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  • 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

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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 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
  • 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

  • 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

  • Radiological outcomes for endovascular treatment of posterior communicating artery aneurysms: a retrospective multicenter study of the occlusion rate. Journal of integrative neuroscience Scerrati, A., Trevisi, G., Sturiale, C. L., Salomi, F., De Bonis, P., Saletti, A., Mangiola, A., Tomatis, A., Di Egidio, V., Vigo, V., Pedicelli, A., Valente, I., Rustemi, O., Beggio, G., Iannucci, G., Milonia, L., Ricciardi, L., Cervo, A., Pero, G., Piano, M. 2021; 20 (4): 919-931

    Abstract

    Although several innovations in techniques and implantable devices were reported over the last decades, a consensus on the best endovascular treatment for intracranial aneurysms originating from the posterior communicating artery is still missing. This work investigates radiological outcomes of different endovascular techniques for posterior communicating artery aneurysms treatment in a retrospective multi-centric cohort. We included patients endovascularly treated for posterior communicating artery aneurysms from 2015 through 2020 in six tertiary referral hospitals. We evaluated the relationship between patients and aneurysms characteristics, baseline neurological status, radiological outcomes, and the different endovascular techniques. Overall, 250 patients were included in this study. Simple coiling was the most frequent treatment in 171 patients (68%), followed by flow-diverter stenting in 32 cases (13%). Complete occlusion was reported in 163 patients (65%), near-complete occlusion in 43 (17%), and incomplete occlusion in 44 (18%). Radiological follow-up was available for 247 (98%) patients. The occlusion rate was stable in 149 (60%), improved in 49 (19%), and worsened in 51 (21%). No significant difference in exclusion rate was seen between ruptured and unruptured aneurysms at the last follow-up (p = 0.4). Posterior communicating artery thrombosis was reported in 25 patients (9%), transient ischemic attack in 6 (2%), and in 38 patients (15%), subsequent procedures were needed due to incomplete occlusion or reperfusion. Endovascular strategies for posterior communicating artery aneurysms represent effective and relatively safe treatments. Simple coiling provides a higher immediate occlusion rate, although recanalization has been frequently reported, conversely, flow-diversion devices provide good long-term radiological outcomes.

    View details for DOI 10.31083/j.jin2004093

    View details for PubMedID 34997715

  • 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