All Publications


  • Type II Odontoid Fractures in the Elderly Presenting to the Emergency Department: An Assessment of Factors Affecting In-Hospital Mortality and Discharge to Skilled Nursing Facilities. The spine journal : official journal of the North American Spine Society Johnstone, T., Shah, V., Schonfeld, E., Sadeghzadeh, S., Haider, G., Stienen, M., Marianayagam, N. J., Veeravagu, A. 2023

    Abstract

    Type II odontoid fractures (OF) are among the most common cervical spine injuries in the geriatric population. However, there is a paucity of literature regarding their epidemiology. Additionally, the optimal management of these injuries remains controversial, and no study has evaluated the short-term outcomes of geriatric patients presenting to emergency departments (ED).This study aims to document the epidemiology of geriatric patients presenting to EDs with type II OFs and determine whether surgical management was associated with early adverse outcomes such as in-hospital mortality and discharge to skilled nursing facilities (SNF).This is a retrospective cohort study.Data was used from the 2016-2020 Nationwide Emergency Department Sample. Patient encounters corresponding to type II OFs were identified. Patients younger than 65 at the time of presentation to the ED and those with concomitant spinal pathology were excluded.The association between the surgical management of geriatric type II OFs and outcomes such as in-hospital mortality and discharge to SNFs.Patient, fracture, and surgical management characteristics were recorded. A propensity score matched cohort was constructed to reduce differences in age, comorbidities, and injury severity between patients undergoing operative and nonoperative management. Additionally, to develop a positive control for the analysis of geriatric patients with type II OFs and no other concomitant spinal pathology, a cohort of patients that had been excluded due to the presence of a concomitant spinal cord injury (SCI) was also constructed. Multivariate regressions were then performed on both the matched and unmatched cohorts to ascertain the associations between surgical treatment and in-hospital mortality, inpatient length of stay, encounter charges, and discharge to SNFs.11,325 encounters were included. The mean total charge per encounter was $60,221. 634 (5.6%) patients passed away during their encounters. 1,005 (8.9%) patients were managed surgically. Surgical management of type II OFs was associated with a 316% increase in visit charge (95% CI: 291%-341%, p<0.001), increased inpatient length of stay (IRR: 2.87, 95% CI: 2.62-3.12, p<0.001), and increased likelihood of discharge to SNFs (OR = 2.62, 95% CI: 2.26-3.05, p <0.001), but decreased in-hospital mortality (OR = 0.32, CI: 0.21-0.45, p<0.001). The propensity score matched cohort consisted of 2,010 patients, matching each of the 1,005 that underwent surgery to 1,005 that did not. These cohorts were well balanced across age (78.24 vs. 77.91 years), Elixhauser Comorbidity Index (3.68 vs. 3.71), and Injury Severity Score (30.15 vs 28.93). This matching did not meaningfully alter the associations determined between surgical management and in-hospital mortality (OR = 0.34, CI = 0.21-0.55, p<0.001) or SNF discharge (OR = 2.59, CI = 2.13-3.16, p<0.001). Lastly, the positive control cohort of patients with concurrent SCI had higher rates of SNF discharge (50.0% vs. 42.6%, p<0.001), surgical management (32.3% vs. 9.7%, p<0.001), and in-hospital mortality (28.9% vs. 5.6%, p<0.001).This study lends insight into the epidemiology of geriatric type II OFs and quantifies risk factors influencing adverse outcomes. Patient informed consent should include a discussion of the protective association between definitive surgical management and in-hospital mortality against potential operative morbidity, increased lengths of hospital stay, and increased likelihood of discharge to SNFs. This information may impact patient treatment selection and decision making.

    View details for DOI 10.1016/j.spinee.2023.11.023

    View details for PubMedID 38101547

  • Sigma-1 receptor expression in a subpopulation of lumbar spinal cord microglia in response to peripheral nerve injury. Scientific reports Schonfeld, E., Johnstone, T. M., Haider, G., Shah, A., Marianayagam, N. J., Biswal, S., Veeravagu, A. 2023; 13 (1): 14762

    Abstract

    Sigma-1 Receptor has been shown to localize to sites of peripheral nerve injury and back pain. Radioligand probes have been developed to localize Sigma-1 Receptor and thus image pain source. However, in non-pain conditions, Sigma-1 Receptor expression has also been demonstrated in the central nervous system and dorsal root ganglion. This work aimed to study Sigma-1 Receptor expression in a microglial cell population in the lumbar spine following peripheral nerve injury. A publicly available transcriptomic dataset of 102,691 L4/5 mouse microglial cells from a sciatic-sural nerve spared nerve injury model and 93,027 age and sex matched cells from a sham model was used. At each of three time points-postoperative day 3, postoperative day 14, and postoperative month 5-gene expression data was recorded for both spared nerve injury and Sham cell groups. For all cells, 27,998 genes were sequenced. All cells were clustered into 12 distinct subclusters and gene set enrichment pathway analysis was performed. For both the spared nerve injury and Sham groups, Sigma-1 Receptor expression significantly decreased at each time point following surgery. At the 5-month postoperative time point, only one of twelve subclusters showed significantly increased Sigma-1 Receptor expression in spared nerve injury cells as compared to Sham cells (p = 0.0064). Pathway analysis of this cluster showed a significantly increased expression of the inflammatory response pathway in the spared nerve injury cells relative to Sham cells at the 5-month time point (p = 6.74e-05). A distinct subcluster of L4/5 microglia was identified which overexpress Sigma-1 Receptor following peripheral nerve injury consistent with neuropathic pain inflammatory response functioning. This indicates that upregulated Sigma-1 Receptor in the central nervous system characterizes post-acute peripheral nerve injury and may be further developed for clinical use in the differentiation between low back pain secondary to peripheral nerve injury and low back pain not associated with peripheral nerve injury in cases where the pain cannot be localized.

    View details for DOI 10.1038/s41598-023-42063-8

    View details for PubMedID 37679500

    View details for PubMedCentralID PMC10484902

  • Screws or Sutures? A Pediatric Cadaveric Study of Tibial Spine Fracture Repairs. The American journal of sports medicine Johnstone, T. M., Baird, D. W., Cuellar-Montes, A., van Deursen, W. H., Tompkins, M., Ganley, T. J., Yen, Y. M., Ellis, H. B., Chan, C. K., Green, D. W., Sherman, S. L., Shea, K. G. 2023: 3635465231181059

    Abstract

    Tibial spine fractures are common in the pediatric population because of the biomechanical properties of children's subchondral epiphyseal bone. Most studies in porcine or adult human bone suggest that suture fixation performs better than screw fixation, but these tissues may be poor surrogates for pediatric bone. No previous study has evaluated fixation methods in human pediatric knees.To quantify the biomechanical properties of 2-screw and 2-suture repair of tibial spine fracture in human pediatric knees.Controlled laboratory study.Cadaveric specimens were randomly assigned to either 2-screw or 2-suture fixation. A standardized Meyers-Mckeever type 3 tibial spine fracture was induced. Screw-fixation fractures were reduced with two 4.0-mm cannulated screws and washers. Suture-fixation fractures were reduced by passing 2 No. 2 FiberWire sutures through the fracture fragment and the base of the anterior cruciate ligament. Sutures were secured through bony tunnels over a 1-cm tibial cortical bridge. Each specimen was mounted at 30° of flexion. A cyclic loading protocol was applied to each specimen, followed by a load-to-failure test. Outcome measures were ultimate failure load, stiffness, and fixation elongation.Twelve matched pediatric cadaveric knees were tested. Repair groups had identical mean (8.3 years) and median (8.5 years) ages and an identical number of samples of each laterality. Ultimate failure load did not significantly differ between screw (mean ± SD, 143.52 ± 41.9 7 N) and suture (135.35 ± 47.94 N) fixations (P = .760). Screws demonstrated increased stiffness and decreased elongation, although neither result was statistically significant at the .05 level (21.79 vs 13.83 N/mm and 5.02 vs 8.46 mm; P = .076 and P = .069, respectively).Screw fixation and suture fixation of tibial spine fractures in human pediatric tissue were biomechanically comparable.Suture fixations are not biomechanically superior to screw fixations in pediatric bone. Pediatric bone fails at lower loads, and in different modes, compared with adult cadaveric bone and porcine bone. Further investigation into optimal repair is warranted, including techniques that may reduce suture pullout and "cheese-wiring" through softer pediatric bone. This study provides new biomechanical data regarding the properties of different fixation types in pediatric tibial spine fractures to inform clinical management of these injuries.

    View details for DOI 10.1177/03635465231181059

    View details for PubMedID 37382335

  • ACI & MACI for the Management of Osteochondritis Dissecans OPERATIVE TECHNIQUES IN SPORTS MEDICINE Johnstone, T., Shea, K. 2023; 31 (2)
  • Biallelic variants in two complex I genes cause abnormal splicing defects in probands with mild Leigh syndrome MOLECULAR GENETICS AND METABOLISM Johnstone, T., Wang, J., Ross, D., Balanda, N., Huang, Y., Godfrey, R., Groden, C., Barton, B. R., Gahl, W., Toro, C., Malicdan, M. 2020; 131 (1-2): 98-106

    Abstract

    Leigh syndrome is a genetically heterogeneous disorder resulting from deficient oxidative energy biogenesis. The syndrome is characterized by subacute episodic decompensations, transiently elevated lactate, and necrotizing brain lesions most often in the striatum and brainstem. Acute decompensation is often triggered by viral infections. Sequalae from repeated episodes leads to progressive neurological deterioration and death. The severity of Leigh syndrome varies widely, from a rapid demise in childhood to rare adult presentations. Although the causes of Leigh syndrome include genes affecting a variety of different pathways, more than 75 of them are nuclear or mitochondrial encoded genes involved in the assembly and catalytic activity of mitochondrial respiratory complex I. Here we report the detailed clinical and molecular phenotype of two adults with mild presentations of NDUFS3 and NDUFAF6-related Leigh Syndrome. Mitochondrial assays revealed slightly reduced complex I activity in one proband and normal complex I activity in the other. The proband with NDUFS3-related Leigh syndrome was mildly affected and lived into adulthood with novel biallelic variants causing aberrant mRNA splicing (NM_004551.2:c.419G > A; p.Arg140Gln; NM_004551.2:c.381 + 6 T > C). The proband with NDUFAF6-related Leigh syndrome had biallelic variants that cause defects in mRNA splicing (NM_152416.3:c.371 T > C; p.Ile124Thr; NM_152416.3:c.420 + 2_420 + 3insTA). The mild phenotypes of these two individuals may be attributed to some residual production of normal NDUFS3 and NDUFAF6 proteins by NDUFS3 and NDUFAF6 mRNA isoforms alongside mutant transcripts. Taken together, these cases reported herein suggest that splice-regulatory variants to complex I proteins could result in milder phenotypes.

    View details for DOI 10.1016/j.ymgme.2020.09.008

    View details for Web of Science ID 000600626600009

    View details for PubMedID 33097395

    View details for PubMedCentralID PMC7749052

  • A national analysis of burn injuries among homeless persons presenting to emergency departments. Burns : journal of the International Society for Burn Injuries Shah, J. K., Liu, F., Cevallos, P., Amakiri, U. O., Johnstone, T., Nazerali, R., Sheckter, C. C. 2024

    Abstract

    Burn injuries among the homeless are increasing as record numbers of people are unsheltered and resort to unsafe heating practices. This study characterizes burns in homeless encounters presenting to US emergency departments (EDs).Burn encounters in the 2019 Nationwide Emergency Department Sample (NEDS) were queried. ICD-10 and CPT codes identified homelessness, injury regions, depths, total body surface area (TBSA %), and treatment plans. Demographics, comorbidities, and charges were analyzed. Discharge weights generated national estimates. Statistical analysis included univariate testing and multivariate modeling.Of 316,344 weighted ED visits meeting criteria, 1919 (0.6%) were homeless. Homeless encounters were older (mean age 44.83 vs. 32.39 years), male-predominant (71% vs. 52%), and had more comorbidities, and were more often White or Black race (p < 0.001). They more commonly presented to EDs in the West and were covered by Medicaid (51% vs. 33%) (p < 0.001). 12% and 5% of homeless burn injuries were related to self-harm and assault, respectively (p < 0.001). Homeless encounters experienced more third-degree burns (13% vs. 4%; p < 0.001), though TBSA % deciles were not significantly different (34% vs. 33% had TBSA % of ten or lower; p = 0.516). Homeless encounters were more often admitted (49% vs. 7%; p < 0.001), and homelessness increased odds of admission (OR 4.779; p < 0.001). Odds of transfer were significantly lower (OR 0.405; p = 0.021).Homeless burn ED encounters were more likely due to assault and self-inflicted injuries, and more severe. ED practitioners should be aware of these patients' unique presentation and triage to burn centers accordingly.

    View details for DOI 10.1016/j.burns.2024.02.030

    View details for PubMedID 38492979

  • Deep Learning Prediction of Cervical Spine Surgery Revision Outcomes Using Standard Laboratory and Operative Variables. World neurosurgery Schonfeld, E., Shah, A., Johnstone, T. M., Rodrigues, A., Morris, G. K., Stienen, M. N., Veeravagu, A. 2024

    Abstract

    INTRODUCTION: Cervical spine procedures represent a major proportion of all spine surgery. Mitigating the revision rate following cervical procedures requires careful patient selection. While complication risk has successfully been predicted, revision risk has proven more challenging. This is likely due to the absence of granular variables in claims databases. The objective of this study was to develop a state-of-the-art of revision prediction of cervical spine surgery using laboratory and operative variables.METHODS: Using the Stanford Research Repository, patients undergoing a cervical spine procedure between 2016-2022 were identified (N=3151) and recent laboratory values were collected. Patients were classified into separate cohorts by revision outcome and timeframe. Machine and deep learning models were trained to predict each revision outcome from laboratory and operative variables.RESULTS: Red blood cell count, Hemoglobin, Hematocrit, Mean Corpuscular Hemoglobin Concentration, Red Blood Cell Distribution Width, Platelet Count, CO2, Anion Gap, and Calcium were all significantly associated with one or more revision cohorts. For the prediction of 3-month revision, the deep neural network achieved AUC of 0.833. The model demonstrated increased performance for anterior than posterior and arthrodesis than decompression procedures.CONCLUSIONS: Our deep learning approach successfully predicted 3-month revision outcomes from demographic variables, standard laboratory values, and operative variables, in a cervical spine surgery cohort. This work introduces standard laboratory values and operative codes as meaningful predictive variables for revision outcome prediction. The increased performance on certain procedures evidences the need for careful development and validation of "one-size-fits-all" risk scores for spine procedures.

    View details for DOI 10.1016/j.wneu.2024.02.112

    View details for PubMedID 38408699

  • Response Letter to the Editor: "Expanding eligibility for intracranial electroencephalography using dexmedetomidine hydrochloride in children with behavioral dyscontrol". Epilepsy & behavior : E&B Johnstone, T., Guinle, M. I., Grant, G. A., Porter, B. E. 2024; 153: 109657

    View details for DOI 10.1016/j.yebeh.2024.109657

    View details for PubMedID 38368786

  • Misplaced intraspinal venous stent causing cauda equina syndrome: illustrative case. Journal of neurosurgery. Case lessons Shah, V., Johnstone, T., Haider, G., Marianayagam, N. J., Stienen, M. N., Chandra, V., Veeravagu, A. 2024; 7 (7)

    Abstract

    Endovenous stents for deep venous thrombosis treatment can be unintentionally placed in the spinal canal, resulting in neurological deficit.The authors report the case of a patient presenting to our institution with intraspinal misplacement of an endovenous stent, resulting in cauda equina syndrome. The authors also performed a systematic literature review, evaluating the few previously reported cases. This review was performed according to the updated Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. In four of five cases describing stent misplacement into the spinal canal, the authors report that only anteroposterior monoplanar imaging modalities were utilized for venous localization and stent deployment. The anteroposterior plane cannot assess the relative depth of structures, nor can it distinguish between superimposed structures well. Therefore, the use of biplanar imaging should at least be considered before stent deployment, as intraspinal stent placement can lead to disastrous consequences.This report should serve as an impetus for the use of biplanar or three-dimensional imaging modalities for iliac venous stent placement. Additionally, this work should increase spine surgeons' awareness about management and operative techniques when faced with this complication.

    View details for DOI 10.3171/CASE23482

    View details for PubMedID 38346298

  • Risk Factors for Hardware Removal Following Bimaxillary Surgery: A National Database Analysis. The Journal of craniofacial surgery Shah, J. K., Silverstein, M., Cevallos, P., Johnstone, T., Wu, R., Nazerali, R., Bruckman, K. 2024

    Abstract

    Orthognathic surgery typically relies on the rigid fixation of fracture fragments using metal hardware. Though hardware is usually intended to be implanted permanently, the removal of hardware (ROH) is sometimes indicated for a variety of reasons. The authors sought to identify risk factors for ROH following orthognathic surgery. The authors conducted a retrospective analysis of the Merative MarketScan Research Databases, 2007-2021 using Current Procedural Terminology (CPT) and International Classification of Disease (ICD-9 and ICD-10) codes to identify patients who underwent an index Le Fort 1 osteotomy and bilateral sagittal split osteotomy operation on the same day. Statistical analysis involved χ2, Shapiro-Wilk, Wilcoxon-Mann-Whitney, Poisson regression, and multivariable logistic regression tests. 4698 patients met the inclusion criteria. The mean age at surgery was 25 years, and 57% were female. ROH occurred in 5.9% of patients. The mean time to hardware removal was 190.5±172.4 days. In a multivariate logistic regression, increased odds of ROH were associated with older patient age [OR: 1.02 (1.01-1.03), P=0.046], sleep apnea [OR: 1.62 (1.13-2.32), P=0.018], and craniofacial syndrome and/or cleft diagnoses [OR: 1.88 (1.14-2.55), P<0.001]. In the same model, postoperative oral antibiotic prophylaxis was not associated with ROH (P=0.494). The incidence of all-cause complications [IRR: 1.03 (1.01-1.05), P<0.001] rose over the study period, while the incidence of ROH did not change significantly (P=0.281). Patients at elevated risk should be counseled on the increased possibility of a second operation for ROH before having orthognathic surgery to ensure expectations and health care utilization decisions align with the evidence.

    View details for DOI 10.1097/SCS.0000000000009929

    View details for PubMedID 38231209

  • Machine Learning in Neurosurgery: Toward Complex Inputs, Actionable Predictions, and Generalizable Translations CUREUS JOURNAL OF MEDICAL SCIENCE Schonfeld, E., Mordekai, N., Berg, A., Johnstone, T., Shah, A., Shah, V., Haider, G., Marianayagam, N. J., Veeravagu, A. 2024; 16 (1)
  • Bard Versus the 2022 American Society of Plastic Surgeons In-Service Examination: Performance on the Examination in Its Intern Year AESTHETIC SURGERY JOURNAL OPEN FORUM Najafali, D., Reiche, E., Araya, S., Camacho, J. M., Liu, F. C., Johnstone, T., Patel, S. A., Morrison, S. D., Dorafshar, A. H., Fox, P. M. 2024; 6: ojad066

    Abstract

    Bard is a conversational generative artificial intelligence (AI) platform released by Google (Mountain View, CA) to the public in May 2023.This study investigates the performance of Bard on the American Society of Plastic Surgeons (ASPS) In-Service Examination to compare it to residents' performance nationally. We hypothesized that Bard would perform best on the comprehensive and core surgical principles portions of the examination.Google's 2023 Bard was used to answer questions from the 2022 ASPS In-Service Examination. Each question was asked as written with the stem and multiple-choice options. The 2022 ASPS Norm Table was utilized to compare Bard's performance to that of subgroups of plastic surgery residents.A total of 231 questions were included. Bard answered 143 questions correctly corresponding to an accuracy of 62%. The highest-performing section was the comprehensive portion (73%). When compared with integrated residents nationally, Bard scored in the 74th percentile for post-graduate year (PGY)-1, 34th percentile for PGY-2, 20th percentile for PGY-3, 8th percentile for PGY-4, 1st percentile for PGY-5, and 2nd percentile for PGY-6.Bard outperformed more than half of the first-year integrated residents (74th percentile). Its best sections were the comprehensive and core surgical principle portions of the examination. Further analysis of the chatbot's incorrect questions might help improve the overall quality of the examination's questions.

    View details for DOI 10.1093/asjof/ojad066

    View details for Web of Science ID 001138526600001

    View details for PubMedID 38196964

    View details for PubMedCentralID PMC10776237

  • Expanding eligibility for intracranial electroencephalography using Dexmedetomidine Hydrochloride in children with behavioral dyscontrol. Epilepsy & behavior : E&B Johnstone, T., Isabel Barros Guinle, M., Grant, G. A., Porter, B. E. 2023; 150: 109541

    Abstract

    Invasive intracranial electroencephalography (IEEG) is advantageous for identifying epileptogenic foci in pediatric patients with medically intractable epilepsy. Patients with behavioral challenges due to autism, intellectual disabilities, and hyperactivity have greater difficulty tolerating prolonged IEEG recording and risk injuring themselves or others. There is a need for therapies that increase the safety of IEEG but do not interfere with IEEG recording or prolong hospitalization. Dexmedetomidine Hydrochloride's (DH) use has been reported to improve safety in patients with behavioral challenges during routine surface EEG recording but has not been characterized during IEEG. Here we evaluated DH administration in pediatric patients undergoing IEEG to assess its safety and impact on the IEEG recordings.A retrospective review identified all pediatric patients undergoing IEEG between January 2016 and September 2022. Patient demographics, DH administration, DH dose, hospital duration, and IEEG seizure data were analyzed. The number of seizures recorded for each patient was divided by the days each patient was monitored with IEEG. The total number of seizures, as well as seizures per day, were compared between DH and non-DH patients via summary statistics, multivariable linear regression, and univariate analysis. Other data were compared across groups with univariate statistics.Eighty-four pediatric patients met the inclusion criteria. Eighteen (21.4 %) received DH treatment during their IEEG recording. There were no statistical differences between the DH and non-DH groups' demographic data, length of hospital stays, or seizure burden. Non-DH patients had a median age of 12.0 years (interquartile range: 7.25-15.00), while DH-receiving patients had a median age of 8.0 years old (interquartile range: 3.00-13.50) (p = 0.07). The non-DH cohort was 57.6 % male, and the DH cohort was 50.0 % male (p = 0.76). The median length of IEEG recordings was 5.0 days (interquartile range: 4.00-6.25) for DH patients versus 6.0 days (interquartile range: 4.00-8.00) for non-DH patients (p = 0.25). Median total seizures recorded in the non-DH group was 8.0 (interquartile range: 5.00-13.25) versus 15.0 in the DH group (interquartile range: 5.00-22.25) (p = 0.33). Median total seizures per day of IEEG monitoring were comparable across groups: 1.50 (interquartile range: 0.65-3.17) for non-DH patients compared to 2.83 (interquartile range: 0.89-4.35) (p = 0.25) for those who received DH. Lastly, non-DH patients were hospitalized for a median of 8.0 days (interquartile range: 6.00-11.25), while DH patients had a median length of stay of 7.00 days (interquartile range: 5.00-8.25) (p = 0.27). No adverse events were reported because of DH administration.Administration of DH was not associated with adverse events. Additionally, the frequency of seizures captured on the IEEG, as well as the duration of hospitalization, were not significantly different between patients receiving and not receiving DH during IEEG. Incorporating DH into the management of patients with behavioral dyscontrol and intractable epilepsy may expand the use of IEEG to patients who previously could not tolerate it, improve safety, and preserve epileptic activity during the recording period.

    View details for DOI 10.1016/j.yebeh.2023.109541

    View details for PubMedID 38035536

  • Accuracy of predicted postoperative segmental lumbar lordosis in spinal fusion using an intraoperative robotic planning and guidance system. Journal of neurosurgical sciences Haider, G., Shah, V., Johnstone, T., Maldaner, N., Stienen, M., Veeravagu, A. 2023

    Abstract

    Restoring lumbar lordosis is one of the main goals in lumbar spinal fusion surgery. The Mazor X-AlignTM software allows for the prediction of postoperative segmental lumbar lordosis based on preoperative imaging. There is limited data on the accuracy of this preoperative prediction, especially in patients undergoing short segment lumbar fusion. The objective of our study was to determine the accuracy of predicted postoperative segmental lumbar lordosis using the Mazor X-AlignTM software in patients requiring short segmental fusion.Retrospective analysis of adult patients undergoing pedicle screw spinal instrumentation of not more than four levels using the Mazor XTM Robot (Medtronic Inc., Minneapolis, MN, USA) between July 2017 to June 2020. The robotic guidance software, Mazor X-AlignTM (Medtronic Inc., Minneapolis, MN, USA) was used to calculate the predicted segmental lumbar lordosis based on preoperative CT-imaging and the plan was executed under intraoperative robotic guidance. Predicted segmental lumbar lordosis was compared to achieved segmental lumbar lordosis on 1-month postoperative x-rays using the Cobb angle methodology.A total of 15 patients (46.6% female) with a mean age of 61.5±10.9 years were included. All patients underwent posterior lumbo-sacral spinal fusion with the Mazor XTM robotic system with 11 patients (73.3%) undergoing anterior column reconstruction prior to posterior fixation. Instrumentation was performed across a mean of 2.6 levels per case. Preoperative, the mean segmental lumbar lordosis was 30.2±13.6 degrees. The mean planned segmental lumbar lordosis was 35.5±17.0 degrees while the mean achieved segmental lumbar lordosis was 35.8±16.7 degrees. There was no significant mean difference between the planned and achieved segmental lumbar lordosis (P=0.334).The Mazor XTM intraoperative robotic planning and guidance is accurate in predicting postoperative segmental lumbar lordosis after short segmental fusion. Our findings may assure surgical decision making and planning.

    View details for DOI 10.23736/S0390-5616.23.06142-8

    View details for PubMedID 37997323

  • Approach, complications, and outcomes for 37 consecutive pediatric patients undergoing laser ablation for medically refractory epilepsy at Stanford Children's Health. Journal of neurosurgery. Pediatrics Barros Guinle, M. I., Johnstone, T., Li, D., Kaur, H., Porter, B. E., Grant, G. A. 2023: 1-11

    Abstract

    OBJECTIVE: The objective of this study was to better understand the safety and efficacy of laser interstitial thermal therapy (LITT) for children with medically refractory epilepsy.METHODS: Thirty-seven consecutive pediatric epilepsy patients at a single pediatric center who underwent LITT ablation of epileptogenic foci between May 2017 and December 2021 were retrospectively reviewed. Patient demographics, medication use, seizure frequency, prior surgical interventions, procedural details, and pre- and postoperative seizure history were analyzed.RESULTS: Thirty-seven pediatric patients (24 male, 13 female) with severe medically refractory epilepsy were included; all underwent stereo-electroencephalography (SEEG) prior to LITT. The SEEG electrode placement was based on the preoperative workup and tailored to each patient by the epileptologist and neurosurgeons working together to identify the epileptic network and hopefully quiet borders. Seizure onset was at a mean age of 2.70 ± 2.82 years (range 0.25-12 years), and the mean age at the time of LITT was 9.46 ± 5.08 years (range 2.41-17.86 years). Epilepsy was lesional in 23 patients (18 tuberous sclerosis, 4 focal cortical dysplasia, 1 gliosis) and nonlesional in 14. Eighteen patients had prior surgical interventions including open resections (n = 13: 11 single and 2 multiple), LITT (n = 4), or both (n = 1). LITT targeted a region adjacent to the previous target in 5 cases. The median number of lasers placed during the procedure was 3 (range 1-5). Complications occurred in 14 (37.8%) cases, only 3 (8.11%) of which resulted in a permanent deficit: 1 venous hemorrhage requiring evacuation following laser ablation, 1 aseptic meningitis, 2 immediate postoperative seizures, and 10 neurological deficits (7 transient and 3 permanent). Postoperatively, 22 (59.5%) patients were seizure free at the last follow-up (median follow-up 18.35 months, range 7.40-48.76 months), and the median modified Engel class was I (Engel class I in 22 patients, Engel class II in 2, Engel class III in 2, and Engel class IV in 11). Patients having tried a greater number of antiseizure medications before LITT were less likely to achieve seizure improvement (p = 0.046) or freedom (p = 0.017). Seizure improvement following LITT was associated with a shorter duration of epilepsy prior to LITT (p = 0.044), although postoperative seizure freedom was not associated with a shorter epilepsy duration (p = 0.667). Caregivers reported postoperative neurocognitive improvement in 17 (45.9%) patients.CONCLUSIONS: In this large single-institution cohort of pediatric patients with medically refractory seizures due to various etiologies, LITT was a relatively safe and effective surgical approach for seizure reduction and seizure freedom at 1 year of follow-up.

    View details for DOI 10.3171/2023.8.PEDS23158

    View details for PubMedID 37922561

  • How Postoperative Infection Affects Reoperations after Implant-based Breast Reconstruction: A National Claims Analysis of Abandonment of Reconstruction. Plastic and reconstructive surgery. Global open Francis, S. D., Thawanyarat, K., Johnstone, T. M., Yesantharao, P. S., Kim, T. S., Rowley, M. A., Sheckter, C. C., Nazerali, R. S. 2023; 11 (6): e5040

    Abstract

    Infection after implant-based breast reconstruction adversely affects surgical outcomes and increases healthcare utilization. This study aimed to quantify how postimplant breast reconstruction infections impact unplanned reoperations, hospital length of stay, and discontinuation of initially desired breast reconstruction.We conducted a retrospective cohort study using Optum's de-identifed Clinformatics Data Mart Database to analyze women undergoing implant breast reconstruction from 2003 to 2019. Unplanned reoperations were identified via Current Procedural Terminology (CPT) codes. Outcomes were analyzed via multivariate linear regression with Poisson distribution to determine statistical significance at P < 0.00625 (Bonferroni correction).In our national claims-based dataset, post-IBR infection rate was 8.53%. Subsequently, 31.2% patients had an implant removed, 6.9% had an implant replaced, 3.6% underwent autologous salvage, and 20.7% discontinued further reconstruction. Patients with a postoperative infection were significantly associated with increased incidence rate of total reoperations (IRR, 3.11; 95% CI, 2.92-3.31; P < 0.001) and total hospital length of stay (IRR, 1.55; 95% CI, 1.48-1.63; P < 0.001). Postoperative infections were associated with significantly increased odds of abandoning reconstruction (OR, 2.92; 95% CI, 0.081-0.11; P < 0.001).Unplanned reoperations impact patients and healthcare systems. This national, claims-level study shows that post-IBR infection was associated with a 3.11× and 1.55× increase in the incidence rate of unplanned reoperations and length of stay. Post-IBR infection was associated with 2.92× increased odds of abandoning further reconstruction after implant removal.

    View details for DOI 10.1097/GOX.0000000000005040

    View details for PubMedID 37325376

    View details for PubMedCentralID PMC10263246

  • Prediction of blood pressure variability during thrombectomy using supervised machine learning and outcomes of patients with ischemic stroke from large vessel occlusion. Journal of thrombosis and thrombolysis Najafali, D., Johnstone, T., Pergakis, M., Buganu, A., Ullah, M., Vuong, K., Panchal, B., Sutherland, M., Yarbrough, K. L., Phipps, M. S., Jindal, G., Tran, Q. K. 2023

    Abstract

    Mechanical thrombectomy (MT) is the standard of care for patients with acute ischemic stroke from large vessel occlusion (AIS-LVO). The association of blood pressure variability (BPV) during MT and outcomes are unknown. We leveraged a supervised machine learning algorithm to predict patient characteristics that are associated with BPV indices. We performed a retrospective review of our comprehensive stroke center's registry of all adult patients undergoing MT between 01/01/2016 and 12/31/2019. The primary outcome was poor functional independence, defined as 90-day modified Rankin Scale (mRS) ≥ 3. We used probit analysis and multivariate logistic regressions to evaluate the association of patients' clinical factors and outcomes. We applied a machine learning algorithm (random forest, RF) to determine predictive factors for the different BPV indices during MT. Evaluation was performed with root-mean-square error (RMSE) and normalized-RMSE (nRMSE) metrics. We analyzed 375 patients with mean age (± standard deviation [SD]) of 65 (15) years. There were 234 (62%) patients with mRS ≥ 3. Univariate probit analysis demonstrated that BPV during MT was associated with poor functional independence. Multivariable logistic regression showed that age, admission National Institutes of Health Stroke Scale (NIHSS), mechanical ventilation, and thrombolysis in cerebral infarction (TICI) score (OR 0.42, 95% CI 0.17-0.98, P = 0.044) were significantly associated with outcome. RF analysis identified that the interval from last-known-well time-to-groin puncture, age, and mechanical ventilation were among important factors significantly associated with BPV. BPV during MT was associated with functional outcome in univariate probit analysis but not in multivariable regression analysis, however, NIHSS and TICI score were. RF algorithm identified risk factors influencing patients' BPV during MT. While awaiting further studies' results, clinicians should still monitor and avoid high BPV during thrombectomy while triaging AIS-LVO candidates quickly to MT.

    View details for DOI 10.1007/s11239-023-02796-9

    View details for PubMedID 37041431

    View details for PubMedCentralID 6972830

  • Use of Local Antibiotic Delivery Systems in Tissue Expander and Implant-Based Breast Reconstruction: A Systematic Review of the Literature. Eplasty Makarewicz, N., Lipman, K., Johnstone, T., Shaheen, M., Shah, J. K., Nazerali, R. 2023; 23: e24

    Abstract

    Periprosthetic infections are a debilitating complication of alloplastic breast reconstruction. Local antibiotic delivery for prophylaxis and infection clearance has been used by other surgical specialties but rarely in breast reconstruction. Because local delivery can maintain high antibiotic concentrations with lower toxicity risk, it may be valuable for infection prophylaxis or salvage in breast reconstruction.A systematic search of the Embase, PubMed, and Cochrane databases was performed in January 2022. Primary literature studies examining local antibiotic delivery systems for either prophylaxis or salvage of periprosthetic infections were included. Study quality and bias were assessed using the validated MINORS criteria.Of 355 publications reviewed, 8 met the predetermined inclusion criteria; 5 papers investigated local antibiotic delivery for salvage, and 3 investigated infection prophylaxis. Implantable antibiotic delivery devices included polymethylmethacrylate, calcium sulfate, and collagen sponges impregnated with antibiotics. Non-implantable antibiotic delivery methods used irrigation with antibiotic solution into the breast pocket. All studies indicated that local antibiotic delivery was either comparable or superior to conventional methods in both the salvage and prophylaxis settings.Despite varied sample sizes and methodologies, all papers endorsed local antibiotic delivery as a safe, effective method of preventing or treating periprosthetic infections in breast reconstruction.

    View details for DOI 10.1002/bjs5.50324

    View details for PubMedID 37187864

    View details for PubMedCentralID PMC10176462

  • Is Plastic Surgery Training Equitable? An Analysis of Health Equity across US Plastic Surgery Residency Programs. Plastic and reconstructive surgery. Global open Cevallos, P., Amakiri, U. O., Johnstone, T., Kim, T. S., Maheta, B., Nazerali, R., Sheckter, C. 2023; 11 (4): e4900

    Abstract

    Achieving health equity includes training surgeons in environments exemplifying access, treatment, and outcomes across the racial, ethnic, and socioeconomic spectrum. Increased attention on health equity has generated metrics comparing hospitals. To establish the quality of health equity in plastic and reconstructive surgery (PRS) residency training, we determined the mean equity score (MES) across training hospitals of US PRS residencies.Methods: The 2021 Lown Institute Hospital Index database was merged with affiliated training hospitals of US integrated PRS residency programs. The Lown equity category is composed of three domains (community benefit, inclusivity, pay equity) generating a health equity grade. MES (standard deviation) was calculated and reported for residency programs (higher MES represented greater health equity). Linear regression modeled the effects of a program's number of training hospitals, safety net hospitals, and geographical region on MES.Results: The MES was 2.64 (0.62). An estimated 5.9% of programs had an MES between 1-2. In total, 56.5% of programs had an MES between 2 and 3, and 37.7% had an MES of 3 or more. The southern region was associated with a higher MES compared with the reference group (Northeast) (P = 0.03). The number of safety net hospitals per program was associated with higher MES (P = 0.02).Conclusions: Two out of three programs train residents in facilities failing to demonstrate high equity healthcare. Programs should promote health equity by diversifying care delivery through affiliated hospitals. This will aid in the creation of a PRS workforce trained to provide care for a socioeconomically, racially, and ethnically diverse population.

    View details for DOI 10.1097/GOX.0000000000004900

    View details for PubMedID 37035124

  • Clinical outcomes and cost differences between patients undergoing primary anterior cervical discectomy and fusion procedures with private or Medicare insurance: a propensity score matched study. World neurosurgery Shah, V., Rodrigues, A. J., Malhotra, S., Johnstone, T., Varshneya, K., Haider, G., Stienen, M. N., Veeravagu, A. 2023

    Abstract

    To assess whether insurance type reflects a patient's quality of care following an ACDF procedure, by comparing differences in post-operative complications, readmission rates, reoperation rates, length of hospital stay, and cost of treatment between patients with Medicare versus private insurance.Propensity score matching (PSM) was employed to match patient cohorts insured by Medicare and private insurance in the MarketScan Commercial Claims and Encounters Database (2007-2016). Age, sex, year of operation, geographic region, comorbidities, and operative factors were used to match cohorts of patients undergoing an ACDF procedure.A total of 110,911 patients met the inclusion criteria, of which 97,543 patients (87.9%) were privately insured and 13,368 patients (12.1%) were insured by Medicare. The PSM algorithm matched 7,026 privately insured patients to 7,026 Medicare patients. After matching, there was no significant difference in 90-day post-operative complication rates, length of stay, or reoperation rates between the Medicare and privately insured cohorts. The Medicare group had lower post-operative readmission rates for all time points: 30 days (1.8% vs. 4.6%; p < 0.001), 60 days (2.5% vs. 6.3%; p < 0.001), and 90 days (4.2% vs. 7.7%; p < 0.001). The median payments to physicians were significantly lower for the Medicare group ($3,885 vs. $5,601; p < 0.001).In this study, propensity score matched patients covered by Medicare and private insurance that underwent an ACDF procedure were found to have similar treatment outcomes.

    View details for DOI 10.1016/j.wneu.2023.02.129

    View details for PubMedID 36871653

  • Postoperative Antibiotics Confer No Protective Association After Fat Grafting for Breast Reconstruction. Annals of plastic surgery Thawanyarat, K., Johnstone, T., Rowley, M., Kim, T., Francis, S., Barrera, J., Cheeseborough, J., Sheckter, C., Nazerali, R. 2023

    Abstract

    INTRODUCTION: Autologous fat grafting after breast reconstruction is a commonly used technique to address asymmetry and irregularities in breast contour. While many studies have attempted to optimize patient outcomes after fat grafting, a key postoperative protocol that lacks consensus is the optimal use of perioperative and postoperative antibiotics. Reports suggest that complication rates for fat grafting are low relative to rates after reconstruction and have been shown to not be correlated to antibiotic protocol. Studies have additionally demonstrated that the use of prolonged prophylactic antibiotics do not lower the complication rates, stressing the need for a more conservative, standardized antibiotic protocol. This study aims to identify the optimal use of perioperative and postoperative antibiotics that optimizes patient outcomes.METHODS: Patients in the Optum Clinformatics Data Mart who underwent all billable forms of breast reconstruction followed by fat grafting were identified via Current Procedural Terminology codes. Patients meeting inclusion criteria had an index reconstructive procedure at least 90 days before fat grafting. Data concerning these patient's demographics, comorbidities, breast reconstructions, perioperative and postoperative antibiotics, and outcomes were collected via querying relevant reports of Current Procedural Terminology; International Classification of Diseases, Ninth Revision; International Classification of Diseases, Tenth Revision; National Drug Code Directory, and Healthcare Common Procedure Coding System codes. Antibiotics were classified by type and temporal delivery: perioperatively or postoperatively. If a patient received postoperative antibiotics, the duration of antibiotic exposure was recorded. Outcomes analysis was limited to the 90-day postoperative period. Multivariable logistic regression was performed to ascertain the effects of age, coexisting conditions, reconstruction type (autologous or implant-based), perioperative antibiotic class, postoperative antibiotic class, and postoperative antibiotic duration on the likelihood of any common postoperative complication occurring. All statistical assumptions made by logistic regression were met successfully. Odds ratios and corresponding 95% confidence intervals were calculated.RESULTS: From more than 86 million longitudinal patient records between March 2004 and June 2019, our study population included 7456 unique records of reconstruction-fat grafting pairs, with 4661 of those pairs receiving some form of prophylactic antibiotics. Age, prior radiation, and perioperative antibiotic administration were consistent independent predictors of increased all-cause complication likelihood. However, administration of perioperative antibiotics approached a statistically significant protective association against infection likelihood. No postoperative antibiotics of any duration or class conferred a protective association against infections or all-cause complications.CONCLUSIONS: This study provides national, claims-level support for antibiotic stewardship during and after fat grafting procedures. Postoperative antibiotics did not confer a protective benefit association against infection or all-cause complication likelihood, while administering perioperative antibiotics conferred a statistically significant increase in the likelihood that a patient experienced postoperative complication. However, perioperative antibiotics approach a significant protective association against postoperative infection likelihood, in line with current guidelines for infection prevention. These findings may encourage the adoption of more conservative postoperative prescription practices for clinicians who perform breast reconstruction, followed by fat grafting, reducing the nonindicated use of antibiotics.

    View details for DOI 10.1097/SAP.0000000000003420

    View details for PubMedID 36880783

  • Optimizing postoperative outcomes following neoadjuvant chemotherapy and mastectomy with immediate reconstruction: A national analysis. Journal of surgical oncology Thawanyarat, K., Johnstone, T., Rowley, M., Navarro, Y., Hinson, C., Nazerali, R. S. 2023

    Abstract

    The optimal timing between last neoadjuvant chemotherapy (NAC) session and mastectomy with immediate reconstruction (MIR) procedures has sparse data to support optimization of postoperative outcomes. Current literature suggests that timing is not a predictor of complications in patients undergoing implant-based reconstruction following NAC and other literature suggests guidelines based on tumor staging. To the best of our knowledge, this is the largest and most recent study characterizing the effect of time between NAC and mastectomy with immediate reconstruction on postoperative complications.Patients in the Optum Clinformatics Data Mart that underwent all billable forms of breast reconstruction following NAC were identified via CPT and ICD-10 codes. Data concerning these patient's demographics, comorbidities, oncologic treatment, and outcomes were collected by querying relevant reports of CPT, ICD-9, and ICD-10 codes. To meet inclusion criteria, patients needed to have an encounter for antineoplastic chemotherapy within 1 year of their associated reconstruction. Patients with other invasive procedures unrelated to their mastectomy-reconstruction pairing within 90 days of reconstruction were excluded. Outcomes analysis was limited to the 90-day postoperative period. The time between the last recorded chemotherapy encounter and breast reconstruction was computed. A multivariate logistic regression analysis was performed to ascertain the effects of age, race, coexisting conditions, reconstruction type (autologous or implant-based), and time between NAC and reconstruction on the likelihood of any common postoperative complication occurring. Linearity of the continuous variables with respect to the logit of the dependent variable was confirmed. Odds ratios and corresponding 95% confidence intervals were calculated.From over 86 million longitudinal patient records, our study population included 139 897 4371 patient records corresponding to 13 399 3759 patients who had NAC and breast reconstruction between January 2003, October 2015, and June 2019. Increased time between last antineoplastic chemotherapy and MIR reconstruction was a statistically significant, independent predictor of decreased complication likelihood. By contrast, autologous reconstruction, hypertension, and type II diabetes mellitus, and African American, White, and Hispanic race (relative to Asian) had statistically significant associations with increased complication likelihood. Waiting an additional day between a patient's most recent chemotherapy session and MIR reconstruction reduces the odds of a complication occurring by 0.25%. This corresponds to reduction in odds of complication occurrence of approximately 7% for each month between neoadjuvant therapy and breast reconstruction.Increased time between NAC and MIR immediate reconstruction decreases the likelihood of experiencing one or more postoperative complications. Ideal time delay between 4 and 8 weeks has been shown to provide the best benefit for future breast reconstrution outcomes. In consultation with the oncologist, this information can be used to balance postoperative complication risk with increased oncologic risk in delaying mastectomy with immediate reconstruction.

    View details for DOI 10.1002/jso.27196

    View details for PubMedID 36602535

  • Use of Antibiotic-impregnated Polymethylmethacrylate (PMMA) Plates for Prevention of Periprosthetic Infection in Breast Reconstruction PLASTIC AND RECONSTRUCTIVE SURGERY-GLOBAL OPEN Johnstone, T., Lipman, K., Makarewicz, N., Shah, J., Turner, E., Posternak, V., Chang, D., Thornton, B., Nazerali, R. 2023; 11 (1)
  • Civilian-Military Medical Partnerships for Operational Readiness Johnstone, T. M. U.S. Naval Institute . Annapolis, MD. 2021 ; Proceedings