognitive and visual function normalized with a postoperative magnetic resonance imagingdemonstrating complete resection, no ischemic events on diffusion-weighted imaging, and resolution of the edema in the hypothalamus and visual pathways.1 She was started on desmopressin and replacement therapy for pituitary function. The patient consented to the procedure.  Patient provided consent for publication.

  View details for DOI 10.1093/ons/opaa250

  View details for PubMedID 32814970

• Experience With the Endoscopic Contralateral Transmaxillary Approach to the Petroclival Skull Base. The Laryngoscope Snyderman, C. H., Gardner, P. A., Wang, E. W., Fernandez-Miranda, J. C., Valappil, B. n. 2020

  Abstract

  The contralateral transmaxillary (CTM) approach is a new surgical approach that improves the surgical trajectory relative to the petrous segment of the internal carotid artery (ICA). Here, we present our clinical experience with the CTM approach to the petroclival region of the skull base.Retrospective review.A retrospective review of 29 patients who underwent a CTM approach for skull base pathology from 2015 to 2020 was performed. Assessment of gross total resection (GTR) was based on postoperative imaging.The male:female ratio was 15:14, with an average age of 52 years (range = 19-78 years). Diagnoses included: 12 chondrosarcomas, 11 chordomas, two meningiomas, one schwannoma, one metastasis, one petrous apicitis, and one arachnoid cyst. CTM was performed in addition to a transclival approach and ipsilateral transpterygoid approach in all patients. Reconstruction of surgical defects included a vascularized flap in all but two patients: 24 nasoseptal flaps and three lateral nasal wall flaps. The reconstructive flap was on the same side as the CTM approach in 22 of 28 (79%) patients. There were no ICA injuries. In a subset of patients with chondromatous tumors, GTR of the targeted area was achieved in 16 of 22 (73%) evaluable chondromatous tumors. With a median follow-up of 13 months, 64% of these patients are without disease or dead of other causes; the remainder are alive with disease.The CTM approach improves the degree of resection of skull base tumors involving the petroclival region using an endoscopic endonasal approach and may minimize risk to the ICA.4 Laryngoscope, 2020.

  View details for DOI 10.1002/lary.28740

  View details for PubMedID 32413156

• Evaluation of Surgical Resection Goal and Its Relationship to Extent of Resection and Patient Outcomes in a Multicenter Prospective Study of Patients With Surgically Treated, Nonfunctioning Pituitary Adenomas: A Case Series OPERATIVE NEUROSURGERY Little, A. S., Chicoine, M. R., Kelly, D. F., Sarris, C. E., Mooney, M. A., White, W. L., Gardner, P. A., Fernandez-Miranda, J. C., Barkhoudarian, G., Chandler, J. P., Prevedello, D. M., Liebelt, B. D., Sfondouris, J., Mayberg, M. R., Transspher Study Grp 2020; 18 (1): 26–33

  View details for DOI 10.1093/ons/opz085

  View details for Web of Science ID 000522854200025

• The Anterior (Endoscopic Endonasal) Approach and Outcomes for Foramen Magnum Tumors SURGERY OF THE CRANIO-VERTEBRAL JUNCTION Zwagerman, N. T., Fernandez-Miranda, J. C., Wang, E. W., Snyderman, C. H., Gardner, P. A., Tessitore, E., Dehdashti, A. R., Schonauer, C., Thome, C. 2020: 395-402

  View details for DOI 10.1007/978-3-030-18700-2_26

  View details for Web of Science ID 000655240600027

• Endoscopic transnasal transmaxillary approach to the upper parapharyngeal space and the skull base. European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery Liu, Q., Wang, H., Zhao, W., Song, X., Sun, X., Yu, H., Wang, D., Fernandez-Miranda, J. C., Snyderman, C. H. 2019

  Abstract

  PURPOSE: Treatment of tumors arising in the upper parapharyngeal space (PPS) or the floor of the middle cranial fossa is challenging. This study aims to present anatomical landmarks for a combined endoscopic transnasal and anterior transmaxillary approach to the upper PPS and the floor of the middle cranial fossa and to further evaluate their clinical application.METHODS: Dissection of the upper PPS using a combined endoscopic endonasal transpterygoid and anterior transmaxillary approach was performed in six cadaveric heads. Surgical landmarks associated with the approach were defined. The defined approach was applied in patients with tumors involving the upper PPS.RESULTS: The medial pterygoid muscle, tensor veli palatini muscle and levator veli palatini muscle were key landmarks of the approach into the upper PPS. The lateral pterygoid plate, foramen ovale and mandibular nerve were important anatomical landmarks for exposing the parapharyngeal segment of the internal carotid artery through a combined endoscopic transnasal and anterior transmaxillary approach. The combined approach provided a better view of the upper PPS and middle skull base, allowing for effective bimanual techniques and bleeding control. Application of the anterior transmaxillary approach also provided a better view of the inferior limits of the upper PPS and facilitated control of the internal carotid artery.CONCLUSIONS: Improving the knowledge of the endoscopic anatomy of the upper PPS allowed us to achieve an optimal approach to tumors arising in the upper PPS. The combined endoscopic transnasal and anterior transmaxillary approach is a minimally invasive alternative approach to the upper PPS.

  View details for DOI 10.1007/s00405-019-05761-6

  View details for PubMedID 31845034

• Promises and Perils of Artificial Intelligence in Neurosurgery. Neurosurgery Panesar, S. S., Kliot, M., Parrish, R., Fernandez-Miranda, J., Cagle, Y., Britz, G. W. 2019

  Abstract

  Artificial intelligence (AI)-facilitated clinical automation is expected to become increasingly prevalent in the near future. AI techniques may permit rapid and detailed analysis of the large quantities of clinical data generated in modern healthcare settings, at a level that is otherwise impossible by humans. Subsequently, AI may enhance clinical practice by pushing the limits of diagnostics, clinical decision making, and prognostication. Moreover, if combined with surgical robotics and other surgical adjuncts such as image guidance, AI may find its way into the operating room and permit more accurate interventions, with fewer errors. Despite the considerable hype surrounding the impending medical AI revolution, little has been written about potential downsides to increasing clinical automation. These may include both direct and indirect consequences. Directly, faulty, inadequately trained, or poorly understood algorithms may produce erroneous results, which may have wide-scale impact. Indirectly, increasing use of automation may exacerbate de-skilling of human physicians due to over-reliance, poor understanding, overconfidence, and lack of necessary vigilance of an automated clinical workflow. Many of these negative phenomena have already been witnessed in other industries that have already undergone, or are undergoing "automation revolutions," namely commercial aviation and the automotive industry. This narrative review explores the potential benefits and consequences of the anticipated medical AI revolution from a neurosurgical perspective.

  View details for DOI 10.1093/neuros/nyz471

  View details for PubMedID 31748800

• Anatomical Variations in the Location of Veins Draining Into the Anterior Superior Sagittal Sinus: Implications for the Transbasal Approach. Operative neurosurgery (Hagerstown, Md.) Borghei-Razavi, H., Raghavan, A., Eguiluz-Melendez, A., Joshi, K., Fernandez-Miranda, J. C., Kshettry, V. R., Recinos, P. F. 2019

  Abstract

  BACKGROUND: Many approaches are used for midline anterior cranial fossa meningioma resection. In the subfrontal approach, the anterior superior sagittal sinus (SSS) is commonly ligated to release the anterior falx. The transbasal approach allows access to the origin of the anterior SSS, allowing for maximum venous preservation.OBJECTIVE: To investigate variations in the first and second veins draining into the SSS.METHODS: We performed stepwise dissections for a transbasal level 1 approach on 8 anatomic specimens. We visualized the first and second veins draining into the sinus and measured the distance from the foramen cecum to these veins. We also measured the orbital bar height to determine the length of sagittal sinus that could be preserved with orbital bar removal.RESULTS: The distance between the foramen cecum and the first vein ranged from 4 to 36 mm while the distance to the second vein ranged from 6 to 48 mm. The mean orbital bar height was 26.4 mm. Based on these measurements, with a traditional bicoronal craniotomy without orbital bar removal, 81% of first veins and 58% of second veins would be sacrificed.CONCLUSION: A supraorbital bar or nasofrontal osteotomy, part of the transbasal skull base approach, is helpful to preserve the first and second veins when ligating the anterior SSS. Based on this study, it may be difficult to preserve these veins without orbital bar removal. Preservation of these veins may be of clinical importance when approaching midline anterior fossa pathologies.

  View details for DOI 10.1093/ons/opz339

  View details for PubMedID 31748805

• Proposal and Validation of a Simple Grading Scale (TRANSSPHER Grade) for Predicting Gross Total Resection of Nonfunctioning Pituitary Macroadenomas After Transsphenoidal Surgery OPERATIVE NEUROSURGERY Mooney, M. A., Sarris, C. E., Zhou, J. J., Barkhoudarian, G., Chicoine, M. R., Fernandez-Miranda, J. C., Gardner, P. A., Hardesty, D. A., Jahnke, H., Kelly, D. F., Liebelt, B. D., Mayberg, M. R., Prevedello, D. M., Sfondouris, J., Sheehy, J. P., Chandler, J. P., Yuen, K. J., White, W. L., Little, A. S., White, W. L., TRANSSPHER Study Grp 2019; 17 (5): 460–69

  View details for DOI 10.1093/ons/opy401

  View details for Web of Science ID 000500030100021

• Nasopharyngeal muscle patch for the management of internal carotid artery injury in endoscopic endonasal surgery. Journal of neurosurgery Wang, W., Lieber, S., Lan, M., Wang, E. W., Fernandez-Miranda, J. C., Snyderman, C. H., Gardner, P. A. 2019: 1–6

  Abstract

  OBJECTIVE: Injury to the internal carotid artery (ICA) is the most critical complication of endoscopic endonasal skull base surgery. Packing with a crushed muscle graft at the injury site has been an effective management technique to control bleeding without ICA sacrifice. Obtaining the muscle graft has typically required access to another surgical site, however. To address this concern, the authors investigated the application of an endonasally harvested longus capitis muscle patch for the management of ICA injury.METHODS: One colored silicone-injected anatomical specimen was dissected to replicate the surgical access to the nasopharynx and the stepwise dissection of the longus capitis muscle in the nasopharynx. Two representative cases were selected to illustrate the application of the longus capitis muscle patch and the relevance of clinical considerations.RESULTS: A suitable muscle graft from the longus capitis muscle could be easily and quickly harvested during endoscopic endonasal skull base surgery. In the illustrative cases, the longus capitis muscle patch was successfully used for secondary prevention of pseudoaneurysm formation following primary bleeding control on the site of ICA injury.CONCLUSIONS: Nasopharyngeal harvest of a longus capitis muscle graft is a safe and practical method to manage ICA injury during endoscopic endonasal surgery.

  View details for DOI 10.3171/2019.7.JNS191370

  View details for PubMedID 31628289

• A minimally invasive endoscopic transnasal retropterygoid approach to the upper parapharyngeal space: anatomic studies and surgical implications. International forum of allergy & rhinology Liu, J., Sun, X., Liu, Q., Gu, Y., Li, H., Zheng, C., Wang, D., Fernandez-Miranda, J. C., Snyderman, C. H., Yu, H. 2019

  Abstract

  BACKGROUND: Surgery remains the mainstay of treatment for lesions in the parapharyngeal space. However, gaining access to the parapharyngeal space is often challenging. In this study we aim to describe a minimally invasive technique of approaching the upper parapharyngeal space through an endoscopic transnasal retropterygoid approach, based on anatomic studies and surgeries.METHODS: Six fresh human cadaver heads were prepared for anatomic study at the Surgical Neuroanatomy Laboratory of the Center for Cranial Base Surgery within the Department of Neurological Surgery at the University of Pittsburgh School of Medicine. Three clinical cases seen in the Department of Otolaryngology, Eye, Ear, Nose, and Throat Hospital, Shanghai Medical College of Fudan University, were used to illustrate the technique and feasibility of this approach and to assess its indications, advantages, and drawbacks.RESULTS: The medial pterygoid plate is the primary landmark of the endoscopic transnasal retropterygoid approach to the upper parapharyngeal space. Access to the upper parapharyngeal space could be obtained by removing the mucosa on the medial pterygoid plate and the mucosa below the pharyngeal orifice of the Eustachian tube. The 3 patients in our study tolerated the procedure well and had no serious complications after surgery.CONCLUSION: The anatomic data and clinical cases in this study confirm that an endoscopic transnasal retropterygoid approach is a feasible and effective surgical treatment for selected tumors in the upper parapharyngeal space.

  View details for DOI 10.1002/alr.22437

  View details for PubMedID 31574593

• Endoscopic endonasal approach for resection of pediatric chordoma with brainstem invasion. Neurosurgical focus: Video Abhinav, K., Hong, D., Yan, C. H., Hwang, P., Fernandez-Miranda, J. C. 2019; 1 (2): V20

  Abstract

  A 14-year-old boy had undergone an orbitozygomatic craniotomy for a pontine lesion. There was growth on surveillance imaging with involvement of posterior clinoids, clivus, and left pons suggestive of chordoma (Fernandez-Miranda et al., 2014b). An endoscopic endonasal approach was undertaken involving full upper and midclival exposure including bilateral posterior clinoidectomy (Fernandez-Miranda et al., 2014a; Truong et al., 2019a, 2019b). The internal carotid artery was skeletonized to maximize exposure and facilitate safe resection. The tumor was removed from between the dural layers of the midclivus while preserving the interdural abducens nerve (Barges-Coll et al., 2010). The brainstem component was resected while preserving the pontine perforators. Postoperative diagnosis was chordoma with MRI demonstrating complete resection. The patient was intact postoperatively. The video can be found here: https://youtu.be/g6SQ5JVK0Ko.

  View details for DOI 10.3171/2019.10.FocusVid.19421

  View details for PubMedID 36284860

  View details for PubMedCentralID PMC9541825

• Validation of training levels in endoscopic endonasal surgery of the skull base LARYNGOSCOPE Lavigne, P., Faden, D., Gardner, P. A., Fernandez-Miranda, J. C., Wang, E. W., Snyderman, C. H. 2019; 129 (10): 2253–57

  View details for DOI 10.1002/lary.27895

  View details for Web of Science ID 000488184200022

• Artificial Intelligence and the Future of Surgical Robotics ANNALS OF SURGERY Panesar, S., Cagle, Y., Chander, D., Morey, J., Fernandez-Miranda, J., Kliot, M. 2019; 270 (2): 223–26

  View details for DOI 10.1097/SLA.0000000000003262

  View details for Web of Science ID 000480739600059

• ICAR: endoscopic skull-base surgery. International forum of allergy & rhinology Wang, E. W., Zanation, A. M., Gardner, P. A., Schwartz, T. H., Eloy, J. A., Adappa, N. D., Bettag, M., Bleier, B. S., Cappabianca, P., Carrau, R. L., Casiano, R. R., Cavallo, L. M., Ebert, C. S., El-Sayed, I. H., Evans, J. J., Fernandez-Miranda, J. C., Folbe, A. J., Froelich, S., Gentili, F., Harvey, R. J., Hwang, P. H., Jane, J. A., Kelly, D. F., Kennedy, D., Knosp, E., Lal, D., Lee, J. Y., Liu, J. K., Lund, V. J., Palmer, J. N., Prevedello, D. M., Schlosser, R. J., Sindwani, R., Solares, C. A., Tabaee, A., Teo, C., Thirumala, P. D., Thorp, B. D., de Arnaldo Silva Vellutini, E., Witterick, I., Woodworth, B. A., Wormald, P., Snyderman, C. H. 2019; 9 (S3): S145–S365

  Abstract

  BACKGROUND: Endoscopic skull-base surgery (ESBS) is employed in the management of diverse skull-base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull-base surgery have produced the International Consensus Statement on Endoscopic Skull-Base Surgery (ICAR:ESBS).METHODS: Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence-based review or evidence-based review with recommendations format. Subsequently, each topic was written and then reviewed by skull-base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus.RESULTS: The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull-base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated.CONCLUSION: A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence-based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull-base community to embrace these opportunities and collaboratively address these shortcomings.

  View details for DOI 10.1002/alr.22326

  View details for PubMedID 31329374

• Surgical Anatomy of the Subcallosal Artery: Implications for Transcranial and Endoscopic Endonasal Surgery in the Suprachiasmatic Region OPERATIVE NEUROSURGERY Najera, E., Belo, J., Truong, H. Q., Gardner, P. A., Fernandez-Miranda, J. C. 2019; 17 (1): 79–87

  View details for DOI 10.1093/ons/opy276

  View details for Web of Science ID 000484381200025

• In Reply: Neurosurgery and Manned Spaceflight NEUROSURGERY Panesar, S. S., Fernandez-Miranda, J. C., Kliot, M., Ashkan, K. 2019; 85 (1): E159–E160

  View details for DOI 10.1093/neuros/nyz107

  View details for Web of Science ID 000484356700040

• Bilateral coagulation of inferior hypophyseal artery and pituitary transposition during endoscopic endonasal interdural posterior clinoidectomy: do they affect pituitary function? JOURNAL OF NEUROSURGERY Truong, H. Q., Borghei-Razavi, H., Najera, E., Nakassa, A., Wang, E. W., Snyderman, C. H., Gardner, P. A., Fernandez-Miranda, J. C. 2019; 131 (1): 141–46

  View details for DOI 10.3171/2018.2.JNS173126

  View details for Web of Science ID 000475838400018

• Endoscopic endonasal surgery and the superior hypophyseal artery: further studies remain mandatory Response JOURNAL OF NEUROSURGERY Truong, H. Q., Fernandez-Miranda, J. C., Gardner, P. A. 2019; 131 (1): 330–31

  View details for DOI 10.3171/2018.10.JNS182590

  View details for Web of Science ID 000475838400049

• Endoscopic endonasal superomedial orbitectomy: How far is safe and possible? The Laryngoscope Cardenas Ruiz-Valdepenas, E., Kaen, A., Gonzalez-Martinez, E., Gardner, P. A., Wang, E. W., Snyderman, C. H., Fernandez-Miranda, J. C. 2019

  Abstract

  OBJECTIVES: During the endoscopic endonasal approach (EEA) to the anterior cranial base, the lateral boundaries are the lamina papyracea (medial orbital walls) bilaterally but further extension in the coronal plane is possible by performing a superomedial orbitectomy. The aims of this study are to describe the technique of the endoscopic endonasal transethmoidal supraorbital approach to the anterior cranial base and to calculate the extension in the coronal plane added with the superomedial orbitectomy.METHODS: Thirty superomedial orbitectomies via EEA were completed in 15 fresh-frozen heads. After finishing the procedure, a bifrontal craniotomy with removal of both frontal lobes was performed in order to measure the width of the supraorbital EEA in the coronal plane. We divided the anterior cranial base into five zones related to distinct anatomical segments: sinusal zone, post-sinusal zone, anterior ethmoidal, inter-ethmoidal zone, and posterior ethmoidal zone. Measurements of each segment of the anterior cranial base were taken.RESULTS: In all specimens, it was possible to perform a superomedial orbitectomy without excessive retraction of the orbital contents. The inter-ethmoidal zone is the segment where the lateral extension was widest. The mean total width in this area was 45.4 mm. The superomedial orbitectomy added a mean of 8 mm on each side to the total anterior skull base exposure.CONCLUSION: The endoscopic endonasal superomedial orbitectomy added important extension in the coronal plane during an EEA to the anterior cranial base. The inter-ethmoidal zone has shown the greatest lateral extension.LEVEL OF EVIDENCE: N/A Laryngoscope, 2019.

  View details for DOI 10.1002/lary.28080

  View details for PubMedID 31206702

• Clinical Experience with Secondary Endoscopic Reconstruction of Clival Defects with Extracranial Pericranial Flaps. Journal of neurological surgery. Part B, Skull base Gode, S., Lieber, S., Nakassa, A. C., Wang, E. W., Fernandez-Miranda, J. C., Gardner, P. A., Snyderman, C. H. 2019; 80 (3): 276–82

  Abstract

  Objectives The aim of this study is to report the clinical outcome of extracranial pericranial flaps (ePCF) used for reconstruction of clival dural defects following failure of primary repair. Design Retrospective review of skull base database. Setting Academic medical center. Participants Patients undergoing reconstruction of clival defects with ePCF following endoscopic endonasal surgery (EES). Main outcome measures Postoperative cerebrospinal fluid (CSF) leak, meningitis, and flap necrosis. Results Seven patients (five males and two females) who underwent ePCF reconstruction for clival defects following EES were included. All patients (ages 8-64 years) had a postoperative CSF leak due to a failed primary clival reconstruction (five had one, one had two, and one had three failed CSF leak repairs prior to ePCF reconstruction). Nasoseptal and inferior turbinate (lateral nasal wall) flaps were not available for secondary reconstruction due to prior surgeries. The immediate success rate of ePCF for the reconstruction of clival defects in patients with multiple flap failures was 58%. Two patients developed CSF leaks that were successfully repaired endoscopically with the addition of free tissue grafts; one patient had partial flap necrosis that required debridement; none required an additional vascularized flap. Width of the defect, length of the defect, properties of the ePCF, and age did not demonstrate significance ( p >0.05) for adverse outcome. Conclusion An ePCF is a reconstructive option for high-risk, large clival defects when other local and regional vascularized flaps are not available or fail. ePCFs can be used for reconstruction of clival defects in all populations, including pediatric patients.

  View details for DOI 10.1055/s-0038-1668517

  View details for PubMedID 31143571

• Proximal Branches of the Anterior Cerebral Artery: Anatomic Study and Applications to Endoscopic Endonasal Surgery OPERATIVE NEUROSURGERY Najera, E., Truong, H. Q., Belo, J., Borghei-Razavi, H., Gardner, P. A., Fernandez-Miranda, J. 2019; 16 (6): 734–42

  View details for DOI 10.1093/ons/opy308

  View details for Web of Science ID 000481431900025

• In Reply: Neurosurgery and Manned Spaceflight. Neurosurgery Panesar, S. S., Fernandez-Miranda, J. C., Kliot, M., Ashkan, K. 2019

  View details for PubMedID 31058971

• Endoscopic Endonasal Petrosectomy: Anatomical Investigation, Limitations, and Surgical Relevance. Operative neurosurgery (Hagerstown, Md.) Borghei-Razavi, H., Truong, H. Q., Fernandes Cabral, D. T., Sun, X., Celtikci, E., Wang, E., Snyderman, C., Gardner, P. A., Fernandez-Miranda, J. C. 2019; 16 (5): 557–70

  Abstract

  BACKGROUND: The endoscopic endonasal approach (EEA) was recently added to the neurosurgical armamentarium as an alternative approach to the petrous apex (PA) region. However, the maximal extension, anatomical landmarks, and indications of this procedure remain to be established.OBJECTIVE: To investigate the limitations and suggest a classification of PA lesions for endoscopic petrosectomy.METHODS: Five anatomical specimens were dissected with EEA to the PA. Anatomical landmarks for the surgical steps and maximal limits were noted. Pre- and postprocedural computed tomographic scan and image-guidance were used. Relevant surgical cases were reviewed and presented.RESULTS: We defined 3 types of petrosectomy: medial, inferior, and inferomedial. Medial petrosectomy was limited within the paraclival internal carotid artery (ICA) anteriorly, lacerum ICA inferiorly, abducens nerve superiorly, and petrous ICA laterally. Among those, abducens nerve and petrous ICA are surgical limits. Full skeletonization of the paraclival ICA and removal of the lingual process are essential for better access to the medial aspect of PA. Inferior petrosectomy was defined by the lacerum foramen synchondrosis anteriorly, jugular foramen inferiorly, internal acoustic canal posteriorly, and PA superolaterally. Those are surgical limits except for the foramen lacerum synchondrosis. The connective tissue at the pterygosphenoidal fissure was a key landmark for the sublacerum approach. Clinical cases in 3 types of PA lesions were presented.CONCLUSION: The EEA provides access to the medial and inferior aspects of the PA. Several technical maneuvers, including paraclival and lacerum ICA skeletonization, sublacerum approach, and lingual process removal, are key to maximize PA drilling.

  View details for PubMedID 30982905

• Endoscopic Endonasal Petrosectomy: Anatomical Investigation, Limitations, and Surgical Relevance OPERATIVE NEUROSURGERY Borghei-Razavi, H., Truong, H. Q., Cabral, D., Sun, X., Celtikci, E., Wang, E., Snyderman, C., Gardner, P. A., Fernandez-Miranda, J. C. 2019; 16 (5): 557–69

  View details for DOI 10.1093/ons/opy195

  View details for Web of Science ID 000483189900018

• Lateral Transorbital Versus Endonasal Transpterygoid Approach to the Lateral Recess of the Sphenoid Sinus-A Comparative Anatomic Study Alves-Belo, J. T., Mangussi-Gomes, J., Truong, H. Q., Cohen, S., Gardner, P. A., Snyderman, C. H., Stefko, S., Wang, E. W., Fernandez-Miranda, J. C. OXFORD UNIV PRESS INC. 2019: 600–606

  View details for DOI 10.1093/ons/opy211

  View details for Web of Science ID 000483189900026

• Prospective validation of a molecular prognostication panel for clival chordoma JOURNAL OF NEUROSURGERY Zenonos, G. A., Fernandez-Miranda, J. C., Mukherjee, D., Chang, Y., Panayidou, K., Snyderman, C. H., Wang, E. W., Seethala, R. R., Gardner, P. A. 2019; 130 (5): 1528–37

  View details for DOI 10.3171/2018.3.JNS172321

  View details for Web of Science ID 000466401100015

• Full tractography for detecting the position of cranial nerves in preoperative planning for skull base surgery: technical note. Journal of neurosurgery Jacquesson, T., Yeh, F., Panesar, S., Barrios, J., Attye, A., Frindel, C., Cotton, F., Gardner, P., Jouanneau, E., Fernandez-Miranda, J. C. 2019: 1–11

  Abstract

  OBJECTIVEDiffusion imaging tractography has allowed the in vivo description of brain white matter. One of its applications is preoperative planning for brain tumor resection. Due to a limited spatial and angular resolution, it is difficult for fiber tracking to delineate fiber crossing areas and small-scale structures, in particular brainstem tracts and cranial nerves. New methods are being developed but these involve extensive multistep tractography pipelines including the patient-specific design of multiple regions of interest (ROIs). The authors propose a new practical full tractography method that could be implemented in routine presurgical planning for skull base surgery.METHODSA Philips MRI machine provided diffusion-weighted and anatomical sequences for 2 healthy volunteers and 2 skull base tumor patients. Tractography of the full brainstem, the cerebellum, and cranial nerves was performed using the software DSI Studio, generalized-q-sampling reconstruction, orientation distribution function (ODF) of fibers, and a quantitative anisotropy-based generalized deterministic algorithm. No ROI or extensive manual filtering of spurious fibers was used. Tractography rendering was displayed in a tridimensional space with directional color code. This approach was also tested on diffusion data from the Human Connectome Project (HCP) database.RESULTSThe brainstem, the cerebellum, and the cisternal segments of most cranial nerves were depicted in all participants. In cases of skull base tumors, the tridimensional rendering permitted the visualization of the whole anatomical environment and cranial nerve displacement, thus helping the surgical strategy.CONCLUSIONSAs opposed to classical ROI-based methods, this novel full tractography approach could enable routine enhanced surgical planning or brain imaging for skull base tumors.

  View details for PubMedID 31003214

• Endoscopic endonasal transoculomotor triangle approach for adenomas invading the parapeduncular space: surgical anatomy, technical nuances, and case series JOURNAL OF NEUROSURGERY Nunes, C., Lieber, S., Truong, H. Q., Zenonos, G., Wang, E. W., Snyderman, C. H., Gardner, P. A., Fernandez-Miranda, J. C. 2019; 130 (4): 1304–14

  Abstract

  OBJECTIVEPituitary adenomas may extend into the parapeduncular space by invading through the roof of the cavernous sinus. Currently, a transcranial approach is the preferred choice, with or without the combination of an endonasal approach. In this paper the authors present a novel surgical approach that takes advantage of the natural corridor provided by the tumor to further open the oculomotor triangle and resect tumor extension into the parapeduncular space.METHODSSix injected specimens were used to demonstrate in detail the surgical anatomy related to the approach. Four cases in which the proposed approach was used were retrospectively reviewed.RESULTSFrom a technical perspective, the first step involves accessing the superior compartment of the cavernous sinus. The interclinoid ligament should be identified and the dura forming the oculomotor triangle exposed. The oculomotor dural opening may be then extended posteriorly toward the posterior petroclinoidal ligament and inferolaterally toward the anterior petroclinoidal ligament. The oculomotor nerve should then be identified; in this series it was displaced superomedially in all 4 cases. The posterior communicating artery should also be identified to avoid its injury. In all 4 cases, the tumor invading the parapeduncular space was completely removed. There were no vascular injuries and only 1 patient had a partial oculomotor nerve palsy that completely resolved in 2 weeks.CONCLUSIONSThe endoscopic endonasal transoculomotor approach is an original alternative for removal of tumor extension into the parapeduncular space in a single procedure. The surgical corridor is increased by opening the dura of the oculomotor triangle and by working below and lateral to the cisternal segment of the oculomotor nerve.

  View details for PubMedID 29652231

• Machine Learning Versus Logistic Regression Methods for 2-Year Mortality Prognostication in a Small, Heterogeneous Glioma Database. World neurosurgery: X Panesar, S. S., D'Souza, R. N., Yeh, F., Fernandez-Miranda, J. C. 2019; 2: 100012

  Abstract

  Background: Machine learning (ML) is the application of specialized algorithms to datasets for trend delineation, categorization, or prediction. ML techniques have been traditionally applied to large, highly dimensional databases. Gliomas are a heterogeneous group of primary brain tumors, traditionally graded using histopathologic features. Recently, the World Health Organization proposed a novel grading system for gliomas incorporating molecular characteristics. We aimed to study whether ML could achieve accurate prognostication of 2-year mortality in a small, highly dimensional database of patients with glioma.Methods: We applied 3 ML techniques (artificial neural networks [ANNs], decision trees [DTs], and support vector machines [SVMs]) and classical logistic regression (LR) to a dataset consisting of 76 patients with glioma of all grades. We compared the effect of applying the algorithms to the raw database versus a database where only statistically significant features were included into the algorithmic inputs (feature selection).Results: Raw input consisted of 21 variables and achieved performance of accuracy/area (C.I.) under the curve of 70.7%/0.70 (49.9-88.5) for ANN, 68%/0.72 (53.4-90.4) for SVM, 66.7%/0.64 (43.6-85.0) for LR, and 65%/0.70 (51.6-89.5) for DT. Feature selected input consisted of 14 variables and achieved performance of 73.4%/0.75 (62.9-87.9) for ANN, 73.3%/0.74 (62.1-87.4) for SVM, 69.3%/0.73 (60.0-85.8) for LR, and 65.2%/0.63 (49.1-76.9) for DT.Conclusions: We demonstrate that these techniques can also be applied to small, highly dimensional datasets. Our ML techniques achieved reasonable performance compared with similar studies in the literature. Although local databases may be small versus larger cancer repositories, we demonstrate that ML techniques can still be applied to their analysis; however, traditional statistical methods are of similar benefit.

  View details for DOI 10.1016/j.wnsx.2019.100012

  View details for PubMedID 31218287

• Results of a prospective multicenter controlled study comparing surgical outcomes of microscopic versus fully endoscopic transsphenoidal surgery for nonfunctioning pituitary adenomas: the Transsphenoidal Extent of Resection (TRANSSPHER) Study. Journal of neurosurgery Little, A. S., Kelly, D. F., White, W. L., Gardner, P. A., Fernandez-Miranda, J. C., Chicoine, M. R., Barkhoudarian, G., Chandler, J. P., Prevedello, D. M., Liebelt, B. D., Sfondouris, J., Mayberg, M. R., TRANSSPHER Study Group 2019: 1–11

  Abstract

  OBJECTIVEMany surgeons have adopted fully endoscopic over microscopic transsphenoidal surgery for nonfunctioning pituitary tumors, although no high-quality evidence demonstrates superior patient outcomes with endoscopic surgery. The goal of this analysis was to compare these techniques in a prospective multicenter controlled study.METHODSExtent of tumor resection was compared after endoscopic or microscopic transsphenoidal surgery in adults with nonfunctioning adenomas. The primary end point was gross-total tumor resection determined by postoperative MRI. Secondary end points included volumetric extent of tumor resection, pituitary hormone outcomes, and standard quality measures.RESULTSSeven pituitary centers and 15 surgeons participated in the study. Of the 530 patients screened, 260 were enrolled (82 who underwent microscopic procedures, 177 who underwent endoscopic procedures, and 1 who cancelled surgery) between February 2015 and June 2017. Surgeons who used the microscopic technique were more experienced than the surgeons who used the endoscopic technique in terms of years in practice and number of transsphenoidal surgeries performed (p < 0.001). Gross-total resection was achieved in 80.0% (60/75) of microscopic surgery patients and 83.7% (139/166) of endoscopic surgery patients (p = 0.47, OR 0.8, 95% CI 0.4-1.6). Volumetric extent of resection, length of stay, surgery-related deaths, and unplanned readmission rates were similar between groups (p > 0.2). New hormone deficiency was present at 6 months in 28.4% (19/67) of the microscopic surgery patients and 9.7% (14/145) of the endoscopic surgery patients (p < 0.001, OR 3.7, 95% CI 1.7-7.7). Microscopic surgery cases were significantly shorter in duration than endoscopic surgery cases (p < 0.001).CONCLUSIONSExperienced surgeons who performed microscopic surgery and less experienced surgeons who performed endoscopic surgery achieved similar extents of tumor resection and quality outcomes in patients with nonfunctioning pituitary adenomas. The endoscopic technique may be associated with lower rates of postoperative pituitary gland dysfunction. This study generally supports the transition to endoscopic pituitary surgery when the procedure is performed by proficient surgeons, although both techniques yield overall acceptable surgical outcomes.■ CLASSIFICATION OF EVIDENCE Type of question: therapeutic; study design: prospective cohort trial; evidence: class III.Clinical trial registration no.: NCT02357498 (clinicaltrials.gov).

  View details for PubMedID 30901746

• Artificial Intelligence and the Future of Surgical Robotics. Annals of surgery Panesar, S., Cagle, Y., Chander, D., Morey, J., Fernandez-Miranda, J., Kliot, M. 2019

  View details for PubMedID 30907754

• Validation of training levels in endoscopic endonasal surgery of the skull base. The Laryngoscope Lavigne, P., Faden, D., Gardner, P. A., Fernandez-Miranda, J. C., Wang, E. W., Snyderman, C. H. 2019

  Abstract

  OBJECTIVE: A five-level training program was first proposed 10years ago for surgeons learning endoscopic endonasal surgery (EES) of the skull base. Levels were based on the complexity of anatomy, risk of neurovascular injury, intradural dissection, technical difficulty and vascularity of tumors.METHOD: A three-phase validation concept is proposed: 1) face validity (the classification is related to clinically significant elements), 2) construct validity (the classification predicts the outcome), and 3) inter-team validation (the classification applies to other surgical teams). Consecutive cases over a 1-year time span were retrospectively classified. Primary outcome measures included: complication rates (cranial nerve injury, stroke and vascular injury, cerebrospinal fluid [CSF] leak and infection), estimated blood loss and duration of surgery.RESULTS: Two hundred and nine consecutive cases were analyzed. The distribution of cases for each category was: 63 cases in level II, 70 cases in level III, 66 cases in level IV, and 10 cases in level V. Construct validity demonstrated statistical difference with increasing rate of complications from level II to level III and from level III to level IV; also, specific rates of cranial nerve injury and CSF leak increased between levels III and IV. Face validity identified 162 citations since publication of the original article. Inter-team validation demonstrated no difference between two teams of surgeons.CONCLUSION: This study provides a three-phase validation of training levels for endoscopic skull base surgery. Adoption of a progressive systematic approach to learning EES from least complex to advanced procedures is expected to minimize the risks while surgical teams gain experience.LEVEL OF EVIDENCE: 3. Laryngoscope, 2019.

  View details for PubMedID 30843604

• Left Pan-Hippocampal Low Grade Glioma2-Stage Transsylvian Transventricular and Paramedian Supracerebellar Transtentorial Approaches: 2-Dimensional Operative Video OPERATIVE NEUROSURGERY Fernandez-Miranda, J. C. 2019; 16 (3): E82

  View details for DOI 10.1093/ons/opy214

  View details for Web of Science ID 000468599200005

• Structure, asymmetry, and connectivity of the human temporo-parietal aslant and vertical occipital fasciculi BRAIN STRUCTURE & FUNCTION Panesar, S. S., Belo, J. A., Yeh, F., Fernandez-Miranda, J. C. 2019; 224 (2): 907-923

  View details for DOI 10.1007/s00429-018-1812-0

  View details for Web of Science ID 000461379400028

• Supracerebellar Infratentorial and Occipital Transtentorial Approaches to the Pulvinar: Ipsilateral Versus Contralateral Corridors OPERATIVE NEUROSURGERY Cohen-Cohen, S., Cohen-Gadol, A. A., Gomez-Amador, J. L., Alves-Belo, J. T., Shah, K. J., Fernandez-Miranda, J. C. 2019; 16 (3): 351–59

  View details for DOI 10.1093/ons/opy173

  View details for Web of Science ID 000468599200027

• Supratotal Resection of Residual Clival Chordoma With Combined Endoscopic Endonasal and Contralateral Transmaxillary Approaches: 2-Dimensional Operative Video OPERATIVE NEUROSURGERY Lavigne, P., Wang, E. W., Fernandez-Miranda, J. C. 2019; 16 (3): E88

  View details for DOI 10.1093/ons/opy220

  View details for Web of Science ID 000468599200009

• Paramedian Supracerebellar Approach in Semi-Sitting Position for Endoscopic Resection of Pineal Cyst: 2-Dimensional Operative Video OPERATIVE NEUROSURGERY Fernandez-Miranda, J. C. 2019; 16 (3): E79

  View details for DOI 10.1093/ons/opy216

  View details for Web of Science ID 000468599200002

• Endoscopic endonasal surgery for epidermoid and dermoid cysts: a 10-year experience JOURNAL OF NEUROSURGERY Vaz-Guimaraes, F., Koutourousiou, M., de Almeida, J. R., Tyler-Kabara, E. C., Fernandez-Miranda, J. C., Wang, E. W., Snyderman, C. H., Gardner, P. A. 2019; 130 (2): 368–78

  Abstract

  OBJECTIVEEpidermoid and dermoid cysts may be found along the cranial base and are commonly resected via open transcranial approaches. The use of endoscopic endonasal approaches for resection of these tumors has been rarely reported.METHODSThe authors retrospectively reviewed the medical records of 21 patients who underwent endoscopic endonasal surgery for epidermoid and dermoid cyst resection at the University of Pittsburgh Medical Center between January 2005 and June 2014. Surgical outcomes and variables that might affect the extent of resection and complications were analyzed.RESULTSTotal resection (total removal of cyst contents and capsule) was achieved in 8 patients (38.1%), near-total resection (total removal of cyst contents, incomplete removal of cyst capsule) in 9 patients (42.9%), and subtotal resection (incomplete removal of cyst contents and capsule) in 4 patients (19%). Larger cyst volume (≥ 3 cm3) and intradural location (15 cysts) were significantly associated with nontotal resection (p = 0.008 and 0.0005, respectively). In the whole series, surgical complications were seen in 6 patients (28.6%). No complications were observed in patients with extradural cysts. Among the 15 patients with intradural cysts, the most common surgical complication was postoperative CSF leak (5 patients, 33.3%), followed by postoperative intracranial infection (4 patients, 26.7%). Larger cysts and postoperative CSF leak were associated with intracranial infection (p = 0.012 and 0.028, respectively). Subtotal resection was marginally associated with intracranial infection when compared with total resection (p = 0.091). All patients with neurological symptoms improved postoperatively with the exception of 1 patient with unchanged abducens nerve palsy.CONCLUSIONSEndoscopic endonasal approaches may be effectively used for resection of epidermoid and dermoid cysts in carefully selected cases. These approaches are recommended for cases in which a total or near-total resection is possible in addition to a multilayer cranial base reconstruction with vascularized tissue to minimize the risk of intracranial infection.

  View details for PubMedID 29547084

• Endonasal Suturing of Nasoseptal Flap to Nasopharyngeal Fascia Using the V-Loc (TM) Wound Closure Device: 2-Dimensional Operative Video OPERATIVE NEUROSURGERY Zwagerman, N. T., Geltzeiler, M. N., Wang, E. W., Fernandez-Miranda, J. C., Snyderman, C. H., Gardner, P. A. 2019; 16 (2): E40–E41

  View details for DOI 10.1093/ons/opy146

  View details for Web of Science ID 000483181700001

• Evaluation of Surgical Resection Goal and Its Relationship to Extent of Resection and Patient Outcomes in a Multicenter Prospective Study of Patients With Surgically Treated, Nonfunctioning Pituitary Adenomas: A Case Series. Operative neurosurgery (Hagerstown, Md.) Little, A. S., Chicoine, M. R., Kelly, D. F., Sarris, C. E., Mooney, M. A., White, W. L., Gardner, P. A., Fernandez-Miranda, J. C., Barkhoudarian, G. n., Chandler, J. P., Prevedello, D. M., Liebelt, B. D., Sfondouris, J. n., Mayberg, M. R. 2019

  Abstract

  The influence of the surgeon's preoperative goal regarding the extent of tumor resection on patient outcomes has not been carefully studied among patients with nonfunctioning pituitary adenomas.To analyze the relationship between surgical tumor removal goal and patient outcomes in a prospective multicenter study.Centrally adjudicated extent of tumor resection (gross total resection [GTR] and subtotal resection [STR]) data were analyzed using standard univariate and multivariable analyses.GTR was accomplished in 148 of 171 (86.5%) patients with planned GTR and 32 of 50 (64.0%) patients with planned STR (P = .001). Sensitivity, specificity, positive predictive value, and negative predictive value of GTR goal were 82.2, 43.9, 86.5, and 36.0%, respectively. Knosp grade 0-2, first surgery, and being an experienced surgeon were associated with surgeons choosing GTR as the goal (P < .01). There was no association between surgical goal and presence of pituitary deficiency at 6 mo (P = .31). Tumor Knosp grade (P = .004) and size (P = .001) were stronger predictors of GTR than was surgical goal (P = .014). The most common site of residual tumor was the cavernous sinus (29 of 41 patients; 70.1%).This is the first pituitary surgery study to examine surgical goal regarding extent of tumor resection and associated patient outcomes. Surgical goal is a poor predictor of actual tumor resection. A more aggressive surgical goal does not correlate with pituitary gland dysfunction. A better understanding of the ability of surgeons to meet their expectations and of the factors associated with surgical result should improve prognostication and preoperative counseling.

  View details for PubMedID 31079156

• Endoscopic anterior transmaxillary "transalisphenoid" approach to Meckel's cave and the middle cranial fossa: an anatomical study and clinical application JOURNAL OF NEUROSURGERY Truong, H. Q., Sun, X., Celtikci, E., Borghei-Razavi, H., Wang, E. W., Snyderman, C. H., Gardner, P. A., Fernandez-Miranda, J. C. 2019; 130 (1): 227-237

  View details for DOI 10.3171/2017.8.JNS171308

  View details for Web of Science ID 000454604000027

• Tractography for Surgical Neuro-Oncology Planning: Towards a Gold Standard NEUROTHERAPEUTICS Panesar, S. S., Abhinav, K., Yeh, F., Jacquesson, T., Collins, M., Fernandez-Miranda, J. 2019; 16 (1): 36-51

  View details for DOI 10.1007/s13311-018-00697-x

  View details for Web of Science ID 000457460900005

• Endoscopic Surgical Anatomy of the Cavernous Sinus TRANSNASAL ENDOSCOPIC SKULL BASE AND BRAIN SURGERY: SURGICAL ANATOMY AND ITS APPLICATIONS, 2ND EDITION Lieber, S., Fernandez-Miranda, J. C., Stamm, A. C. 2019: 313–24

  View details for Web of Science ID 000571426100035

• Endoscopic Transnasal Approaches to the Skull Base and Brain: Classifications and its Applications TRANSNASAL ENDOSCOPIC SKULL BASE AND BRAIN SURGERY: SURGICAL ANATOMY AND ITS APPLICATIONS, 2ND EDITION Snyderman, C. H., Wang, E. W., Fernandez-Miranda, J. C., Gardner, P. A., Stamm, A. C. 2019: 93–103

  View details for Web of Science ID 000571426100011

• Skull Base Reconstruction: An Overview TRANSNASAL ENDOSCOPIC SKULL BASE AND BRAIN SURGERY: SURGICAL ANATOMY AND ITS APPLICATIONS, 2ND EDITION Mangussi-Gomes, J., Stamm, A. C., Snyderman, C. H., Fernandez-Miranda, J. C., Gardner, P. A., Wang, E. W., Stamm, A. C. 2019: 595–603

  View details for Web of Science ID 000571426100068

• Endoscopic Endonasal Approach for Olfactory Groove Meningiomas TRANSNASAL ENDOSCOPIC SKULL BASE AND BRAIN SURGERY: SURGICAL ANATOMY AND ITS APPLICATIONS, 2ND EDITION Gardner, P. A., Fernandez-Miranda, J. C., Snyderman, C. H., Wang, E. W., Stamm, A. C. 2019: 219–26

  View details for Web of Science ID 000571426100025

• Endonasal Endoscopic Transplanum/Transtuberculum Approach: Surgical Anatomy (Step by Step) and Technical Nuances TRANSNASAL ENDOSCOPIC SKULL BASE AND BRAIN SURGERY: SURGICAL ANATOMY AND ITS APPLICATIONS, 2ND EDITION Lieber, S., Wang, W., Nunez, M., Cohen, S. C., Fernandez-Miranda, J. C., Stamm, A. C. 2019: 240–52

  View details for Web of Science ID 000571426100027

• Automatic Removal of False Connections in Diffusion MRI Tractography Using Topology-Informed Pruning (TIP) NEUROTHERAPEUTICS Yeh, F., Panesar, S., Barrios, J., Fernandes, D., Abhinav, K., Meola, A., Fernandez-Miranda, J. C. 2019; 16 (1): 52–58

  View details for DOI 10.1007/s13311-018-0663-y

  View details for Web of Science ID 000457460900006

• Effect of oxidized cellulose on human respiratory mucosa and submucosa and its implications for endoscopic skull-base approaches. International forum of allergy & rhinology Goldschmidt, E. n., Schneck, M. n., Gau, D. M., Carey, L. n., Rasmussen, J. n., Ferreyro, B. n., Ajler, P. n., Snyderman, C. n., Wang, E. n., Fernandez-Miranda, J. n., Gardner, P. A. 2019

  Abstract

  Regenerated oxidized cellulose (ROC) sheets have gained popularity as an adjunct to a vascularized nasoseptal flap for closure of dural defects after endoscopic endonasal skull-base approaches (EESBS). However, evidence supporting its impact on the healing process is uncertain. This study was performed to evaluate the impact of ROC on the nasal mucosa and assess its effects on tissue pH, structure, and cell viability.In 5 patients, a 1-cm2 piece of ROC gauze was placed on the surface of the middle turbinate before it was resected as part of a standard EESBS. Mucosa treated with ROC was separated from untreated mucosa and a histologic examination of structural changes in the respiratory epithelium was performed. To assess the effect of ROC on pH, increasing amounts of ROC were added to culture medium. Nasal fibroblasts viability was assessed in the presence of ROC before and after the pH was neutralized.Compared with unexposed controls, treated mucosa exhibited a higher incidence of cell necrosis and epithelial cell detachment. When added to Dulbecco's modified Eagle medium, ROC caused a dose-dependent decrease in pH of the medium. Only 1 ± 0.8% of cultured fibroblasts exposed to the ROC-induced acidic medium were alive, whereas 98.25 ± 0.5% of the cells were viable when the pH was neutralized (p < 0.001).ROC applied in vivo to nasal mucosa induced epithelial necrosis likely by diminishing the medium pH, because pH neutralization prevents its effect. The ultimate effect of this material on the healing process is yet to be determined.

  View details for DOI 10.1002/alr.22495

  View details for PubMedID 31856397

• Endoscopic Nasopharyngectomy Combined with a Nerve-sparing Transpterygoid Approach. The Laryngoscope Geltzeiler, M. n., Turner, M. n., Rimmer, R. n., Zenonos, G. n., Hebert, A. n., Snyderman, C. n., Gardner, P. n., Fernandez-Miranda, J. n., Wang, E. W. 2019

  Abstract

  Surgical management of nasopharyngeal tumors has evolved in the endoscopic era. Lateral exposure remains difficult especially near the petrous internal carotid artery and bony Eustachian tube (ET). Our study examines the need to sacrifice the vidian and greater palatine nerves in order to successfully perform en bloc endoscopic nasopharyngectomy.Four cadaveric specimens (eight sides) were dissected bilaterally using a binarial, extended, endoscopic endonasal approach (EEA). Nasopharyngectomy was completed including an extended transptyergoid approach for resection of the cartilaginous ET at its junction with the bony ET. Dissection was attempted without sacrifice of the vidian or palatine nerves.Successful en bloc nasopharyngectomy combined with a nerve-sparing transpterygoid approach was achieved in all specimens with successful preservation of the palatine and vidian nerves. The approach provided exposure of foramen lacerum, the petrous carotid, foramen spinosum, and foramen ovale as well as all segments of the cartilaginous Eustachian tube, Meckel's cave and the parapharyngeal carotid. There was no inadvertent exposure or injury of the internal carotid artery.Endoscopic nasopharyngectomy combined with a nerve-sparing transpterygoid approach allows for en bloc resection of the cartilaginous Eustachian tube and nasopharyngeal contents with broad skull base exposure and preservation of the internal carotid artery, vidian and palatine nerves.VI Laryngoscope, 2019.

  View details for DOI 10.1002/lary.28479

  View details for PubMedID 31841236

• Patient-specific 3-dimensionally printed models for neurosurgical planning and education. Neurosurgical focus Panesar, S. S., Magnetta, M. n., Mukherjee, D. n., Abhinav, K. n., Branstetter, B. F., Gardner, P. A., Iv, M. n., Fernandez-Miranda, J. C. 2019; 47 (6): E12

  Abstract

  Advances in 3-dimensional (3D) printing technology permit the rapid creation of detailed anatomical models. Integration of this technology into neurosurgical practice is still in its nascence, however. One potential application is to create models depicting neurosurgical pathology. The goal of this study was to assess the clinical value of patient-specific 3D printed models for neurosurgical planning and education.The authors created life-sized, patient-specific models for 4 preoperative cases. Three of the cases involved adults (2 patients with petroclival meningioma and 1 with trigeminal neuralgia) and the remaining case involved a pediatric patient with craniopharyngioma. Models were derived from routine clinical imaging sequences and manufactured using commercially available software and hardware.Life-sized, 3D printed models depicting bony, vascular, and neural pathology relevant to each case were successfully manufactured. A variety of commercially available software and hardware were used to create and print each model from radiological sequences. The models for the adult cases were printed in separate pieces, which had to be painted by hand, and could be disassembled for detailed study, while the model for the pediatric case was printed as a single piece in separate-colored resins and could not be disassembled for study. Two of the models were used for patient education, and all were used for presurgical planning by the surgeon.Patient-specific 3D printed models are useful to neurosurgical practice. They may be used as a visualization aid for surgeons and patients, or for education of trainees.

  View details for DOI 10.3171/2019.9.FOCUS19511

  View details for PubMedID 31786547

• Pituitary gland recovery following fully endoscopic transsphenoidal surgery for nonfunctioning pituitary adenoma: results of a prospective multicenter study. Journal of neurosurgery Little, A. S., Gardner, P. A., Fernandez-Miranda, J. C., Chicoine, M. R., Barkhoudarian, G. n., Prevedello, D. M., Yuen, K. C., Kelly, D. F. 2019: 1–7

  Abstract

  Recovery from preexisting hypopituitarism after transsphenoidal surgery for pituitary adenoma is an important outcome to investigate. Furthermore, pituitary function has not been thoroughly evaluated after fully endoscopic surgery, and benchmark outcomes have not been clearly established. Here, the authors characterize pituitary gland outcomes with a focus on gland recovery following endoscopic transsphenoidal removal of clinically nonfunctioning adenomas.This multicenter prospective study was conducted at 6 US pituitary centers among adult patients with nonfunctioning pituitary macroadenomas who had undergone endoscopic endonasal pituitary surgery. Pituitary gland function was evaluated 6 months after surgery.The 177 enrolled patients underwent fully endoscopic transsphenoidal surgery; 169 (95.5%) of them were available for follow-up. Ninety-five (56.2%) of the 169 patients had had a preoperative deficiency in at least one hormone axis, and 20/95 (21.1%) experienced recovery in at least one axis at the 6-month follow-up. Patients with adrenal insufficiency were more likely to recover (10/34 [29.4%]) than were those with hypothyroidism (8/72 [11.1%]) or male hypogonadism (5/50 [10.0%]). At the 6-month follow-up, 14/145 (9.7%) patients had developed at least one new deficiency. The study did not identify any predictors of gland recovery (p ≥ 0.20). Permanent diabetes insipidus was observed in 4/166 (2.4%) patients. Predictors of new gland dysfunction included a larger tumor size (p = 0.009) and Knosp grade 3 and 4 (p = 0.051).Fully endoscopic pituitary surgery resulted in improvement of pituitary gland function in a substantial minority of patients. The deficiency from which patients were most likely to recover was adrenal insufficiency. Overall rates of postoperative permanent diabetes insipidus were low. This study provides multicenter benchmark neuroendocrine clinical outcome data for the endoscopic technique.

  View details for DOI 10.3171/2019.8.JNS191012

  View details for PubMedID 31731279

• Commentary: The Nomenclature of Human White Matter Association Pathways: Proposal for a Systematic Taxonomic Anatomical Classification. Frontiers in neuroanatomy Panesar, S. S., Fernandez-Miranda, J. 2019; 13: 61

  View details for DOI 10.3389/fnana.2019.00061

  View details for PubMedID 31244620

• The endoscopic endonasal approach for sinonasal and nasopharyngeal adenoid cystic carcinoma. The Laryngoscope Kashiwazaki, R. n., Turner, M. T., Geltzeiler, M. n., Fernandez-Miranda, J. C., Gardner, P. A., Snyderman, C. H., Wang, E. W. 2019

  Abstract

  To determine factors affecting outcomes for patients with sinonasal and nasopharyngeal adenoid cystic carcinoma (SNACC) treated using the endoscopic endonasal approach (EEA) with preservation of key structures followed by adjuvant radiotherapy (RT).Retrospective case series of 30 patients treated at the University of Pittsburgh between 2000 and 2014. Hospital records were reviewed for clinical and pathologic data. Outcome measures included overall survival (OS), disease-free survival (DFS), local recurrence-free survival (LRFS) and distant metastasis-free survival (DMFS) rates.The majority of patients had T4a and T4b disease (23.3%, and 63.3%). Microscopically positive margins were present in 21 patients (63.6%). Positive margins were present in nine patients (30.0%). The mean and median follow-up were 3.97 and 3.29 years. Five-year OS, DFS, LRFS, and DMFS were 62.66%, 58.45%, 87.54%, and 65.26%. High-/intermediate-grade tumors had worse DFS (P = .023), and LRFS (P = .026) (HR = 4.837, 95% CI, 1.181-19.812). No factors were associated with significantly worse DMFS. No patient suffered CSF leak, optic nerve, or internal carotid injury. The mean and median length of hospital stay was 4.1 days and 2.0 days (range: 0-32 days).Organ-preserving EEA with adjuvant RT for low-grade SNACC offers 5-year survival similar to that reported by other studies, which include radical, open skull base surgery. Patients with high-grade disease do poorly and may benefit from novel treatment strategies. For low-grade disease, organ-preserving EEA with RT may be the best option, offering a balance of survival, quality of life, and decreased morbidity for patients with this difficult-to-cure disease.4 Laryngoscope, 2019.

  View details for DOI 10.1002/lary.28100

  View details for PubMedID 31194275

• Surgical Anatomy of the Subcallosal Artery: Implications for Transcranial and Endoscopic Endonasal Surgery in the Suprachiasmatic Region. Operative neurosurgery (Hagerstown, Md.) Najera, E., Alves Belo, J. T., Truong, H. Q., Gardner, P. A., Fernandez-Miranda, J. C. 2018

  Abstract

  BACKGROUND: Suprachiasmatic subcallosal lesions may have an intimate relationship with the anterior communicating artery (AcomA); injury to AcomA branches can result in basal forebrain infarction and cognitive dysfunction.OBJECTIVE: To evaluate anatomic variations of the AcomA basal perforating branches, especially the subcallosal artery (ScA), for clinical implications when approaching the suprachiasmatic subcallosal region from endonasal and transcranial routes.METHODS: The origin, course, diameter, and branching pattern of the AcomA's perforating branches were studied in 33 specimens from transcranial and endonasal perspectives.RESULTS: The ScA was present in 79% of the specimens as a single dominant artery arising from the posterior/posterosuperior surface of the AcomA, along with hypothalamic arteries (55%), or as a single artery (24%). It coursed posteriorly towards the lamina terminalis region, curving superiorly to the subcallosal area. The ScA gave off many branches to provide the main blood supply to the subcallosal region. Importantly, it supplies the septal/subcallosal region bilaterally. The ScA can be found posterior, superior, or inferior to the AcomA when using a transylvian, interhemispheric, or endonasal approach, respectively. In specimens with no ScA (21%), the median callosal artery (MdCA) was the dominant artery arising from the AcomA. It followed an identical course to the ScA, providing supply to the same structures bilaterally, but its distal extension reached the body/splenium of the corpus callosum. The MdCA is a ScA variant.CONCLUSION: The ScA is a unique vessel because it supplies the septal/subcallosal region bilaterally; preservation of this vessel during surgery is crucial for successful outcomes.

  View details for PubMedID 30561716

• Tractography for Surgical Neuro-Oncology Planning: Towards a Gold Standard. Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics Panesar, S. S., Abhinav, K., Yeh, F., Jacquesson, T., Collins, M., Fernandez-Miranda, J. 2018

  Abstract

  Magnetic resonance imaging tractography permits in vivo visualization of white matter structures. Aside from its academic value, tractography has been proven particularly useful to neurosurgeons for preoperative planning. Preoperative tractography permits both qualitative and quantitative analyses of tumor effects upon surrounding white matter, allowing the surgeon to specifically tailor their operative approach. Despite its benefits, there is controversy pertaining to methodology, implementation, and interpretation of results in this context. High-definition fiber tractography (HDFT) is one of several non-tensor tractography approaches permitting visualization of crossing white matter trajectories at high resolutions, dispensing with the well-known shortcomings of diffusion tensor imaging (DTI) tractography. In this article, we provide an overview of the advantages of HDFT in a neurosurgical context, derived from our considerable experience implementing the technique for academic and clinical purposes. We highlight nuances of qualitative and quantitative approaches to using HDFT for brain tumor surgery planning, and integration of tractography with complementary operative adjuncts, and consider areas requiring further research.

  View details for PubMedID 30542904

• Structure, asymmetry, and connectivity of the human temporo-parietal aslant and vertical occipital fasciculi. Brain structure & function Panesar, S. S., Belo, J. T., Yeh, F., Fernandez-Miranda, J. C. 2018

  Abstract

  We previously proposed a bipartite 'dorsal-ventral' model of human arcuate fasciculus (AF) morphology. This model does not, however, account for the 'vertical,' temporo-parietal subdivision of the AF described in earlier dissection and tractographic studies. In an effort to address the absence of the vertical AF (VAF) within 'dorsal-ventral' nomenclature, we conducted a dedicated tractographic and white-matter dissection study of this tract and another short, vertical, posterior-hemispheric fascicle: the vertical occipital fasciculus (VOF). We conducted atlas-based, non-tensor, deterministic tractography in 30 single subjects from the Human Connectome Project database and verified our results using an average diffusion atlas compiled from 842 separate normal subjects. We also performed white-matter dissection in four post-mortem specimens. Our tractography results demonstrate that the VAF is, in fact, a bipartite system connecting the ventral parietal and temporal regions, with variable connective, and no volumetric lateralization. The VOF is a non-lateralized, non-segmented system connecting lateral occipital areas with basal-temporal regions. Importantly, the VOF was spatially dissociated from the VAF. As the VAF demonstrates no overall connective or volumetric lateralization, we postulate its distinction from the AF system and propose its re-naming to the 'temporo-parietal aslant tract,' (TPAT), with unique dorsal and ventral subdivisions. Our tractography results were supported by diffusion atlas and white-matter dissection findings.

  View details for PubMedID 30542766

• Endoscope-Assisted Retrosigmoid Approach for Cerebellopontine Angle Epidermoid Tumor. Journal of neurological surgery. Part B, Skull base Vaz-Guimaraes, F., Gardner, P. A., Fernandez-Miranda, J. C. 2018; 79 (Suppl 5): S409–S410

  Abstract

  Objectives Surgical resection is the only effective treatment modality for epidermoid tumors. Complete resection with preservation of neurological function must be pursued whenever possible, because it offers a cure for patients. However, the inability to identify hidden remnants, interdigitating around cranial nerves, especially in larger tumors, may be a contributing factor for incomplete resection. This operative video demonstrates the technical nuances in achieving complete resection of a cerebellopontine angle epidermoid tumor via an endoscope-assisted retrosigmoid approach. Design and Setting Operative video of an endoscope-assisted retrosigmoid, approach for complete resection of a cerebellopontine angle epidermoid tumor. The patient was a 16-year-old female, who presented with 1-year history of worsening headaches and imbalance. Her neurological exam was normal, including normal cranial nerve function, and hearing. Radiological evaluation revealed an epidermoid tumor in the right cerebellopontine angle, extending to the interpeduncular cistern. Surgical resection was recommended. Given extension of the tumor across the midline, an endoscope-assisted procedure was planned to increase the odds of complete resection. Results The video demonstrates the surgical technique applied for tumor resection. The patient's clinical symptoms resolved completely after surgery and she remained neurologically intact. Postoperative magnetic resonance imaging (MRI) confirmed complete tumor resection. There were no postoperative complications. Conclusions The use of endoscopic techniques for resection of cerebellopontine angle epidermoid tumor is safe and effective and may increase the odds of complete resection, especially in larger tumors spreading across the midline, by enabling the surgeon clear visualization of deep-seated and contralateral relevant neurovascular structures, not readily accessible by the surgical microscope. The link to the video can be found at: https://youtu.be/X6YP_7OeQQE .

  View details for PubMedID 30456044

• Evaluation of Intranasal Flap Perfusion by Intraoperative Indocyanine Green Fluorescence Angiography Geltzeiler, M., Nakassa, A., Turner, M., Setty, P., Zenonos, G., Hebert, A., Wang, E., Fernandez-Miranda, J., Snyderman, C., Gardner, P. OXFORD UNIV PRESS INC. 2018: 672-676

  View details for DOI 10.1093/ons/opy002

  View details for Web of Science ID 000457600400037

• Left Transsylvian Transcisternal and Transinferior Insular Sulcus Approach for Resection of Uncohippocampal Tumor: 3-Dimensional Operative Video OPERATIVE NEUROSURGERY Fernandez-Miranda, J. C. 2018; 15 (6): E79

  View details for DOI 10.1093/ons/opy106

  View details for Web of Science ID 000457600400003

• Endoscope-Assisted Retrosigmoid Approach for Cerebellopontine Angle Epidermoid Tumor JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Vaz-Guimaraes, F., Gardner, P. A., Fernandez-Miranda, J. C. 2018; 79: S409-S410

  View details for DOI 10.1055/s-0038-1669983

  View details for Web of Science ID 000450452800013

• Evaluation of bendable surgical suction devices made of shape memory alloy for the endonasal transsphenoid removal of pituitary tumors ENT-EAR NOSE & THROAT JOURNAL Grunert, R., Klietz, S., Gardner, P. A., Fernandez-Miranda, J. C., Snyderman, C. H. 2018; 97 (12): 413–16

  Abstract

  In minimally invasive surgeries, it can be difficult to reach desired anatomic areas with rigid instruments, especially when obstacles are present in the surgical corridor (e.g., during transnasal pituitary surgery). We developed a new kind of suction device constructed of the shape-memory alloy Nitinol (nickel titanium), which is adaptable to a patient's specific anatomy. Use of this device minimizes surgical risks by allowing physicians to use an endonasal transsphenoid approach. The suction device, which is equipped with a cannula made of the shape-memory alloy, was planned and manufactured with three different handpiece designs. Experienced pituitary surgeons tested the prototypes in human cadaver skulls and rated the devices on specific questionnaires. The results of their evaluation indicate that this device is a suitable tool for improving the surgical procedure. Its potential benefits include a more effective surgery and reductions in the risk of injury, the duration of surgery, and costs.

  View details for Web of Science ID 000453803200011

  View details for PubMedID 30540892

• Neurosurgery and Manned Spaceflight. Neurosurgery Panesar, S. S., Fernandez-Miranda, J. C., Kliot, M., Ashkan, K. 2018

  Abstract

  There has been a renewed interest in manned spaceflight due to endeavors by private and government agencies. Publicized goals include manned trips to or colonization of Mars. These missions will likely be of long duration, exceeding existing records for human exposure to extra-terrestrial conditions. Participants will be exposed to microgravity, temperature extremes, and radiation, all of which may adversely affect their physiology. Moreover, pathological mechanisms may differ from those of a terrestrial nature. Known central nervous system (CNS) changes occurring in space include rises in intracranial pressure and spinal unloading. Intracranial pressure increases are thought to occur due to cephalad re-distribution of body fluids secondary to microgravity exposure. Spinal unloading in microgravity results in potential degenerative changes to the bony vertebrae, intervertebral discs, and supportive musculature. These phenomena are poorly understood. Trauma is of highest concern due to its potential to seriously incapacitate crewmembers and compromise missions. Traumatic pathology may also be exacerbated in the setting of altered CNS physiology. Though there are no documented instances of CNS pathologies arising in space, existing diagnostic and treatment capabilities will be limited relative to those on Earth. In instances where neurosurgical intervention is required in space, it is not known whether open or endoscopic approaches are feasible. It is obvious that prevention of trauma and CNS pathology should be emphasized. Further research into neurosurgical pathology, its diagnosis, and treatment in space are required should exploratory or colonization missions be attempted.

  View details for PubMedID 30407580

• Endoscopic Endonasal Transclival Approach for Resection of a Pontine Glioma: Surgical Planning, Surgical Anatomy, and Technique OPERATIVE NEUROSURGERY Cabral, D., Zenonos, G. A., Nunez, M., Celtikci, P., Snyderman, C., Wang, E., Gardner, P. A., Fernandez-Miranda, J. C. 2018; 15 (5): 589-599

  View details for DOI 10.1093/ons/opy005

  View details for Web of Science ID 000449390100055

• Iatrogenic seeding of skull base chordoma following endoscopic endonasal surgery JOURNAL OF NEUROSURGERY Cabral, D., Zenonos, G. A., Fernandez-Miranda, J. C., Wang, E. W., Gardner, P. A. 2018; 129 (4): 947–53

  Abstract

  Iatrogenic tumor seeding after open surgery for chordoma has been well described in the literature. The incidence and particularities related to endoscopic endonasal surgery (EES) have not been defined.The authors retrospectively reviewed their experience with EES for clival chordoma, focusing on cases with iatrogenic seeding. The clinical, radiographic, pathological, and molecular characterization data were reviewed.Among 173 EESs performed for clival chordomas at the authors' institution between April 2003 and May 2016, 2 cases complicated by iatrogenic seeding (incidence 1.15%) were identified. The first case was a 10-year-old boy, who presented 21 months after an EES for a multiply recurrent clival chordoma with a recurrence along the left inferior turbinate, distinct from a right petrous apex recurrence. Both appeared as a T2-hypertintense, T1-isointense, and heterogeneously enhancing lesion on MRI. Resection of the inferior turbinate recurrence and debulking of the petrous recurrence were both performed via a purely endoscopic endonasal approach. Unfortunately, the child died 2 years later due progression of disease at the primary site, but with no sign of progression at the seeded site. The second patient was a 79-year-old man with an MRI-incompatible pacemaker who presented 19 months after EES for his clival chordoma with a mass involving the floor of the left nasal cavity that was causing an oro-antral fistula. On CT imaging, this appeared as a homogeneously contrast-enhancing mass eroding the hard palate inferiorly, the nasal septum superiorly, and the nasal process of the maxilla, with extension into the subcutaneous tissue. This was also treated endoscopically (combined transnasal-transoral approach) with resection of the mass, and repair of the fistula by using a palatal and left lateral wall rotational flap. Adjuvant hypofractionated stereotactic CyberKnife radiotherapy was administered using 35 Gy in 5 fractions. No recurrence was appreciated endoscopically or on imaging at the patient's last follow-up, 12 months after this last procedure. In both cases, pathological investigation of the original tumors revealed a fairly aggressive biology with 1p36 deletions, and high Ki-67 levels (10%-15%, and > 20%, respectively). The procedures were performed by a team of right-handed surgeons (otolaryngology and neurosurgery), using a 4-handed technique (in which the endoscope and suction are typically passed through the right nostril, and other instruments are passed through the left nostril without visualization).Although uncommon, iatrogenic seeding occurs during EES for clival chordomas, probably because of decreased visualization during tumor removal combined with mucosal trauma and exposure of subepithelial elements (either inadvertently or because of mucosal flaps). In addition, tumors with more aggressive biology (1p36 deletions, elevated Ki-67, or both) are probably at a higher risk and require increased vigilance on surveillance imaging and endoscopy. Further prospective studies are warranted to evaluate the authors' proposed strategies for decreasing the incidence of iatrogenic seeding after EES for chordomas.

  View details for PubMedID 29271711

• Automatic Removal of False Connections in Diffusion MRI Tractography Using Topology-Informed Pruning (TIP). Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics Yeh, F., Panesar, S., Barrios, J., Fernandes, D., Abhinav, K., Meola, A., Fernandez-Miranda, J. C. 2018

  Abstract

  Diffusion MRI fiber tracking provides a non-invasive method for mapping the trajectories of human brain connections, but its false connection problem has been a major challenge. This study introduces topology-informed pruning (TIP), a method that automatically identifies singular tracts and eliminates them to improve the tracking accuracy. The accuracy of the tractography with and without TIP was evaluated by a team of 6 neuroanatomists in a blinded setting to examine whether TIP could improve the accuracy. The results showed that TIP improved the tracking accuracy by 11.93% in the single-shell scheme and by 3.47% in the grid scheme. The improvement is significantly different from a random pruning (p value <0.001). The diagnostic agreement between TIP and neuroanatomists was comparable to the agreement between neuroanatomists. The proposed TIP algorithm can be used to automatically clean-up noisy fibers in deterministic tractography, with a potential to confirm the existence of a fiber connection in basic neuroanatomical studies or clinical neurosurgical planning.

  View details for PubMedID 30218214

• Population-averaged atlas of the macroscale human structural connectome and its network topology NEUROIMAGE Yeh, F., Panesar, S., Fernandes, D., Meola, A., Yoshino, M., Fernandez-Miranda, J. C., Vettel, J. M., Verstynen, T. 2018; 178: 57–68

  View details for DOI 10.1016/j.neuroimage.2018.05.027

  View details for Web of Science ID 000438467800006

• Lateral Transorbital Versus Endonasal Transpterygoid Approach to the Lateral Recess of the Sphenoid Sinus-A Comparative Anatomic Study. Operative neurosurgery (Hagerstown, Md.) Alves-Belo, J. T., Mangussi-Gomes, J., Truong, H. Q., Cohen, S., Gardner, P. A., Snyderman, C. H., Stefko, S. T., Wang, E. W., Fernandez-Miranda, J. C. 2018

  Abstract

  BACKGROUND: The treatment of cerebrospinal fluid leaks of the lateral recess of the sphenoid sinus (LRSS) faces difficulties due to the deep location of the osseous defect. When treated with craniotomies, brain retraction is a concern. The endoscopic endonasal transpterygoid approach (EETA) is a direct and less invasive procedure; however, it may require transection of the vidian nerve (VN).OBJECTIVE: To investigate the feasibility of a lateral transorbital approach (LTOA) as an alternative pathway to the LRSS that avoids VN sacrifice.METHODS: Six embalmed heads with well-pneumatized LRSS were preselected by inspecting their computed tomography scans. One LTOA and one EETA were performed on 1 side of each specimen. The approaches were compared regarding working distance and neurovascular structures being sacrificed. The working area of the LTOA was also measured.RESULTS: The average working distances were 59.9 (±2.94) mm for the LTOA and 76.4 (±3.99) mm for the EETA (P <.001). The LTOA generated a working area with a diameter of 9 to 14 mm. The EETA demanded the sacrifice of VN and the sphenopalatine artery in all specimens to expose the LRSS. No neurovascular structures were found in the trajectory of the LTOA.CONCLUSION: The LTOA to the LRSS is feasible, with minimal risk of injuring neurovascular structures. It offers a shorter pathway when compared to the EETA. Although the LTOA provides no options for vascularized flap reconstruction, it allows immediate access to muscle grafts. The LTOA may serve as an alternative to treating cerebrospinal fluid leaks of the LRSS.

  View details for PubMedID 30107582

• Supracerebellar Infratentorial and Occipital Transtentorial Approaches to the Pulvinar: Ipsilateral Versus Contralateral Corridors. Operative neurosurgery (Hagerstown, Md.) Cohen-Cohen, S., Cohen-Gadol, A. A., Gomez-Amador, J. L., Alves-Belo, J. T., Shah, K. J., Fernandez-Miranda, J. C. 2018

  Abstract

  BACKGROUND: Due to the critical neurovascular structures that surround the pulvinar, deciding the best surgical approach can be challenging, with multiple options available.OBJECTIVE: To analyze and compare the ipsilateral vs the contralateral version of the 2 main approaches to the cisternal pulvinar surface: paramedian supracerebellar infratentorial (PSCI) and interhemispheric occipital transtentorial (IOT).METHODS: The PSCI and IOT approaches were performed on 7 formalin-fixed adult cadaveric heads to evaluate qualitatively and quantitatively the microsurgical exposure of relevant anatomic structures. We quantitatively measured the corridor distance to our target with each approach.RESULTS: The ipsilateral PSCI approach provided an easier access and a better exposure of the anteromedial portion of the cisternal pulvinar surface. The contralateral approach provided a wider and more accessible exposure of the posterolateral portion of the cisternal pulvinar surface. When protrusion of the posterior parahippocampal gyrus above the free edge of the tentorium was present, the contralateral PSCI approach provided an unobstructed view to both areas. The IOT approach provided a better view of the anteromedial portion of the cisternal pulvinar surface, especially with a contralateral approach.CONCLUSION: Multiple approaches to the pulvinar have been described, modified, and improved. Based on this anatomic study we believe that although the corridor distance with a contralateral approach is longer, the surgical view and access can be better. We recommend the use of a PSCI contralateral approach especially when a significant protrusion of the posterior parahippocampal gyrus is present.

  View details for PubMedID 30010967

• Surgical anatomy of the superior hypophyseal artery and its relevance for endoscopic endonasal surgery. Journal of neurosurgery Truong, H. Q., Najera, E., Zanabria-Ortiz, R., Celtikci, E., Sun, X., Borghei-Razavi, H., Gardner, P. A., Fernandez-Miranda, J. C. 2018: 1–9

  Abstract

  OBJECTIVE The endoscopic endonasal approach has become a routine corridor to the suprasellar region. The superior hypophyseal arteries (SHAs) are intimately related to lesions in the suprasellar space, such as craniopharyngiomas and meningiomas. Here the authors investigate the surgical anatomy and variations of the SHA from the endoscopic endonasal perspective. METHODS Thirty anatomical specimens with vascular injection were used for endoscopic endonasal dissection. The number of SHAs and their origin, course, branching, anastomoses, and areas of supply were collected and analyzed. RESULTS A total of 110 SHAs arising from 60 internal carotid arteries (ICAs), or 1.83 SHAs per ICA (range 0-3), were found. The most proximal SHA always ran in the preinfundibular space and provided the major blood supply to the infundibulum, optic chiasm, and proximal optic nerve; it was defined as the primary SHA (pSHA). The more distal SHA(s), present in 78.3% of sides, ran in the retroinfundibular space and supplied the stalk and may also supply the tuber cinereum and optic tracts. In the two sides (3.3%) in which no SHA was present, the territory was covered by a pair of infundibular arteries originating from the posterior communicating artery. Two-thirds of the pSHAs originated proximal to the distal dural ring; half of these arose from the carotid cave portion of the ICA, whereas the other half originated proximal to the cave. Four branching patterns of the pSHA were recognized, with the most common pattern (41.7%) consisting of three or more branches with a tree-like pattern. Descending branches were absent in 25% of cases. Preinfundibular anastomoses between pSHAs were found in all specimens. Anastomoses between the pSHA and the secondary SHA (sSHA) or the infundibular arteries were found in 75% cases. CONCLUSIONS The first SHA almost always supplies the infundibulum, optic chiasm, and proximal optic nerve and represents the pSHA. Compromising this artery can cause a visual deficit. Unilateral injury to the pSHA is less likely to cause an endocrine deficit given the artery's abundant anastomoses. A detailed understanding of the surgical anatomy of the SHA and its many variations may help surgeons when approaching challenging lesions in the suprasellar region.

  View details for DOI 10.3171/2018.2.JNS172959

  View details for PubMedID 30004277

• Dorsal extensions of the fastigium cerebelli: an anatomical study using magnetic resonance imaging SURGICAL AND RADIOLOGIC ANATOMY Tsutsumi, S., Fernandez-Miranda, J., Ishii, H., Ono, H., Yasumoto, Y. 2018; 40 (7): 829–34

  Abstract

  The fastigium cerebelli is an important topographical landmark for neurosurgeons and radiologists. However, few studies have characterized the morphology of the fastigium cerebelli. We aimed to investigate the fastigium cerebelli using postmortem specimens and magnetic resonance imaging (MRI) in vivo.Three cadaveric brains were midsagittally sectioned for observing the fastigium cerebelli. Additionally, 66 outpatients underwent MRI, including sagittal T1-weighted imaging, axial T2-weighted imaging, and coronal constructive interference in steady-state (CISS) sequence.In the cadaveric specimens, the fastigium cerebelli was observed as a beak-like dorsal protrusion of the fourth ventricle. Its inner surface was observed as a small fovea. On serial CISS images, the fastigium cerebelli consistently possessed a pair of triangular-shaped, dorsal extensions lying parasagittally along the nodule. These extensions were classified as symmetrical, right-side dominant, or left-side dominant. The symmetrical type was the most predominant and comprised 60.6% of the extensions, while the right-side dominant and left-side dominant types comprised 13.6 and 25.8%, respectively. In 91% of the 66 patients, the number of slices covering the entirety of the dorsal extensions were the same on both sides. The fastigial angle (θ) formed by lines tangent to the superior and inferior medullary velums varied widely.The fastigium cerebelli has a pair of dorsal extensions lying parasagittally along the nodule. Coronal CISS sequence is useful in delineating the fastigium cerebelli in vivo.

  View details for PubMedID 29651568

• Prospective validation of a molecular prognostication panel for clival chordoma. Journal of neurosurgery Zenonos, G. A., Mukherjee, D., Chang, Y., Panayidou, K., Snyderman, C. H., Fernandez-Miranda, J. C., Wang, E. W., Seethala, R. R., Gardner, P. A. 2018: 1–10

  Abstract

  OBJECTIVE There are currently no reliable means to predict the wide variability in behavior of clival chordoma so as to guide clinical decision-making and patient education. Furthermore, there is no method of predicting a tumor's response to radiation therapy. METHODS A molecular prognostication panel, consisting of fluorescence in situ hybridization (FISH) of the chromosomal loci 1p36 and 9p21, as well as immunohistochemistry for Ki-67, was prospectively evaluated in 105 clival chordoma samples from November 2007 to April 2016. The results were correlated with overall progression-free survival after surgery (PFSS), as well as progression-free survival after radiotherapy (PFSR). RESULTS Although Ki-67 and the percentages of tumor cells with 1q25 hyperploidy, 1p36 deletions, and homozygous 9p21 deletions were all found to be predictive of PFSS and PFSR in univariate analyses, only 1p36 deletions and homozygous 9p21 deletions were shown to be independently predictive in a multivariate analysis. Using a prognostication calculator formulated by a separate multivariate Cox model, two 1p36 deletion strata (0%-15% and > 15% deleted tumor cells) and three 9p21 homozygous deletion strata (0%-3%, 4%-24%, and ≥ 25% deleted tumor cells) accounted for a range of cumulative hazard ratios of 1 to 56.1 for PFSS and 1 to 75.6 for PFSR. CONCLUSIONS Homozygous 9p21 deletions and 1p36 deletions are independent prognostic factors in clival chordoma and can account for a wide spectrum of overall PFSS and PFSR. This panel can be used to guide management after resection of clival chordomas.

  View details for PubMedID 29905508

• Left Transsylvian Transcisternal and Transinferior Insular Sulcus Approach for Resection of Uncohippocampal Tumor: 3-Dimensional Operative Video. Operative neurosurgery (Hagerstown, Md.) Fernandez-Miranda, J. C. 2018

  Abstract

  The medial temporal lobe can be divided in anterior, middle, and posterior segments. The anterior segment is formed by the uncus and hippocampal head, and it has extra and intraventricular structures. There are 2 main approaches to the uncohippocampal region, the anteromedial temporal lobectomy (Spencer's technique) and the transsylvian selective amygdalohippocampectomy (Yasargil's technique).In this video, we present the case of a 29-yr-old man with new onset of generalized seizures and a contrast-enhancing lesion in the left anterior segment of the medial temporal lobe compatible with high-grade glioma. He had a medical history of cervical astrocytoma at age 8 requiring craniospinal radiation therapy and ventriculoperitoneal shunt placement.The tumor was approached using a combined transsylvian transcisternal and transinferior insular sulcus approach to the extra and intraventricular aspects of the uncohippocampal region. It was resected completely, and the patient was neurologically intact after resection with no further seizures at 6-mo follow-up. The diagnosis was glioblastoma IDH-wild type, for which he underwent adjuvant therapy.Surgical anatomy and technical nuances of this approach are illustrated using a 3-dimensional video and anatomic dissections. The selective approach, when compared to an anteromedial temporal lobectomy, has the advantage of preserving the anterolateral temporal cortex, which is particularly relevant in dominant-hemisphere lesions, and the related fiber tracts, including the inferior fronto-occipital and inferior longitudinal fascicles, and most of the optic radiation fibers. The transsylvian approach, however, is technically and anatomically more challenging and potentially carries a higher risk of vascular injury and vasospasm.Page 1 and figures from Fernandez-Miranda JC et al, Microvascular Anatomy of the Medial Temporal Region: Part 1: Its Application to Arteriovenous Malformation Surgery, Operative Neurosurgery, 2010, Volume 67, issue 3, ons237-ons276, by permission of the Congress of Neurological Surgeons (1:26-1:37 in video).Page 1 from Fernandez-Miranda JC et al, Three-Dimensio-nal Microsurgical and Tractographic Anatomy of the White Matter of the Human Brain, Neurosurgery, 2008, Volume 62, issue suppl_3, SHC989-SHC1028, by permission of the Congress of Neurological Surgeons (1:54-1:56 in video).

  View details for PubMedID 29878277

• A Quantitative Tractography Study Into the Connectivity, Segmentation and Laterality of the Human Inferior Longitudinal Fasciculus FRONTIERS IN NEUROANATOMY Panesar, S. S., Yeh, F., Jacquesson, T., Hula, W., Fernandez-Miranda, J. C. 2018; 12: 47

  Abstract

  The human inferior longitudinal fasciculus (ILF) is a ventral, temporo-occipital association tract. Though described in early neuroanatomical works, its existence was later questioned. Application of in vivo tractography to the neuroanatomical study of the ILF has generally confirmed its existence, however, consensus is lacking regarding its subdivision, laterality and connectivity. Further, there is a paucity of detailed neuroanatomic data pertaining to the exact anatomy of the ILF. Generalized Q-Sampling imaging (GQI) is a non-tensor tractographic modality permitting high resolution imaging of white-matter structures. As it is a non-tensor modality, it permits visualization of crossing fibers and accurate delineation of close-proximity fiber-systems. We applied deterministic GQI tractography to data from 30 healthy subjects and a large-volume, averaged diffusion atlas, to delineate ILF anatomy. Post-mortem white matter dissection was also carried out in three cadaveric specimens for further validation. The ILF was found in all 60 hemispheres. At its occipital extremity, ILF fascicles demonstrated a bifurcated, ventral-dorsal morphological termination pattern, which we used to further subdivide the bundle for detailed analysis. These divisions were consistent across the subject set and within the atlas. We applied quantitative techniques to study connectivity strength of the ILF at its anterior and posterior extremities. Overall, both morphological divisions, and the un-separated ILF, demonstrated strong leftward-lateralized connectivity patterns. Leftward-lateralization was also found for ILF volumes across the subject set. Due to connective and volumetric leftward-dominance and ventral location, we postulate the ILFs role in the semantic system. Further, our results are in agreement with functional and lesion-based postulations pertaining to the ILFs role in facial recognition.

  View details for PubMedID 29922132

• The limits of transsellar/transtuberculum surgery for craniopharyngioma. Journal of neurosurgical sciences Koutourousiou, M., Fernandez-Miranda, J. C., Wang, E. W., Snyderman, C. H., Gardner, P. A. 2018; 62 (3): 301–9

  Abstract

  The proximity of craniopharyngiomas to vital neurovascular structures and their high recurrence rates make them one of the most challenging brain tumors to treat. Although surgery remains the first line of therapy and offers the best chance of radical resection and oncological cure, the high recurrence tendency of craniopharyngiomas, even after apparent total removal, often makes adjuvant treatment essential. The endoscopic endonasal approach (EEA) has been recently introduced as a treatment option for both pediatric and adult craniopharyngiomas, rapidly gaining wide acceptance over the traditional transcranial approaches. Although the primary role of EEA over traditional transcranial approaches has been slowly accepted in the literature, little has been written about the limitations and potential contraindications of this approach in the treatment of craniopharyngiomas. This article presents the advantages and highlights the limitations of endoscopic transsellar/transtuberculum surgery for craniopharyngiomas. In every case, surgery should be tailored to individuals based on their age and comorbidities, presenting symptoms, tumor characteristics, prior treatment and treatment tolerance, as well as the surgeon's preference based on personal experience and comfort.

  View details for PubMedID 29480694

• The limits of transsellar/transtuberculum surgery for craniopharyngioma JOURNAL OF NEUROSURGICAL SCIENCES Koutourousiou, M., Fernandez-Miranda, J. C., Wang, E. W., Snyderman, C. H., Gardner, P. A. 2018; 62 (3): 301-309

  View details for DOI 10.23736/S0390-5616.18.04376-X

  View details for Web of Science ID 000445306200010

• Risk of Postoperative Complications in Patients with Obstructive Sleep Apnea following Skull Base Surgery OTOLARYNGOLOGY-HEAD AND NECK SURGERY Huyett, P., Soose, R. J., Schell, A. E., Fernandez-Miranda, J. C., Gardner, P. A., Snyderman, C. H., Wang, E. W. 2018; 158 (6): 1140–47

  Abstract

  Objectives Obstructive sleep apnea (OSA) presents several challenges in skull base surgery, including increased intracranial pressure, worsened OSA with nasal packing, and avoidance of positive airway pressure (PAP) therapy postoperatively. The objective of this study was to examine the risk of postoperative complications in a skull base population with OSA in which PAP therapy is withheld. Study Design Retrospective cohort study. Setting Tertiary care hospital. Subjects and Methods Medical records of 414 adult patients undergoing anterior skull base procedures between January 1, 2014, and January 7, 2017, were retrospectively reviewed. Revision surgeries, skull base infections, sinus surgery, and orbital cases were excluded. Results Fifty-four (13.0%) patients with a diagnosis of OSA were identified. While the known patients with OSA were more likely to require postoperative supplemental oxygen (odds ratio [OR], 4.29; 95% confidence interval [CI], 2.38-7.75; P < .001), there was no increased risk of serious respiratory events or cerebrospinal fluid leak (CSF). To address the likely underdiagnosis of OSA in this cohort, subgroup analyses were performed of patients at high risk for OSA (body mass index >30 kg/m2 and hypertension) and demonstrated an increased risk of serious respiratory events (OR, 4.41; 95% CI, 1.24-15.7; P = .034) and CSF leak (13.6% vs 4.7%; P = .018). Conclusions Skull base patients with known OSA can be successfully managed with diligent care in the perioperative period when PAP therapy is withheld. However, OSA is likely underdiagnosed in the skull base population, and patients at high risk for undiagnosed OSA may be at the greatest risk for respiratory complications and CSF leak. Increased presurgical awareness and implementation of a perioperative management algorithm is needed.

  View details for PubMedID 29688821

• A Comparative Analysis of Endoscopic-Assisted Transoral and Transnasal Approaches to Parapharyngeal Space: A Cadaveric Study JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Sun, X., Yan, B., Truong, H. Q., Borghei-Razavi, H., Snyderman, C. H., Fernandez-Miranda, J. C. 2018; 79 (3): 229–40

  Abstract

  Background  Surgical resection of parapharyngeal space (PPS) tumors is very challenging. An endoscopic-assisted surgical approach to this region requires detailed and precise anatomic knowledge. The main purpose of this study is to describe and compare the detailed anatomy of the PPS via transnasal transpterygoid (TP) and endoscopic-assisted transoral (TO) approaches. Materials and Methods  Six fresh injected cadaver heads (12 sides) were prepared for dissection of the PPS via TP and TO approaches. Computed tomography (CT) with image-based navigation (Navigation System II; Stryker, Kalamazoo, Michigan, United States) was used to identify bony structures around the PPS. Results  TP and TO approaches could both expose the detailed anatomical structures in the PPS. The TP approach can provide a direct route to the upper PPS, but it is limited inferiorly by the hard palate and laterally by the medial and lateral pterygoid muscles. However, the TO approach can provide a direct route to the lower PPS, but it is difficult to expose the area around the Eustachian tube. The styloglossus and stylopharyngeus muscles could be considered as the safe anterior boundary of the parapharyngeal internal carotid artery (ICA) with the TO approach. Dissection between the stylopharyngeus muscle and the superior pharyngeal constrictor muscle provides direct access to the parapharyngeal ICA. Conclusion  The TP and TO approaches provide new strategies to manage lesions in the PPS. The important neurovascular structures of the PPS could be identified with these approaches. The endoscopic-assisted TO approach can provide direct access to the parapharyngeal ICA.

  View details for PubMedID 29765820

  View details for PubMedCentralID PMC5951712

• Injury of the Carotid Artery during Endoscopic Endonasal Surgery: Surveys of Skull Base Surgeons JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Rowan, N. R., Turner, M. T., Valappil, B., Fernandez-Miranda, J. C., Wang, E. W., Gardner, P. A., Snyderman, C. H. 2018; 79 (3): 302–8

  Abstract

  Objectives  This study aimed to review endoscopic skull base surgeon experience with internal carotid artery (ICA) injuries during endoscopic endonasal surgery (EES) to provide an estimate of the incidence of ICA injury, the associated factors and identify the best training modalities for the management of this complication. Design  Anonymous electronic survey of past participants at a well-established endoscopic skull base surgery course and a global online community of skull base surgeons. Main Outcome Measures  Relative incidence of ICA injuries during EES, associated anatomic and intraoperative factors, and surgeon experience. Results  At least 20% of surgeons in each surveyed population experienced a carotid artery injury. Reported carotid artery injuries were most common during tumor exposure and removal (48%). The parasellar carotid artery was the most commonly injured segment (39%). Carotid artery injuries were more common in high-volume surgeons, but only statistically significant in one of the two populations. Attendance at a skull base course or courses did not change the incidence of carotid artery injury in either surveyed population. In both surveys, respondents preferred live surgeries or active (not computer simulated) training models. Conclusions  ICA injury is underreported and most common when manipulating the parasellar carotid artery for exposure and tumor dissection. Given the high morbidity and mortality associated with these injuries, vascular injury management should be prioritized and taught in a graduated approach by modern endoscopic skull base courses.

  View details for PubMedID 29765829

  View details for PubMedCentralID PMC5951699

• Endonasal Suturing of Nasoseptal Flap to Nasopharyngeal Fascia Using the V-Loc Wound Closure Device: 2-Dimensional Operative Video. Operative neurosurgery (Hagerstown, Md.) Zwagerman, N. T., Geltzeiler, M. N., Wang, E. W., Fernandez-Miranda, J. C., Snyderman, C. H., Gardner, P. A. 2018

  Abstract

  We present a case of cerebrospinal fluid (CSF) leak after endoscopic endonasal resection of a large clival chordoma in an obese patient. The leak was at the lower reconstruction at the craniocervical junction and had failed repositioning. Using the V-Loc wound closure device (Covidien, New Haven, Connecticut) to suture the nasoseptal flap to the nasopharyngeal fascia, a water-tight seal was created and, along with a lumbar drain, the patient healed successfully.CSF leak after an endoscopic endonasal approach (EEA) to intradural pathologies remains one of the more common complications.1-4 Various closure techniques have been developed5-8 with success in mitigating this risk, but all have their limitations and rely on multiple layers including vascularized flaps like the nasoseptal flap.9-11 Endonasal suturing of graft materials offers the advantage of creating a water-tight seal. We present the use of the V-Loc wound closure device (Covidien) to successfully seal a postoperative CSF leak. The absorbable V-Loc wound closure device does not require the surgeon to tie knots, which is the most challenging step in a deep, 2-dimensional corridor. The suture is barbed and is anchored by threading the needle through a prefabricated loop at the end of the suture which locks in place. Each throw of the suture through tissue maintains the suture line as the barbs catch the tissue and prevent retraction. After successful closure, the needle can simply be cut off.The V-Loc wound closure device (Covidien) is a safe and effective adjunct to reconstruction after endoscopic endonasal skull base surgery as it provides an option for graft/flap suturing.A written release from the patient whose name or likeness is submitted as part of this Work is on file.

  View details for PubMedID 29850916

• Population-averaged atlas of the macroscale human structural connectome and its network topology. NeuroImage Yeh, F., Panesar, S., Fernandes, D., Meola, A., Yoshino, M., Fernandez-Miranda, J. C., Vettel, J. M., Verstynen, T. 2018; 178: 57–68

  Abstract

  A comprehensive map of the structural connectome in the human brain has been a coveted resource for understanding macroscopic brain networks. Here we report an expert-vetted, population-averaged atlas of the structural connectome derived from diffusion MRI data (N = 842). This was achieved by creating a high-resolution template of diffusion patterns averaged across individual subjects and using tractography to generate 550,000 trajectories of representative white matter fascicles annotated by 80 anatomical labels. The trajectories were subsequently clustered and labeled by a team of experienced neuroanatomists in order to conform to prior neuroanatomical knowledge. A multi-level network topology was then described using whole-brain connectograms, with subdivisions of the association pathways showing small-worldness in intra-hemisphere connections, projection pathways showing hub structures at thalamus, putamen, and brainstem, and commissural pathways showing bridges connecting cerebral hemispheres to provide global efficiency. This atlas of the structural connectome provides representative organization of human brain white matter, complementary to traditional histologically-derived and voxel-based white matter atlases, allowing for better modeling and simulation of brain connectivity for future connectome studies.

  View details for PubMedID 29758339

• Endoscopic Endonasal and Transcranial Surgery for Microsurgical Resection of Ventral Foramen Magnum Meningiomas: A Preliminary Experience. Operative neurosurgery (Hagerstown, Md.) Khattar, N., Koutourousiou, M., Chabot, J. D., Wang, E. W., Cohen-Gadol, A. A., Snyderman, C. H., Fernandez-Miranda, J. C., Gardner, P. A. 2018; 14 (5): 503–14

  Abstract

  BACKGROUND: Purely ventral foramen magnum meningiomas are challenging tumors to treat given their location, and proximity and relationship to vital neurovascular structures.OBJECTIVE: To present endoscopic endonasal surgery (EES) as a complementary approach to the far-lateral suboccipital approach (FLA) for ventral midline tumors.METHODS: From May 2008 to October 2013, 5 patients underwent EES and 5 FLA for primary ventral foramen magnum meningiomas. We retrospectively reviewed their records to evaluate outcomes.RESULTS: Nine of 10 patients presented with long-tract and lower cranial nerve deficits. All patients who presented with deficits preoperatively completely normalized after tumor resection regardless of approach. Gross total resection was achieved in 2 cases in the EES group and 4 cases in the FLA group (the rest were near total). Vascular encasement was a limitation to gross total resection with both approaches. Preoperative median Karnofsky Performance Scale score was 80 and improved to 100 in both groups. Following EES, 1 patient developed cerebrospinal fluid leak with resultant meningitis. Two patients developed hydrocephalus, one of which developed an epidural abscess following necrosis of the nasoseptal flap, requiring debridement. In the FLA group, 1 patient developed a pseudomeningocele associated with hydrocephalus. One patient developed an abdominal fat graft site hematoma.CONCLUSION: Both approaches provide excellent results for resection of ventral foramen magnum meningiomas, with reconstruction and hydrocephalus as the main sources of complication. In our practice, EES is a preferred technique in ventral, purely midline tumors with limited inferior extension and reduced lower cranial nerve manipulation, whereas FLA is preferred in tumors with lateral and caudal extension below the tip of the dens.

  View details for PubMedID 28973693

• Endoscopic Endonasal and Transcranial Surgery for Microsurgical Resection of Ventral Foramen Magnum Meningiomas: A Preliminary Experience OPERATIVE NEUROSURGERY Khattar, N., Koutourousiou, M., Chabot, J. D., Wang, E. W., Cohen-Gadol, A. A., Snyderman, C. H., Fernandez-Miranda, J. C., Gardner, P. A. 2018; 14 (5): 503-513

  View details for DOI 10.1093/ons/opx160

  View details for Web of Science ID 000449370400011

• Nasoseptal flap necrosis: a rare complication of endoscopic endonasal surgery JOURNAL OF NEUROSURGERY Chabot, J. D., Patel, C. R., Hughes, M. A., Wang, E. W., Snyderman, C. H., Gardner, P. A., Fernandez-Miranda, J. C. 2018; 128 (5): 1463–72

  Abstract

  OBJECTIVE The vascularized nasoseptal flap (NSF) has become the workhorse for skull base reconstruction during endoscopic endonasal surgery (EES) of the ventral skull base. Although infrequently reported, as with any vascularized flap the NSF may undergo ischemic necrosis and become a nidus for infection. The University of Pittsburgh Medical Center's experience with NSF was reviewed to determine the incidence of necrotic NSF in patients following EES and describe the clinical presentation, imaging characteristics, and risk factors associated with this complication. METHODS The electronic medical records of 1285 consecutive patients who underwent EES at the University of Pittsburgh Medical Center between January 2010 and December 2014 were retrospectively reviewed. From this first group, a list of all patients in whom NSF was used for reconstruction was generated and further refined to determine if the patient returned to the operating room and the cause of this reexploration. Patients were included in the final analysis if they underwent endoscopic reexploration for suspected CSF leak or meningitis. Those patients who returned to the operating room for staged surgery or hematoma were excluded. Two neurosurgeons and a neuroradiologist, who were blinded to each other's results, assessed the MRI characteristics of the included patients. RESULTS In total, 601 patients underwent NSF reconstruction during the study period, and 49 patients met the criteria for inclusion in the final analysis. On endoscopic exploration, 8 patients had a necrotic, nonviable NSF, while 41 patients had a viable NSF with a CSF leak. The group of patients with a necrotic, nonviable NSF was then compared with the group with viable NSF. All 8 patients with a necrotic NSF had clinical and laboratory evidence indicative of meningitis compared with 9 of 41 patients with a viable NSF (p < 0.001). Four patients with necrotic flaps developed epidural empyema compared with 2 of 41 patients in the viable NSF group (p = 0.02). The lack of NSF enhancement on MR (p < 0.001), prior surgery (p = 0.043), and the use of a fat graft (p = 0.004) were associated with necrotic NSF. CONCLUSIONS The signs of meningitis after EES in the absence of a clear CSF leak with the lack of NSF enhancement on MRI should raise the suspicion of necrotic NSF. These patients should undergo prompt exploration and debridement of nonviable tissue with revision of skull base reconstruction.

  View details for PubMedID 28731395

• Fluorescence-aided evaluation of nasoseptal flap perfusion Response JOURNAL OF NEUROSURGERY Nakassa, A., Geltzeiler, M. N., Wang, E. W., Snyderman, C. H., Gardner, P. A., Fernandez-Miranda, J. C. 2018; 128 (5): 1596–97

  View details for Web of Science ID 000440650000044

• Diagnosis and endoscopic endonasal management of nontraumatic pseudoaneurysms of the cranial base INTERNATIONAL FORUM OF ALLERGY & RHINOLOGY Faden, D. L., Hughes, M. A., Lavigne, P., Jankowitz, B. T., Wang, E. W., Fernandez-Miranda, J. C., Gardner, P. A., Snyderman, C. H. 2018; 8 (5): 641–47

  Abstract

  Nontraumatic pseudoaneurysms of the cranial base are rare and present unique diagnostic and treatment dilemmas compared with both true aneurysms and pseudoaneurysms outside of the cranial base. There is a dearth of knowledge regarding the management of these complicated lesions.Nontraumatic pseudoaneurysms of the cranial base internal carotid artery (ICA) were retrospectively identified at the University of Pittsburgh Medical Center through a key word search of cranial base cases from 2010 to 2017.Three cases were identified, demonstrating pseudoaneurysms of the cavernous and petrous ICA. Each patient underwent diagnostic work-up with computed tomography, magnetic resonance imaging, and angiography, followed by endovascular occlusion and endoscopic endonasal surgery, which resulted in relief of presenting complaints and ablation of the pseudoaneurysm.Symptomatic cranial base pseudoaneurysms should undergo treatment to obliterate the aneurysm and relieve the mass effect. First, formal angiography is necessary for accurate diagnosis and treatment planning. Next, endovascular occlusion is performed, with a preference for coiling or endoluminal reconstruction with a flow diverter. Last, endoscopic intervention follows in cases where: (1) decompression of vital structures is indicated; (2) diagnosis of the pseudoaneurysm cannot be definitively confirmed with angiography; or (3) the etiology of the confirmed pseudoaneurysm requires further investigation.

  View details for PubMedID 29485762

• The epitrigeminal approach to the brainstem. Journal of neurosurgery Zenonos, G. A., Fernandes-Cabral, D., Nunez, M., Lieber, S., Fernandez-Miranda, J. C., Friedlander, R. M. 2018; 128 (5): 1512–21

  Abstract

  OBJECTIVE Surgical approaches to the ventrolateral pons pose a significant challenge. In this report, the authors describe a safe entry zone to the brainstem located just above the trigeminal entry zone which they refer to as the "epitrigeminal entry zone." METHODS The approach is presented in the context of an illustrative case of a cavernous malformation and is compared with the other commonly described approaches to the ventrolateral pons. The anatomical nuances were analyzed in detail with the aid of surgical images and video, anatomical dissections, and high-definition fiber tractography (HDFT). In addition, using the HDFT maps obtained in 77 normal subjects (154 sides), the authors performed a detailed anatomical study of the surgically relevant distances between the trigeminal entry zone and the corticospinal tracts. RESULTS The patient treated with this approach had a complete resection of his cavernous malformation, and improvement of his symptoms. With regard to the HDFT anatomical study, the average direct distance of the corticospinal tracts from the trigeminal entry zone was 12.6 mm (range 8.7-17 mm). The average vertical distance was 3.6 mm (range -2.3 to 8.7 mm). The mean distances did not differ significantly from side to side, or across any of the groups studied (right-handed, left-handed, and ambidextrous). CONCLUSIONS The epitrigeminal entry zone to the brainstem appears to be safe and effective for treating intrinsic ventrolateral pontine pathological entities. A possible advantage of this approach is increased versatility in the rostrocaudal axis, providing access both above and below the trigeminal nerve. Familiarity with the subtemporal transtentorial approach, and the reliable surgical landmark of the trigeminal entry zone, should make this a straightforward approach.

  View details for DOI 10.3171/2016.12.JNS162561

  View details for PubMedID 28841124

• Risk factors associated with postoperative cerebrospinal fluid leak after endoscopic endonasal skull base surgery JOURNAL OF NEUROSURGERY Fraser, S., Gardner, P. A., Koutourousiou, M., Kubik, M., Fernandez-Miranda, J. C., Snyderman, C. H., Wang, E. W. 2018; 128 (4): 1066–71

  Abstract

  OBJECTIVE The aim in this paper was to determine risk factors for the development of a postoperative CSF leak after an endoscopic endonasal approach (EEA) for resection of skull base tumors. METHODS A retrospective review of patients who underwent EEA for the resection of intradural pathology between January 1997 and June 2012 was performed. Basic demographic data were collected, along with patient body mass index (BMI), tumor pathology, reconstruction technique, lumbar drainage, and outcomes. RESULTS Of the 615 patients studied, 103 developed a postoperative CSF leak (16.7%). Sex and perioperative lumbar drainage did not affect CSF leakage rates. Posterior fossa tumors had the highest rate of CSF leakage (32.6%), followed by anterior skull base lesions (21.0%) and sellar/suprasellar lesions (9.9%) (p < 0.0001). There was a higher leakage rate for overweight and obese patients (BMI > 25 kg/m2) than for those with a healthy-weight BMI (18.7% vs 11.5%; p = 0.04). Patients in whom a pedicled vascularized flap was used for reconstruction had a lower leakage rate than those in whom a free graft was used (13.5% vs 27.8%; p = 0.0015). In patients with a BMI > 25 kg/m2, the use of a pedicled flap reduced the rate of CSF leakage from 29.5% to 15.0% (p = 0.001); in patients of normal weight, this reduction did not reach statistical significance (21.9% [pedicled flap] vs 9.2% [free graft]; p = 0.09). CONCLUSIONS Preoperative BMI > 25 kg/m2 and tumor location in the posterior fossa were associated with higher rates of postoperative CSF leak. Use of a pedicled vascularized flap may be associated with reduced risk of a CSF leak, particularly in overweight patients.

  View details for PubMedID 28598276

• Endoscopic Endonasal Transoculomotor Triangle Approach for the Resection of a Pituitary Adenoma with Ambient Cistern Extension JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Zenonos, G., Wang, E., Fernandez-Miranda, J. C. 2018; 79: S283

  Abstract

  Objectives  The current video presents the nuances of the endoscopic endonasal transoculomotor triangle approach for the resection of a pituitary adenoma with extension into the ambient cistern. Design  The video analyzes the presentation, preoperative workup and imaging, surgical steps and technical nuances of the surgery, the clinical outcome, and follow-up imaging. Setting  The patient was treated by a skull base team consisting of a neurosurgeon and an ENT surgeon at a teaching academic institution. Participants  The case refers to a 62-year-old female who presented with vision loss and headaches, and was found to have a pituitary adenoma with extension into the ambient cistern. Main Outcome Measures  The main outcome measures consist of the reversal of the patient symptoms (headaches), the recurrence-free survival based on imaging, as well as the absence of any complications. Results  The patient's headaches improved. There was no evidence of recurrence. Conclusions  The endoscopic endonasal transoculomotor triangle approach is safe and effective for addressing pituitary tumors which extend into the ambient cistern. The link to the video can be found at: https://youtu.be/EBLwEWhohxY .

  View details for PubMedID 29588903

  View details for PubMedCentralID PMC5868899

• Minimally Invasive Approaches for Anterior Skull Base Meningiomas: Supraorbital Eyebrow, Endoscopic Endonasal, or a Combination of Both? Anatomic Study, limitations, and Surgical Application WORLD NEUROSURGERY Borghei-Razavi, H., Truong, H. Q., Fernandes-Cabral, D. T., Celtikci, E., Chabot, J. D., Stefko, S., Wang, E. W., Snyderman, C. H., Cohen-Gadol, A., Gardner, P. A., Fernandez-Miranda, J. C. 2018; 112: E666–E674

  Abstract

  Minimally invasive accesses to the anterior skull base include the endoscopic endonasal approach (EEA) and the supraorbital eyebrow approach. These 2 are often seen as competing approaches, not alternative or combinatory approaches. In this study, we evaluated the anatomic limitations of each approach and the combined approach for accessing the anterior skull base.Ten neurovascular injected cadaver heads were used for the study. The supraorbital approach to the anterior skull base was performed on 5 heads, and EEA was done on the other 5 heads. Then, the supraorbital approach was added to the 5 heads receiving EEA. Visualization and surgical limitations were recorded by the ability to perform resection of the crista galli, anterior clinoid, cribriform plate, and planum sellae.The maximal lateral extension of EEA for anterior skull base was the midorbit line anteriorly but narrowing down toward the orbital apex. The limitation of the supraorbital approach was found mostly medial and anterior. Drilling of anterior skull base was impossible medially between the sphenoethmoidal suture and the posterior aspect of the crista galli. The combined approach showed complementary areas of visualization and surgical maneuverability. Three clinical cases were presented to illustrate the indications for the stand-alone supraorbital approach, EEA, and combined approach.The limitations of the EEA when dealing with lateral extension of anterior skull base meningiomas, and the limitations of the supraorbital eyebrow approach for medial skull base drilling and reconstruction, can be overcome by a judicious, anatomically based combination of both approaches.

  View details for PubMedID 29378344

• Endoscopic Endonasal Approach for Complex Macroadenoma with Suprasellar and Retrochiasmatic Extension JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Najera, E., Snyderman, C. H., Fernandez-Miranda, J. C. 2018; 79: S284

  Abstract

  In this video, we describe the technical nuances of an endoscopic endonasal approach (EEA) for a complex macroadenoma with suprasellar and retrochiasmatic extension. The patient is a 51-year-old male with several years' history of progressive visual loss. Neuro-ophthalmology assessment revealed a profound visual loss with homonymous hemianopsia and left optic nerve atrophy. His pituitary hormonal profile was normal. The options for surgical approach included transcranial, endoscopic endonasal, or a combination of both. An EEA was the preferred surgical option, because it allows for early identification of the pituitary gland, and provides access to the suprasellar region including pre- and retrochiasmatic spaces, which facilitates tumor removal while minimizing manipulation of the optic apparatus. While most pituitary adenomas do not require extracapsular subarachnoidal dissection, there are complex adenomas with subarachnoidal invasion and multilobulated morphology, such as the one presented here, that require a combination of internal debulking, extracapsular and subarachnoidal dissection. The technique presented here allows for complete tumor resection, avoiding the risk of postoperative apoplexy of residual adenoma, and facilitates identification of perforating branches and neural structures that require meticulous preservation. Here, we also illustrate the proper management of reconstruction-related complications. Postoperative course was complicated with meningitis with necrotic nasoseptal flap and required surgical debridement, new inferior turbinate flap, fascia lata, lumbar drain, and 6-week antibiotic treatment. Imaging follow-up showed complete removal of tumor. The patient had significant improvement in visual fields and left visual acuity, and no postoperative hormonal dysfunction. The link to the video can be found at: https://youtu.be/9T5b167bVJA .

  View details for PubMedID 29588904

  View details for PubMedCentralID PMC5868913

• Evaluation of Intranasal Flap Perfusion by Intraoperative Indocyanine Green Fluorescence Angiography. Operative neurosurgery (Hagerstown, Md.) Geltzeiler, M., Nakassa, A. C., Turner, M., Setty, P., Zenonos, G., Hebert, A., Wang, E., Fernandez-Miranda, J., Snyderman, C., Gardner, P. 2018

  Abstract

  BACKGROUND: Vascularized intranasal flaps are the primary reconstructive option for endoscopic skull base defects. Flap vascularity may be compromised by injury to the pedicle or prior endonasal surgery. There is currently no validated technique for intraoperative evaluation of intranasal flap viability.OBJECTIVE: To evaluate the efficacy of indocyanine green (ICG) near-infrared angiography in predicting the viability of pedicled intranasal flaps during endoscopic skull base surgery through a pilot study.METHODS: ICG near-infrared fluorescence endoscopy was performed during endoscopic endonasal surgery for skull base tumors. Intraoperative and postoperative data were collected regarding enhancement of the flap body and pedicle. Fluorescence was rated qualitatively. Postoperatively, flap perfusion was evaluated via MRI-contrast enhancement in addition to clinical outcomes (cerebrospinal fluid leak and endoscopic flap appearance).RESULTS: Thirty-eight patients underwent ICG fluorescence angiography. Both the body and pedicle enhanced in 20 patients (53%), while the pedicle only enhanced for 12 patients (32%), the body only for 3 (8%), and neither for 3 (8%). When both the pedicle and body enhanced with ICG, the rate of postoperative MRI contrast enhancement was 100% and the rate of flap necrosis was 0%. The sensitivity and specificity of flap pedicle ICG enhancement for predicting postoperative flap MRI enhancement were 97% and 67%, respectively. Two of 3 patients without enhancement developed flap necrosis.CONCLUSION: ICG fluorescence angiography of intraoperative flap perfusion is feasible and correlates well with outcomes of postoperative MRI flap enhancement and flap necrosis. Additional study is needed to further refine the imaging technique and optimally characterize the clinical utility.

  View details for PubMedID 29554360

• Endoscopic Endonasal Transclival Approach for Resection of a Pontine Glioma: Surgical Planning, Surgical Anatomy, and Technique. Operative neurosurgery (Hagerstown, Md.) Fernandes Cabral, D. T., Zenonos, G. A., Nunez, M., Celtikci, P., Snyderman, C., Wang, E., Gardner, P. A., Fernandez-Miranda, J. C. 2018

  Abstract

  BACKGROUND: The endoscopic endonasal approach (EEA) has been proposed as a potential alternative for ventral brainstem lesions. The surgical anatomy, feasibility, and limitations of the EEA for intrinsic brainstem lesions are still poorly understood.OBJECTIVE: To describe the surgical planning, anatomy, and technique of an intrinsic pontine glioma operated via EEA.METHODS: Six-human brainstems were prepared for white matter microdissection. Ten healthy subjects were studied with high-definition fiber tractography (HDFT). A 56-yr-old female with right-hemiparesis underwent EEA for an exophytic pontine glioma. Pre- and postoperative HDFTs were implemented.RESULTS: The corticospinal tracts (CSTs) are the most eloquent fibers in the ventral brainstem. At the pons, CSTs run between the pontine nuclei and the middle cerebellar peduncle (MCP). At the lower medulla, the pyramidal decussation leaves no room for safe ventral access. In our illustrative case, preoperative HDFT showed left-CST displaced posteromedially and partially disrupted, right-CST posteriorly displaced, and MCP severely disrupted. A transclival exposure was performed achieving a complete resection of the exophytic component with residual intra-axial tumor. Immediately postop, patient developed new left-side abducens nerve palsy and worse right-hemiparesis. Ten days postop, her strength returned to baseline. HDFT showed preservation and trajectory restoration of the CSTs.CONCLUSION: The EEA provides direct access to the ventral brainstem, overcoming the limitations of lateral approaches. For intrinsic pathology, HDFT helps choosing the most appropriate surgical route/boundaries for safer resection. Further experience is needed to determine the indications and limitations of this approach that should be performed by neurosurgeons with high-level expertise in EEA.

  View details for PubMedID 29538708

• Generalized q-sampling imaging fiber tractography reveals displacement and infiltration of fiber tracts in low-grade gliomas NEURORADIOLOGY Celtikci, P., Fernandes-Cabral, D. T., Yeh, F., Panesar, S. S., Fernandez-Miranda, J. C. 2018; 60 (3): 267–80

  Abstract

  Low-grade gliomas (LGGs) are slow growing brain tumors that often cause displacement and/or infiltration of the surrounding white matter pathways. Differentiation between infiltration and displacement of fiber tracts remains a challenge. Currently, there is no reliable noninvasive imaging method capable of revealing such white matter alteration patterns. We employed quantitative anisotropy (QA) derived from generalized q-sampling imaging (GQI) to identify patterns of fiber tract alterations by LGGs.Sixteen patients with a neuropathological diagnosis of LGG (WHO grade II) were enrolled. Peritumoral fiber tracts underwent qualitative and quantitative evaluation. Contralateral hemisphere counterparts were used for comparison. Tracts were qualitatively classified as unaffected, displaced, infiltrated or displaced, and infiltrated at once. The average QA of whole tract (W), peritumoral tract segment (S), and their ratio (S/W) were obtained and compared to the healthy side for quantitative evaluation.Qualitative analysis revealed 9 (13.8%) unaffected, 24 (36.9%) displaced, 13 (20%) infiltrated, and 19 (29.2%) tracts with a combination of displacement and infiltration. There were no disrupted tracts. There was a significant increase in S/W ratio among displaced tracts in the pre-operative scans in comparison with the contralateral side. QA values of peritumoral tract segments (S) were significantly lower in infiltrated tracts.WHO grade II LGGs might displace, infiltrate, or cause a combination of displacement and infiltration of WM tracts. QA derived from GQI provides valuable information that helps to differentiate infiltration from displacement. Anisotropy changes correlate with qualitative alterations, which may serve as a potential biomarker of fiber tract integrity.

  View details for PubMedID 29372286

• Endoscopic endonasal resection of the odontoid process: clinical outcomes in 34 adults JOURNAL OF NEUROSURGERY Zwagerman, N. T., Tormenti, M. J., Tempel, Z. J., Wang, E. W., Snyderman, C. H., Fernandez-Miranda, J. C., Gardner, P. A. 2018; 128 (3): 923–31

  Abstract

  OBJECTIVE Treatment of odontoid disease from a ventral corridor has consisted of a transoral approach. More recently, the endoscopic endonasal approach (EEA) has been used to access odontoid pathology. METHODS A retrospective review was conducted of patients who underwent an EEA for odontoid pathology from 2004 to 2013. During our analysis, the mean follow-up duration was 42.6 months (range 1-80 months). Patient outcomes, complications, and postoperative swallowing function were assessed either by clinic visit or phone contact. RESULTS Thirty-four patients underwent an EEA for symptomatic odontoid pathology. The most common pathology treated was basilar invagination (n = 17). Other pathologies included odontoid fractures, os odontoideum, and metastatic carcinoma. The mean patient age was 71.5 years. Thirty-one patients underwent a posterior fusion. All 34 patients experienced stability or improvement in symptoms and all had successful radiographic decompression. The overall complication rate was 76%. Nearly all of these complications were transient (86%) and the overall complication rate excluding mild transient dysphagia was only 44%. Twenty-one patients (62%) suffered from transient postoperative dysphagia: 15 cases were mild, transient subjective dysphagia (6 of whom had documented preoperative dysphagia), whereas 6 other patients required tube feedings for decreased oral intake, malnutrition, and dysphagia in the perioperative setting (5 of these patients had documented preoperative dysphagia). Sixteen patients had documented preoperative dysphagia and 6 of these had lower cranial nerve dysfunction. Postoperatively, 6 (37.5%) of 16 patients with preoperative dysphagia and 4 (67%) of 6 with lower cranial nerve dysfunction had significant dysphagia/respiratory complications. Eighteen patients had no documented preoperative dysphagia and only 2 had significant postoperative dysphagia/respiratory complications (11%). The rates of these complications in patients without preoperative dysphagia were lower than in those with any preoperative dysphagia (p = 0.07) and especially those with preexisting lower cranial neuropathies (p = 0.007). Dysphagia was also significantly more common in patients who underwent occipitocervical fixation (19/26, 73%) than in patients who underwent cervical fusion alone or no fusion (2/8, 25%; p = 0.02). All patients with perioperative dysphagia had improved at follow-up and all patients were tolerating oral diets. No patient suffered from velopalatal insufficiency. Two patients had intraoperative CSF leaks. One of these patients underwent a negative exploratory surgery for a questionable postoperative CSF leak. One patient developed infection in the resection bed requiring debridement and antibiotics. One patient died 8 days following surgery from an unknown cause. The 90-day perioperative mortality rate was 2.9%. CONCLUSIONS A completely EEA can be performed for compressive odontoid disease in all cases of neoplastic, degenerative, or invaginative atlantoaxial disease with satisfactory outcomes and low morbidity. Transient perioperative dysphagia and respiratory complications are common, usually as an exacerbation and reflection of underlying disease or occipitocervical fusion rather than the EEA, emphasizing the importance of avoiding transoral surgery.

  View details for PubMedID 28498058

• Endoscopic anterior transmaxillary "transalisphenoid" approach to Meckel's cave and the middle cranial fossa: an anatomical study and clinical application. Journal of neurosurgery Truong, H. Q., Sun, X., Celtikci, E., Borghei-Razavi, H., Wang, E. W., Snyderman, C. H., Gardner, P. A., Fernandez-Miranda, J. C. 2018: 1–11

  Abstract

  OBJECTIVE Multiple approaches have been designed to reach the medial middle fossa (for lesions in Meckel's cave, in particular), but an anterior approach through the greater wing of the sphenoid (transalisphenoid) has not been explored. In this study, the authors sought to assess the feasibility of and define the anatomical landmarks for an endoscopic anterior transmaxillary transalisphenoid (EATT) approach to Meckel's cave and the middle cranial fossa. METHODS Endoscopic dissection was performed on 5 cadaver heads injected intravascularly with colored silicone bilaterally to develop the approach and define surgical landmarks. The authors then used this approach in 2 patients with tumors that involved Meckel's cave and provide their illustrative clinical case reports. RESULTS The EATT approach is divided into the following 4 stages: 1) entry into the maxillary sinus, 2) exposure of the greater wing of the sphenoid, 3) exposure of the medial middle fossa, and 4) exposure of Meckel's cave and lateral wall of the cavernous sinus. The approach provided excellent surgical access to the anterior and lateral portions of Meckel's cave and offered the possibility of expanding into the infratemporal fossa and lateral middle fossa and, in combination with an endonasal transpterygoid approach, accessing the anteromedial aspect of Meckel's cave. CONCLUSIONS The EATT approach to Meckel's cave and the middle cranial fossa is technically feasible and confers certain advantages in specific clinical situations. The approach might complement current surgical approaches for lesions of Meckel's cave and could be ideal for lesions that are lateral to the trigeminal ganglion in Meckel's cave or extend from the maxillary sinus, infratemporal fossa, or pterygopalatine fossa into the middle cranial fossa, Meckel's cave, and cavernous sinus, such as schwannomas, meningiomas, and sinonasal tumors and perineural spread of cutaneous malignancy.

  View details for PubMedID 29393751

• Infrasellar Endoscopic Endonasal Approach for a Pituitary Adenoma Extending into the Third Ventricle, with Anterior Displacement of the Pituitary Gland JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Zenonos, G. A., Wang, E. W., Fernandez-Miranda, J. 2018; 79 (2): S233–S234

  Abstract

  Objectives  The current video presents the nuances of the infrasellar endoscopic endonasal approach for a pituitary adenoma extending into the third ventricle, with anterior displacement of the pituitary gland. Design  The video analyzes the presentation, preoperative workup and imaging, surgical steps and technical nuances of the surgery, the clinical outcome, and follow-up imaging. Setting  The patient was treated by a skull base team consisting of a neurosurgeon and an ENT surgeon at a teaching academic institution. Participants  The case refers to 73-year-old female patient who was found to have a sellar mass after failure of vision to improve with cataract surgery. She also reported a several-month history of progressive loss of vision along with daily retro-orbital headaches. The adenoma extended into the clivus as well as in the retrosellar and suprasellar regions, eroding into the floor of the third ventricle. The normal gland was displaced anteriorly. Main Outcome Measures  The main outcome measures consisted of reversal of patient symptoms (headaches and visual disturbance), recurrence-free survival based on imaging, as well as absence of any complications. Results  The patient's headaches and visual fields improved. There was no evidence of recurrence. Conclusion  The infrasellar endoscopic endonasal approach is safe and effective for pituitary adenomas extending into the third ventricle, with anterior displacement of the pituitary gland. The link to the video can be found at: https://youtu.be/zp_06mEyRvY .

  View details for PubMedID 29770288

  View details for PubMedCentralID PMC5954279

• Complete endoscopic resection of a pituitary stalk epidermoid cyst using a combined infrasellar interpituitary and suprasellar endonasal approach: case report JOURNAL OF NEUROSURGERY Nakassa, A. I., Chabot, J. D., Snyderman, C. H., Wang, E. W., Gardner, P. A., Fernandez-Miranda, J. C. 2018; 128 (2): 437–43

  Abstract

  Intracranial epidermoid cysts are benign lesions of epithelial origin that most frequently present with symptoms of mass effect. Although they are often associated with a high rate of residual tumor and recurrence, maximal safe resection usually leads to good outcomes. The authors report a complete resection of an uncommon pituitary stalk epidermoid cyst with intrasellar extension using a combined suprasellar and infrasellar interpituitary, endoscopic endonasal transsphenoidal approach. The patient, a 54-year-old woman, presented with headache, visual disturbance, and diabetes insipidus. Postoperatively, she reported improvement in her visual symptoms and well-controlled diabetes insipidus using 0.1 mg of desmopressin at bedtime and normal anterior pituitary gland function. One year later, she continues to receive the same dosage of desmopressin and is also taking 50 mcg of levothyroxine daily after developing primary hypothyroidism unrelated to the surgical procedure. A combined infrasellar interpituitary and suprasellar approach to this rare location for an epidermoid cyst can lead to a safe and complete resection with good clinical outcomes.

  View details for PubMedID 28409722

• Surgical Anatomy of the Skull Base CHORDOMAS AND CHONDROSARCOMAS OF THE SKULL BASE AND SPINE, 2ND EDITION Zenonos, G., Lieber, S., Fernandez-Miranda, J. C., Harsh, G. R., VazGuimaraes, F. 2018: 89–106

  View details for DOI 10.1016/B978-0-12-804257-1.00009-8

  View details for Web of Science ID 000426245100011

• Paratrigeminal, Paraclival, Precavernous, or All of the Above? A Circumferential Anatomical Study of the C3-C4 Transitional Segment of the Internal Carotid Artery. Operative neurosurgery (Hagerstown, Md.) Marcati, E. n., Andaluz, N. n., Froelich, S. C., Zimmer, L. A., Leach, J. L., Fernandez-Miranda, J. C., Kurbanov, A. n., Keller, J. T. 2018; 14 (4): 432–40

  Abstract

  Although the term paraclival carotid pervades recent skull base literature, no clear consensus exists regarding boundaries or anatomical segments.To reconcile various internal carotid artery (ICA) nomenclatures for transcranial and endoscopic-endonasal perspectives, we reexamined the transition between lacerum (C3) and cavernous (C4) segments using a C1-C7 segments schema. In this cadaveric study, we obtained a 360°-circumferential view integrating histological, microsurgical, endoscopic, and neuroradiological analyses of this C3-C4 region and identified a distinct transitional segment.In 13 adult, silicone-injected, formalin-fixed cadaveric heads (26 sides), transcranial-extradural-subtemporal and endoscopic-endonasal CT-guided dissections were performed. A quadrilateral area was noted medial to Meckel's cave between cranial nerve VI, anterolateral and posterolateral borders of the lateral-paratrigeminal aspect of the precavernous ICA, and posterior longitudinal ligament. Endoscopically, a medial-paraclival aspect was defined. Anatomical correlations were made with histological and neuroradiological slides.We identified a distinct precavernous C3-C4 transitional segment. In 18 (69%) specimens, venous channels were absent at the quadrilateral area, on the paratrigeminal border of the precavernous ICA. A trigeminal membrane, seen consistently on the superior border of V2, defined the lateral aspect of the cavernous sinus floor. The medial aspect of the precavernous ICA corresponded with the paraclival ICA.Our study revealing the juncture of 2 complementary borders of the ICA, endoscopic endonasal (paraclival) and transcranial (paratrigeminal), reconciles various nomenclature. A precavernous segment may clarify controversies about the paraclival ICA and support the concept of a "safe door" for lesions involving Meckel's cave, cavernous sinus, and petrous apex.

  View details for PubMedID 28531285

• The medial wall of the cavernous sinus. Part 2: Selective medial wall resection in 50 pituitary adenoma patients. Journal of neurosurgery Cohen-Cohen, S. n., Gardner, P. A., Alves-Belo, J. T., Truong, H. Q., Snyderman, C. H., Wang, E. W., Fernandez-Miranda, J. C. 2018: 1–10

  Abstract

  OBJECTIVEPituitary adenomas often invade the medial wall of the cavernous sinus (CS), but this structure is generally not surgically removed because of the risk of vascular and cranial nerve injury. The purpose of this study was to report the surgical outcomes in a large series of cases of invasive pituitary adenoma in which the medial wall of the CS was selectively removed following an anatomically based, stepwise surgical technique.METHODSThe authors' institutional database was reviewed to identify cases of pituitary adenoma with isolated invasion of the medial wall, based on an intraoperative evaluation, in which patients underwent an endoscopic endonasal approach with selective resection of the medial wall of the CS. Cases with CS invasion beyond the medial wall were excluded. Patient complications, resection, and remission rates were assessed.RESULTSFifty patients were eligible for this study, 15 (30%) with nonfunctional adenomas and 35 (70%) with functional adenomas, including 16 growth hormone-, 10 prolactin-, and 9 adrenocorticotropic hormone (ACTH)-secreting tumors. The average tumor size was 2.3 cm for nonfunctional and 1.3 cm for functional adenomas. Radiographically, 11 cases (22%) were Knosp grade 1, 23 (46%) Knosp grade 2, and 16 (32%) Knosp grade 3. Complete tumor resection, based on intraoperative impression and postoperative MRI, was achieved in all cases. The mean follow-up was 30 months (range 4-64 months) for patients with functional adenomas and 16 months (range 4-30 months) for those with nonfunctional adenomas. At last follow-up, complete biochemical remission (using current criteria) without adjuvant treatment was seen in 34 cases (97%) of functional adenoma. No imaging recurrences were seen in patients who had nonfunctional adenomas. A total of 57 medial walls were removed in 50 patients. Medial wall invasion was histologically confirmed in 93% of nonfunctional adenomas and 83% of functional adenomas. There were no deaths or internal carotid artery injuries, and the average blood loss was 378 ml. Four patients (8%) developed a new, transient cranial nerve palsy, and 2 of these patients required reoperation for blood clot evacuation and fat graft removal. There were no permanent cranial nerve palsies.CONCLUSIONSThe medial wall of the CS can be removed safely and effectively, with minimal morbidity and excellent resection and remission rates. Further follow-up is needed to determine the long-term results of this anatomically based technique, which should only be performed by very experienced endonasal skull base teams.

  View details for PubMedID 30192191

• Does lumbar drainage reduce postoperative cerebrospinal fluid leak after endoscopic endonasal skull base surgery? A prospective, randomized controlled trial. Journal of neurosurgery Zwagerman, N. T., Wang, E. W., Shin, S. S., Chang, Y. F., Fernandez-Miranda, J. C., Snyderman, C. H., Gardner, P. A. 2018: 1–7

  Abstract

  OBJECTIVE: Based on a null hypothesis that the use of short-term lumbar drainage (LD) after endoscopic endonasal surgery (EES) for intradural pathology does not prevent postoperative CSF leaks, a trial was conducted to assess the effect of postoperative LD on postoperative CSF leak following standard reconstruction. METHODS: A prospective, randomized controlled trial of lumbar drain placement after endoscopic endonasal skull base surgery was performed from February 2011 to March 2015. All patients had 3-month follow-up data. Surgeons were blinded to which patients would or would not receive the drain until after closure was completed. An a priori power analysis calculation assuming 80% of power, 5% postoperative CSF leak rate in the no-LD group, and 16% in the LD group determined a planned sample size of 186 patients. A routine data and safety check was performed with every 50 patients being recruited to ensure the efficacy of randomization and safety. These interim tests were run by a statistician who was not blinded to the arms they were evaluating. This study accrued 230 consecutive adult patients with skull base pathology who were eligible for endoscopic endonasal resection. Inclusion criteria (high-flow leak) were dural defect greater than 1 cm2 (mandatory), extensive arachnoid dissection, and/or dissection into a ventricle or cistern. Sixty patients were excluded because they did not meet the inclusion criteria. One hundred seventy patients were randomized to either receive or not receive a lumbar drain. RESULTS: One hundred seventy patients were randomized, with a mean age of 51.6 years (range 19-86 years) and 38% were male. The mean BMI for the entire cohort was 28.1 kg/m2. The experimental cohort with postoperative LD had an 8.2% rate of CSF leak compared to a 21.2% rate in the control group (odds ratio 3.0, 95% confidence interval 1.2-7.6, p = 0.017). In 106 patients in whom defect size was measured intraoperatively, a larger defect was associated with postoperative CSF leak (6.2 vs 2.9 cm2, p = 0.03). No significant difference was identified in BMI between those with (mean 28.4 ± 4.3 kg/m2) and without (mean 28.1 ± 5.6 kg/m2) postoperative CSF leak (p = 0.79). Furthermore, when patients were grouped based on BMI < 25, 25-29.9, and > 30 kg/m2, no difference was noted in the rates of CSF fistula (p = 0.97). CONCLUSIONS: Among patients undergoing intradural EES judged to be at high risk for CSF leak as defined by the study's inclusion criteria, perioperative LD used in the context of vascularized nasoseptal flap closure significantly reduced the rate of postoperative CSF leaks.Clinical trial registration no.: NCT03163134 (clinicaltrials.gov).

  View details for PubMedID 30485224

• The foramen lacerum: surgical anatomy and relevance for endoscopic endonasal approaches. Journal of neurosurgery Wang, W. H., Lieber, S. n., Mathias, R. N., Sun, X. n., Gardner, P. A., Snyderman, C. H., Wang, E. W., Fernandez-Miranda, J. C. 2018: 1–12

  Abstract

  OBJECTIVEThe foramen lacerum is a relevant skull base structure that has been neglected for many years. From the endoscopic endonasal perspective, the foramen lacerum is a key structure due to its location at the crossroad between the sagittal and coronal planes. The objective of this study was to provide a detailed investigation of the surgical anatomy of the foramen lacerum and its adjacent structures based on anatomical dissections and imaging studies, propose several relevant key surgical landmarks, and demonstrate the surgical technique for its full exposure with several illustrative cases.METHODSTen colored silicone-injected anatomical specimens were dissected using a transpterygoid approach to the foramen lacerum region in a stepwise manner. Five similar specimens were used for a comparative transcranial approach. The osseous anatomy was examined in 32 high-resolution multislice CT studies and 1 disarticulated skull. Representative cases were selected to illustrate the application of the findings.RESULTSThe pterygosphenoidal fissure is the synchondrosis between the lacerum process of the pterygoid bone and the floor of the sphenoid bone. It constantly converges with the posterior end of the vidian canal at a 45° angle, and its posterolateral end points directly to the lacerum foramen. The pterygoid tubercle separates the vidian canal from the pterygosphenoidal fissure, and forms the anterior wall of the lower part of the foramen lacerum. The lingual process, which forms the lateral wall of the foramen lacerum, was identified in 53 of 64 sides and featured an average height of 5 mm. The mandibular strut separates the foramen lacerum from the foramen ovale and had an average width of 5 mm.CONCLUSIONSThis study provides relevant surgical landmarks and a systematic approach to the foramen lacerum by defining anterior, medial, lateral, and inferior walls that may facilitate its safe exposure for effective removal of lesions while minimizing the risk of injury to the internal carotid artery.

  View details for PubMedID 30544351

• The Endoscopic Endonasal Approach to Chordomas and Chondrosarcomas CHORDOMAS AND CHONDROSARCOMAS OF THE SKULL BASE AND SPINE, 2ND EDITION Gardner, P. A., Snyderman, C. H., Fernandez-Miranda, J. C., Wang, E. W., Harsh, G. R., VazGuimaraes, F. 2018: 141–49

  View details for DOI 10.1016/B978-0-12-804257-1.00012-8

  View details for Web of Science ID 000426245100014

• "Live Cadaver" Model for Internal Carotid Artery Injury Simulation in Endoscopic Endonasal Skull Base Surgery. Operative neurosurgery (Hagerstown, Md.) Pacca, P., Jhawar, S. S., Seclen, D. V., Wang, E., Snyderman, C., Gardner, P. A., Aboud, E., Fernandez-Miranda, J. C. 2017; 13 (6): 732–38

  Abstract

  BACKGROUND: Intraoperative injury of the internal carotid artery (ICA) is the most dreaded complication in endoscopic endonasal surgery (EES) of skull base. Training for ICA injury is practically impossible in live operative settings.OBJECTIVE: To evaluate a pulsatile perfusion-based live cadaveric model for ICA injury simulation in a laboratory setting. The major emphasis of the study was to evaluate various means of controlling acute bleeding and evaluating the practical utility of this model for training purposes.METHODS: Five embalmed, uninjected cadaveric heads were prepared for study by connecting to a pulsatile perfusion pump system filled with artificial blood solution. EES approaches were used to evaluate different types of ICA injuries similar to operative scenarios. Various methods of managing ICA injuries such as packing, clipping, and trapping, were evaluated. The educational advantages of the live cadaver model were assessed using questionnaires given to participants in a hands-on dissection course.RESULTS: The trainee was faced with several scenarios similar to those encountered during an actual intraoperative ICA injury. Packing, clipping, and trapping of the ICA injury were successfully achieved in all segments of the ICA. Clip-based reconstruction techniques were successfully developed. All trainees reported gaining new knowledge, learning new techniques. The responses to the questionnaire confirmed the significant educational value of this model.CONCLUSION: The live cadaver model presented here provides real-life experience with major vessel injury during EES in a laboratory setting. This model could significantly improve current training for the management of intraoperative vascular injuries during EES.

  View details for PubMedID 28666364

• A diffusion spectrum imaging-based tractographic study into the anatomical subdivision and cortical connectivity of the ventral external capsule: uncinate and inferior fronto-occipital fascicles NEURORADIOLOGY Panesar, S. S., Yeh, F., Deibert, C. P., Fernandes-Cabral, D., Rowthu, V., Celtikci, P., Celtikci, E., Hula, W. D., Pathak, S., Fernandez-Miranda, J. C. 2017; 59 (10): 971–87

  Abstract

  The inferior fronto-occipital fasciculus (IFOF) and uncinate fasciculus (UF) are major fronto-capsular white matter pathways. IFOF connects frontal areas of the brain to parieto-occipital areas. UF connects ventral frontal areas to anterior temporal areas. Both fascicles are thought to subserve higher language and emotion roles. Controversy pertaining to their connectivity and subdivision persists in the literature, however.High-definition fiber tractography (HDFT) is a non-tensor tractographic method using diffusion spectrum imaging data. Its major advantage over tensor-based tractography is its ability to trace crossing fiber pathways. We used HDFT to investigate subdivisions and cortical connectivity of IFOF and UF in 30 single subjects and in an atlas comprising averaged data from 842 individuals. A per-subject aligned, atlas-based approach was employed to seed fiber tracts and to study cortical terminations.For IFOF, we observed a tripartite arrangement corresponding to ventrolateral, ventromedial, and dorsomedial frontal origins. IFOF volume was not significantly lateralized to either hemisphere. UF fibers arose from ventromedial and ventrolateral frontal areas on the left and from ventromedial frontal areas on the right. UF volume was significantly lateralized to the left hemisphere. The data from the averaged atlas was largely in concordance with subject-specific findings. IFOF connected to parietal, occipital, but not temporal, areas. UF connected predominantly to temporal poles.Both IFOF and UF possess subdivided arrangements according to their frontal origin. Our connectivity results indicate the multifunctional involvement of IFOF and UF in language tasks. We discuss our findings in context of the tractographic literature.

  View details for PubMedID 28721443

• Apples and Oranges: Proper Comparison of Costs - Endonasal vs. Transnasal WORLD NEUROSURGERY Gardner, P. A., Snyderman, C. H., Fernandez-Miranda, J. C., Wang, E. W. 2017; 106: 984–85

  View details for PubMedID 28985664

• Fully Endoscopic Minimally Invasive Transrectus Capitis Posterior Muscle Triangle Approach to the Posterolateral Condyle and Jugular Tubercle JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Wang Mingdong, Fernandez-Miranda, J. C., Mathias, R., Wang, E., Gardner, P., Hong Wang 2017; 78 (5): 359–70

  Abstract

  Background  We evaluated a transrectus capitis posterior muscle triangle approach to the posterolateral foramen magnum, occipital condyles, jugular tubercle, and the fourth ventricle. We also assessed factors that affect the amount of bone removal required. Objective  To evaluate if the proposed approach is as effective as standard open approaches to expose the lateral portion of the foramen magnum. Methods  The proposed minimally invasive fully endoscopic approach was performed in 15 cadaveric specimens using 4-mm (0- and 45-degree) endoscopes. Results  Using a 5-cm straight paramedian incision, the rectus capitis posterior minor and major muscles were partially removed unilaterally, providing a corridor through the muscles to reach the foramen magnum region. After meticulous soft tissue dissection, key anatomical landmarks can be identified such as the greater occipital nerve, the vertebral artery that wraps around the atlanto-occipital joint, and the bony protuberance that heralds the occipital condyle. A suboccipital craniotomy associated with the transcondylar, supracondylar or paracondylar approach is performed depending on the amount of bone removal desired to maximize the surgical view. By doing so, the jugular foramen can be exposed laterally as well as the fourth ventricle medially. Conclusion  The proposed endoscopic approach can provide access through the transrectus capitis posterior muscle triangle leading directly to the occipital condyle. A stepwise approach is critical to gain a surgical corridor to the inferolateral petroclival region and the fourth ventricle.

  View details for PubMedID 28875113

  View details for PubMedCentralID PMC5582958

• Endoscopic Endonasal Interdural Middle Fossa Approach to the Maxillary Nerve: Anatomic Considerations and Surgical Relevance OPERATIVE NEUROSURGERY Abhinav, K., Panczykowski, D., Wang, W., Synderman, C. H., Gardner, P. A., Wang, E. W., Fernandez-Miranda, J. C. 2017; 13 (4): 522–28

  Abstract

  The maxillary nerve (V2) can be approached via the open middle fossa approach.To delineate the anatomy of V2 and its specific segments with respect to the endonasal landmarks. We present the endoscopic endonasal interdural middle fossa approach to V2 and its potential application for the treatment of perineural spread in sinonasal/skull base tumors.Five human head silicon-injected specimens underwent bilateral endoscopic endonasal transpterygoid approaches. V2 prominence and the maxillary strut were identified in the lateral recess along with paraclival carotid protruberance. The regions superior and inferior to V2 corresponding to the anteromedial and anterolateral triangles of the middle fossa were exposed.V2 can be classified into 3 segments: interdural (from the Gasserian ganglion to the proximal part of the maxillary strut), intracanalicular (corresponding to the anteroposterior length of the maxillary strut), and pterygopalatine (distal to the maxillary strut and the site of its divisions). Endonasally, the average length of the interdural and the intracanalicular segments were approximately 9 and 4.4 mm, respectively. V2, following its division distal to the maxillary strut, was successfully dissected off the middle fossa dura and transected just distal to the Gasserian ganglion.Endonasally, the interdural segment can be safely mobilized between the periosteal and meningeal dural layers while ensuring the integrity of the middle fossa dura. This allows transection of infiltrated V2 to facilitate tumor resection without entering the intradural/arachnoidal space. Posteriorly, this is limited by the Gasserian ganglion and superomedially by the dural envelope surrounding the cavernous sinus and the paraclival carotid artery.

  View details for PubMedID 28838109

• Endoscopic Endonasal Approach to the Ventral Jugular Foramen: Anatomical Basis, Technical Considerations, and Clinical Series OPERATIVE NEUROSURGERY Vaz-Guimaraes, F., Nakassa, A. I., Gardner, P. A., Wang, E. W., Snyderman, C. H., Fernandez-Miranda, J. C. 2017; 13 (4): 482–90

  Abstract

  Surgical exposure of the jugular foramen (JF) is challenging given its complex regional anatomy and proximity to critical neurovascular structures.To describe the anatomical basis, surgical technique, and outcomes of a group of patients who underwent the endoscopic endonasal approach to the JF.Five silicon-injected anatomical specimens were prepared for dissection. Additionally, a chart review was conducted through our patient database, searching for endonasal exposure of the JF. Demographic data, clinical presentation, pathological findings, extent of resection in the JF, and occurrence of complications were analyzed.The endonasal exposure of the JF requires 3 sequential steps: a transpterygoid, a "far-medial," and an "extreme-medial" approach. Mobilization or transection of the cartilaginous portion of the eustachian tube (ET) is necessary. In the clinical series, cranial neuropathies were the presenting symptoms in 16 patients (89%). Eighteen tumors (10 chondrosarcomas, 7 chordomas, 1 adenocarcinoma) extended secondarily into the JF. Total tumor resection was achieved in 10 patients (56%), near total (≥90%) in 6 (33%), and subtotal (<90%) in 2 (11%). ET dysfunction (75% of cases), transient palatal numbness (17%), cerebrospinal fluid leakage (17%), and lower cranial nerve palsy (17%) were the most common postoperative complications. There were no carotid artery or jugular vein injuries.The endoscopic endonasal approach to the JF requires mobilization or transection of the cartilaginous portion of the ET. This maneuver provides a safe infrapetrosal surgical route to the JF. It may be considered a valid option, in well-selected cases, for resection of malignant and recurrent cranial base tumors.

  View details for PubMedID 28838115

• Endoscopic Endonasal Surgery for Cranial Base Chondrosarcomas OPERATIVE NEUROSURGERY Vaz-Guimaraes, F., Fernandez-Miranda, J. C., Koutourousiou, M., Hamilton, R. L., Wang, E. W., Snyderman, C. H., Gardner, P. A. 2017; 13 (4): 421–34

  Abstract

  Microsurgical resection via open approaches is considered the main treatment modality for cranial base chondrosarcomas (CBCs). The use of endoscopic endonasal approaches (EEAs) has been rarely reported.To present the endoscopic endonasal experience with CBCs at our institution.Retrospective review of the medical records of 35 consecutive patients who underwent EEA for CBC resection between January 2004 and April 2013. Surgical outcomes and variables that might affect extent of resection, complications, and recurrence were analyzed.Forty-eight operations were performed (42 EEAs and 6 open approaches). Gross-total resection was achieved in 22 patients (62.9%), near total (≥90% tumor resection) in 11 (31.4%). Larger tumors were associated with incomplete resection in univariate and multivariate analysis ( P = .004, .015, respectively). In univariate analysis, tumors involving the lower clivus and cerebellopontine angle were associated with increased number of complications, especially postoperative cerebrospinal fluid leak ( P = .015) and new cranial neuropathy ( P = .037), respectively. Other major complications included 2 cases of meningitis and deep venous thrombosis, and 1 case of hydrocephalus and carotid injury. Involvement of the lower clivus, parapharyngeal space, and cervical spine required a combination of approaches to maximize tumor resection ( P = .017, .044, .017, respectively). No predictors were significantly associated with increased risk of recurrence. The average follow-up time was 44.6 ± 31 months.EEAs may be considered a good option for managing CBCs without significant posterolateral extension beyond the basal foramina and can be used in conjunction with open approaches for maximal resection with acceptable morbidity.

  View details for PubMedID 28838112

• Surgical Management of Vertex Epidural Hematoma: Technical Case Report and Literature Review WORLD NEUROSURGERY Fernandes-Cabral, D. T., Kooshkabadi, A., Panesar, S. S., Celtikci, E., Borghei-Razavi, H., Celtikci, P., Fernandez-Miranda, J. C. 2017; 103: 475–83

  Abstract

  Vertex epidural hematoma (VEH) is an uncommon presentation of extra-axial hematomas. It can represent a surgical dilemma regarding when and how to operate, particularly considering the potential implication of the superior sagittal sinus (SSS).Here, we illustrate the surgical technique for VEH as well as a review of the existing literature.A 60-year-old man sustained a ground-level fall resulting in complete diastasis of the sagittal suture with underlying large VEH causing significant mass effect on the SSS and bihemispheric convexities. Twenty-four hours later, the patient deteriorated, with decreased level of alertness and worsening asymmetric paresis on his lower extremities. He subsequently underwent surgical evacuation of the hematoma, decompression of the SSS, and fracture repair. A modified bicoronal approach, with bilateral parasagittal craniotomies, was performed. A central island of bone was left intact to spare the diastatic fracture from the craniotomies. This was done to ensure a stable anchor point for tacking-up the underlying displaced dura and SSS. The central bone prevents extensive bleeding from the diastatic fracture and eliminates the risk of further blood reaccumulation and tearing of a possible injured sinus during bone flap elevation.The technique performed allowed us to evacuate completely the hematoma while preserving the SSS and repairing the sagittal suture to avoid further bleeding. Complete neurologic recovery of the patient occurred after VEH evacuation.Because of its rare nature, VEH represents a surgical challenge. Because neurosurgeons encounter this condition relatively infrequently, literature regarding the medical and surgical management of this entity is warranted.

  View details for PubMedID 28427975

• Endoscopic Endonasal Surgery for Tumors of the Cavernous Sinus: A Series of 234 Patients WORLD NEUROSURGERY Koutourousiou, M., Guimaraes Filho, F., Fernandez-Miranda, J. C., Wang, E. W., Stefko, S., Snyderman, C. H., Gardner, P. A. 2017; 103: 713–32

  Abstract

  Cavernous sinus (CS) tumors often are considered inoperable. We present our experience with endoscopic endonasal surgery (EES) and compare the outcomes for different tumor.EES (medial or lateral approach) was used in 234 patients with CS tumors. The cohort included 175 (75%) pituitary adenomas and 59 (25%) nonadenomatous lesions.Presenting symptoms were significantly different between the 2 groups, with cranial neuropathies occurring mainly in nonadenomas (P < 0.0001). The overall gross total tumor resection rate from the CS was 37.3% (37.1% in adenomas, 38.1% in non-adenomas). In total, preexisting cranial nerve (CN) dysfunction improved in 56.4% of the patients. After treatment completion (including radiation of residual tumor), 83.3% of acromegalic patients, 50% of prolactinomas and 33.3% of Cushing's disease, were in remission. Visual loss improved in 86.8% of adenomas and in 70.8% of nonadenomas. Intracavernous CN palsies improved in 77.3% of adenomas and 42.4% of nonadenomas. New permanent CN palsies occurred in 7 nonadenomas, which is significantly greater than in adenomas (P = 0.007). The leak rate of cerebrospinal fluid was 6.3% for adenomas and 11.9% for nonadenomas. Four patients suffered an internal carotid artery injury with no neurologic sequelae in 3 cases and 1 death (0.4%).EES provides an easily accessible midline corridor to the CS with equivalent or superior results to transcranial approaches in the management of select tumors. Symptomatology due to CS invasion is more likely to improve in pituitary adenomas and the rate of surgical complications is greater in nonadenomas. Using a team approach, the overall mortality due to vascular injury is low.

  View details for PubMedID 28450229

• Lateral Orbitotomy Approach for Resection of Intraosseous SphenoidWing Meningioma: 3-Dimensional Operative Video OPERATIVE NEUROSURGERY Chabot, J. D., Stefko, S., Fernandez-Miranda, J. C. 2017; 13 (3): 399

  View details for PubMedID 28521357

• Multicorridor Endoscopic Endonasal and Supraorbital Approach for Orbital Roof Meningioma: 3-Dimensional Operative Video OPERATIVE NEUROSURGERY Chabot, J. D., Stefko, S., Snyderman, C., Fernandez-Miranda, J. 2017; 13 (3): 401

  View details for PubMedID 28521341

• Endoscopic Endonasal Approach for Adrenocorticotropic Hormone-Secreting Pituitary Adenomas: Outcomes and Analysis of Remission Rates and Tumor Biochemical Activity with Respect to Tumor Invasiveness WORLD NEUROSURGERY Shin, S. S., Gardner, P. A., Ng, J., Faraji, A. H., Agarwal, N., Chivukula, S., Fernandez-Miranda, J. C., Snyderman, C. H., Challinor, S. M. 2017; 102: 651-+

  Abstract

  The purpose of this study was to analyze the outcomes and complications of the endoscopic endonasal approach (EEA) performed on patients with Cushing disease at our Pituitary Center during the past 11 years.Clinical information and imaging in electronic medical records were reviewed for patients who underwent EEA. Statistical analysis was performed with χ2 testing and Student's t-test.Remission was achieved in 39 patients (79.6%) at initial evaluation within 2 weeks of surgery. At last follow-up, remission persisted in 70% of 50 patients with EEA alone (mean follow-up time, 37.5 ± 4.6 months; median, 26.2 months; range, 2.5-155.0 months). At last follow-up, remission rates were 80% among magnetic resonance imaging-negative adenomas, 70.6% among noninvasive or minimally invasive adenomas (Knosp 0, 1, 2), and 50% among invasive adenomas (Knosp 3, 4). There were no statistical differences in the remission rates among these categories (P = 0.444). Women had higher proportions of initial remission than men (P = 0.033) and patients who had no initial remission were older (P = 0.046). Higher preoperative normalized adrenocroticotropic hormone level was associated with a greater degree of invasiveness (P = 0.021). However, there was no association between preoperative normalized urine-free cortisol levels and degree of invasiveness (P = 0.582). Complications included panhypopituitarism (n = 3), hypothyroidism (n = 3), growth hormone deficiency (n = 1), hypogonadism (n = 1), postoperative cerebrospinal fluid leak (n = 2), and transient diabetes insipidus (n = 4).The EEA for Cushing disease resulted in remission and complication rates comparable with previous analyses of EEA, as well as microsurgical series. Preoperative adrenocorticotropic hormone levels were associated with invasiveness.

  View details for PubMedID 26252984

• Anatomic Considerations for Sinonasal and Ventral Skull Base Malignancy OTOLARYNGOLOGIC CLINICS OF NORTH AMERICA Willson, T. J., Fernandez-Miranda, J. C., Nunes, C., Lieber, S., Wang, E. W. 2017; 50 (2): 245-+

  Abstract

  Malignancies of the sinonasal region and ventral skull base include a varied group of uncommon tumors that are a challenge to treat. These malignancies, with few exceptions, often present late because of their insidious growth and bland symptomatology. As with malignancies of other sites, the primary goal in surgical management is complete resection with negative margins. This presents a unique surgical challenge in that these lesions lie within a region of densely populated anatomic real estate. This fact reinforces the importance of complete preoperative work-up and a sound anatomic understanding. This article discusses key anatomic regions and their importance from an endonasal perspective.

  View details for PubMedID 28104275

• The Making of a Skull Base Team and the Value of Multidisciplinary Approach in the Management of Sinonasal and Ventral Skull Base Malignancies OTOLARYNGOLOGIC CLINICS OF NORTH AMERICA Snyderman, C. H., Wang, E. W., Fernandez-Miranda, J. C., Gardner, P. A. 2017; 50 (2): 457-+

  Abstract

  The management of sinonasal and ventral skull base malignancies is best performed by a team. Although the composition of the team may vary, it is important to have multidisciplinary representation. There are multiple obstacles, both individual and institutional, that must be overcome to develop a highly functioning team. Adequate training is an important part of team-building and can be fostered with surgical telementoring. A quality improvement program should be incorporated into the activities of a skull base team.

  View details for PubMedID 28160995

• Outcomes of Endonasal and Lateral Approaches to Petroclival Meningiomas WORLD NEUROSURGERY Koutourousiou, M., Fernandez-Miranda, J. C., Vaz-Guimaraes Filho, F., de Almeida, J. R., Wang, E. W., Snyderman, C. H., Gardner, P. A. 2017; 99: 500–517

  Abstract

  Transpetrosal approaches for the treatment of petroclival meningiomas are often associated with substantial morbidity and long recovery. With the goal of early clinical improvement, we have used less invasive surgical approaches for petroclival meningiomas.We retrospectively reviewed 32 patients with petroclival meningiomas. Eleven patients (34.4%) were managed with lateral approaches (retrosigmoid or far lateral approach), 17 (53.1%) with anterior midline approaches (endoscopic endonasal approach [EEA]), and 4 (12.5%) with a combination.The average Karnofsky Performance Score (KPS) at presentation was 73.8. The average postoperative KPS improved to 87.9 (P < 0.001) during short-term follow-up of 14 months (range, 1-42) and was significantly higher in primary tumors (P = 0.013), tumors <4 cm (P = 0.039), and tumors without vascular encasement (P = 0.002) but remained significant regardless of age, tumor size, or vascular encasement. The greatest benefit occurred with primary tumors, in young patients and in those who underwent nontotal resection (P < 0.001). EEA had a significantly greater potential for improved KPS (P = 0.002). Gross (n = 6) or near total (n = 9) resection was achieved in 15 of 32 cases (47%). Complications included new cranial nerve palsies affecting mainly the abducens nerve (18.7%). New lower cranial nerve palsies occurred in only 1 case (3.1%). Other complications included postoperative hydrocephalus (15.6%) and cerebrospinal fluid leak (28.1%). One patient died in the perioperative period (3.1%).In the short-term, less aggressive cranial base approaches, including retrosigmoid exposures and the recently introduced EEA, are effective alternatives to transpetrosal approaches for debulking petroclival meningiomas with significant early clinical improvement and limited major surgical complications.

  View details for PubMedID 27965073

• Lateral Orbitotomy Approach for Lesions Involving the Middle Fossa: A Retrospective Review of Thirteen Patients NEUROSURGERY Chabot, J. D., Gardner, P. A., Stefko, S., Zwagerman, N. T., Fernandez-Miranda, J. 2017; 80 (2): 309–22

  Abstract

  Classically used for treatment of orbital lesions, the lateral orbitotomy with cantholysis can be combined with a temporal craniectomy for lesions involving the middle cranial fossa.To present a single-center experience with the lateral orbitotomy approach for lesions involving the middle fossa.Twenty-five patients underwent lateral orbitotomies from April 2012 to July 2015. Excluding patients with solely intraorbital pathologies, 13 patients’ clinical and radiographic records were retrospectively reviewed.Signs/symptoms in the 13 patients (ages 28-81) included proptosis (69%), decreased visual acuity (31%), diplopia (54%), and afferent pupillary defect (69%). Pathologies were meningioma (8), esthesioneuroblastoma, lymphoma, chordoma, Ewing's sarcoma, and squamous cell carcinoma. Surgical goals were maximal safe resection in 8 patients, palliative debulking in 3 patients, and cavernous sinus biopsy in 2 patients. In 8 patients for whom maximal resection was the goal, 2 had gross total resection, while 6 had near-total resection. All patients (3) for whom palliation was the goal had symptomatic improvement. Both cavernous sinus biopsies obtained diagnostic tissue without complications. All patients with proptosis (n = 9) and diplopia (n = 7), and 2 of 4 patients with decreased visual acuity had improvement in their symptoms. No patient reported worsening of their symptoms. Mean follow-up was 12 mo (2-30 mo). Complications included oculorrhea (1), pseudomeningocele (2), transient ptosis (2), and forehead numbness (1).The lateral orbitotomy is a promising approach for carefully selected lesions with involvement of both the lateral orbit and middle cranial fossa. It provides minimally invasive access for biopsy, decompression, or resection.

  View details for PubMedID 28175869

• High-Definition Fiber Tractography in Evaluation and Surgical Planning of Thalamopeduncular Pilocytic Astrocytomas in Pediatric Population: Case Series and Review of Literature WORLD NEUROSURGERY Celtikci, E., Celtikci, P., Fernandes-Cabral, D., Ucar, M., Fernandez-Miranda, J., Borcek, A. 2017; 98: 463–69

  Abstract

  Thalamopeduncular tumors (TPTs) of childhood present a challenge for neurosurgeons due to their eloquent location. Preoperative fiber tracking provides total or near-total resection, without additional neurologic deficit. High-definition fiber tractography (HDFT) is an advanced white matter imaging technique derived from magnetic resonance imaging diffusion data, shown to overcome the limitations of diffusion tensor imaging. We aimed to investigate alterations of corticospinal tract (CST) and medial lemniscus (ML) caused by TPTs and to demonstrate the application of HDFT in preoperative planning.Three pediatric patients with TPTs were enrolled. CSTs and MLs were evaluated for displacement, infiltration, and disruption. The relationship of these tracts to tumors was identified and guided surgical planning. Literature was reviewed for publications on pediatric thalamic and TPTs that used diffusion imaging.Two patients had histologic diagnosis of pilocytic astrocytoma. One patient whose imaging suggested a low-grade glioma was managed conservatively. All tracts were displaced (1 CST anteriorly, 2 CSTs, 1 ML anteromedially, 1 ML medially, and 1 ML posteromedially). Literature review revealed 2 publications with 15 pilocytic astrocytoma cases, which investigated CST only. The condition of sensory pathway or anteromedial displacement of the CST in these tumors was not reported previously.Displacement patterns of the perilesional fiber bundles by TPTs are not predictable. Fiber tracking, preferably HDFT, should be part of preoperative planning to achieve maximal extent of resection for longer survival rates in this young group of patients, while preserving white matter tracts and thus quality of life.

  View details for PubMedID 27888085

• Endoscopic Endonasal Optic Nerve Decompression for Fibrous Dysplasia JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE DeKlotz, T. R., Stefko, S., Fernandez-Miranda, J. C., Gardner, P. A., Snyderman, C. H., Wang, E. W. 2017; 78 (1): 24–29

  Abstract

  Objective To evaluate visual outcomes and potential complications for optic nerve decompression using an endoscopic endonasal approach (EEA) for fibrous dysplasia. Design Retrospective chart review of patients with fibrous dysplasia causing extrinsic compression of the canalicular segment of the optic nerve that underwent an endoscopic endonasal optic nerve decompression at the University of Pittsburgh Medical Center from 2010 to 2013. Main Outcome Measures The primary outcome measure assessed was best-corrected visual acuity (BCVA) with secondary outcomes, including visual field testing, color vision, and complications associated with the intervention. Results A total of four patients and five optic nerves were decompressed via an EEA. All patients were symptomatic preoperatively and had objective findings compatible with compressive optic neuropathy: decreased visual acuity was noted preoperatively in three patients while the remaining patient demonstrated an afferent pupillary defect. BCVA improved in all patients postoperatively. No major complications were identified. Conclusion EEA for optic nerve decompression appears to be a safe and effective treatment for patients with compressive optic neuropathy secondary to fibrous dysplasia. Further studies are required to identify selection criteria for an open versus an endoscopic approach.

  View details for PubMedID 28180039

  View details for PubMedCentralID PMC5288111

• Total Human Eye Allotransplantation: Developing Surgical Protocols for Donor and Recipient Procedures PLASTIC AND RECONSTRUCTIVE SURGERY Davidson, E. H., Wang, E. W., Yu, J. Y., Fernandez-Miranda, J. C., Wang, D. J., Richards, N., Miller, M., Schuman, J. S., Washington, K. M. 2016; 138 (6): 1297–1308

  Abstract

  Vascularized composite allotransplantation of the eye is an appealing, novel method for reconstruction of the nonfunctioning eye. The authors' group has established the first orthotopic model for eye transplantation in the rat. With advancements in immunomodulation strategies together with new therapies in neuroregeneration, parallel development of human surgical protocols is vital for ensuring momentum toward eye transplantation in actual patients.Cadaveric donor tissue harvest (n = 8) was performed with orbital exenteration, combined open craniotomy, and endonasal approach to ligate the ophthalmic artery with a cuff of paraclival internal carotid artery, for transection of the optic nerve at the optic chiasm and transection of cranial nerves III to VI and the superior ophthalmic vein at the cavernous sinus. Candidate recipient vessels (superficial temporal/internal maxillary/facial artery and superficial temporal/facial vein) were exposed. Vein grafts were required for all anastomoses. Donor tissue was secured in recipient orbits followed by sequential venous and arterial anastomoses and nerve coaptation. Pedicle lengths and calibers were measured. All steps were timed, photographed, video recorded, and critically analyzed after each operative session.The technical feasibility of cadaveric donor procurement and transplantation to cadaveric recipient was established. Mean measurements included optic nerve length (39 mm) and caliber (5 mm), donor artery length (33 mm) and caliber (3 mm), and superior ophthalmic vein length (15 mm) and caliber (0.5 mm). Recipient superficial temporal, internal maxillary artery, and facial artery calibers were 0.8, 2, and 2 mm, respectively; and superior temporal and facial vein calibers were 0.8 and 2.5 mm, respectively.This surgical protocol serves as a benchmark for optimization of technique, large-animal model development, and ultimately potentiating the possibility of vision restoration transplantation surgery.Therapeutic, V.

  View details for PubMedID 27879599

  View details for PubMedCentralID PMC5457795

• Endoscopic endonasal skull base surgery for vascular lesions: a systematic review of the literature JOURNAL OF NEUROSURGICAL SCIENCES Vaz-Guimaraes, F., Gardner, P. A., Fernandez-Miranda, J. C., Wang, E. W., Snyderman, C. H. 2016; 60 (4): 503–13

  Abstract

  Endoscopic endonasal skull base surgery for vascular lesions is a controversial topic in neurosurgical practice. Concerns regarding the ability to effectively work through the relatively narrow and deep endonasal corridor and manage serious hemorrhagic complications such as inadvertent internal carotid artery (ICA) injury during endoscopic surgery (EES) are relevant sources of disagreement between neurosurgeons. Nevertheless, following careful preoperative evaluation, EES may be indicated for rare, well-selected cases, including medially-projecting paraclinoid aneurysms and cavernous malformations (CMs) located next to the ventral surface of the brainstem. To date, only small retrospective case series and case reports, attesting the safety, feasibility and technical aspects of the EES for aneurysm clipping, CM resection and arterio-venous malformations (AVMs), have been published in the literature.In this manuscript, we conducted a systematic review of the literature applying the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines on EES for treatment of intracranial vascular lesions. We discuss the indications, advantages, limitations and technical aspects of EES for vascular lesions.Although rarely indicated, EES may be considered as an alternative treatment and part of the armamentarium of cerebrovascular neurosurgeons dealing with these challenging lesions.

  View details for PubMedID 27327518

• Endoscopic transnasal skull base surgery: pushing the boundaries JOURNAL OF NEURO-ONCOLOGY Zwagerman, N. T., Zenonos, G., Lieber, S., Wang, W., Wang, E. W., Fernandez-Miranda, J. C., Snyderman, C. H., Gardner, P. A. 2016; 130 (2): 319–30

  Abstract

  The endoscopic endonasal approach (EEA) has significantly evolved since its initial uses in pituitary and sinonasal surgery. The literature is filled with reports and case series demonstrating efficacy and advantages for the entire ventral skull base. With competence in 'minimally invasive' parasellar approaches, larger and more complex approaches were developed to utilize the endonasal corridor to create maximally invasive endoscopic skull base procedures. The challenges of these more complex endoscopic procedures include a long learning curve and navigating in a narrow corridor; reconstruction of defects presented new challenges and early experience revealed a significantly higher risk of cerebrospinal fluid leak. Despite these challenges, there are many benefits to the EEA including avoidance of brain and neurovascular retraction, improved visualization, a direct corridor onto many tumors and the two-surgeon approach. Most importantly, the EEA provides a midline corridor to directly access tumors, which displace critical neurovascular structures laterally, giving it an inherent advantage of minimizing any manipulation of these structures and thus decreasing their potential injury.

  View details for PubMedID 27766473

• Do Corticosteroids Compromise Survival in Glioblastoma? NEUROSURGERY Alkhalili, K., Zenonos, G., Fernandez-Miranda, J. C. 2016; 79 (4): N15–N16

  View details for PubMedID 27635969

• Clinical Considerations for Vascularized Composite Allotransplantation of the Eye JOURNAL OF CRANIOFACIAL SURGERY Davidson, E. H., Wang, E. W., Yu, J. Y., Fernandez-Miranda, J. C., Wang, D. J., Li, Y., Miller, M., Sivak, W. N., Bourne, D., Wang, H., Solari, M. G., Schuman, J. S., Washington, K. M. 2016; 27 (7): 1622–28

  Abstract

  Vascularized composite allotransplantation represents a potential shift in approaches to reconstruction of complex defects resulting from congenital differences as well as trauma and other acquired pathology. Given the highly specialized function of the eye and its unique anatomical components, vascularized composite allotransplantation of the eye is an appealing method for restoration, replacement, and reconstruction of the nonfunctioning eye. Herein, we describe conventional treatments for eye restoration and their shortcomings as well as recent research and events that have brought eye transplantation closer to a potential clinical reality. In this article, we outline some potential considerations in patient selection, donor facial tissue procurement, eye tissue implantation, surgical procedure, and potential for functional outcomes.

  View details for PubMedID 27513765

  View details for PubMedCentralID PMC5342906

• Human Connectome-Based Tractographic Atlas of the Brainstem Connections and Surgical Approaches NEUROSURGERY Meola, A., Yeh, F., Fellows-Mayle, W., Weed, J., Fernandez-Miranda, J. C. 2016; 79 (3): 437–54

  Abstract

  The brainstem is one of the most challenging areas for the neurosurgeon because of the limited space between gray matter nuclei and white matter pathways. Diffusion tensor imaging-based tractography has been used to study the brainstem structure, but the angular and spatial resolution could be improved further with advanced diffusion magnetic resonance imaging (MRI).To construct a high-angular/spatial resolution, wide-population-based, comprehensive tractography atlas that presents an anatomical review of the surgical approaches to the brainstem.We applied advanced diffusion MRI fiber tractography to a population-based atlas constructed with data from a total of 488 subjects from the Human Connectome Project-488. Five formalin-fixed brains were studied for surgical landmarks. Luxol Fast Blue-stained histological sections were used to validate the results of tractography.We acquired the tractography of the major brainstem pathways and validated them with histological analysis. The pathways included the cerebellar peduncles, corticospinal tract, corticopontine tracts, medial lemniscus, lateral lemniscus, spinothalamic tract, rubrospinal tract, central tegmental tract, medial longitudinal fasciculus, and dorsal longitudinal fasciculus. Then, the reconstructed 3-dimensional brainstem structure was sectioned at the level of classic surgical approaches, namely supracollicular, infracollicular, lateral mesencephalic, perioculomotor, peritrigeminal, anterolateral (to the medulla), and retro-olivary approaches.The advanced diffusion MRI fiber tracking is a powerful tool to explore the brainstem neuroanatomy and to achieve a better understanding of surgical approaches.CN, cranial nerveCPT, corticopontine tractCST, corticospinal tractCTT, central tegmental tractDLF, dorsal longitudinal fasciculusHCP, Human Connectome ProjectML, medial lemniscusMLF, medial longitudinal fasciculusRST, rubrospinal tractSTT, spinothalamic tract.

  View details for PubMedID 26914259

• A description of the anatomy of the glossopharyngeal nerve as encountered in transoral surgery LARYNGOSCOPE Wang, C., Kundaria, S., Fernandez-Miranda, J., Duvvuri, U. 2016; 126 (9): 2010–15

  Abstract

  To illustrate detailed anatomy of the extracranial portion of the glossopharyngeal nerve in the parapharyngeal space as encountered during transoral surgery.Prospective cadaveric dissection. All dissections were performed transorally and confirmed with transcervical dissection.Eight color-injected cadaveric heads (16 sides) were dissected to demonstrate the course and anatomy of the glossopharyngeal nerve. Conventional external dissections were performed to verify our anatomic measurements. Anatomical measurements of the glossopharyngeal nerve, including segments, branches in each segment, relationship with stylopharyngeus muscle, internal carotid artery, and pharyngeal branch of Vagus were recorded and analyzed.The glossopharyngeal nerve was separated into three segments according to the relationship with the stylopharyngeus muscle. Total lengths of the glossopharyngeal nerve are 32.6 ± 3.1 (left side) and 30.6 ± 3.7 (right side) mm, respectively. The average number of branches in the upper, middle, and lower segments is 3 (range 1-3), 4 (range 2-4), and 3 (range 1-3), respectively. The total number of branches is 8 (range 6-9). The average diameter of the main trunk of the glossopharyngeal nerve is 1.2 ± 0.3 mm, and the average diameter of the lingual branch of the glossopharyngeal nerve is approximately 0.6 ± 0.2 mm. In 75% of cases, pharyngeal branch of Vagus crosses the glossopharyngeal nerve, whereas in 25% of cases it parallels the course of the glossopharyngeal nerve to form the pharyngeal nerve plexus to innervate the pharyngeal wall.Understanding the precise and detailed anatomy of the glossopharyngeal nerve in the parapharyngeal space is important in transoral surgery for indications such as transoral robotic surgery or transoral laser microsurgery tumor resection, lingual tonsillectomy, glossopharyngeal neuralgia, glossopharyngeal nerve block, and internal carotid artery dissection.N/A. Laryngoscope, 126:2010-2015, 2016.

  View details for PubMedID 27312369

• Total Human Eye Allotransplantation (THEA): Preclincal Cadaveric Studies Miller, M. R., Davidson, E. H., Wang, E. W., Yu, J., Fernandez-Miranda, J. C., Wang, D. J., Schuman, J. S., Washington, K. M. ASSOC RESEARCH VISION OPHTHALMOLOGY INC. 2016

  View details for Web of Science ID 000394174002127

• Prof. Rhoton: Master and Mentor Tribute JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Fernandez-Miranda, J. C. 2016; 77 (4): 288–90

  View details for PubMedID 27478755

  View details for PubMedCentralID PMC4949055

• Visual Outcomes after Endoscopic Endonasal Approach for Craniopharyngioma: The Pittsburgh Experience JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Stefko, S., Snyderman, C., Fernandez-Miranda, J., Tyler-Kabara, E., Wang, E., Bodily, L., Bilonick, R. A., Gardner, P. A. 2016; 77 (4): 326–32

  Abstract

  This series of patients has been published in the neurosurgical literature earlier this year, detailing multiple aspects of both the surgical technique and postoperative outcomes. Our aim in this series is not to revisit all the aspects of this publication, but rather to analyze more specifically the benefits of this procedure as it pertains to the preservation of neurological structures of vision-specifically the optic chiasm-and provide a more detailed analysis of visual outcomes in these patients.

  View details for PubMedID 27441158

  View details for PubMedCentralID PMC4949065

• High-Definition Fiber Tractography in the Evaluation and Surgical Planning of Lhermitte-Duclos Disease: A Case Report WORLD NEUROSURGERY Fernandes-Cabral, D. T., Zenonos, G. A., Hamilton, R. L., Panesar, S. S., Fernandez-Miranda, J. C. 2016; 92: 587.e9–587.e13

  Abstract

  Preoperative delineation of normal tissue displacement patterns in Lhermitte-Duclos disease has not been feasible with conventional imaging means. Surgical resection of this type of lesion remains challenging, because the boundaries of the lesion are indistinguishable during surgery.The clinical presentation, preoperative and postoperative magnetic resonance imaging (MRI) findings, high-definition fiber tractography (HDFT) and histopathological studies, are presented in a 46-year-old male subject with symptomatic Lhermitte-Duclos disease. HDFT was performed using a quantitative anisotropy-based generalized deterministic tracking algorithm to define fiber tracts. Displacement of the cerebellar and brainstem tracts on the affected side was performed using the unaffected contralateral side as a comparison. The displacement of the normal tissues was not apparent on preoperative MRI but was immediately evident on the preoperative HDFT. Of note, there was a relative paucity of fiber tracts within the lesion. By tailoring our operative boundaries based on the HDFT findings, we were able to spare the displaced fiber tracts when debulking the tumor. Restoration of normal fiber tract anatomy on postoperative HDFT imaging was correlated with clinical resolution of preoperative symptoms.This case report suggests that HDFT may be a powerful surgical planning tool in cases of Lhermitte-Duclos disease, in which the pattern of normal tissue displacement is not evident with conventional imaging, allowing maximal lesion resection without damage to the unaffected tracts. Therefore, this report contributes to solving the greatest challenge when operating on this type of lesion, which has not been resolved in any previous report in our review of the English literature.

  View details for PubMedID 27168233

• Alu Methylation in Peripheral Blood Shows Promise for the Diagnosis and Prognostication of Glioma Patients WORLD NEUROSURGERY Alkhalili, K., Zenonos, G., Fernandez-Miranda, J. 2016; 92: 471–72

  View details for PubMedID 27262648

• Visualization of Cranial Nerves Using High-Definition Fiber Tractography NEUROSURGERY Yoshino, M., Abhinav, K., Yeh, F., Panesar, S., Fernandes, D., Pathak, S., Gardner, P. A., Fernandez-Miranda, J. C. 2016; 79 (1): 146–65

  Abstract

  Recent studies have demonstrated diffusion tensor imaging tractography of cranial nerves (CNs). Spatial and angular resolution, however, is limited with this modality. A substantial improvement in image resolution can be achieved with high-angle diffusion magnetic resonance imaging and atlas-based fiber tracking to provide detailed trajectories of CNs.To use high-definition fiber tractography to identify CNs in healthy subjects and patients with brain tumors.Five neurologically healthy adults and 3 patients with brain tumors were scanned with diffusion spectrum imaging that allowed high-angular-resolution fiber tracking. In addition, a 488-subject diffusion magnetic resonance imaging template constructed from the Human Connectome Project data was used to conduct atlas space fiber tracking of CNs.The cisternal portions of most CNs were tracked and visualized in each healthy subject and in atlas fiber tracking. The entire optic radiation, medial longitudinal fasciculus, spinal trigeminal nucleus/tract, petroclival portion of the abducens nerve, and intrabrainstem portion of the facial nerve from the root exit zone to the adjacent abducens nucleus were identified. This suggested that the high-angular-resolution fiber tracking was able to distinguish the facial nerve from the vestibulocochlear nerve complex. The tractography clearly visualized CNs displaced by brain tumors. These tractography findings were confirmed intraoperatively.Using high-angular-resolution fiber tracking and atlas-based fiber tracking, we were able to identify all CNs in unprecedented detail. This implies its potential in localization of CNs during surgical planning.CN, cranial nerveDSI, diffusion spectrum imagingDTI, diffusion tensor imagingHCP, Human Connectome ProjectHDFT, high-definition fiber tractographyMLF, medial longitudinal fasciculusODF, orientation distribution functionROI, region of interest.

  View details for PubMedID 27070917

• Management of Major Vascular Injury During Endoscopic Endonasal Skull Base Surgery OTOLARYNGOLOGIC CLINICS OF NORTH AMERICA Gardner, P. A., Snyderman, C. H., Fernandez-Miranda, J. C., Jankowitz, B. T. 2016; 49 (3): 819-+

  Abstract

  A major vascular injury is the most feared complication of endoscopic sinus and skull base surgery. Risk factors for vascular injury are discussed, and an algorithm for management of a major vascular injury is presented. A team of surgeons (otolaryngology and neurosurgery) is important for identification and control of a major vascular injury applying basic principles of vascular control. A variety of techniques can be used to control a major injury, including coagulation, a muscle patch, sacrifice of the artery, and angiographic stenting. Immediate and close angiographic follow-up is critical to prevent and manage subsequent complications of vascular injury.

  View details for PubMedID 27267028

• Interfascial Dissection for Protection of the Nerve Branches to the Frontalis Muscles during Supraorbital Trans-Eyebrow Approach: An Anatomical Study and Technical Note JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Mathias, R., Lieber, S., Pires de Aguiar, P., Calfat Maldaun, M., Gardner, P., Fernandez-Miranda, J. C. 2016; 77 (3): 265–70

  Abstract

  Introduction Preservation of the temporal branches of the facial nerve during anterolateral craniotomies is important. Damaging it can inflict undesirable cosmetic defects to the patient. The supraorbital trans-eyebrow approach (SOTE) is a versatile keyhole craniotomy but still has a high rate of frontalis muscle (FM) palsy. Objective Anatomical study to implement the interfascial dissection during the SOTE to preserve the nerves to the FM. Methods Slight modification of the standard technique of the SOTE was performed in 6 cadaveric specimens (12 sides). Results Distal rami to the FM were exposed. The standard "u-shape" incision of the FM can cross over the nerves. Alternatively, an "l-shape" incision was performed until the superior temporal line (STL). An interfascial dissection was performed near to the STL and the interfascial fat pad was used as a protective layer for the nerves. Conclusion Various pathologies can be addressed with the SOTE. In the majority of the cases the cosmetic results are good, but FM palsy remains a drawback of this approach. The interfascial dissection may be used in an attempt to prevent frontalis rami palsy.

  View details for PubMedID 27175323

  View details for PubMedCentralID PMC4862837

• The nondecussating pathway of the dentatorubrothalamic tract in humans: human connectome-based tractographic study and microdissection validation JOURNAL OF NEUROSURGERY Meola, A., Comert, A., Yeh, F., Sivakanthan, S., Fernandez-Miranda, J. C. 2016; 124 (5): 1406–12

  Abstract

  OBJECT The dentatorubrothalamic tract (DRTT) is the major efferent cerebellar pathway arising from the dentate nucleus (DN) and decussating to the contralateral red nucleus (RN) and thalamus. Surprisingly, hemispheric cerebellar output influences bilateral limb movements. In animals, uncrossed projections from the DN to the ipsilateral RN and thalamus may explain this phenomenon. The aim of this study was to clarify the anatomy of the dentatorubrothalamic connections in humans. METHODS The authors applied advanced deterministic fiber tractography to a template of 488 subjects from the Human Connectome Project (Q1-Q3 release, WU-Minn HCP consortium) and validated the results with microsurgical dissection of cadaveric brains prepared according to Klingler's method. RESULTS The authors identified the "classic" decussating DRTT and a corresponding nondecussating path (the nondecussating DRTT, nd-DRTT). Within each of these 2 tracts some fibers stop at the level of the RN, forming the dentatorubro tract and the nondecussating dentatorubro tract. The left nd-DRTT encompasses 21.7% of the tracts and 24.9% of the volume of the left superior cerebellar peduncle, and the right nd-DRTT encompasses 20.2% of the tracts and 28.4% of the volume of the right superior cerebellar peduncle. CONCLUSIONS The connections of the DN with the RN and thalamus are bilateral, not ipsilateral only. This affords a potential anatomical substrate for bilateral limb motor effects originating in a single cerebellar hemisphere under physiological conditions, and for bilateral limb motor impairment in hemispheric cerebellar lesions such as ischemic stroke and hemorrhage, and after resection of hemispheric tumors and arteriovenous malformations. Furthermore, when a lesion is located on the course of the dentatorubrothalamic system, a careful preoperative tractographic analysis of the relationship of the DRTT, nd-DRTT, and the lesion should be performed in order to tailor the surgical approach properly and spare all bundles.

  View details for PubMedID 26452117

• 2-Hydroxy-Glutarate 3-Dimensional Functional Spectroscopy in the Evaluation of Isocitrate Dehydrogenase-Mutant Glioma Response to Therapy NEUROSURGERY Alkhalili, K., Zenonos, G. A., Fernandez-Miranda, J. C. 2016; 78 (4): N9

  View details for PubMedID 26986647

• Nasal Deformities Following Nasoseptal Flap Reconstruction of Skull Base Defects JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Rowan, N. R., Wang, E. W., Gardner, P. A., Fernandez-Miranda, J. C., Snyderman, C. H. 2016; 77 (1): 14–18

  Abstract

  Objectives To identify the prevalence and risk factors for nasal deformities after endoscopic endonasal surgery (EES) of the skull base. Design Retrospective case series. Setting Tertiary referral academic center. Participants EES patients from January 2011 to October 2013. Main Outcome Measures Surgical approach, method of skull base reconstruction, and postoperative nasal deformities. Results Of 328 patients, 19 patients (5.8%) had nasal dorsum collapse, 3 (0.9%) with new septal perforations and 2 (0.6%) with septal deviations requiring surgical correction. Postoperative deformities were only found in the setting of nasoseptal flap reconstruction (p = 0.0001) and were most common in patients who had undergone an approach involving more than one anatomical subsite (p = 0.0021). Patients with nasal deformities were on average 6 years younger (p = 0.08) and were more likely to have a malignant pathology (p = 0.08). Conclusions All deformities were associated with use of a nasoseptal flap for reconstruction and were most common in combined approaches, suggesting that flap size may play a role in the development of nasal deformities. The mechanism of nasal dorsum collapse is unclear but does not appear to be related to septal cartilage necrosis. These findings warrant a prospective analysis to identify risk factors for postoperative nasal deformities and data for counseling of patients.

  View details for PubMedID 26949583

  View details for PubMedCentralID PMC4777617

• Skull Base Anatomy OTOLARYNGOLOGIC CLINICS OF NORTH AMERICA Patel, C. R., Fernandez-Miranda, J. C., Wang, W., Wang, E. W. 2016; 49 (1): 9-+

  Abstract

  The anatomy of the skull base is complex with multiple neurovascular structures in a small space. Understanding all of the intricate relationships begins with understanding the anatomy of the sphenoid bone. The cavernous sinus contains the carotid artery and some of its branches; cranial nerves III, IV, VI, and V1; and transmits venous blood from multiple sources. The anterior skull base extends to the frontal sinus and is important to understand for sinus surgery and sinonasal malignancies. The clivus protects the brainstem and posterior cranial fossa. A thorough appreciation of the anatomy of these various areas allows for endoscopic endonasal approaches to the skull base.

  View details for PubMedID 26614826

• Atlanto-occipital Instability Following Endoscopic Endonasal Approach for Lower Clival Lesions: Experience With 212 Cases NEUROSURGERY Kooshkabadi, A., Choi, P. A., Koutourousiou, M., Snyderman, C. H., Wang, E. W., Fernandez-Miranda, J. C., Gardner, P. A. 2015; 77 (6): 888–97

  Abstract

  The endoscopic endonasal approach (EEA) for craniocervical lesions involving the lower clivus and occipital condyles carries an unclear risk of atlanto-occipital (AO) instability requiring arthrodesis.Elucidate risk factors for AO instability following EEA for clival lesions.We reviewed patients with clival tumors who underwent EEA at our institution between 2002 and 2012. Resection of the lower clivus, foramen magnum, AO joint, and occipital condyles were evaluated on fine-cut postoperative computed tomography.Two hundred twelve patients (mean age 47.9 years, 57.1% male) underwent transclival EEA for lower clival lesions. In addition to the lower clivus, resection involved the condyle in 14.2% of patients, the foramen magnum in 16.5%, and the AO joint in 1.4%. Quantification of condyle resection revealed complete resection in 3 cases, 75% resection in 8 cases, 50% resection in 6 cases, and 25% resection in 13 cases. Seven of these patients had EEA combined with an open, far-lateral approach. In total, 7 patients required arthrodesis following EEA (3.3%), 4 of them after a combined approach. All patients who underwent arthrodesis had primary bone tumors such as chordoma, chondrosarcoma, or osteosarcoma (P = .022). Degree of condyle resection was a significant factor predisposing to occipitocervical instability (P = .001 and P < .001 for 75% and 100% condyle resection, respectively). Use of a combined approach was significantly associated with arthrodesis (P < .001).EEA resection of the occipital condyles that results in greater than 75% condyle resection or EEA in combination with an open approach significantly increases the risk of AO instability and likely necessitates AO fixation.AO, atlanto-occipitalEEA, endoscopic endonasal approachOC, occipitocervical.

  View details for PubMedID 26237341

• The Controversial Existence of the Human Superior Fronto-Occipital Fasciculus: Connectome-Based Tractographic Study With Microdissection Validation HUMAN BRAIN MAPPING Meola, A., Comert, A., Yeh, F., Stefaneanu, L., Fernandez-Miranda, J. C. 2015; 36 (12): 4964–71

  Abstract

  The superior fronto-occipital fasciculus (SFOF), a long association bundle that connects frontal and occipital lobes, is well-documented in monkeys but is controversial in human brain. Its assumed role is in visual processing and spatial awareness. To date, anatomical and neuroimaging studies on human and animal brains are not in agreement about the existence, course, and terminations of SFOF. To clarify the existence of the SFOF in human brains, we applied deterministic fiber tractography to a template of 488 healthy subjects and to 80 individual subjects from the Human Connectome Project (HCP) and validated the results with white matter microdissection of post-mortem human brains. The imaging results showed that previous reconstructions of the SFOF were generated by two false continuations, namely between superior thalamic peduncle (STP) and stria terminalis (ST), and ST and posterior thalamic peduncle. The anatomical microdissection confirmed this finding. No other fiber tracts in the previously described location of the SFOF were identified. Hence, our data suggest that the SFOF does not exist in the human brain.

  View details for PubMedID 26435158

  View details for PubMedCentralID PMC4715628

• Comparison of endoscopic endonasal and bifrontal craniotomy approaches for olfactory groove meningiomas: A matched pair analysis of outcomes and frontal lobe changes on MRI. Journal of clinical neuroscience de Almeida, J. R., Carvalho, F., Vaz Guimaraes Filho, F., Kiehl, T., Koutourousiou, M., Su, S., Vescan, A. D., Witterick, I. J., Zadeh, G., Wang, E. W., Fernandez-Miranda, J. C., Gardner, P. A., Gentili, F., Snyderman, C. H. 2015; 22 (11): 1733-1741

  Abstract

  We compare the outcomes and postoperative MRI changes of endoscopic endonasal (EEA) and bifrontal craniotomy (BFC) approaches for olfactory groove meningiomas (OGM). All patients who underwent either BFC or EEA for OGM were eligible. Matched pairs were created by matching tumor volumes of an EEA patient with a BFC patient, and matching the timing of the postoperative scans. The tumor dimensions, peritumoral edema, resectability issues, and frontal lobe changes were recorded based on preoperative and postoperative MRI. Postoperative fluid-attenuated inversion recovery (FLAIR) hyperintensity and residual cystic cavity (porencephalic cave) volume were compared using univariable and multivariable analyses. From a total of 70 patients (46 EEA, 24 BFC), 10 matched pairs (20 patients) were created. Three patients (30%) in the EEA group and two (20%) in the BFC had postoperative cerebrospinal fluid leaks (p=0.61). Gross total resections were achieved in seven (70%) of the EEA group and nine (90%) of the BFC group (p=0.26), and one patient from each group developed a recurrence. On postoperative MRI, there was no significant difference in FLAIR signal volumes between EEA and BFC approaches (6.9 versus 13.3 cm(3); p=0.17) or in porencephalic cave volumes (1.7 versus 5.0 cm(3); p=0.11) in univariable analysis. However, in a multivariable analysis, EEA was associated with less postoperative FLAIR change (p=0.02) after adjusting for the volume of preoperative edema. This study provides preliminary evidence that EEA is associated with quantifiable improvements in postoperative frontal lobe imaging.

  View details for DOI 10.1016/j.jocn.2015.03.056

  View details for PubMedID 26275331

• Endoscopic Endonasal Clipping of Intracranial Aneurysms: Surgical Technique and Results WORLD NEUROSURGERY Gardner, P. A., Vaz-Guimaraes, F., Jankowitz, B., Koutourousiou, M., Fernandez-Miranda, J. C., Wang, E. W., Snyderman, C. H. 2015; 84 (5): 1380–93

  Abstract

  Microsurgical clipping of intracranial aneurysms requires meticulous technique and is usually performed through open approaches. Endoscopic endonasal clipping of intracranial aneurysms may use the same techniques through an alternative corridor. The aim of this article is to report a series of patients who underwent an endoscopic endonasal approach (EEA) for microsurgical clipping of intracranial aneurysms.We conducted a retrospective chart review. Surgical outcome and complications were noted. The conceptual application and the technical nuances of these procedures are discussed.Ten patients underwent EEA for clipping of 11 intracranial aneurysms arising from the paraclinoidal internal carotid artery (n = 9) and vertebrobasilar system (n = 2). The internal carotid artery aneurysms projected medially, whereas the vertebrobasilar artery aneurysms were directly ventral to the brainstem with low-lying basilar apices. One patient required craniotomy for distal control given the size and thrombosed nature of the aneurysm. Proximal and distal vascular control with direct visualization of the aneurysm was obtained in all patients. In all cases, aneurysms were completely occluded. Among complications, 3 patients had postoperative cerebrospinal fluid leakage and 2 other patients had meningitis. Two patients suffered lacunar strokes. One recovered completely and the other remains with mild disabling symptoms.EEAs can provide direct access for microsurgical clipping of rare and carefully selected intracranial aneurysms. The basic principles of cerebrovascular surgery have to be followed throughout the procedure. These surgeries require a skull base team with a neurosurgeon well versed in both endoscopic endonasal and cerebrovascular surgery, working in concert with an otolaryngologist experienced in skull base endoscopy and reconstruction.

  View details for PubMedID 26117084

• Longitudinal evaluation of corticospinal tract in patients with resected brainstem cavernous malformations using high-definition fiber tractography and diffusion connectometry analysis: preliminary experience JOURNAL OF NEUROSURGERY Faraji, A. H., Abhinav, K., Jarbo, K., Yeh, F., Shin, S. S., Pathak, S., Hirsch, B. E., Schneider, W., Fernandez-Miranda, J. C., Friedlander, R. M. 2015; 123 (5): 1133–44

  Abstract

  Brainstem cavernous malformations (CMs) are challenging due to a higher symptomatic hemorrhage rate and potential morbidity associated with their resection. The authors aimed to preoperatively define the relationship of CMs to the perilesional corticospinal tracts (CSTs) by obtaining qualitative and quantitative data using high-definition fiber tractography. These data were examined postoperatively by using longitudinal scans and in relation to patients' symptomatology. The extent of involvement of the CST was further evaluated longitudinally using the automated "diffusion connectometry" analysis.Fiber tractography was performed with DSI Studio using a quantitative anisotropy (QA)-based generalized deterministic tracking algorithm. Qualitatively, CST was classified as being "disrupted" and/or "displaced." Quantitative analysis involved obtaining mean QA values for the CST and its perilesional and nonperilesional segments. The contralateral CST was used for comparison. Diffusion connectometry analysis included comparison of patients' data with a template from 90 normal subjects.Three patients (mean age 22 years) with symptomatic pontomesencephalic hemorrhagic CMs and varying degrees of hemiparesis were identified. The mean follow-up period was 37.3 months. Qualitatively, CST was partially disrupted and displaced in all. Direction of the displacement was different in each case and progressively improved corresponding with the patient's neurological status. No patient experienced neurological decline related to the resection. The perilesional mean QA percentage decreases supported tract disruption and decreased further over the follow-up period (Case 1, 26%-49%; Case 2, 35%-66%; and Case 3, 63%-78%). Diffusion connectometry demonstrated rostrocaudal involvement of the CST consistent with the quantitative data.Hemorrhagic brainstem CMs can disrupt and displace perilesional white matter tracts with the latter occurring in unpredictable directions. This requires the use of tractography to accurately define their orientation to optimize surgical entry point, minimize morbidity, and enhance neurological outcomes. Observed anisotropy decreases in the perilesional segments are consistent with neural injury following hemorrhagic insults. A model using these values in different CST segments can be used to longitudinally monitor its craniocaudal integrity. Diffusion connectometry is a complementary approach providing longitudinal information on the rostrocaudal involvement of the CST.

  View details for PubMedID 26047420

• [Surgical anatomy, technique and application of endoscopic endonasal transpterygoid approach in skull base surgery]. Zhonghua er bi yan hou tou jing wai ke za zhi = Chinese journal of otorhinolaryngology head and neck surgery Liu, J., Han, J., Yang, D., Liu, D., Li, R., Yu, Y., Zhang, Q., Fernandez Miranda, J. C., Gardner, P. A., Snyderman, C. H. 2015; 50 (11): 909–14

  Abstract

  OBJECTIVE: To identify the landmarks of transpterygoid approach and to report its application in a series of cases.METHODS: Two silicon-injected adult cadaveric heads(4 sides) were dissected by performing an endoscopic endonasal transpterygoid approach after CT scanning for imaging guidance. High-quality pictures were obtained. This approach was used to treat twelve patients with skull base lesions including 3 spontaneous cerebrospinal fluid (CSF) leaks in the lateral recess of the sphenoid sinus, 2 neurofibromas and 2 Schwannomas involving the pterygopalatine fossa and infratemporal fossa, 1 dermoid cyst involving the middle fossa and infratemporal fossa, 1 invasive fungal sinusitis invading the middle fossa base, 1 basal cell adenoma in the upper parapharyngeal space, 1 chondrosarcoma in the parasellar region and 1 adenoid cystic carcinoma. Clinical records were reviewed.RESULTS: In terms of approach dissection, important landmarks, such as the sphenopalatine foramen and artery, vidian canal and nerve, foramen rotundum and maxillary branch of trigeminal nerve, foramen ovale and mandibular branch of trigeminal nerve, as well as pterygoid segment of Eustachian tube were identified. In terms of clinical data, three patients with spontaneous CSF leak underwent repair. Six patients with benign lesions underwent complete tumor resection. In the patient with invasive fungal disease, thorough debridement was undertaken and antifungal drug was administered for one month. For these benign skull base lesions, there was no recurrence during the follow-up period. In the patient with chondrosarcoma, most of the tumor was removed in the first operation, and was followed by two endoscopic operations because of fast growth of the tumor. Final control was achieved with chemotherapy and radiation. In the patient with adenoid cystic carcinoma, tumor recurred five years after surgery, and was reoperated.CONCLUSION: An understanding of the landmarks of the transpterygoid approach is paramount for surgically dealing with disease located within and adjacent to the region of the pterygoid process of the sphenoid bone. The endoscopic endonasal transpterygoid approach is feasible and safe in selected patients with skull base lesions.

  View details for PubMedID 26887995

• Anatomy of the posterior septal artery with surgical implications on the vascularized pedicled nasoseptal flap HEAD AND NECK-JOURNAL FOR THE SCIENCES AND SPECIALTIES OF THE HEAD AND NECK Zhang, X., Wang, E. W., Wei, H., Shi, J., Snyderman, C. H., Gardner, P. A., Fernandez-Miranda, J. C. 2015; 37 (10): 1470–76

  Abstract

  The purpose of this study was to define the anatomic characteristics of the posterior septal artery related to the design of the vascularized pedicled nasoseptal flap.The course and branching pattern of the posterior septal artery and its relationship with landmarks and other regional arteries were studied in 26 vascular latex-injected head sides.The posterior septal artery is divided into 2 septal branches within the sphenoidal segment, which occurred either close to the sphenopalatine foramen (65.4%) or at the posterior border of the nasal septum (34.6%). The inferior branch was frequently dominant (61.5%). The dominant branch was always below the axial plane of the sphenoid ostium. On the posterior nasal septum, the inferior branch may run downward before coursing anteroinferiorly.We identify 2 high-risk areas for the design of the vascularized PNSF, namely, at the inferior aspect of the sphenoid ostium and the junction of the posterior nasal septum and the choana arch.

  View details for PubMedID 24846837

• Screw fixation technique JOURNAL OF NEUROSURGERY-SPINE Gardner, P. A., Fernandez-Miranda, J. C., Snyderman, C. H., Wang, E. W. 2015; 23 (4): 536–37

  View details for PubMedID 26161516

• Impact of Dynamic Endoscopy and Bimanual-Binarial Dissection in Endoscopic Endonasal Surgery Training: A Laboratory Investigation JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Vaz-Guimaraes, F., Rastelli, M. M., Fernandez-Miranda, J. C., Wang, E. W., Gardner, P. A., Snyderman, C. H. 2015; 76 (5): 365–71

  Abstract

  Objective The lack of a standard technique may be a relevant issue in teaching endoscopic endonasal surgery (EES) to novice surgeons. The objective of this article is to compare different endoscope positioning and microsurgical dissection techniques in EES training. Methods A comparative trial was designed to evaluate three techniques: group A, one surgeon performing binarial two-hands dissection using an endoscope holder (rigid endoscopy); group B, two surgeons performing a combined binarial two- and three-handed dissection with one surgeon guiding the endoscope (dynamic endoscopy); and group C, two surgeons performing a binarial two-hands dissection with one surgeon dedicated to endoscope positioning and the other dedicated to a two-handed dissection. Trainees were randomly assigned to these groups and oriented to complete surgical tasks in a validated training model for EES. A global rating scale, and a specific-task checklist for EES were used to assess surgical skills. Results The mean scores of the global rating scale and the specific-task checklist were higher (p = 0.001 and 0.002, respectively) for group C, reflecting the positive impact of dynamic endoscopy and bimanual dissection on training performance. Conclusions We found that dynamic endoscopic and bimanual-binarial microdissection techniques had a significant positive impact on EES training.

  View details for PubMedID 26401478

  View details for PubMedCentralID PMC4569494

• Hemostasis in Endoscopic Endonasal Skull Base Surgery JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Vaz-Guimaraes, F., Su, S. Y., Fernandez-Miranda, J. C., Wang, E. W., Snyderman, C. H., Gardner, P. A. 2015; 76 (4): 296–302

  Abstract

  William Halsted established the basic principles of modern surgical technique highlighting the importance of meticulous hemostasis and careful tissue handling. These concepts hold true today and are even more critical for endoscopic visualization, making hemostasis one of the most relevant cornerstones for the safe practice of endoscopic endonasal surgery (EES) of the skull base. During preoperative assessment, patients at higher risk for serious hemorrhagic complications must be recognized. From an anatomical point of view, EES can be grossly divided in two major components: sinonasal surgery and sellar-cranial base surgery. This division affects the choice of appropriate technique for control of bleeding that relies mainly on the source of hemorrhage, the tissue involved, and the proximity of critical neurovascular structures. Pistol-grip or single-shaft instruments constitute the most important and appropriately designed instruments available for EES. Electrocoagulation and a variety of hemostatic materials are also important tools and should be applied wisely. This article describes the experience of our team in the management of hemorrhagic events during EES with an emphasis on technical nuances.

  View details for PubMedID 26225320

  View details for PubMedCentralID PMC4516727

• Endonasal endoscopic surgery for squamous cell carcinoma of the sinonasal cavities and skull base: Oncologic outcomes based on treatment strategy and tumor etiology HEAD AND NECK-JOURNAL FOR THE SCIENCES AND SPECIALTIES OF THE HEAD AND NECK de Almeida, J. R., Su, S. Y., Koutourousiou, M., Guimaraes Filho, F., Miranda, J., Wang, E. W., Gardner, P. A., Snyderman, C. H. 2015; 37 (8): 1163–69

  Abstract

  Oncologic outcomes for sinonasal and skull base squamous cell carcinoma (SCC) treated with an endoscopic endonasal approach (EEA) needs investigation.Patients with SCC treated with EEA were stratified by treatment strategy and tumor etiology and reviewed.Thirty-four patients were treated with EEA, or which 27 had definitive resection and 7 had debulking surgery. In the definitive group, 17 had de novo tumors and 10 had tumors arising from inverted papilloma. Definitive resection was associated with better 5-year disease-free survival (DFS) and overall survival (OS) than debulking (62% vs 17%; p = .02; and 78% vs 30%; p = .03). Patients with de novo tumors had similar 5-year DFS and OS to those arising from inverted papilloma (62% vs 62%; p = .75; and 75% vs 86%; p = .24).Definitive resection of sinonasal SCC with EEA provides sound oncologic outcomes. SCC arising from inverted papilloma does not have prognostic significance.

  View details for PubMedID 24798497

• Response to Letter to the Editor on "Extended Inferior Turbinate Flap for Endoscopic Reconstruction of Skull Base Defects." J Neurol Surg B 2014;75(B4):225-230 JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Snyderman, C. H., Wang, E. W., Fernandez-Miranda, J. C., Gardner, P. A. 2015; 76 (3): 248

  View details for PubMedID 26225309

  View details for PubMedCentralID PMC4433387

• Fully endoscopic retrosigmoid approach for posterior petrous meningioma and trigeminal microvascular decompression ACTA NEUROCHIRURGICA Vaz-Guimaraes, F., Gardner, P. A., Fernandez-Miranda, J. C. 2015; 157 (4): 611–15

  Abstract

  Cerebellopontine angle tumor resection and cranial nerve microvascular decompression are usually performed with the aid of the surgical microscope. The endoscope is commonly used as an adjuvant.A retrosigmoid craniectomy is done. Upon dural opening, the endoscope is inserted into the operative field along the petrotentorial junction. Cerebrospinal fluid drainage provides a wider space for introduction of the endoscope and surgical instruments. Traditional microsurgical techniques are used during the entire procedure.A fully endoscopic retrosigmoid approach is a safe and effective procedure for cerebellopontine angle tumor resection and cranial nerve microvascular decompression.• Careful examination of preoperative studies is needed to identify anatomical peculiarities. • Patient positioning: the head must be gently flexed and its vertex gently tilted toward the floor. • Neurophysiologic monitoring and intraoperative navigation. • Craniectomy: partial exposure of the transverse and sigmoid sinuses. • Curvilinear dural incision reflected laterally to minimize the risk of sinus injury. • Opening the cerebellomedullary cistern for CSF drainage and cerebellar relaxation. • Dynamic endoscopy enhances depth perception and must be performed by a team with experience in endoscopic intracranial surgery. • Traditional microsurgical techniques have to be applied during the entire operation. • Multilayer reconstruction, including watertight dural closure. • Meningiomas causing brainstem shift are not suitable for endoscopic resection.

  View details for PubMedID 25596641

• Classification of Sphenoid Sinus Pneumatization: Relevance for Endoscopic Skull Base Surgery LARYNGOSCOPE Vaezi, A., Cardenas, E., Pinheiro-Neto, C., Paluzzi, A., Branstetter, B. F., Gardner, P. A., Snyderman, C. H., Fernandez-Miranda, J. C. 2015; 125 (3): 577–81

  Abstract

  The goal of this study was to present a classification based on the degree of pneumatization of the sphenoid sinus in the coronal plane that can be used to instruct preoperative planning for endoscopic endonasal surgery (EES).Observational anatomical study.The geometry of sphenoid sinus pneumatization was characterized (n = 204 hemisinus) on high-resolution computed tomography scans, and its associations with the location of the foramen rotundum (FR) and the vidian canal (VC) were measured. Based on these findings, we propose a simple classification of pneumatization of the sphenoid sinus relevant for EES.The lateral recess of the sphenoid sinus was pneumatized lateral to the FR in the coronal plane in 54% of patients. The distance separating the FR and the VC correlated strongly with the depth of the lateral recess. Based on these findings, we propose three types of pneumatization: type I, where the pneumatization extends from the midline to the medial edge of the VC (25%); type II, where the pneumatization reaches the medial edge of the FR (39%); and type III, where the pneumatization extends beyond the medial border of the FR (37%).The proposed sphenoid sinus pneumatization classification in the coronal plane is simple and reproducible. It predicts the distance between vidian and maxillary nerve, determines the size of the surgical window to access the middle cranial fossa transnasally, and instructs on the potential risk to neurovascular structures during surgery.

  View details for PubMedID 25417777

• Validation of a Chicken Wing Training Model for Endoscopic Microsurgical Dissection LARYNGOSCOPE Kaplan, D. J., Vaz-Guimaraes, F., Fernandez-Miranda, J. C., Snyderman, C. H. 2015; 125 (3): 571–76

  Abstract

  To determine if training with a chicken wing model improves performance of endoscopic endonasal surgery (EES) with microvascular dissection.Randomized experimental study.A single-blinded randomized clinical trial of trainees with various levels of endoscopic experience was conducted to determine if prior training on a nonhuman model augments endoscopic skill and efficiency in a surrogate model for live surgery. Medical students, residents, and fellows were randomized to two groups: a control group that performed an endoscopic transantral internal maxillary artery dissection on a silicone-injected anatomical specimen, and an interventional group that underwent microvascular dissection training on a chicken wing model prior to performing the anatomic dissection on the cadaver specimen. Time to completion and quality of dissection were measured.A Mann-Whitney test demonstrated a significant improvement in time and quality outcomes respectively across all interventional groups, with the greatest improvements seen in participants with less endoscopic experience: medical students (P = .032, P = .008), residents and fellows (P = .016, P = .032).Prior training on the chicken wing model improves surgical performance in a surrogate model for live EES.

  View details for PubMedID 25417605

• Delayed Nasoseptal Flaps for Endoscopic Skull Base Reconstruction: Proof of Concept and Evaluation of Outcomes OTOLARYNGOLOGY-HEAD AND NECK SURGERY Choby, G. W., Mattos, J. L., Hughes, M. A., Fernandez-Miranda, J. C., Gardner, P. A., Snyderman, C. H., Wang, E. W. 2015; 152 (2): 255-259

  Abstract

  To assess delayed nasoseptal flaps as a viable reconstructive option for sellar defects, evaluate postoperative vascularity of delayed nasoseptal flaps, and compare cerebrospinal fluid leak and surgery-specific complication rates of primary to delayed nasoseptal flaps.Case series with chart review.University of Pittsburgh Medical Center.All patients undergoing transsellar approaches for skull base tumors from 2009 to 2013 were evaluated. In cases where the necessity of a vascularized reconstructive flap was made evident only after tumor resection, the nasoseptal flap was raised after tumor resection and/or cerebrospinal fluid leak development, thus constituting a delayed nasoseptal flap. Outcome measures include postoperative magnetic resonance imaging (MRI) findings, cerebrospinal leak rates, and complication rates.During this timeframe, 437 patients underwent transsellar approaches. Primary nasoseptal flaps were used to reconstruct 179 patients while 32 patients had delayed flaps. All available postoperative MRI scans of delayed nasoseptal flap patients maintained vascularity on examination of T1 postcontrast images. There was no significant difference in cerebrospinal fluid leak rate between primary (3.4%) and delayed flaps (3.1%) (P = .95). There was no significant difference in surgery-specific complication rates between primary flaps (10.6%) and delayed flaps (3.1%; P = .14). Logistic regression analysis demonstrated no significant effect of flap type, age, or sex on cerebrospinal fluid leak rates.Delayed nasoseptal flaps are a viable reconstructive option for sellar skull base defects. They maintain vascularity as evidenced on postoperative MRI and are comparable to primary nasoseptal flaps with regard to cerebrospinal fluid leak rates and complication rates.

  View details for DOI 10.1177/0194599814561431

  View details for Web of Science ID 000349468100012

  View details for PubMedID 25475502

• "Round-the-Clock" Surgical Access to the Orbit JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Paluzzi, A., Gardner, P. A., Fernandez-Miranda, J. C., Tormenti, M. J., Stefko, S., Snyderman, C. H., Maroon, J. C. 2015; 76 (1): 12–24

  Abstract

  Objective To describe an algorithm to guide surgeons in choosing the most appropriate approach to orbital pathology. Methods A review of 12 selected illustrative cases operated on at the neurosurgical department of University of Pittsburgh Medical Center over 3 years from 2009 to 2011 was performed. Preoperative coronal magnetic resonance imaging and/or computed tomography views were compared using a "clock model" of the orbit with its center at the optic nerve. The rationale for choosing an external, endoscopic, or combined approach is discussed for each case. Results Using the right orbit for demonstration of the clock model, the medial transconjunctival approach provides access to the anterior orbit from 1 to 6 o'clock; endoscopic endonasal approaches provide access to the mid and posterior orbit and orbital apex from 1 to 7 o'clock. The lateral micro-orbitotomy gives access to the orbit from 8 to 10 o'clock. The frontotemporal craniotomy with orbital osteotomy accesses the orbit from 9 to 1 o'clock; addition of a zygomatic osteotomy to this extends access from 6 to 8 o'clock. Conclusions Combined, the approaches described provide 360 degrees of access to the entire orbit with the choice of the optimal approach guided primarily by the avoidance of crossing the plane of the optic nerve.

  View details for PubMedID 25685644

  View details for PubMedCentralID PMC4318736

• Discordance between growth hormone and insulin-like growth factor-1 after pituitary surgery for acromegaly: a stepwise approach and management PITUITARY Zeinalizadeh, M., Habibi, Z., Fernandez-Miranda, J. C., Gardner, P. A., Hodak, S. P., Challinor, S. M. 2015; 18 (1): 48–59

  Abstract

  Follow-up management of patients with acromegaly after pituitary surgery is performed by conducting biochemical assays of growth hormone (GH) and insulin-like growth factor-1 (IGF1). Despite concordant results of these two tests in the majority of cases, there is increasing recognition of patients who show persistent or intermittent discordance between GH and IGF1 (normal GH and elevated IGF1 or vice versa).In this narrative review, the last three decades materials on the issue of discrepancy between GH and IGF1 were thoroughly assessed.Various studies have obtained different discordance rates, ranging from 5.4 to 39.5%. At present, despite the use of current sensitive assays and more stringent criteria to define remission, the rate of discordance still remains high. A number of mechanisms have been proposed to explain the postoperative discordance of GH and IGF1 including; altered dynamics of the GH secretion after surgery, early postoperative hormone assay, inaccurate or less sensitive tests and laboratory errors, too high cut-off point for GH suppression in the GH assays, GH nadir values not adjusted to age, sex, and body mass index, the influence of concomitant medication, co-existing physiologic and pathologic conditions, and many other proposed reasons. Nevertheless, the underlying mechanisms are still far from clear, and the solution continues to evade complete elucidation. Similarly, the impacts of such a discrepancy over mortality and morbidity and the risk of biochemical and/or clinical recurrence are unclear.As a challenging clinical problem, a stepwise evaluation and management of these patients appears to be more rational.

  View details for DOI 10.1007/s11102-014-0556-y

  View details for Web of Science ID 000351565400007

  View details for PubMedID 24496953

• Endoscopic endonasal posterior clinoidectomy Response JOURNAL OF NEUROSURGERY Fernandez-Miranda, J. C., Gardner, P. A., Snyderman, C. H. 2015; 122 (2): 479

  View details for Web of Science ID 000348408400040

  View details for PubMedID 25763434

• Peduncles Without Cerebellum: The Cerebellar Agenesis EUROPEAN NEUROLOGY Meola, A., Fernandez-Miranda, J. C. 2015; 74 (3-4): 162

  View details for DOI 10.1159/000441055

  View details for Web of Science ID 000366741200007

  View details for PubMedID 26452266

• Magnetic resonance imaging fluid-attenuated inversion recovery sequence signal reduction after endoscopic endonasal transcribiform total resection of olfactory groove meningiomas. Surgical neurology international Prevedello, D. M., Ditzel Filho, L. F., Fernandez-Miranda, J. C., Solari, D. n., do Espírito Santo, M. P., Wehr, A. M., Carrau, R. L., Kassam, A. B. 2015; 6: 158

  Abstract

  Olfactory groove meningiomas grow insidiously and compress adjacent cerebral structures. Achieving complete removal without further damage to frontal lobes can be difficult. Microsurgical removal of large lesions is a challenging procedure and usually involves some brain retraction. The endoscopic endonasal approaches (EEAs) for tumors arising from the anterior fossa have been well described; however, their effect on the adjacent brain tissue has not. Herein, the authors utilized the magnetic resonance imaging fluid attenuated inversion recovery (FLAIR) sequence signal as a marker for edema and gliosis on pre- and post-operative images of olfactory groove meningiomas, thus presenting an objective parameter for brain injury after surgical manipulation.Imaging of 18 olfactory groove meningiomas removed through EEAs was reviewed. Tumor and pre/postoperative FLAIR signal volumes were assessed utilizing the DICOM image viewer OsiriX(®). Inclusion criteria were: (1) No previous treatment; (2) EEA gross total removal; (3) no further treatment.There were 14 females and 4 males; the average age was 53.8 years (±8.85 years). Average tumor volume was 24.75 cm(3) (±23.26 cm(3), range 2.8-75.7 cm(3)), average preoperative FLAIR volume 31.17 cm(3) (±39.38 cm(3), range 0-127.5 cm(3)) and average postoperative change volume, 4.16 cm(3) (±6.18 cm(3), range 0-22.2 cm(3)). Average time of postoperative scanning was 6 months (range 0.14-20 months). In all cases (100%) gross total tumor removal was achieved. Nine patients (50%) had no postoperative FLAIR changes. In 2 patients (9%) there was minimal increase of changes postoperatively (2.2 cm(3) and 6 cm(3) respectively); all others demonstrated image improvement. The most common complication was postoperative cerebrospinal fluid leakage (27.8%); 1 patient (5.5%) died due to systemic complications and pulmonary sepsis.FLAIR signal changes tend to resolve after endonasal tumor resection and do not seem to worsen with this operative technique.

  View details for PubMedID 26539309

  View details for PubMedCentralID PMC4604640

• Eustachian Tube and Internal Carotid Artery in Skull Base Surgery: An Anatomical Study LARYNGOSCOPE Liu, J., Pinheiro-Neto, C. D., Fernandez-Miranda, J. C., Snyderman, C. H., Gardner, P. A., Hirsch, B. E., Wang, E. 2014; 124 (12): 2655–64

  Abstract

  The eustachian tube (ET) is an important landmark in skull base surgery, which has a close relationship with the petrous segment of the internal carotid artery (ICA). The goal of the current study was to establish the detailed anatomic relationship of the ET and petrous segment of the ICA.Anatomical study.Six silicon-injected adult cadaveric heads (12 sides) were dissected using a lateral infratemporal fossa approach (type C) and endoscopic endonasal approach. The ET and ICA were exposed; their detailed relationships were demonstrated. High-quality pictures were obtained.In the anterior genu/foramen lacerum segment of the ICA, the vidian nerve was an important landmark. The cartilaginous ET was divided into four segments, from anterior to posterior: nasopharyngeal, pterygoid, lacerum, and petrosal segment. The anterior and inferior wall of the carotid canal was consistently between the horizontal ICA and petrous segment of the cartilaginous ET. In the posterior genu of the ICA, the bony part of the ET, and the tendon of the tensor tympani muscle were paramount landmarks. The posterior genu of the ICA was imbedded in the carotid canal. The landmarks of the junction of the cartilaginous ET and bony ET were the sphenoid spine and foramen spinosum.The anatomical segmentation of the ET provides the basis for safe and effective transection of the ET in skull base surgery. An understanding of the complex relationships of the ET and petrous segment of the ICA is paramount for surgically dealing with disease located within the region of the ET and petrous segment of the ICA.NA

  View details for PubMedID 25290349

• Advanced diffusion MRI fiber tracking in neurosurgical and neurodegenerative disorders and neuroanatomical studies: A review BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR BASIS OF DISEASE Abhinav, K., Yeh, F., Pathak, S., Suski, V., Lacomis, D., Friedlander, R. M., Fernandez-Miranda, J. C. 2014; 1842 (11): 2286–97

  Abstract

  Diffusion MRI enabled in vivo microstructural imaging of the fiber tracts in the brain resulting in its application in a wide range of settings, including in neurological and neurosurgical disorders. Conventional approaches such as diffusion tensor imaging (DTI) have been shown to have limited applications due to the crossing fiber problem and the susceptibility of their quantitative indices to partial volume effects. To overcome these limitations, the recent focus has shifted to the advanced acquisition methods and their related analytical approaches. Advanced white matter imaging techniques provide superior qualitative data in terms of demonstration of multiple crossing fibers in their spatial orientation in a three dimensional manner in the brain. In this review paper, we discuss the advancements in diffusion MRI and introduce their roles. Using examples, we demonstrate the role of advanced diffusion MRI-based fiber tracking in neuroanatomical studies. Results from its preliminary application in the evaluation of intracranial space occupying lesions, including with respect to future directions for prognostication, are also presented. Building upon the previous DTI studies assessing white matter disease in Huntington's disease and Amyotrophic lateral sclerosis; we also discuss approaches which have led to encouraging preliminary results towards developing an imaging biomarker for these conditions.

  View details for PubMedID 25127851

• Chondrosarcomas of the head and neck EUROPEAN ARCHIVES OF OTO-RHINO-LARYNGOLOGY Coca-Pelaz, A., Rodrigo, J. P., Triantafyllou, A., Hunt, J. L., Fernandez-Miranda, J. C., Strojan, P., de Bree, R., Rinaldo, A., Takes, R. P., Ferlito, A. 2014; 271 (10): 2601–9

  Abstract

  Chondrosarcoma represents approximately 11% of all primary malignant bone tumors. It is the second most common sarcoma arising in bone after osteosarcoma. Chondrosarcomas of the head and neck are rare and may involve the sinonasal tract, jaws, larynx or skull base. Depending on the anatomical location, the tumor can produce a variety of symptoms. Computed tomography and magnetic resonance imaging are the preferred imaging modalities. The histology of conventional chondrosarcoma is relatively straightforward; major challenges are the distinction between grade I chondrosarcomas and chondromas, and the differential diagnosis with chondroblastic osteosarcoma and chondroid chordoma. Surgery alone or followed by adjuvant radiotherapy is the treatment of choice. Radiotherapy alone has also been reported to be effective and can be considered if mutilating radical surgery is the only curative alternative. The 5-year survival for chondrosarcoma reaches 80%; distant metastases and/or local recurrences significantly worsen prognosis. The present review aims to summarize the current state of information about the biology, diagnosis and management of these rare tumors.

  View details for DOI 10.1007/s00405-013-2807-3

  View details for Web of Science ID 000341498500002

  View details for PubMedID 24213203

• A Description of Arterial Variants in the Transoral Approach to the Parapharyngeal Space CLINICAL ANATOMY Wang, C., Kundaria, S., Fernandez-Miranda, J., Duvvuri, U. 2014; 27 (7): 1016–22

  Abstract

  This study demonstrates variations in the vascular anatomy of the parapharyngeal space (PPS) as seen from the transoral approach compared with the transcervical approach. The PPS was dissected in injected cadaveric specimens. Anatomical measurements, including those of branches of the external and internal carotid arteries (ECA and ICA) and the styloglossus and stylopharyngeus muscles, were recorded and analyzed. In 67% (8/12) of cases, the ascending palatine artery (APA) originated from the facial artery and crossed the styloglossus muscle. The diameter of the APA at its origin was 1.4 ± 0.3 mm. In 75% (9/12) of cases, the ascending pharyngeal artery (aPA) arose from the medial surface of the ECA near its origin. In 58% (7/12) of cases, the aPA ascended vertically between the ICA and the lateral pharynx to the skull base, along the longus capitus muscle. The aPA crossed the styloglossus muscle 12.6 ± 3.9 mm from the insertion into the tongue. In 92% (11/12) of cases, the ECA and ICA were separated by the styloid diaphragm and pharyngeal venous plexus. In 8% (1/12), the ECA bulged into the parapharyngeal fat between the styloglossus and stylopharyngeus muscles adjacent to the pharyngeal constrictors. Knowledge of the precise anatomy of the PPS is important for transoral robotic surgery (TORS). Control of the vessels that supply and traverse the PPS can help the TORS surgeon avoid those critical structures and reduce surgical morbidity and potential hemorrhage.

  View details for PubMedID 24510490

• Endoscopic endonasal surgery for olfactory groove meningiomas: outcomes and limitations in 50 patients NEUROSURGICAL FOCUS Koutourousiou, M., Fernandez-Miranda, J. C., Wang, E. W., Snyderman, C. H., Gardner, P. A. 2014; 37 (4): E8

  Abstract

  Recently, endoscopic endonasal surgery (EES) has been introduced in the management of skull base tumors, with constantly improving outcomes and increasing indications. The authors retrospectively reviewed the effectiveness of EES in the management of olfactory groove meningiomas.Between February 2003 and December 2012, 50 patients (64% female) with olfactory groove meningiomas underwent EES at the University of Pittsburgh Medical Center. The authors present the results of EES and analyze the resection rates, clinical outcome, complications, and limitations of this approach.Forty-four patients presented with primary tumors, whereas six were previously treated elsewhere. The patients' mean age was 57.1 years (range 27-88 years). Clinical presentation included altered mental status (36%), visual loss (30%), headache (24%), and seizures (20%). The mean maximum tumor diameter was 41.6 mm (range 18-80 mm). All patients underwent EES, which was performed in stages in 18 giant tumors. Complete tumor resection (Simpson Grade I) was achieved in 66.7% of the 45 patients in whom it was the goal, and 13 (28.9%) had neartotal resection (> 95% of the tumor). Tumor size, calcification, and absence of cortical cuff from vasculature were significant factors that influenced the degree of resection (p = 0.002, p = 0.024, and p = 0.028, respectively). Tumor residual was usually at the most lateral and anterior tumor margins. Following EES, mental status was improved or normalized in 77.8% of the cases, vision was improved or restored in 86.7%, and headaches resolved in 83.3%. There was no postoperative deterioration of presenting symptoms. Complications were increased in tumors > 40 mm and included CSF leakage (30%), which was significantly associated with lobular tumor configuration (p = 0.048); pulmonary embolism/deep vein thrombosis, more commonly in elderly patients (20%); sinus infections (10%); and delayed abscess months or years after EES (6%). One patient had an intraoperative vascular injury resulting in transient hemiparesis (2%). There were no perioperative deaths. During a mean follow-up period of 32 months (median 22 months, range 1-115 months), 1 patient underwent repeat EES for tumor regrowth.Endoscopic endonasal surgery has shown good clinical outcomes regardless of patient age, previous treatment, or tumor characteristics. Tumor size > 40 mm, calcification, and absence of cortical vascular cuff limit GTR with EES; in addition, large tumors are associated with increased postoperative complications. Significant lateral and anterior dural involvement may represent indications for using traditional craniotomies for the management of these tumors. Postoperative CSF leakage remains a problem that necessitates innovations in EES reconstruction techniques.

  View details for DOI 10.3171/2014.7.FOCUS14330

  View details for Web of Science ID 000343230900009

  View details for PubMedID 25391163

• Endoscopic Endonasal Surgery for Tumors of the Cavernous Sinus: Experience of 234 Cases Koutourousiou, M., Guimaraes Filho, F., Fernandez-Miranda, J. C., Wang, E. W., Snyderman, C. H., Gardner, P. A. ELSEVIER SCIENCE INC. 2014: S68

  View details for DOI 10.1016/j.jamcollsurg.2014.07.159

  View details for Web of Science ID 000342420900134

• Extended Inferior Turbinate Flap for Endoscopic Reconstruction of Skull Base Defects JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Choby, G. W., Pinheiro-Neto, C. D., de Almeida, J. R., Ruiz-Valdepenas, E. C., Wang, E. W., Fernandez-Miranda, J. C., Gardner, P. A., Snyderman, C. H. 2014; 75 (4): 225-230

  Abstract

  Objective When the use of the nasoseptal flap for endoscopic skull base reconstruction has been precluded, the posterior pedicle inferior turbinate flap is a viable option for small midclival defects. Limitations of the inferior turbinate flap include its small surface area and limited arc of rotation. We describe a novel extended inferior turbinate flap that expands the reconstructive applications of this flap. Design Cadaveric anatomical study. Participants Cadaveric specimens. Main Outcome Measures Flap size, arc of rotation, and reconstructive applications were assessed. Results The average width of the flap was 5.46 ± 0.58 cm (7.32 ± 0.59 cm with septal mucosa). The average length of the flap was 5.01 ± 0.58 cm (5.28 ± 0.37 cm with septal mucosa). The average surface area of the flap was ∼ 27.26 ± 3.65 cm(2) (40.53 ± 6.45 cm(2) with septal mucosa). The extended inferior turbinate flap was sufficient to cover clival defects extending between the paraclival internal carotid arteries. The use of the flap in 22 cadavers and 5 clinical patients is described. Conclusion The extended inferior turbinate flap presents an additional option for reconstruction of skull base defects when the nasoseptal flap is unavailable.

  View details for DOI 10.1055/s-0033-1358791

  View details for Web of Science ID 000340488900002

  View details for PubMedID 25093144

  View details for PubMedCentralID PMC4108488

• Pontine encephalocele and abnormalities of the posterior fossa following transclival endoscopic endonasal surgery Clinical article JOURNAL OF NEUROSURGERY Koutourousiou, M., Guimaraes Filho, F., Costacou, T., Fernandez-Miranda, J. C., Wang, E. W., Snyderman, C. H., Rothfus, W. E., Gardner, P. A. 2014; 121 (2): 359–66

  Abstract

  Transclival endoscopic endonasal surgery (EES) has recently been used for the treatment of posterior fossa tumors. The optimal method of reconstruction of large clival defects following EES has not been established.A morphometric analysis of the posterior fossa was performed in patients who underwent transclival EES to compare those with observed postoperative anatomical changes (study group) to 50 normal individuals (anatomical control group) and 41 matched transclival cases with preserved posterior fossa anatomy (case-control group) using the same parameters. Given the absence of clival bone following transclival EES, the authors used the line between the anterior commissure and the basion as an equivalent to the clival plane to evaluate the location of the pons. Four parameters were studied and compared in the two populations: the pontine location/displacement, the maximum anteroposterior (AP) diameter of the pons, the maximum AP diameter of the fourth ventricle, and the cervicomedullary angle (CMA). All measurements were performed on midsagittal 3-month postoperative MR images in the study group.Among 103 posterior fossa tumors treated with transclival EES, 14 cases (13.6%) with postoperative posterior fossa anatomy changes were identified. The most significant change was anterior displacement of the pons (transclival pontine encephalocele) compared with the normal location in the anatomical control group (p < 0.0001). Other significant deformities were expansion of the AP diameter of the pons (p = 0.005), enlargement of the fourth ventricle (p = 0.001), and decrease in the CMA (p < 0.0001). All patients who developed these changes had undergone extensive resection of the clival bone (> 50% of the clivus) and dura. Nine (64.3%) of the 14 patients were overweight (body mass index [BMI] > 25 kg/m(2)). An association between BMI and the degree of pontine encephalocele was observed, but did not reach statistical significance. The use of a fat graft as part of the reconstruction technique following transclival EES with dural opening was the single significant factor that prevented pontine displacement (p = 0.02), associated with 91% lower odds of pontine encephalocele (OR = 0.09, 95% CI 0.01-0.77). The effect of fat graft reconstruction was more pronounced in overweight/obese individuals (p = 0.04) than in normal-weight patients (p = 0.52). Besides reconstruction technique, other noticeable findings were the tendency of younger adults to develop pontine encephalocele (p = 0.05) and the association of postoperative meningitis with the development of posterior fossa deformities (p = 0.05). One patient developed a transient, recurrent subjective diplopia; all others remained asymptomatic.Significant changes in posterior fossa anatomy that have potential clinical implications have been observed following transclival transdural EES. These changes are more common in younger patients or those with meningitis and may be associated with BMI. The use of a fat graft combined with the vascularized nasoseptal flap appears to minimize the risk of pontine herniation following transclival EES with dural opening.

  View details for DOI 10.3171/2013.12.JNS13756

  View details for Web of Science ID 000339473000018

  View details for PubMedID 24506240

• Endoscopic endonasal approach for pituitary adenomas: a series of 555 patients PITUITARY Paluzzi, A., Fernandez-Miranda, J. C., Stefko, S., Challinor, S., Snyderman, C. H., Gardner, P. A. 2014; 17 (4): 307–19

  Abstract

  To report the results of a consecutive series of patients who underwent an endoscopic endonasal approach (EEA) for resection of a pituitary adenoma and compare them to previous series of microscopic and endoscopic approaches.A retrospective review of clinical and radiographic outcomes of a consecutive series of patients operated at our center between 2002 and 2011 was performed.555 patients underwent an EEA for removal of a pituitary adenoma. The mean follow up was 3.1 years (range 3 months to 9.5 years); 36 were lost to follow up. Ninety-one (17.5%) harbored recurrent adenomas. An expanded approach to reach the supra-, para- and infra-sellar spaces was employed in 290 patients (55.9%). Reconstruction with a nasal septal flap was used in 238 cases (65.6%). The rate of gross total resection was 65.3% in the 359 patients with non-functioning adenomas. The remission rates with EEA alone were 82.5% in the 57 ACTH-secreting adenomas, 65.3% in the 49 GH-secreting adenomas and 54.7% in the 53 prolactinomas. Of the 237 patients presenting with visual loss, 190 (80.2%) improved or normalized, 41 (17.3%) remained unchanged and 4 (1.7%) experienced transient visual deterioration due to postoperative apoplexy. In addition, no patient without preexisting visual loss suffered new visual decline. The overall post-operative CSF leak rate was 5% and this decreased to 2.9% after the introduction of reconstruction with the naso-septal flap. Two patients (0.3%) had an ICA injury.The EEA is a safe and effective way to surgically approach pituitary adenomas, particularly in recurrent tumors, those with supra-sellar extension or cavernous sinus invasion. The remission and complication rates are comparable or favorable compared with those reported in previous series of microscopic and endoscopic approaches.

  View details for PubMedID 23907570

• Application of High-Definition Fiber Tractography in the Management of Supratentorial Cavernous Malformations: A Combined Qualitative and Quantitative Approach NEUROSURGERY Abhinav, K., Pathak, S., Richardson, R., Engh, J., Gardner, P., Yeh, F., Friedlander, R. M., Fernandez-Miranda, J. C. 2014; 74 (6): 668–80

  Abstract

  High-definition fiber tractography (HDFT), an advanced white matter (WM) imaging technique, was evaluated in the management of supratentorial cavernous malformations.To investigate the relationship of cavernous malformations to the relevant perilesional WM tracts with HDFT and to characterize associated changes first qualitatively and then quantitatively with our novel imaging measure, quantitative anisotropy (QA).Imaging analysis was carried out by researchers blinded to the clinical details. Contralateral WM tracts were used for comparison. Mean QA values were obtained for whole WM tracts. Qualitatively affected superior longitudinal fasciculus/arcuate fibers and corticospinal tracts were further analyzed with the use of mean QA values for the perilesional segments.Of 10 patients, HDFT assisted with the decision-making process and the offer of surgical resection in 2 patients, lesion approach and removal in 7 patients, and conservative management in 1 patient. Of 17 analyzed WM tracts, HDFT demonstrated partial disruption in 2 tracts, complete disruption in 2 tracts, a combination of displacement and partial disruption in 1 tract, displacement only in 7 tracts, and no change in 5 tracts. Qualitative changes correlated with clinical symptoms. Mean QA values for the whole WM tracts were similar, with the exception of 1 case demonstrating complete disruption of 2 WM tracts. QA-based perilesional segment analysis was consistent with qualitative data in 5 assessed WM tracts.HDFT illustrated the precise spatial relationship of cavernous malformations to multiple WM tracts in a 3-dimensional fashion, optimizing surgical planning, and demonstrated associated disruption and/or displacement, with both occurring perilesionally. These changes were supported by our quantitative marker, which needs further validation.

  View details for PubMedID 24589561

• Use of diffusion spectrum imaging in preliminary longitudinal evaluation of amyotrophic lateral sclerosis: development of an imaging biomarker FRONTIERS IN HUMAN NEUROSCIENCE Abhinav, K., Yeh, F., El-Dokla, A., Ferrando, L. M., Chang, Y., Lacomis, D., Friedlander, R. M., Fernandez-Miranda, J. C. 2014; 8: 270

  Abstract

  Previous diffusion tensor imaging (DTI) studies have shown white matter pathology in amyotrophic lateral sclerosis (ALS), predominantly in the motor pathways. Further these studies have shown that DTI can be used longitudinally to track pathology over time, making white matter pathology a candidate as an outcome measure in future trials. DTI has demonstrated application in group studies, however its derived indices, for example fractional anisotropy, are susceptible to partial volume effects, making its role questionable in examining individual progression. We hypothesize that changes in the white matter are present in ALS beyond the motor tracts, and that the affected pathways and associated pattern of disease progression can be tracked longitudinally using automated diffusion connectometry analysis. Connectometry analysis is based on diffusion spectrum imaging and overcomes the limitations of a conventional tractography approach and DTI. The identified affected white matter tracts can then be assessed in a targeted fashion using High definition fiber tractography (a novel white matter MR imaging technique). Changes in quantitative and qualitative markers over time could then be correlated with clinical progression. We illustrate these principles toward developing an imaging biomarker for demonstrating individual progression, by presenting results for five ALS patients, including with longitudinal data in two. Preliminary analysis demonstrated a number of changes bilaterally and asymmetrically in motoric and extramotoric white matter pathways. Further the limbic system was also affected possibly explaining the cognitive symptoms in ALS. In the two longitudinal subjects, the white matter changes were less extensive at baseline, although there was evidence of disease progression in a frontal pattern with a relatively spared postcentral gyrus, consistent with the known pathology in ALS.

  View details for PubMedID 24808852

• Application of Ultrasonic Bone Curette in Endoscopic Endonasal Skull Base Surgery: Technical Note JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Rastelli, M. M., Pinheiro-Neto, C. D., Fernandez-Miranda, J. C., Wang, E. W., Snyderman, C. H., Gardner, P. A. 2014; 75 (2): 90–95

  Abstract

  Background Endoscopic endonasal surgery (EES) of the skull base often requires extensive bone work in proximity to critical neurovascular structures. Objective To demonstrate the application of an ultrasonic bone curette during EES. Methods Ten patients with skull base lesions underwent EES from September 2011 to April 2012 at the University of Pittsburgh Medical Center. Most of the bone work was done with high-speed drill and rongeurs. The ultrasonic curette was used to remove specific structures. Results All the patients were submitted to fully endoscopic endonasal procedures and had critical bony structures removed with the ultrasonic bone curette. Two patients with degenerative spine diseases underwent odontoid process removal. Five patients with clival and petroclival tumors underwent posterior clinoid removal. Two patients with anterior fossa tumors underwent crista galli removal. One patient underwent unilateral optic nerve decompression. No mechanical or heat injury resulted from the ultrasonic curette. The surrounding neurovascular structures and soft tissue were preserved in all cases. Conclusion In selected EES, the ultrasonic bone curette was successfully used to remove loose pieces of bone in narrow corridors, adjacent to neurovascular structures, and it has advantages to high-speed drills in these specific situations.

  View details for PubMedID 24719795

  View details for PubMedCentralID PMC3969437

• Comparative Analysis of the Transcranial "Far Lateral" and Endoscopic Endonasal "Far Medial" Approaches: Surgical Anatomy and Clinical Illustration WORLD NEUROSURGERY Benet, A., Prevedello, D. M., Carrau, R. L., Rincon-Torroella, J., Fernandez-Miranda, J. C., Prats-Galino, A., Kassam, A. B. 2014; 81 (2): 385–96

  Abstract

  The main aim of our study was to analyze and compare the surgical anatomy pertinent to the dorsal transcranial transcondylar (far lateral approach) with that of the ventral endoscopic endonasal transcondylar (far medial approach) route.Eight cadaveric specimens were dissected and analyzed bilaterally. Brainstem exposure and surgical corridor areas were measured. In addition, we present three clinical scenarios to illustrate the clinical feasibility of the proposed surgical strategies.The hypoglossal nerve, vertebral artery, and hypoglossal canal divide the lower third of the clivus into ventromedial and dorsolateral compartments. The far medial approach provides significantly larger exposure of the brainstem in the ventromedial compartment (464.6 ± 68.34 mm(2)) compared with the far lateral approach (126.35 ± 32.25 mm(2)), P < 0.01. The far lateral approach provides a wide exposure of the brainstem in the dorsolateral compartment (295.24 ± 58.03 mm(2), 74% of the dorsolateral compartment). The exposure of the brainstem in the dorsolateral compartment is not possible using the endonasal route. The surgical corridor from one compartment to the other, through the lower cranial nerves, was significantly larger on the far lateral approach (78.19 ± 14.54 mm(2)) than on the far medial (23.77 ± 15.17 mm(2)), P = 0.03.The far medial approach offers a safe, wide exposure of the lower third of the clivus for lesions that expand ventromedial to the hypoglossal nerve. The far lateral approach is most suitable for lesions located dorsolateral to the lower cranial nerves. The vertebral artery and hypoglossal canal are the most important landmarks to guide surgical planning. A combined endonasal-transcranial approach should be considered for resection of extensive lesions involving both ventromedial and dorsolateral compartments. We strive to encourage skull base surgeons to integrate endoscopic and microscopic approaches to the posterior fossa.

  View details for PubMedID 23369939

• ICP, BMI, Surgical Repair, and CSF Diversion in Patients Presenting With Spontaneous CSF Otorrhea OTOLOGY & NEUROTOLOGY Vivas, E. X., Mccall, A., Raz, Y., Fernandez-Miranda, J. C., Gardner, P., Hirsch, B. E. 2014; 35 (2): 344–47

  Abstract

  To assess intracranial pressure (ICP), body mass index (BMI), surgical repair, and cerebrospinal fluid (CSF) diversion in patients presenting with spontaneous CSF otorrhea.Retrospective series review.Tertiary referral center.Thirty-two patients were treated surgically from 2004 to 2013 for spontaneous CSF otorrhea by the principal investigators. Patients with a history of chronic ear disease and cholesteatoma, previous mastoid surgery, head trauma, or iatrogenic injury were excluded. Average age was 56 years. Twenty-two patients (69%) were female.Middle fossa repair, transmastoid repair, lumbar puncture, V-P shunt, L-P shunt, and magnetic resonance imaging.Patients underwent middle fossa or transmastoid repair of tegmen defects. Intracranial pressures were determined with lumbar puncture at time of surgical repair or shortly after surgery. CSF diversion procedures were performed in patients who were found to have elevated ICP, which was not controlled medically, presented with recurrent leak or had ICP of 25 cm or greater of H2O. Preoperative BMI was calculated.Thirty-two patients underwent 37 operations. Average BMI was 35.0 kg/m2 (median, 34.7; range, 18.7-53.2 kg/m2). There were 21 repairs on the left and 16 on the right. The majority underwent a middle fossa craniotomy for repair (27/32). Two patients had bilateral repairs. Three patients (8%) underwent revision surgery, of which, 2 had untreated intracranial hypertension (ICP 24.5 and 24 cm H2O). ICP measurements were available for 29 patients. The mean ICP was 23.4 cm H2O (median, 24; range, 13-36 cm H20). Twenty-two patients (69%) had ICP of 20 cm or greater of H20; of those, 13 had an ICP of 25 cm or greater of H20. Seventeen patients (53%) underwent CSF diversion procedures.Our findings of elevated ICP and BMI in patients presenting with spontaneous CSF otorrhea are consistent with previous reports in the literature. The percentage of patients that underwent CSF diversion procedures was high at 53% and represents an aggressive stance in managing elevated ICP in a population that may be at risk for subsequent leaks.

  View details for PubMedID 24448295

• Extended Dissection of the Septal Flap Pedicle for Ipsilateral Endoscopic Transpterygoid Approaches LARYNGOSCOPE Pinheiro-Neto, C. D., Paluzzi, A., Fernandez-Miranda, J. C., Scopel, T. F., Wang, E. W., Gardner, P. A., Snyderman, C. H. 2014; 124 (2): 391–96

  View details for PubMedID 23775318

• A 23-Year-Old Female with a Mixed Germ Cell Tumor of the Pituitary Infundibulum: The Challenge of Differentiating Neoplasm from Lymphocytic Infundibuloneurohypophysitis-A Case Report and Literature Review CASE REPORTS IN ENDOCRINOLOGY Mon, S., Mahmud, H., Abbasi, M., Murdoch, G., Fernandez-Miranda, J. C., Gardner, P. A., Challinor, S. M. 2014: 129471

  Abstract

  The pathologic spectrum of diseases that infiltrate the pituitary infundibulum includes a broad variety of clinical entities. There are significant differences in the prevalence of these etiologies depending on the age of presentation. Lymphocytic infundibuloneurohypophysitis (LINH) predominates over other causes of infundibular disease in adults over age 21. Differentiating LINH from other causes of infundibular disease can be difficult because the various etiologies often have similar clinical presentations and radiologic imaging characteristics. We report the first case in an adult of a mixed germ cell tumor comprised of germinoma and embryonal cell carcinoma infiltrating the pituitary infundibulum. In our case, a 23-year-old female was initially misdiagnosed as having LINH. She presented with panhypopituitarism and diabetes insipidus, which is the most common initial presentation in both entities. The two diagnoses are difficult to distinguish based on MRI imaging, CSF findings, and histopathological examination. Our case demonstrates the need for close follow-up of patients with isolated lesions of the pituitary infundibulum and reinforces the need for biopsy of an infundibular lesion when progression of disease is demonstrated. In our case, biopsy with comprehensive immunohistochemical staining was the sole means of making a definitive diagnosis.

  View details for PubMedID 25045548

  View details for PubMedCentralID PMC4087301

• Detection of White Matter Injury in Concussion Using High-Definition Fiber Tractography CONCUSSION Shin, S. S., Pathak, S., Presson, N., Bird, W., Wagener, L., Schneider, W., Okonkwo, D. O., Fernandez-Miranda, J. C., Niranjan, A., Lunsford, L. D. 2014; 28: 86–93

  Abstract

  Over the last few decades, structural imaging techniques of the human brain have undergone significant strides. High resolution provided by recent developments in magnetic resonance imaging (MRI) allows improved detection of injured regions in patients with moderate-to-severe traumatic brain injury (TBI). In addition, diffusion imaging techniques such as diffusion tensor imaging (DTI) has gained much interest recently due to its possible utility in detecting structural integrity of white matter pathways in mild TBI (mTBI) cases. However, the results from recent DTI studies in mTBI patients remain equivocal. Also, there are important shortcomings for DTI such as limited resolution in areas of multiple crossings and false tract formation. The detection of white matter damage in concussion remains challenging, and development of imaging biomarkers for mTBI is still in great need. In this chapter, we discuss our experience with high-definition fiber tracking (HDFT), a diffusion spectrum imaging-based technique. We also discuss ongoing developments and specific advantages HDFT may offer concussion patients.

  View details for PubMedID 24923395

• Carotid Artery Injury During Endoscopic Endonasal Skull Base Surgery: Incidence and Outcomes NEUROSURGERY Gardner, P. A., Tormenti, M. J., Pant, H., Fernandez-Miranda, J. C., Snyderman, C. H., Horowitz, M. B. 2013; 73: 261–69

  Abstract

  Injury to the internal carotid artery (ICA) during endoscopic endonasal skull base surgery is a feared complication that is not well studied or reported.To evaluate the incidence, to identify potential risk factors, and to present management strategies and outcomes of ICA injury during endonasal skull base surgery at our institution.We performed a retrospective review of all endoscopic endonasal operations performed at our institution between 1998 and 2011 to examine potential factors predisposing to ICA injury. We also documented the perioperative management and outcomes after injury.There were 7 ICA injuries encountered in 2015 endonasal skull base surgeries, giving an incidence of 0.3%. Most injuries (5 of 7) involved the left ICA, and the most common diagnosis was chondroid neoplasm (chordoma, chondrosarcoma; 3 of 7 [2% of 142 cases]). Two injuries occurred during 660 pituitary adenoma resections (0.3%). The paraclival ICA segment was the most commonly injured site (5 of 7), and transclival and transpterygoid approaches had a higher incidence of injury, although neither factor reached statistical significance. Four of 7 injured ICAs were sacrificed either intraoperatively or postoperatively. No patient suffered a stroke or neurological deficit. There were no intraoperative mortalities; 1 patient died postoperatively of cardiac ischemia. One of the 3 preserved ICAs developed a pseudoaneurysm over a mean follow-up period of 5 months that was treated endovascularly.ICA injury during endonasal skull base surgery is an infrequent and manageable complication. Preservation of the vessel remains difficult. Chondroid tumors represent a higher risk and should be resected by surgical teams with significant experience.

  View details for PubMedID 23695646

• Endoscopic Endonasal Approach to the Infraorbital Nerve with Nasolacrimal Duct Preservation JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Peris-Celda, M., Pinheiro-Neto, C. D., Scopel, T. F., Fernandez-Miranda, J. C., Gardner, P. A., Snyderman, C. H. 2013; 74 (6): 393–98

  Abstract

  Objectives Infraorbital nerve (ION) decompression, excision to remove intrinsic tumors, and resection with oncological margins in malignancies with perineural invasion or dissemination are usually accomplished with an open approach. The objective is to describe the surgical anatomy, technique, and indications of the endonasal endoscopic approach (EEA) to the ION with nasolacrimal duct preservation. Design Eleven sides of formalin-fixed specimens were dissected. An anterior maxillary antrostomy was performed. The length of the ION prominence within the sinus and anatomic features of the covering bone were studied. A 45-degree endoscope visualized the infraorbital prominence endonasally. An angled dissector and dural blade allowed for dissection and resection of the ION ipsilaterally and contralaterally. Results The bone features of the ION prominence allowed for ipsilateral dissection in 10 out of 11 sides. In one case with the ION surrounded by thick cortical bone, the dissection could only be started by drilling contralaterally. The 45-degree endoscope visualized 92.2% and 100% of the length of the nerve using the ipsilateral and contralateral nostrils, respectively. Ipsilaterally, 83% of its length was resected, and 96.3% was resected contralaterally. Conclusion The ION can be approached using an ipsilateral EEA with nasolacrimal duct preservation in most cases. The contralateral approach provides a wider angle to access the ION. This technique is primarily indicated in cases where the EEA can be used for tumor resection and oncological margins within the ION.

  View details for PubMedID 24436942

  View details for PubMedCentralID PMC3836806

• The Extended Nasoseptal Flap for Skull Base Reconstruction of the Clival Region: An Anatomical and Radiological Study JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Peris-Celda, M., Pinheiro-Neto, C., Funaki, T., Fernandez-Miranda, J. C., Gardner, P., Snyderman, C., Rhoton, A. L. 2013; 74 (6): 369–85

  Abstract

  Objective Reconstruction of large clival defects after an endoscopic endonasal procedure is challenging. The objective is to analyze the morphology, indications, and limitations of the extended nasoseptal flap, which adds the nasal floor and inferior meatus mucosa, compared with the standard nasoseptal flap, for clival reconstruction. Design Twenty-seven sides of formalin-fixed anatomical specimens and 13 computed tomography (CT) scans were used. Under 0-degree endoscopic visualization, a standard flap on one side and an extended flap on the other side were performed, as well as exposure of the sella, cavernous sinus, and clival dura mater. Coverage of both flaps was assessed, and they were incised and extracted for measurements. Results The extended flap has two parts: septal and inferior meatal. The extended flaps are 20 mm longer and add 774 mm(2) of mucosal area. They cover a clival defect from tuberculum to foramen magnum in 66.6% cases and from below the sella in 91.6%. They cover both parasellar and paraclival segments of the internal carotid arteries. The lateral inferior limits are the medial aspect of the hypoglossal canals and Eustachian tubes. CT scans can predict the need or limitation of an extended nasoseptal flap. Conclusions The nasal floor and inferior meatus mucosa adds a significant area for reconstruction of the clivus. A defect laterally beyond the hypoglossal canals is not likely covered with this variation of the flap. Preoperative CT scans are useful to guide the reconstruction techniques.

  View details for PubMedID 24436940

  View details for PubMedCentralID PMC3836807

• Chicken Wing Training Model for Endoscopic Microsurgery JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Jusue-Torres, I., Sivakanthan, S., Pinheiro-Neto, C., Gardner, P. A., Snyderman, C. H., Fernandez-Miranda, J. C. 2013; 74 (5): 286–91

  Abstract

  Objectives To present and validate a chicken wing model for endoscopic endonasal microsurgical skill development. Setting A surgical environment was constructed using a Styrofoam box and measurements from radiological studies. Endoscopic visualization and instrumentation were utilized in a manner to mimic operative setting. Design Five participants were instructed to complete four sequential tasks: (1) opening the skin, (2) exposing the main artery in its neurovascular sheath, (3) opening the neurovascular sheath, and (4) separating the nerve from the artery. Time to completion of each task was recorded. Participants Three junior attendings, one senior resident, and one medical student were recruited internally. Main Outcome Measures Time to perform the surgical tasks measured in seconds. Results The average time of the first training session was 48.8 minutes; by the 10th training session, the average time was 22.4 minutes. The range of improvement was 25.7 minutes to 72.4 minutes. All five participants exhibited statistically significant decrease in time after 10 trials. Kaplan-Meier analysis revealed that an improvement of 50% was achieved by an average of five attempts at the 95% confidence interval. Conclusions The ex vivo chicken wing model is an inexpensive and relatively realistic model to train endoscopic dissection using microsurgical techniques.

  View details for PubMedID 24436926

  View details for PubMedCentralID PMC3774829

• Transposition of the Pterygopalatine Fossa during Endoscopic Endonasal Transpterygoid Approaches JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Pinheiro-Neto, C. D., Fernandez-Miranda, J. C., Prevedello, D. M., Carrau, R. L., Gardner, P. A., Snyderman, C. H. 2013; 74 (5): 266–70

  Abstract

  Introduction Complete or partial removal of the pterygoid process provides lateral extension of the endonasal corridor necessary to approach the Meckel cave, infrapetrous skull base, and medial infratemporal fossa. This paper provides the anatomical foundations for the endoscopic endonasal transpterygoid approach with preservation of all neurovascular structures inside the pterygopalatine fossa. Methods Eight endoscopic transpterygoid approaches were performed in fresh cadaveric specimens. In all dissections the vidian nerve and the periosteal sac enclosing the pterygopalatine fossa were preserved. Results We reliably transposed the pterygopalatine fossa to approach the Meckel cave, infrapetrous skull base, and medial infratemporal region, preserving the neurovascular structures inside the pterygopalatine fossa in all specimens. Conclusions The transposition of the pterygopalatine fossa neurovascular structures for endoscopic endonasal approaches to the skull base is an alternative technique that is both feasible and desirable. The transposition requires no additional technical skills but requires comprehensive knowledge of its anatomy. The anatomical preservation of the neurovascular structures is potentially beneficial to the quality of life of patients. Clinical studies are necessary to prove the real benefits of this technique.

  View details for PubMedID 24436922

  View details for PubMedCentralID PMC3774828

• Beyond diffusion tensor imaging JOURNAL OF NEUROSURGERY Fernandez-Miranda, J. C. 2013; 118 (6): 1363–65

  View details for DOI 10.3171/2012.10.JNS121800

  View details for Web of Science ID 000319366400037

  View details for PubMedID 23540267

• Endoscopic endonasal skull base surgery in the pediatric population JOURNAL OF NEUROSURGERY-PEDIATRICS Chivukula, S., Koutourousiou, M., Snyderman, C. H., Fernandez-Miranda, J. C., Gardner, P. A., Tyler-Kabara, E. C. 2013; 11 (3): 227–41

  Abstract

  The use of endoscopic endonasal surgery (EES) for skull base pathologies in the pediatric population presents unique challenges and has not been well described. The authors reviewed their experience with endoscopic endonasal approaches in pediatric skull base surgery to assess surgical outcomes and complications in the context of presenting patient demographics and pathologies.A retrospective review of 133 pediatric patients who underwent EES at our institution from July 1999 to May 2011 was performed.A total of 171 EESs were performed for skull base tumors in 112 patients and bony lesions in 21. Eighty-five patients (63.9%) were male, and the mean age at the time of surgery was 12.7 years (range 2.3-18.0 years). Skull base tumors included angiofibromas (n = 24), craniopharyngiomas (n = 16), Rathke cleft cysts (n = 12), pituitary adenomas (n = 11), chordomas/chondrosarcomas (n = 10), dermoid/epidermoid tumors (n = 9), and 30 other pathologies. In total, 19 tumors were malignant (17.0%). Among patients with follow-up data, gross-total resection was achieved in 16 cases of angiofibromas (76.2%), 9 of craniopharyngiomas (56.2%), 8 of Rathke cleft cysts (72.7%), 7 of pituitary adenomas (70%), 5 of chordomas/chondrosarcomas (50%), 6 of dermoid/epidermoid tumors (85.7%), and 9 cases of other pathologies (31%). Fourteen patients received adjuvant radiotherapy, and 5 received chemotherapy. Sixteen patients (15.4%) showed tumor recurrence and underwent reoperation. Bony abnormalities included skull base defects (n = 12), basilar invagination (n = 4), optic nerve compression (n = 3) and trauma (n = 2); preexisting neurological dysfunction resolved in 12 patients (57.1%), improved in 7 (33.3%), and remained unchanged in 2 (9.5%). Overall, complications included CSF leak in 14 cases (10.5%), meningitis in 5 (3.8%), transient diabetes insipidus in 8 patients (6.0%), and permanent diabetes insipidus in 12 (9.0%). Five patients (3.8%) had transient and 3 (2.3%) had permanent cranial nerve palsies. The mean follow-up time was 22.7 months (range 1-122 months); 5 patients were lost to follow-up.Endoscopic endonasal surgery has proved to be a safe and feasible approach for the management of a variety of pediatric skull base pathologies. When appropriately indicated, EES may achieve optimal outcomes in the pediatric population.

  View details for PubMedID 23240846

• The Medial Opticocarotid Recess: An Anatomic Study of an Endoscopic "Key Landmark" for the Ventral Cranial Base NEUROSURGERY Labib, M., Prevedello, D. M., Fernandez-Miranda, J. C., Sivakanthan, S., Benet, A., Morera, V., Carrau, R., Kassam, A. 2013; 72: 66–76

  Abstract

  The medial opticocarotid recess (MOCR) has become an important landmark for endoscopic approaches to the cranial base.To examine the anatomy of the MOCR and outline its role as a "key landmark" for approaches to the sellar and suprasellar regions.Ten silicone-injected cadaveric specimens and 96 dry crania were examined. Dissections were done endoscopically and microscopically.The lateral tubercular recess is an osseous depression located at the lateral edge of the tuberculum when viewed from the sphenoid sinus. Intracranially, it corresponds to the lateral tubercular crest (LTC), a ridge situated at the superomedial aspect of the carotid sulcus. The MOCR is a teardrop-shaped osseous indentation formed at the medial junction of the paraclinoid carotid canal and the optic canal. Dorsally, it is represented by a teardrop-shaped area with vertices at the inferior aspect of the LTC, the medial aspect of the junction of the superior and posterior surfaces of the optic strut, and the superolateral aspect of the tuberculum. The middle clinoid process is situated inferior to the LTC. The distal osseous arch of the carotid sulcus connects the lateral opticocarotid recess to the lateral tubercular recess and is a landmark for the paraclinoid internal carotid artery. Only 44% of the specimens had middle clinoid processes.The MOCR and middle clinoid process are distinct structures. Because of its location at the confluence of the optic canal, the carotid canal, the sella, and the anterior cranial base, the MOCR is a key landmark for endoscopic approaches.

  View details for DOI 10.1227/NEU.0b013e318271f614

  View details for Web of Science ID 000315944800018

  View details for PubMedID 23271222

• Rare Infundibular Tumors: Clinical Presentation, Imaging Findings, and the Role of Endoscopic Endonasal Surgery in Their Management JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Koutourousiou, M., Gardner, P. A., Kofler, J. K., Fernandez-Miranda, J. C., Snyderman, C. H., Lunsford, L. 2013; 74 (1): 1–11

  Abstract

  Background The spectrum of infundibular lesions is broad and distinct from sellar pathologies. In many cases, histology is needed to establish the correct diagnosis and determine the treatment approach. Methods Medical files of eight patients with distinct infundibular tumors were reviewed. Histopathologically confirmed diagnosis included three pituicytomas, three granular cell tumors, and two pilocytic astrocytomas. Results Patients shared similar imaging findings and clinical symptoms, including visual impairment (n = 5), hypopituitarism (n = 4), and headache (n = 4); one patient presented with disseminated disease and symptoms from spinal metastases. All the pituicytomas, two granular cell tumors, and one infundibular pilocytic astrocytoma case underwent endoscopic endonasal surgery; gross total resection was achieved in five patients, three developed postoperative diabetes insipidus, and two developed hypopituitarism. No recurrences were observed. One granular cell tumor patient was treated with gamma-knife radiosurgery after stereotactic biopsy; the tumor remained stable in size for over 9 years. The infundibular pilocytic astrocytoma patient who presented with spinal metastases received radiotherapy and systemic chemotherapy. The overall mean follow-up period was 25.1 months. Conclusion Infundibular tumors are rare entities that represent a diagnostic challenge. Histopathological examination is essential for definitive diagnosis. Surgery, radiation therapy, and chemotherapy all have a role in the management of these tumors.

  View details for PubMedID 24436883

  View details for PubMedCentralID PMC3699169

• The anatomical relationship between the eustachian tube and petrous internal carotid artery LARYNGOSCOPE Ozturk, K., Snyderman, C. H., Gardner, P. A., Fernandez-Miranda, J. C. 2012; 122 (12): 2658–62

  Abstract

  The aim of the present study was to investigate the relationship between the eustachian tube (ET) and petrous internal carotid artery (ICA) in whole-mount human temporal bone specimens.Descriptive study.Histologically prepared serial sections of 10 adult temporal bones were included in the study. Five specific landmarks were selected to evaluate relationships between the petrous segment of the ICA and the ET. The selected distances were measured using computer software (Metamorph 7.5.2.0; Molecular Devices, LLC, Sunnyvale, CA).The ET and the ICA get close posteriorly, and the bony part of the ET and the ICA generally share the same wall.The junctional part of the ET may be a safe landmark to identify and protect the ICA during endoscopic endonasal surgery of the cranial base. Knowledge of the anatomical relationships of the ET and petrous part of the ICA, as well as their relationship with other surgical and radiological landmarks, would be useful to surgeons.

  View details for DOI 10.1002/lary.23679

  View details for Web of Science ID 000312540000009

  View details for PubMedID 23161486

• Endoscopic Endonasal Middle Clinoidectomy: Anatomic, Radiological, and Technical Note NEUROSURGERY Fernandez-Miranda, J. C., Tormenti, M., Latorre, F., Gardner, P., Snyderman, C. 2012; 71: 233-239

  View details for DOI 10.1227/NEU.0b013e3182690b6b

  View details for Web of Science ID 000312001300011

• Endoscopic Endonasal Pituitary Surgery: Impact of Surgical Education on Operation Length and Patient Morbidity JOURNAL OF NEUROLOGICAL SURGERY PART B-SKULL BASE Dedhia, R. C., Lord, C. A., Pinheiro-Neto, C. D., Fernandez-Miranda, J. C., Wang, E. W., Gardner, P. A., Snyderman, C. H. 2012; 73 (6): 405–9

  Abstract

  Objectives To determine the difference in operative times and associated complications for cases performed solely by attending-level surgeons versus cases assisted by surgeons-in-training for endoscopic endonasal pituitary surgeries. Design Retrospective chart review. Setting Tertiary-care academic medical center. Participants A total of 228 patients having undergone endoscopic endonasal pituitary surgery from 2005 to 2011. Main Outcome Measure Duration of surgery comparing attending only (AO) and trainee-assisted (TA) surgeries. Results Thirty-seven (19%) of 198 cases were identified as AO surgeries, the remaining 161 (81%) were TA. Operative times (minutes) for the AO group were significantly shorter than the TA group (149.1 ± 54.8 vs 219.5 ± 83.7, p < 0.001). The AO group had fewer intraoperative cerebrospinal fluid leaks (30% vs 39%, p = 0.318), decreased estimated blood loss (408 mL vs 523 mL, p = 0.176), fewer postoperative complications (27% vs 37%, p = 0.268), and shorter length of stay (3.5 vs 4.3 days, p = 0.294). Conclusions This is the first study in otolaryngology or neurosurgery to compare operative times and outcomes for AO versus TA cases at a single academic institution. Operative times were significantly decreased and a trend toward a decrease in patient morbidity was noted for cases performed solely by attendings. The valuation of teaching activities in the operating room is a necessary first step toward optimizing the allocation of resources and funding of surgical education.

  View details for PubMedID 24294558

• Retracing the Etymology of Terms in Neuroanatomy CLINICAL ANATOMY Paluzzi, A., Fernandez-Miranda, J., Torrenti, M., Gardner, P. 2012; 25 (8): 1005–14

  Abstract

  Researching the origin of the terms that we use to identify neuroanatomical structures is a helpful and fascinating exercise. It can provide neuroscientists with a better insight and understanding of the macroscopic anatomy of the cranium and its contents. It can also help the novice to this discipline to become acquainted with structures whose three dimensional anatomy is often difficult to appreciate. The purpose of this article was to investigate the etymology of some of the terms referring to the macroscopic anatomical structures of the skull and the intracranial cavity. We observed how each name unravels an interesting story, sometimes linked to mythological creatures, other times to the shape of animals or objects and tools of everyday life. We conclude that even without a deep knowledge of the Greek, Latin, or Arabic language, learning who described a particular structure and how they decided to name it, makes the study of neuroanatomy more complete and fulfilling.

  View details for PubMedID 23112209

• Combined Endoscopic Endonasal Transorbital Approach with Transconjunctival-Medial Orbitotomy for Excisional Biopsy of the Optic Nerve: Technical Note JOURNAL OF NEUROLOGICAL SURGERY REPORTS Koutourousiou, M., Gardner, P. A., Stefko, S., Paluzzi, A., Fernandez-Miranda, J. C., Snyderman, C. H., Maroon, J. C. 2012; 73 (1): 52–56

  Abstract

  Background Access to the intraorbital optic nerve segment can be facilitated via a transcranial approach that allows access to the entire orbital cavity. The endoscopic endonasal approach (EEA) combined with a transconjunctival-medial orbitotomy represents an alternative technique to achieve the same goal. Objective Report a surgical technique that allows total resection of the intraorbital optic nerve with minimal trauma and excellent results. Further extend and define the limits and indications of the EEA to orbital surgery. Methods A patient with rapidly progressive, but asymmetric, vision loss underwent EEA for optic nerve biopsy. Due to the undetermined histopathological diagnosis and complete unilateral vision loss, diagnostic total optic nerve resection was indicated. The entire intraorbital length of the nerve was resected via an endoscopic endonasal transorbital approach combined with transconjunctival-medial orbitotomy. Results A 2-cm intraorbital nerve segment was sent for pathological examination. The patient maintained normal extraocular movements and experienced no complications. The postoperative course was uneventful and the patient was discharged the next day. Conclusion The EEA provides another option for access to the entire optic nerve. It is a safe and effective technique lacking cosmetic defects and providing an alternative corridor to traditional transcranial approaches to the orbit.

  View details for PubMedID 23946927

  View details for PubMedCentralID PMC3658658

• The expanding role of endoscopic skull base surgery BRITISH JOURNAL OF NEUROSURGERY Paluzzi, A., Gardner, P., Fernandez-Miranda, J., Snyderman, C. 2012; 26 (5): 649–61

  Abstract

  The endoscopic endonasal approach (EEA) is a surgical technique where a small aperture, the nostrils, can give access to the whole ventral skull base. Its principles differ from the ones of traditional skull base approaches where a wide external opening is often accompanied by a relatively small working area. Most of the results of EEAs published in the literature come from retrospective case series and the follow-up is still limited, however the consensus is that this technique is safe and effective in selected cases and when performed within dedicated skull base centres. This article sets to give an overview of the current state of endoscopic skull base surgery, based on the recent evidence and our centre's experience with nearly 2000 EEAs. The team's experience with endoscopic as well as open approaches plays a critical role in achieving satisfactory results when treating pathologies of the skull base. Guided by the principle of least neural and vascular manipulation, the team should be able to select the least traumatic route (open or endoscopic) and be able to approach the skull base from all angles.

  View details for PubMedID 22471243

• Endoscopic Endonasal Approach for Resection of Cranial Base Chordomas: Outcomes and Learning Curve NEUROSURGERY Koutourousiou, M., Gardner, P. A., Tormenti, M. J., Henry, S. L., Stefko, S. T., Kassam, A. B., Fernandez-Miranda, J. C., Snyderman, C. H. 2012; 71 (3): 614–24

  Abstract

  Gross total resection (GTR) of cranial base chordomas represents a surgical challenge because of the location, invasiveness, and tumor extension. In the past decade, the endoscopic endonasal approach (EEA) has been used with notable outcomes.To present the endoscopic endonasal experience in the treatment of cranial base chordomas at our institution.From April 2003 to March 2011, 60 patients underwent an EEA for primary (n = 35) or previously treated (n = 25) cranial base chordomas. We evaluated the degree of GTR and complications. We studied the factors that influenced outcomes and compared our surgical results in the early and late years of our experience.The overall rate of GTR of cranial base chordomas was 66.7% (82.9% in primary and 44% in previously treated patients). The most important limitations for GTR were tumor volume greater than 20 cm (P = .042), tumor location in the lower clivus with lateral extension (P = .022), and previously treated disease (P = .002). The learning curve had a significant impact on GTR, increasing the success rate to 88.9% (92.6% in primary patients and 63.6% in previously treated patients) during recent years (P < .0001). The most frequent complication was cerebrospinal fluid leak (20%) resulting in meningitis in 3.3%. Carotid injuries occurred in 2 patients without any resulting deficit. Neurological complications included new cranial neuropathies (6.7%) and long tract deficits (1.7%). There was no operative mortality in our series.For the treatment of cranial base chordomas, the EEA is a competitive alternative to transcranial approaches with minimal morbidity and high success rates of GTR when performed by experienced cranial base surgeons.

  View details for PubMedID 22592328

• Comentario al trabajo "Estesioneuroblastoma. Abordaje endonasal expandido transcribiforme-transfovea etmoidalis. Nota tecnica" de Simal et al. Neurocirugia (Asturias, Spain) Fernandez-Miranda, J. C. 2012; 23 (4): 163–64

  View details for PubMedID 22795163

• Petrous apex cholesterol granulomas: Endonasal versus infracochlear approach LARYNGOSCOPE Scopel, T., Fernandez-Miranda, J. C., Pinheiro-Neto, C. D., Peris-Celda, M., Paluzzi, A., Gardner, P. A., Hirsch, B. E., Snyderman, C. H. 2012; 122 (4): 751–61

  Abstract

  The aim of this study was to investigate and compare the surgical anatomy of two different routes to access and drain petrous apex (PA) cholesterol granulomas: the expanded endonasal approach (EEA) and the transcanal infracochlear approach (TICA).Anatomic and radiologic study.The EEA and TICA to the PA were performed in 11 anatomic specimens with the assistance of imaging guidance. The PA was categorized into three zones: superior PA, anterior-inferior PA, and posterior-inferior PA. The maximum drainage window achieved by each approach was calculated using the imaging studies of each anatomic specimen.The EEA was able to reach superior PA and anterior-inferior PA in all specimens and posterior-inferior PA in 90%. The TICA did not provide access to superior PA in any case. The TICA was suitable to reach anterior-inferior PA in 80% of specimens and posterior-inferior PA in 60%. Based on the radiologic study, the EEA provided a drainage window three times larger than the TICA.The transnasal approach provides reliable access to the PA when combined with internal carotid artery exposure and allows for large drainage window. The transcanal approach is less versatile and more limited than the transnasal approach but provides access to the most posterior and inferior portion of the PA without Eustachian tube transection. Here we propose a new surgical classification that may help to decide the most suitable approach to the PA according to the location and extension of the lesion.

  View details for PubMedID 22434679

• Endonasal transpterygoid approach to the infratemporal fossa: Correlation of endoscopic and multiplanar CT anatomy HEAD AND NECK-JOURNAL FOR THE SCIENCES AND SPECIALTIES OF THE HEAD AND NECK Hosseini, S., Razfar, A., Carrau, R. L., Prevedello, D. M., Fernandez-Miranda, J., Zanation, A., Kassam, A. B. 2012; 34 (3): 313–20

  Abstract

  The infratemporal fossa anatomy, from an endoscopic standpoint, is poorly understood. Our purpose was to design an anatomic model that illustrates the anatomy of the infratemporal fossa from the endoscopic standpoint and serves as a training model for surgeons interested in pursuing this endeavor.Red and blue silicone dyes were respectively injected into the great vessels of the neck. Digital data acquired from a high resolution CT scan was imported to a navigational system. An endoscopic endonasal dissection of the infratemporal fossa was completed under conditions that mimicked our operating suite.A detailed anatomic dissection of the infratemporal fossa was correlated to the image guidance (navigation) system. This provided a surgical map highlighting critical neurovascular structures and illustrating the potential surgical corridors.A thorough understanding of the anatomy of infratemporal fossa from the endoscopic perspective allows the surgeon to plan an adequate corridor.

  View details for DOI 10.1002/hed.21725

  View details for Web of Science ID 000299939000002

  View details for PubMedID 21584894

• Endoscopy or microscopy? JOURNAL OF NEUROSURGERY-PEDIATRICS Snyderman, C. H., Gardner, P. A., Fernandez-Miranda, J. C. 2012; 9 (3): 336–37

  View details for DOI 10.3171/2011.8.PEDS11337

  View details for Web of Science ID 000300652900024

  View details for PubMedID 22380966

• Endoscopic endonasal approach for a tuberculum sellae meningioma. Neurosurgical focus Fernandez-Miranda, J. C., Pinheiro-Neto, C. D., Gardner, P. A., Snyderman, C. H. 2012; 32 Suppl 1: E8

  Abstract

  The authors present the technical and anatomical nuances needed to perform an endoscopic endonasal removal of a tuberculum sellae meningioma. The patient is a 47-year-old female with headaches and an incidental finding of a small tuberculum sellae meningioma with no vascular encasement, no optic canal invasion, but mild inferior to superior compression of the cisternal segment of the left optic nerve. Neuroophthalmology assessment revealed no visual defects. Treatment options included clinical observation with imaging follow-up studies, radiosurgery, and resection. The patient elected to undergo surgical removal and an endonasal endoscopic approach was the preferred surgical option. Preoperative radiological studies showed the presence of an osseous ring between the left middle and anterior clinoids, the so-called carotico-clinoidal ring. The surgical implications of this finding and its management are illustrated. The surgical anatomy of the suprasellar region is reviewed, including concepts such as the chiasmatic sulcus and limbus sphenoidale, medial and lateral optico-carotid recesses, and the paraclinoidal and supraclinoidal segments of the internal carotid artery. Emphasis is made in the importance of exposing the distal dural ring of the internal carotid artery and the precanalicular segment of the optic nerve for adequate intradural dissection. The endonasal route allows for early coagulation of the tumor meningeal supply and extensive resection of dural attachments, and importantly, provides an inferior to superior access to the infrachiasmatic region that facilitates complete tumor removal without any manipulation of the optic nerve. The lateral limit of dural removal is formed by the distal dural ring, which is gently coagulated after the tumor is resected. A 45° scope is used to inspect for any residual tumor, in particular at the entrance of the optic nerve into the optic canal and at the most anterior margin of the exposure (limbus sphenoidale). The steps for reconstruction are detailed and include intradural placement of dural substitute and extradural placement of the nasoseptal flap. The nuances for proper harvesting, positioning, and reinforcement of the flap are described. No lumbar drain was used. The patient had an uneventful recovery with no CSF leak or any other complications. Imaging follow-up at 6 months showed complete removal of the tumor. The patient had no sinonasal or neurological symptoms, and olfaction was fully preserved. The video can be found here: http://youtu.be/kkuV-yyEHMg .

  View details for PubMedID 26018978

• Endoscopic endonasal repair of spontaneous CSF fistulae. Neurosurgical focus Tormenti, M. J., Paluzzi, A. n., Pinheiro-Neto, C. D., Fernandez-Miranda, J. C., Snyderman, C. H., Gardner, P. A. 2012; 32 Suppl 1: E6

  Abstract

  The authors present a fully endoscopic endonasal repair of a spontaneous CSF leak caused by a defect in the anterior fossa floor. Patients were positioned supine in a Mayfield headholder in slight extension. A complete ethmoidectomy was performed to expose the defect. The middle turbinate was removed to increase visualization and allow for more working room. The defect was identified and exposed. A nasoseptal flap was raised and placed over the defect. A free-mucosal graft fashioned from the removed middle turbinate was placed on the nasoseptal donor site. The video can be found here: http://youtu.be/gAN2cvQVXCE .

  View details for PubMedID 26018976

• Endoscopic endonasal approach for a tuberculum sellae meningioma. Journal of neurosurgery Fernandez-Miranda, J. C., Pinheiro-Nieto, C. n., Gardner, P. A., Snyderman, C. H. 2012; 32 Suppl: E8

  Abstract

  The authors present the technical and anatomical nuances needed to perform an endoscopic endonasal removal of a tuberculum sellae meningioma. The patient is a 47-year-old female with headaches and an incidental finding of a small tuberculum sellae meningioma with no vascular encasement, no optic canal invasion, but mild inferior to superior compression of the cisternal segment of the left optic nerve. Neuroophthalmology assessment revealed no visual defects. Treatment options included clinical observation with imaging follow-up studies, radiosurgery, and resection. The patient elected to undergo surgical removal and an endonasal endoscopic approach was the preferred surgical option. Preoperative radiological studies showed the presence of an osseous ring between the left middle and anterior clinoids, the so-called carotico-clinoidal ring. The surgical implications of this finding and its management are illustrated. The surgical anatomy of the suprasellar region is reviewed, including concepts such as the chiasmatic sulcus and limbus sphenoidale, medial and lateral optico-carotid recesses, and the paraclinoidal and supraclinoidal segments of the internal carotid artery. Emphasis is made in the importance of exposing the distal dural ring of the internal carotid artery and the precanalicular segment of the optic nerve for adequate intradural dissection. The endonasal route allows for early coagulation of the tumor meningeal supply and extensive resection of dural attachments, and importantly, provides an inferior to superior access to the infrachiasmatic region that facilitates complete tumor removal without any manipulation of the optic nerve. The lateral limit of dural removal is formed by the distal dural ring, which is gently coagulated after the tumor is resected. A 45° scope is used to inspect for any residual tumor, in particular at the entrance of the optic nerve into the optic canal and at the most anterior margin of the exposure (limbus sphenoidale). The steps for reconstruction are detailed and include intradural placement of dural substitute and extradural placement of the nasoseptal flap. The nuances for proper harvesting, positioning, and reinforcement of the flap are described. No lumbar drain was used. The patient had an uneventful recovery with no CSF leak or any other complications. Imaging follow-up at 6 months showed complete removal of the tumor. The patient had no sinonasal or neurological symptoms, and olfaction was fully preserved. The video can be found here: http://youtu.be/kkuV-yyEHMg.

  View details for PubMedID 22251256

• Anatomical correlates of endonasal surgery for sinonasal malignancies CLINICAL ANATOMY Pinheiro-Neto, C. D., Fernandez-Miranda, J. C., Wang, E. W., Gardner, P. A., Snyderman, C. H. 2012; 25 (1): 129–34

  Abstract

  In recent years, endoscopic endonasal techniques have been applied to the treatment of sinonasal malignancies. Comprehensive anatomical knowledge is essential to preserve oncological principles and minimize surgical morbidity. The bones that form the anterior cranial base are pneumatized and the sinuses provide surgical corridors for the endoscopic endonasal approach to the skull base. During endoscopic endonasal resection of sinonasal malignancies, usually, the intranasal portion of the tumor is first debulked to provide visualization of the margins and assess the extent of the tumor. Afterwards the tumor is completely removed and the margins of resection are defined. In case of dural resection, the reconstruction is done with vascularized tissue (septal flap or pericranial flap). Sinonasal malignant neoplasms that invade the skull base can be resected accordingly to oncological principles using endoscopic endonasal techniques. Profound knowledge of the endoscopic anatomy of the ventral cranial base is paramount in order to perform a safe resection and reconstruction.

  View details for PubMedID 22139715

• Endoscopic anatomy of the palatovaginal canal (palatosphenoidal canal) LARYNGOSCOPE Pinheiro-Neto, C. D., Fernandez-Miranda, J. C., Rivera-Serrano, C. M., Paluzzi, A., Snyderman, C. H., Gardner, P. A., Sennes, L. U. 2012; 122 (1): 6–12

  Abstract

  Demonstrate the endoscopic anatomy of the palatovaginal (PV) canal and artery for identification and dissection of the vidian nerve during endoscopic transpterygoid approaches. Evaluate the length of the PV canal and its relation with the vidian nerve. Show that the traditionally known PV canal is a misnomer and should be renamed.Experimental study: anatomical and radiological.Dissection of eight cadaveric heads was performed to demonstrate the endoscopic anatomy of the PV canal. Computed tomography scan analysis of 20 patients was used to evaluate the length of the PV canal, the angle formed between this canal and the vidian nerve, and the distance between the vidian canal and the PV canal. Study of 10 dry skull bases was performed to verify the structures involved in the formation of the PV canal.Anatomic steps and foundations for dissection of the vidian nerve using the PV canal as a landmark were described. The mean length of the PV canal was 7.15 mm. The mean proximal distance between the vidian and the PV canal was 1.95 mm, and the mean distal distance was 4.14 mm. The mean angle between those canals was 48 degrees. The osteology study showed the vaginal process of the sphenoid bone did not contribute to the formation of the PV canal.Our anatomic investigations, radiologic studies, and surgical experience demonstrate the important anatomic relationship of the PV canal with the vidian canal and the relevance of the PV canal as a surgical landmark in endoscopic endonasal transpterygoid approaches. Anatomically, PV canal is a misnomer and should be replaced with palatosphenoidal canal.

  View details for PubMedID 22086784

• Endoscopic endonasal repair of spontaneous CSF fistulae. Journal of neurosurgery Tormenti, M. J., Paluzzi, A., Pinheiro-Nieto, C., Fernandez-Miranda, J. C., Snyderman, C. H., Gardner, P. A. 2012; 32 Suppl: E6

  Abstract

  The authors present a fully endoscopic endonasal repair of a spontaneous CSF leak caused by a defect in the anterior fossa floor. Patients were positioned supine in a Mayfield headholder in slight extension. A complete ethmoidectomy was performed to expose the defect. The middle turbinate was removed to increase visualization and allow for more working room. The defect was identified and exposed. A nasoseptal flap was raised and placed over the defect. A free-mucosal graft fashioned from the removed middle turbinate was placed on the nasoseptal donor site. The video can be found here: http://youtu.be/gAN2cvQVXCE.

  View details for PubMedID 22251254

• Microsurgical anatomy of the temporal lobe and its implications on temporal lobe epilepsy surgery. Epilepsy research and treatment Kucukyuruk, B., Richardson, R. M., Wen, H. T., Fernandez-Miranda, J. C., Rhoton, A. L. 2012; 2012: 769825

  Abstract

  Objective. We review the neuroanatomical aspects of the temporal lobe related to the temporal lobe epilepsy. The neuronal, the ventricular, and the vascular structures are demonstrated. Methods. The previous articles published from the laboratory of the senior author are reviewed. Results. The temporal lobe has four surfaces. The medial surface has a complicated microanatomy showing close relation to the intraventricular structures, such as the amygdala or the hippocampus. There are many white matter bundles in the temporal lobe showing relation to the extra- and intraventricular structures. The surgical approaches commonly performed to treat temporal lobe epilepsy are discussed under the light of these data. Conclusion. A thorough knowledge of the microanatomy is necessary in cortical, subcortical, and intraventricular structures of the temporal lobe to achieve better results.

  View details for PubMedID 22957242

• Commentary on the work Pneumocephalus Tension caused by treatment with cabergoline in patients with a large invasive prolactinoma apropos of an event by J. Castro and cols. NEUROCIRUGIA Fernandez-Miranda, J. C. 2011; 22 (6): 561

  View details for Web of Science ID 000298898100011

• Study of the Nasoseptal Flap for Endoscopic Anterior Cranial Base Reconstruction LARYNGOSCOPE Pinheiro-Neto, C. D., Ramos, H. F., Peris-Celda, M., Fernandez-Miranda, J. C., Gardner, P. A., Snyderman, C. H., Sennes, L. U. 2011; 121 (12): 2514–20

  Abstract

  Measure the dimensions of the nasoseptal (NS) flap and the anterior skull base (ASB) defect. Verify whether the flap is sufficient to cover the defect. Study the anatomy of the septal artery (SA).Anatomical and radiological study.After endoscopic craniofacial resection, sufficiency of the flap to cover the ASB defect was assessed. The SA was dissected. The number of branches in the pedicle and the distance between the artery and the sphenoid ostium were noted. Radiologic study analyzing CT scans of 30 patients for comparison among measurements of the NS flap and the ASB defect was performed.In all cases the flap was sufficient to cover the ASB. Two branches of the SA were found in the pedicle in 71.4%. The distance between the SA and the sphenoid ostium was 9.3 mm. The reconstruction area of the flap (17.12 cm(2) ) was larger than the defect area (8.64 cm(2) ) (P < .001). The difference between the superior length of the flap and the anterior-posterior distance of the defect was ≤ 5 mm in 26.7%. Comparison between the anterior flap width and the anterior defect width revealed that in 33% the difference was ≤ 5 mm.The dimensions of NS flap are sufficient to cover completely the ASB defect. The anterior edge of the defect presents increased risk for failure in coverage. Additional width adding the nasal floor mucosa to the flap is important to decrease the risk of gap in the anterior orbit-orbit defect. It is more common to find two branches of the SA in the pedicle.

  View details for PubMedID 22109750

• Posterior pedicle lateral nasal wall flap: New reconstructive technique for large defects of the skull base AMERICAN JOURNAL OF RHINOLOGY & ALLERGY Rivera-Serrano, C. M., Bassagaisteguy, L. H., Hadad, G., Carrau, R. L., Kelly, D., Prevedello, D. M., Fernandez-Miranda, J., Kassam, A. B. 2011; 25 (6): E212–E216

  Abstract

  Indications for expanded endoscopic approaches continue to grow, resulting in larger and more complex skull base defects. Reconstructive developments, however, have lagged our extirpative capabilities. As the complexity of clinical scenarios continues to escalate, challenging our current reconstructive strategies, we are compelled to develop alternative techniques to prevent cerebrospinal fluid leaks and protect neurovascular structures. In this article we show the anatomic basis for a new posterior pedicled flap from the lateral wall of the nose (Carrau-Hadad [C-H] flap) for the reconstruction of median skull base defects and present our early clinical experience.Using a cadaveric model, we designed a posterior pedicle flap comprising the nasal inferolateral wall mucoperiosteum. We applied this information clinically, to reconstruct transmural skull base defects.In our cadaveric model, we harvested and transposed C-H flaps into various defects of the planum sphenoidale, sella turcica, clivus, and nasopharynx. Then, we used the C-H flap in four patients, successfully reconstructing their clival (n = 3) and sellar (n = 1) surgical defects. All patients healed uneventfully.Our anatomic study and early clinical experience support the use of the posterior pedicle lateral nasal wall flap to reconstruct large cranial base defects resulting from endoscopic skull base surgery in properly selected patients.

  View details for PubMedID 22185727

• Endoscopic Endonasal Approach for Nonvestibular Schwannomas NEUROSURGERY Shin, S. S., Gardner, P. A., Stefko, S., Madhok, R., Fernandez-Miranda, J. C., Snyderman, C. H. 2011; 69 (5): 1046–57

  Abstract

  Nonvestibular schwannomas of the skull base often represent a challenge owing to their anatomic location. With improved techniques in endoscopic endonasal skull base surgery, resection of various ventral skull base tumors, including schwannomas, has become possible.To assess the outcomes of using endoscopic endonasal approach (EEA) for nonvestibular schwannomas of the skull base.Seventeen patients operated on for skull base schwannomas by EEA at the University of Pittsburgh Medical Center from 2003 to 2009 were reviewed.Three patients underwent combined approaches with retromastoid craniectomy (n = 2) and orbitopterional craniotomy (n = 1). Three patients underwent multistage EEA. The rest received a single EEA operation. Data on degree of resection were found for 15 patients. Gross total resection (n = 9) and near-total (>90%) resection (n = 3) were achieved in 12 patients (80%). There were no tumor recurrences or postoperative cerebrospinal fluid leaks. In 3 of 7 patients with preoperative sensory deficits of trigeminal nerve distribution, there were partial improvements. Patients with preoperative reduced vision (n = 1) and cranial nerve VI or III palsies (n = 3) also showed improvement. Five patients had new postoperative trigeminal nerve deficits: 2 had sensory deficits only, 1 had motor deficit only, and 2 had both motor and sensory deficits. Three of these patients had partial improvement, but 3 developed corneal neurotrophic keratopathy.An EEA provides adequate access for nonvestibular schwannomas invading the skull base, allowing a high degree of resection with a low rate of complications.

  View details for PubMedID 21673609

• Skull Base Chordomas OTOLARYNGOLOGIC CLINICS OF NORTH AMERICA Koutourousiou, M., Snyderman, C. H., Fernandez-Miranda, J., Gardner, P. A. 2011; 44 (5): 1155-+

  Abstract

  Skull base chordomas are rare midline malignancies of clival origin that represent one of the most challenging skull base tumors to treat, given their location, invasiveness, potential extension around vital neurovascular structures, and high recurrence rate. Total tumor resection is the mainstay of treatment. The combination of surgery and postoperative irradiation appears to provide the best outcome.

  View details for PubMedID 21978899

• Endoscopic Nasopharyngectomy and its Role in Managing Locally Recurrent Nasopharyngeal Carcinoma OTOLARYNGOLOGIC CLINICS OF NORTH AMERICA Ong, Y., Solares, C., Lee, S., Snyderman, C. H., Fernandez-Miranda, J., Gardner, P. A. 2011; 44 (5): 1141-+

  Abstract

  Local recurrence after primary radiation of nasopharyngeal carcinoma (NPC) remains an important cause of morbidity and mortality. Salvage treatment using reirradiation or surgery has been shown to improve survival over nontreatment. Surgery is traditionally performed using an open approach. Advances in endoscopic approaches for resection of paranasal sinus tumors have been extended to NPC. This article reviews the treatment options, in particular the role of endoscopic nasopharyngectomy in the management of recurrent NPC. The endoscopic anatomy, surgical principles, and published results on endoscopic nasopharyngectomy are presented. Short-term outcomes for early-stage recurrences are promising but long-term follow-up is needed.

  View details for DOI 10.1016/j.otc.2011.07.002

  View details for Web of Science ID 000296213400006

  View details for PubMedID 21978898

• Training in Neurorhinology: The Impact of Case Volume on the Learning Curve OTOLARYNGOLOGIC CLINICS OF NORTH AMERICA Snyderman, C. H., Fernandez-Miranda, J., Gardner, P. A. 2011; 44 (5): 1223-+

  Abstract

  This article presents a current view of training in neurorhinology and focuses on the level of evidence for the clinical question of "how many cases are needed to achieve proficiency in endoscopic endonasal skull base surgery?" The authors discuss what defines surgical proficiency, what makes up the learning curve and how it shifts with increasing experience, comparisons of learning curves for different skull base surgeries, and conclude with a discussion and recommendations for achieving high-level proficiency.

  View details for PubMedID 21978903

• Endoscopic Endonasal Infrasellar Approach to the Sellar and Suprasellar Regions: Technical Note SKULL BASE-AN INTERDISCIPLINARY APPROACH Paluzzi, A., Fernandez-Miranda, J. C., Pinheiro-Neto, C., Alcocer-Barradas, V., Lopez-Alvarez, B., Gardner, P., Snyderman, C. 2011; 21 (5): 335–42

  Abstract

  We report a technical variation of the endoscopic endonasal approach to the sellar and suprasellar regions which relies on the use of a 45-degree angled endoscope. The so-called "infrasellar approach" aims at excising lesions situated within the intermediate and posterior lobes of the pituitary gland without damaging the anterior lobe, thus potentially minimizing endocrinological morbidity. In this regard the endoscopic infrasellar approach might be advantageous in selected cases when compared with the traditional transsphenoidal approach with the microscope. We describe the technique and illustrate it with representative clinical cases.

  View details for DOI 10.1055/s-0031-1280682

  View details for Web of Science ID 000294955000009

  View details for PubMedID 22451835

  View details for PubMedCentralID PMC3312132

• Endoscopic Endonasal Surgery for Nasal Dermoids OTOLARYNGOLOGIC CLINICS OF NORTH AMERICA Pinheiro-Neto, C. D., Snyderman, C. H., Fernandez-Miranda, J., Gardner, P. A. 2011; 44 (4): 981-+

  Abstract

  Midline congenital lesions are rare and commonly comprise nasal dermoids (NDs), encephaloceles, and gliomas. This article discusses the epidemiology of NDs. Management is also discussed, as well as prognosis.

  View details for PubMedID 21819884

• Anterior Pedicle Lateral Nasal Wall Flap: A Novel Technique for the Reconstruction of Anterior Skull Base Defects LARYNGOSCOPE Hadad, G., Rivera-Serrano, C. M., Bassagaisteguy, L. H., Carrau, R. L., Fernandez-Miranda, J., Prevedello, D. M., Kassam, A. B. 2011; 121 (8): 1606–10

  Abstract

  Expansion of the clinical indications for ablative endoscopic endonasal approaches has behooved us to search for new reconstruction alternatives. We present the anatomic foundations of a novel anterior pedicled lateral wall flap (Hadad-Bassagaisteguy 2 or HB2 flap) for the vascularized reconstruction of anterior skull base defects.Anatomic description. Feasibility study. Technical reportUsing a cadaveric model, we investigated the feasibility of harvesting an anteriorly based mucoperiosteal flap from the lateral nasal wall. We then applied the techniques developed in the anatomical laboratory to reconstruct two patients with defects resulting from the endoscopic endonasal resection of esthesioneuroblastomas and one patient with an extensive meningoencephalocoele of the anterior cranial fossa.HB2 flaps were harvested and transposed to reconstruct anterior skull base defects in cadaveric specimens, and subsequently, in three patients. The HB2 flap provided adequate coverage in the cadaveric model, as well as clinically in our three patients. Their postoperative healing was uneventful.The HB2 flap is a feasible alternative for the reconstruction of anterior skull base defects in select patients.

  View details for DOI 10.1002/lary.21889

  View details for Web of Science ID 000293803400003

  View details for PubMedID 21792948

• Endoscopic Port Surgery for Resection of Lesions of the Cerebellar Peduncles: Technical Note NEUROSURGERY Ochalski, P. G., Fernandez-Miranda, J. C., Prevedello, D. M., Pollack, I. F., Engh, J. A. 2011; 68 (5): 1444–50

  Abstract

  Mass lesions of the inferior, middle, and superior cerebellar peduncles (cerebellar peduncle complex [CPC]) present numerous surgical pitfalls when resection or debulking is warranted. Success has been achieved through multiple approaches, but complications can be severe.To report the surgical technique for and clinical results of the treatment of lesions in the CPC with an endoscopic port via a lateral transcerebellar corridor.Three patients underwent resection of intrinsic lesions of the CPC via a lateral transcerebellar approach with an endoscopic port. Deployment of the port was performed with frameless image-guided placement into the area of interest. Resection was performed using bimanual microsurgical technique under parallel endoscopic visualization.Three patients 43, 27, and 13 years of age underwent successful resection of lesion in the CPC. Histopathological diagnosis consisted of cavernous malformation, glioblastoma multiforme, and a juvenile pilocytic astrocytoma. All had complete gross total resection except for the patient with a high-grade glioma. Clinically, all had excellent outcomes, with 1 patient suffering postoperative facial palsy after resection of her high-grade glioma.The lateral transcerebellar approach to the CPC with an endoscopic port may be a feasible alternative to standard microsurgical resection in such difficult cases. Careful patient selection is critical to identify those who may be suitable for endoscopic port surgery on the basis of clinical, radiographic, and anatomical considerations.

  View details for PubMedID 21273935

• Prevertebral Corridor: Posterior Pathway for Reconstruction of the Ventral Skull Base Durmaz, A., Fernandez-Miranda, J., Snyderman, C. H., Rivera-Serrano, C., Tosun, F. LIPPINCOTT WILLIAMS & WILKINS. 2011: 848–53

  Abstract

  Regional vascularized flaps, such as the pericranial and temporoparietal fascia flaps, are currently used for reconstruction of skull base defects after endoscopic endonasal surgery whenever local vascularized flaps, such as the nasoseptal flap, are not available. Two different transposition pathways, infratemporal transpterygoid and subfrontal, have been proposed for regional flaps. The objective of this study was to describe and assess the feasibility of the transposition of a vascularized pedicled flap from the occipital galeopericranium via the prevertebral space corridor into the nasopharynx.Ten heads were injected with colored silicone. An endoscopic endonasal anterior craniofacial resection and panclival approach were performed in each specimen. The occipital flap was harvested using a previously described technique. The prevertebral corridor, extending from the neck to the nasopharynx, was dissected superficial to the paraspinal muscles. Computed tomography-based image guidance was used to assess the relationship between the corridor and adjacent neurovascular structures. Length of the corridor and pedicle and area of the donor flap were measured.The flap was harvested and successfully transposed into the nasopharynx using the proposed corridor in all studied specimens (10 heads, 20 sides). All flaps provided complete coverage of the skull base defects. The average length of the pedicle was 70.5 (SD, 6.5) mm, and the average length and width of the flap were 99.9 (SD, 14.6) mm and 59.3 (SD, 10.9) mm, respectively. The average length of the prevertebral corridor was 49.7 (SD, 4.8) mm.The occipital flap has favorable anatomic characteristics for use in skull base reconstruction. Transposition of the flap via the prevertebral corridor is a suitable option for vascularized reconstruction of expanded endonasal skull base defects when other local or regional flaps are not available. Additional clinical studies are necessary to define its role in endoscopic endonasal surgery.

  View details for DOI 10.1097/SCS.0b013e31820f7d86

  View details for Web of Science ID 000290732100019

  View details for PubMedID 21558931

• In Response to Pedicled Nasoseptal Flap Is Not the Standard of Care for Skull Base Defects LARYNGOSCOPE Caicedo-Granados, E., Carrau, R., Kassam, A., Snyderman, C. H., Prevedello, D., Fernandez-Miranda, J., Gardner, P. 2011; 121 (4): 898

  View details for DOI 10.1002/lary.21552

  View details for Web of Science ID 000288817900039

• Vidian Nerve Transposition for Endoscopic Endonasal Middle Fossa Approaches (vol 67, ons478, 2010) NEUROSURGERY Fernandez-Miranda, J. C., Gardner, P. A., Snyderman, C. H. 2011; 68 (2)

  View details for DOI 10.1227/01.neu.0000393361.87423.b7

  View details for Web of Science ID 000285994300035

• Vidian Nerve Transposition for Endoscopic Endonasal Middle Fossa Approaches NEUROSURGERY Prevedello, D. M., Pinheiro-Neto, C. D., Fernandez-Miranda, J. C., Carrau, R. L., Snyderman, C. H., Gardner, P. A., Kassam, A. B. 2010; 67

  View details for DOI 10.1227/NEU.0b013e3181faaa70

  View details for Web of Science ID 000284838900040

• High-definition fiber tracking guidance for intraparenchymal endoscopic port surgery JOURNAL OF NEUROSURGERY Fernandez-Miranda, J. C., Engh, J. A., Pathak, S. K., Madhok, R., Boada, F. E., Schneider, W., Kassam, A. B. 2010; 113 (5): 990–99

  Abstract

  The authors have applied high-definition fiber tracking (HDFT) to the resection of an intraparenchymal dermoid cyst by using a minimally invasive endoscopic port. The lesion was located within the mesial frontal lobe, septal area, hypothalamus, and suprasellar recess. Using high-dimensional (256 directions) diffusion imaging, more than 250,000 fiber tracts were imaged before and after surgery. Trajectory planning using HDFT in a computer model was used to facilitate cannulation of the cyst with the endoscopic port. Analysis of the proposed initial surgical route was overlaid onto the fiber tracts and was predicted to produce substantial disruption to prefrontal projection fibers (anterior limb of the internal capsule) and the cingulum. Adjustment of the cannulation entry point 1 cm medially was predicted to cross the corpus callosum instead of the anterior limb of the internal capsule or the cingulum. Following cyst resection performed using endoscopic port surgery, postoperative imaging demonstrated accurate cannulation of the lesion, with improved quantitative signal from both the anterior limb of the internal capsule and the cingulum. The observed fiber preservation from the cingulum and the anterior limb of the internal capsule, with minor injury to the corpus callosum, was in close agreement with preoperative trajectory modeling. Comparison of pre- and postoperative HDFT data facilitated quantification of the benefits and costs of the surgical trajectory. Future studies will help to determine whether HDFT combined with endoscopic port surgery facilitates anatomical and functional preservation in such challenging cases.

  View details for PubMedID 19943732

• Animal Model for Endoscopic Neurosurgical Training: Technical Note MINIMALLY INVASIVE NEUROSURGERY Fernandez-Miranda, J. C., Barges-Coll, J., Prevedello, D. M., Engh, J., Snyderman, C., Carrau, R., Gardner, P. A., Kassam, A. B. 2010; 53 (5-6): 286–89

  Abstract

  The learning curve for endonasal endoscopic and neuroendoscopic port surgery is long and often associated with an increase in complication rates as surgeons gain experience. We present an animal model for laboratory training aiming to encourage the young generation of neurosurgeons to pursue proficiency in endoscopic neurosurgical techniques.20 Wistar rats were used as models. The animals were introduced into a physical trainer with multiple ports to carry out fully endoscopic microsurgical procedures. The vertical and horizontal dimensions of the paired ports (simulated nostrils) were: 35×20 mm, 35×15 mm, 25×15 mm, and 25×10 mm. 2 additional single 11.5 mm endoscopic ports were added. Surgical depth varied as desired between 8 and 15 cm. The cervical and abdominal regions were the focus of the endoscopic microsurgical exercises.The different endoscopic neurosurgical techniques were effectively trained at the millimetric dimension. Levels of progressive surgical difficulty depending upon the endoneurosurgical skills set needed for a particular surgical exercise were distinguished. LEVEL 1 is soft-tissue microdissection (exposure of cervical muscular plane and retroperitoneal space); LEVEL 2 is soft-tissue-vascular and vascular-capsule microdissection (aorto-cava exposure, carotid sheath opening, external jugular vein isolation); LEVEL 3 is artery-nerve microdissection (carotid-vagal separation); LEVEL 4 is artery-vein microdissection (aorto-cava separation); LEVEL 5 is vascular repair and microsuturing (aortic rupture), which verified the lack of current proper instrumentation.The animal training model presented here has the potential to shorten the length of the learning curve in endonasal endoscopic and neuroendoscopic port surgery and reduce the incidence of training-related surgical complications.

  View details for PubMedID 21302201

• Use of Acoustic Doppler Sonography to Ascertain the Feasibility of the Pedicled Nasoseptal Flap After Prior Bilateral Sphenoidotomy LARYNGOSCOPE Pinheiro-Neto, C. D., Carrau, R. L., Prevedello, D. M., Fernandez-Miranda, J. C., Snyderman, C. S., Gardner, P. A., Kassam, A. B. 2010; 120 (9): 1798–1801

  Abstract

  Blood supply to the Hadad-Bassagasteguy pedicled nasoseptal flap may be interrupted by surgery of the pterygopalatine fossa, posterior septectomy, or large sphenoidotomies. This would preclude its use for reconstruction of skull base defects after expanded endonasal approaches (EEA). We present a novel method to ascertain the patency of the nasoseptal artery after prior surgery, and consequently the availability of the nasoseptal flap, using acoustic Doppler sonography.Retrospective clinical review.Four patients who underwent EEAs were evaluated intraoperatively with acoustic Doppler sonography. The mucosa that covers the inferior aspect of the rostrum of the sphenoid sinus was scanned with the tip of the probe. Reflection of sound waves representing intravascular blood flow was assessed.In three patients, the artery was identified in at least one side. One remaining patient showed no acoustic signal suggesting loss of the nasoseptal artery bilaterally, therefore necessitating the use of a fat graft for the reconstruction.Acoustic Doppler sonography seems to be a feasible and effective way to ascertain the availability of the nasoseptal artery. It is a relatively inexpensive and simple technique that can be performed by any endoscopic surgeon.

  View details for DOI 10.1002/lary.20996

  View details for Web of Science ID 000281430600014

  View details for PubMedID 20715092

• Stereotactically Guided Endoscopic Port Surgery for Intraventricular Tumor and Colloid Cyst Resection NEUROSURGERY Engh, J. A., Lunsford, L., Amin, D. V., Ochalski, P. G., Fernandez-Miranda, J., Prevedello, D. M., Kassam, A. B. 2010; 67 (3): 198–204

  Abstract

  Intraventricular lesions are challenging entities that may be difficult to resect completely and safely, especially larger lesions with high vascularity or firm consistency.To assess the results of stereotactically guided endoscopic port (SEP) surgery for resection of colloid cysts and intraventricular tumors.The authors developed a minimally invasive microsurgical technique for intraventricular surgery using parallel endoscopy to visualize the lesion. Surgical resection was performed via an 11.5-mm transparent conduit (Neuroendoport) deployed under stereotactic guidance. Forty-seven consecutive cases were performed, and all had a minimum 1-year follow-up to assess the efficacy of the technique.For colloid cysts, gross total resection was achieved in 31 (96.9%) of the 32 cases. The transient neurologic morbidity rate was 9.4%; no permanent neurologic morbidity occurred. For intraventricular tumors, gross or near total resection was achieved in 80% of cases. The transient neurological morbidity rate was 6.7%, and no permanent neurological morbidity occurred.SEP surgery for colloid cysts and intraventricular tumors proved to be a safe and effective alternative to conventional microsurgical resection. This technique was not limited by the vascularity, friability, or size of any of the lesions.

  View details for PubMedID 20679929

• Endonasal endoscopic pituitary surgery: is it a matter of fashion? ACTA NEUROCHIRURGICA Fernandez-Miranda, J. C., Prevedello, D. M., Gardner, P., Carrau, R., Snyderman, C. H., Kassam, A. B. 2010; 152 (8): 1281–82

  View details for DOI 10.1007/s00701-009-0487-y

  View details for Web of Science ID 000279704300002

  View details for PubMedID 19696960

• Reverse Rotation Flap for Reconstruction of Donor Site After Vascular Pedicled Nasoseptal Flap in Skull Base Surgery LARYNGOSCOPE Caicedo-Granados, E., Carrau, R., Snyderman, C. H., Prevedello, D., Fernandez-Miranda, J., Gardner, P., Kassam, A. 2010; 120 (8): 1550–52

  Abstract

  Endonasal skull base surgery is growing exponentially as a subspecialty. In recent years, advances in endoscopic techniques and intraoperative navigation systems have allowed us to expand the indications of endoscopic skull base surgery. Major skull base centers worldwide are addressing larger and more complex lesions using endoscopic techniques. As a consequence, the skull base defects are more challenging to reconstruct. In this report, we present a novel technique to reconstruct the denuded septum remaining after the use of the vascular pedicled nasoseptal flap.

  View details for PubMedID 20564666

• Prevention and Management of Vascular Injuries in Endoscopic Surgery of the Sinonasal Tract and Skull Base OTOLARYNGOLOGIC CLINICS OF NORTH AMERICA Solares, C., Ong, Y., Carrau, R. L., Fernandez-Miranda, J., Prevedello, D. M., Snyderman, C. H., Kassam, A. B. 2010; 43 (4): 817-+

  Abstract

  In the past 2 decades, endoscopic sinus surgery has been widely used as a safe and effective treatment for disorders of the paranasal sinuses that are refractory to medical therapy. Advances in surgical technique, including powered instrumentation and stereotactic image-guided surgery, have improved the efficiency and safety of this procedure. These techniques have been further expanded to manage skull base pathologies. This expansion has been facilitated by a better understanding of the endonasal skull base anatomy. Despite these advances, complications are still encountered. Vascular injuries are particularly troublesome. Interior ethmoid artery injuries during sinus surgery that led to orbital hematoma were discussed extensively in a recent issue of this journal. Therefore, this article focuses mainly on inadvertent carotid artery injuries during routine sinus surgery and vascular injuries during endoscopic skull base surgery.

  View details for DOI 10.1016/j.otc.2010.04.008

  View details for Web of Science ID 000280482100010

  View details for PubMedID 20599086

• High-definition fiber tractography and language JOURNAL OF NEUROSURGERY Fernandez-Miranda, J. C., Pathak, S., Schneider, W. 2010; 113 (1): 156–57

  View details for DOI 10.3171/2009.10.JNS091460

  View details for Web of Science ID 000279107300039

  View details for PubMedID 20450278

• Avoiding Injury to the Abducens Nerve During Expanded Endonasal Endoscopic Surgery: Anatomic and Clinical Case Studies NEUROSURGERY Barges-Coll, J., Fernandez-Miranda, J., Prevedello, D. M., Gardner, P., Morera, V., Madhok, R., Carrau, R. L., Snyderman, C. H., Rhoton, A. L., Kassam, A. B. 2010; 67 (1): 144–54

  Abstract

  Understanding the course of the most medially located parasellar cranial nerve, the abducens, becomes critical when performing an expanded endonasal approach.We report an anatomoclinical study of the abducens nerve and describe relevant surgical nuances to avoid its injury.Ten anatomic specimens were dissected using endoscopes attached to an high-definition camera. A series of anatomic measurements and relationships of the abducens nerve were noted. Illustrative clinical cases are described to translate those findings into practice.Cisternal, interdural, gulfar, and cavernous segments of the abducens were identified intracranially. The mean distance from the vertebrobasilar junction (VBJ) to the pontomedullary sulcus (PMS) was 4 mm; horizontal distance between both abducens nerves at the PMS was 10 mm, and between both abducens at the interdural segment was 18.5 mm. The upper limit of the lacerum segment of the internal carotid artery was at the same level of the dural entry point of the sixth cranial nerve posteriorly. The sellar floor at the sphenoid sinus marks the level of the gulfar segment in the craniocaudal axis. At the superior orbital fissure, the abducens nerve and V2 were at an average vertical distance of 11.5 mm.Anatomic landmarks to localize the abducens nerve intraoperatively, such as the VBJ for the transclival approach, the lacerum segment of the carotid, and the sellar floor for the medial petrous apex approach, and V2 for Meckel's cave approach, are reliable and complementary to the use of intraoperative electrophysiological monitoring.

  View details for PubMedID 20559102

• The transclival endoscopic endonasal approach (EEA) for prepontine neuroenteric cysts: report of two cases ACTA NEUROCHIRURGICA Prevedello, D. M., Fernandez-Miranda, J., Gardner, P., Madhok, R., Sigounas, D., Snyderman, C. H., Carrau, R. L., Kassam, A. B. 2010; 152 (7): 1223–29

  Abstract

  The transclival endoscopic endonasal approach was used to completely remove a prepontine neuroenteric cyst in two different patients.Full clinical improvement without postoperative complication was achieved in both cases. The postoperative hospital stay was limited to 2 and 3 days.In comparison to posterolateral skull base approaches, the transclival endoscopic endonasal approach allows direct access to the prepontine cistern without unnecessary manipulation of neurovascular structures at the cerebellopontine angle. In contrast to transoral surgery, patients may have decreased risk of infection and can be fed orally immediately without the risks of palatal and oropharyngeal dehiscence.Neuronavigation technology, strict adherence to microsurgical principles, and significant endoneurosurgical experience are strongly recommended when approaching these challenging lesions.

  View details for PubMedID 19997946

• Endoscopic Endonasal Dissection of the Pterygopalatine fossa, Infratemporal fossa, and Post-styloid compartment. Anatomical Relationships and Importance of Eustachian Tube in the Endoscopic Skull Base Surgery Rivera-Serrano, C. M., Terre-Falcon, R., Fernandez-Miranda, J., Prevedello, D., Snyderman, C. H., Gardner, P., Kassam, A., Carrau, R. L. WILEY-BLACKWELL. 2010: S244

  View details for PubMedID 21225842

• Middle Turbinate Flap for Skull Base Reconstruction: Cadaveric Feasibility Study LARYNGOSCOPE Prevedello, D. M., Barges-Coll, J., Fernandez-Miranda, J., Morera, V., Jacobson, D., Madhok, R., dos Santos, M. J., Zanation, A., Snyderman, C. H., Gardner, P., Kassam, A. B., Carrau, R. 2009; 119 (11): 2094–98

  Abstract

  Surgical resection of intradural pathology through an endonasal corridor creates defects that communicate the subarachnoid space with the sinonasal tract. Reconstruction of these defects with vascularized tissue is superior to any other method. The purpose of this study is to describe a novel vascularized pedicled flap from the middle turbinate (MT) mucosa and to assess its feasibility using a cadaveric model.Twelve middle turbinate flaps (MTFs) were raised in six fresh cadaveric heads previously injected with colored silicone. Arteries supplying the MT were identified as the turbinate mucoperiosteum was harvested from both its medial and lateral aspects. Length and surface area of the flaps, as well as their ability to cover dural defects of the sella, planum sphenoidale, and fovea ethmoidalis reach were noted.All MTFs adequately covered defects of the planum and fovea ethmoidalis; however, two of the twelve MTFs were not suitable to cover a sellar defect. The mean surface area of the MTFs was 5.6 cm(2). As an independent factor surface area did not correlate with the ability of the flap to cover the sellar defects. However, those flaps that were not suitable for sellar repair were less than 4.0 cm in length.Harvesting of a vascular pedicle flap from the MT is feasible, albeit technically demanding. It should be considered as an alternative for the reconstruction of small defects of the fovea ethmoidalis, planum, and sella, particularly for patients for whom a reconstruction with vascularized tissue is desirable but the nasoseptal flap is not available.

  View details for PubMedID 19718761

• Sphenoid Septations and Their Relationship With Internal Carotid Arteries: Anatomical and Radiological Study LARYNGOSCOPE Fernandez-Miranda, J. C., Prevedello, D. M., Madhok, R., Morera, V., Barges-Coll, J., Reineman, K., Snyderman, C. H., Gardner, P., Carrau, R., Kassam, A. B. 2009; 119 (10): 1893–96

  Abstract

  We sought to investigate the anatomical relation of the intrasphenoid septations to the internal carotid artery (ICA).Twenty-seven preoperative high-resolution computed tomography angiographic (CTA) scans with 1 mm of separation acquisition were examined. In addition, an endoscopic endonasal approach and high-resolution computed tomography were done on 27 fresh-frozen cadaveric heads. The number of intrasphenoid septa and their relation to the ICAs were analyzed endoscopically and radiologically. Complete and incomplete septations were included in the analysis. A total of 54 sphenoid sinuses were studied.Out of 27 sphenoid sinuses radiologically studied from real patients, 23 (85%) and 11 (41%) had at least one or two septa, respectively, touching one of the ICA. Out of 27 sphenoid sinuses endoscopically examined from cadavers (excluding one conchal type), 24 (89%) had at least one septation inserted in the ICAs. Two or more septations were inserted in the carotid prominence in 48% of sphenoid sinuses. The radiological examination of the anatomical specimens revealed similar results, with discrepancy in just one case (1/27) where it did not identify an incomplete septation inserting at ICA. No significant differences were found between the groups. From a total of 54 sphenoid sinuses studied, 47 (87%) had at least one septum related to the ICA, and only 13% presented a typical isolated midline septation.As demonstrated both radiographically and endoscopically, most intrasphenoidal septa insert at the parasellar or paraclival carotid prominence. As such, extreme care should be taken when identifying and removing these septations intraoperatively.

  View details for PubMedID 19655331

• Expanded endonasal approach for olfactory groove meningioma ACTA NEUROCHIRURGICA Fernandez-Miranda, J. C., Gardner, P. A., Prevedello, D. M., Kassam, A. B. 2009; 151 (3): 287–88

  View details for DOI 10.1007/s00701-009-0201-0

  View details for Web of Science ID 000264091000015

  View details for PubMedID 19229470

• Three-dimensional microsurgical and tractographic anatomy of the white matter of the human brain. Neurosurgery Fernandez-Miranda, J. C., Rhoton, A. L., Alvarez-Linera, J., Kakizawa, Y., Choi, C., de Oliveira, E. P. 2008; 62 (6 Suppl 3): 989

  Abstract

  OBJECTIVE: We sought to investigate the three-dimensional structure of the white matter of the brain by means of the fiber-dissection technique and diffusion-tensor magnetic resonance imaging to assess the usefulness of the combination of both techniques, compare their results, and review the potential functional role of fiber tracts.METHODS: Fifteen formalin-fixed human hemispheres were dissected according to Klingler's fiber-dissection technique with the aid of 36 to 340 magnification. Three-dimensional anatomic images were created with the use of specific software. Two hundred patients with neurological symptoms and five healthy volunteers were studied with diffusion-tensor magnetic resonance imaging (3 T) and tractographic reconstruction.RESULTS: The most important association, projection, and commissural fasciculi were identified anatomically and radiologically. Analysis of their localization, configuration, and trajectory was enhanced by the combination of both techniques. Three-dimensional anatomic reconstructions provided a better perception of the spatial relationships among the white matter tracts. Tractographic reconstructions allowed for inspection of the relationships between the tracts as well as between the tracts and the intracerebral lesions. The combination of topographical anatomic studies of human fiber tracts and neuroanatomic research in experimental animals, with data from the clinicoradiological analysis of human white matter lesions and intraoperative subcortical stimulation, aided in establishing the potential functional role of the tracts.CONCLUSION: The fiber-dissection and diffusion-tensor magnetic resonance imaging techniques are reciprocally enriched not only in their application to the study of the complex intrinsic architecture of the brain, but also in their practical use for diagnosis and surgical planning.

  View details for PubMedID 18695585

• Blood supply of the facial nerve in the middle fossa: the petrosal artery. Neurosurgery El-Khouly, H., Fernandez-Miranda, J., Rhoton, A. L. 2008; 62 (5 Suppl 2): ONS297

  Abstract

  OBJECTIVE: To define the arterial supply to the facial nerve that crosses the floor of the middle cranial fossa.METHODS: Twenty-five middle fossae from adult cadaveric-injected specimens were examined under 3 to 40x magnification.RESULTS: The petrosal branch of the middle meningeal artery is the sole source of supply that crossed the floor of the middle fossa to irrigate the facial nerve. The petrosal artery usually arises from the first 10-mm segment of the middle meningeal artery after it passes through the foramen spinosum, but it can arise within or just below the foramen spinosum. The petrosal artery is commonly partially or completely hidden in the bone below the middle fossa floor. It most commonly reaches the facial nerve by passing through the bone enclosing the geniculate ganglion and tympanic segment of the nerve and less commonly by passing through the hiatus of the greater petrosal nerve. The petrosal artery frequently gives rise to a branch to the trigeminal nerve. The middle meningeal artery was absent in one of the 25 middle fossae, and a petrosal artery could not be identified in four middle fossae. The petrosal arteries were divided into three types based on their pattern of supply to the facial nerve.CONCLUSION: The petrosal artery is at risk of being damaged during procedures in which the dura is elevated from the floor of the middle fossa, the middle fossa floor is drilled, or the middle meningeal artery is embolized or sacrificed. Several recommendations are offered to avoid damaging the facial nerve supply while performing such interventions.

  View details for PubMedID 18596507

• Blood supply of the facial nerve in the middle fossa: The petrosal artery NEUROSURGERY El-Khouly, H., Fernandez-Miranda, J., Rhoton, A. L. 2008; 62 (5): 297-303

  View details for DOI 10.1227/01.NEU.0000297131.15689.EB

  View details for Web of Science ID 000257221000005

• The claustrum and its projection system in the human brain: a microsurgical and tractographic anatomical study JOURNAL OF NEUROSURGERY Ferandez-Miranda, J. C., Rhoton, A. L., Kakaawa, Y., Choi, C., Alvarez-Linera, J. 2008; 108 (4): 764–74

  Abstract

  The goal in this study was to examine the microsurgical and tractographic anatomy of the claustrum and its projection fibers, and to analyze the functional and surgical implications of the findings.Fifteen formalin-fixed human brain hemispheres were dissected using the Klingler fiber dissection technique, with the aid of an operating microscope at x 6-40 magnification. Magnetic resonance imaging studies of 5 normal brains were analyzed using diffusion tensor (DT) imaging-based tractography software.Both the claustrum and external capsule have 2 parts: dorsal and ventral. The dorsal part of the external capsule is mainly composed of the claustrocortical fibers that converge into the gray matter of the dorsal claustrum. Results of the tractography studies coincided with the fiber dissection findings and showed that the claustrocortical fibers connect the claustrum with the superior frontal, precentral, postcentral, and posterior parietal cortices, and are topographically organized. The ventral part of the external capsule is formed by the uncinate and inferior occipitofrontal fascicles, which traverse the ventral part of the claustrum, connecting the orbitofrontal and prefrontal cortex with the amygdaloid, temporal, and occipital cortices. The relationship between the insular surface and the underlying fiber tracts, and between the medial lower surface of the claustrum and the lateral lenticulostriate arteries is described.The combination of the fiber dissection technique and DT imaging-based tractography supports the presence of the claustrocortical system as an integrative network in humans and offers the potential to aid in understanding the diffusion of gliomas in the insula and other areas of the brain.

  View details for PubMedID 18377257

• Microsurgical approaches to the medial temporal region: An anatomical study NEUROSURGERY Campero, A., Troccoli, G., Martins, C., Fernandez-Miranda, J. C., Yasuda, A., Rhoton, A. L. 2006; 59 (4): 279-307

  View details for DOI 10.1227/NEU.0000223509.21474.2E

  View details for Web of Science ID 000241419500019

• Meyer's loop and the optic radiations in the transsylvian approach to the mediobasal temporal lobe NEUROSURGERY Choi, C., Rubino, P. A., Fernandez-Miranda, J. C., Abe, H., Rhoton, A. L. 2006; 59 (4): 228-235

  View details for DOI 10.1227/01.NEU.0000223374.69144.81

  View details for Web of Science ID 000241419500007

• Microsurgical approaches to the medial temporal region: an anatomical study. Neurosurgery Campero, A. n., Tróccoli, G. n., Martins, C. n., Fernandez-Miranda, J. C., Yasuda, A. n., Rhoton, A. L. 2006; 59 (4 Suppl 2): ONS279–307; discussion ONS307–8

  Abstract

  To describe the surgical anatomy of the anterior, middle, and posterior portions of the medial temporal region and to present an anatomic-based classification of the approaches to this area.Twenty formalin-fixed, adult cadaveric specimens were studied. Ten brains provided measurements to compare different surgical strategies. Approaches were demonstrated using 10 silicon-injected cadaveric heads. Surgical cases were used to illustrate the results by the different approaches. Transverse lines at the level of the inferior choroidal point and quadrigeminal plate were used to divide the medial temporal region into anterior, middle, and posterior portions. Surgical approaches to the medial temporal region were classified into four groups: superior, lateral, basal, and medial, based on the surface of the lobe through which the approach was directed. The approaches through the medial group were subdivided further into an anterior approach, the transsylvian transcisternal approach, and two posterior approaches, the occipital interhemispheric and supracerebellar transtentorial approaches.The anterior portion of the medial temporal region can be reached through the superior, lateral, and basal surfaces of the lobe and the anterior variant of the approach through the medial surface. The posterior group of approaches directed through the medial surface are useful for lesions located in the posterior portion. The middle part of the medial temporal region is the most challenging area to expose, where the approach must be tailored according to the nature of the lesion and its extension to other medial temporal areas.Each approach to medial temporal lesions has technical or functional drawbacks that should be considered when selecting a surgical treatment for a given patient. Dividing the medial temporal region into smaller areas allows for a more precise analysis, not only of the expected anatomic relationships, but also of the possible choices for the safe resection of the lesion. The systematization used here also provides the basis for selection of a combination of approaches.

  View details for PubMedID 17041498

• Meyer's loop and the optic radiations in the transsylvian approach to the mediobasal temporal lobe. Neurosurgery Choi, C. n., Rubino, P. A., Fernandez-Miranda, J. C., Abe, H. n., Rhoton, A. L. 2006; 59 (4 Suppl 2): ONS228–35; discussion ONS235–6

  Abstract

  In the transsylvian approach to the mediobasal temporal structures, the temporal horn is approached through the floor of the sylvian fissure. The anterior bundle of the optic radiations (Meyer's loop) courses between the floor of the sylvian fissure and roof of the temporal horn and could be damaged in this approach. This study was designed to define the route through the floor of the sylvian fissure least likely to damage the optic pathways.Meyer's loop was dissected by applying Klingler's fiber dissection technique in 10 formalin-fixed human hemispheres. Several measurements quantified the relationship of the Meyer's loop to surgically important structures.This study identified a triangular safe area below the floor of the sylvian fissure through which the temporal horn could be accessed in the transsylvian approach with a low risk of damaging the optic radiations. An incision in the floor of the sylvian fissure directed downward at the level of limen insula and the adjacent 5 mm of the inferior insular sulcus would avoid the optic radiations. An incision directed straight downward 10, 15, and 20 mm behind the limen in the inferior insular sulcus would cross Meyer's loop and would need to be directed downward and medially as much as 80 degrees from the sagittal plane to avoid Meyer's loop.In the transsylvian approach to the temporal horn, incisions at the level of the limen, or adjacent 5 mm of the inferior insular sulcus, are less likely to damage Meyer's loop and the optic radiations than more posterior incisions along the inferior insular sulcus. Incision at this safe level commonly opens into the amygdala, a portion of which is removed to provide entry into the temporal horn for removal of the mediobasal structures.

  View details for PubMedID 17041492