Lumbar Drain Use during Middle Fossa Approaches for Nonneoplastic Pathology of the Skull Base.

Introduction The middle fossa craniotomy (MFCs) is commonly utilized for spontaneous cerebrospinal fluid (CSF) leaks, encephaloceles, and superior semicircular canal dehiscence (SSCD). This study compares postoperative outcomes of MFCs with and without LD use. Methods A retrospective cohort study of adults over the age of 18 years presenting for the repair of nonneoplastic CSF leak, encephalocele, or SSCD via MFC from 2009 to 2021 was conducted. The main exposure of interest was the placement of an LD. The primary outcome was the presence of postoperative complications (acute/delayed neurologic deficit, meningitis, intracranial hemorrhage, and stroke). Secondary outcomes included operating room (OR) time, length of stay, recurrence, and need for reoperation. Results In total, 172 patients were included, 96 of whom received an LD and 76 who did not. Patients not receiving an LD were more likely to receive intraoperative mannitol ( n = 24, 31.6% vs. n = 16, 16.7%, p = 0.02). On univariate logistic regression, LD placement did not influence overall postoperative complications (OR: 0.38, 95% confidence interval [CI]: 0.05-2.02, p = 0.28), CSF leak recurrence (OR: 0.75, 95% CI: 0.25-2.29, p = 0.61), or need for reoperation (OR: 1.47, 95% CI: 0.48-4.96, p = 0.51). While OR time was shorter for patients not receiving LD (349 ± 71 vs. 372 ± 85 minutes), this difference was not statistically significant ( p = 0.07). Conclusion No difference in postoperative outcomes was observed in patients who had an intraoperative LD placed compared to those without LD. Operative times were increased in the LD cohort, but this difference was not statistically significant. Given the similar outcomes, we conclude that LD is not necessary to facilitate safe MCF for nonneoplastic skull base pathologies.

Resident Salary Compared to Living Wages at United States Training Institutions.

OBJECTIVE: To compare living wages and salaries at US residency programs. SUMMARY BACKGROUND DATA: It is unknown how resident salary compares to living wages across the United States (US). METHODS: Cross-sectional analysis of publicly available resident salary affordability from training centers with post-graduate-year (PGY)-1 through PGY-7 resident compensation for 2022-2023 was compared with the Massachusetts Institute of Technology (MIT) Living-Wage Calculator. Resident salary to living wage ratios were calculated using PGY-4 salary for each family composition. Univariate and multivariable analysis of PGY-4 salary affordability was performed, accounting for proportion of expected living wages to taxes, transportation, housing, healthcare, childcare, and food, as well as unionization and state income-tax. RESULTS: 118 residency programs, representing over 60% of US trainees, were included, 20 (17%) of which were unionized. Single-parent families were unable to earn a living wage until PGY-7. Residents with 1 child in 2-adult (single-income) and 2-adult (dual-income) families earn below living wages until PGY-5 and PGY-3, respectively. Residents with more than 1 child never earn a living wage. Multivariable regression analysis using PGY-4 salary: living wage ratios in single-child, 2-parent homes showed food expense and unionization status were consistent predictors of affordability. Unionization was associated with lower affordability pre-stipend, almost equivalent affordability post-stipend, and lower affordability post-stipend and union dues. CONCLUSIONS: Resident salaries often preclude residents with children from earning a living wage. Unionization is not associated with increased resident affordability in this cross-sectional analysis. All annual reimbursement data should be centrally compiled, and additional stipends should be considered for residents with children.

Velociraptor: Cross-Platform Quantitative Search Using Hallmark Cell Features.

A key challenge for single cell discovery analysis is to identify new cell types, describe them quantitatively, and seek these novel cells in new studies often using a different platform. Over the last decade, tools were developed to address identification and quantitative description of cells in human tissues and tumors. However, automated validation of populations at the single cell level has struggled due to the cytometry field's reliance on hierarchical, ordered use of features and on platform-specific rules for data processing and analysis. Here we present Velociraptor, a workflow that implements Marker Enrichment Modeling in three cross-platform modules: 1) identification of cells specific to disease states, 2) description of hallmark features for each cell and population, and 3) searching for cells matching one or more hallmark feature sets in a new dataset. A key advance is that Velociraptor registers cells between datasets, including between flow cytometry and quantitative imaging using different, overlapping feature sets. Four datasets were used to challenge Velociraptor and reveal new biological insights. Working at the individual sample level, Velociraptor tracked the abundance of clinically significant glioblastoma brain tumor cell subsets and characterized the cells that predominate in recurrent tumors as a close match for rare, negative prognostic cells originally observed in matched pre-treatment tumors. In patients with inborn errors of immunity, Velociraptor identified genotype-specific cells associated with GATA2 haploinsufficiency. Finally, in cross-platform analysis of immune cells in multiplex imaging of breast cancer, Velociraptor sought and correctly identified memory T cell subsets in tumors. Different phenotypic descriptions generated by algorithms or humans were shown to be effective as search inputs, indicating that cell identity need not be described in terms of per-feature cutoffs or strict hierarchical analyses. Velociraptor thus identifies cells based on hallmark feature sets, such as protein expression signatures, and works effectively with data from multiple sources, including suspension flow cytometry, imaging, and search text based on known or theoretical cell features.

IL-8 Instructs Macrophage Identity in Lateral Ventricle Contacting Glioblastoma.

Adult IDH-wildtype glioblastoma (GBM) is a highly aggressive brain tumor with no established immunotherapy or targeted therapy. Recently, CD32+ HLA-DRhi macrophages were shown to have displaced resident microglia in GBM tumors that contact the lateral ventricle stem cell niche. Since these lateral ventricle contacting GBM tumors have especially poor outcomes, identifying the origin and role of these CD32+ macrophages is likely critical to developing successful GBM immunotherapies. Here, we identify these CD32+ cells as M_IL-8 macrophages and establish that IL-8 is sufficient and necessary for tumor cells to instruct healthy macrophages into CD32+ M_IL-8 M2 macrophages. In ex vivo experiments with conditioned medium from primary human tumor cells, inhibitory antibodies to IL-8 blocked the generation of CD32+ M_IL-8 cells. Finally, using a set of 73 GBM tumors, IL-8 protein is shown to be present in GBM tumor cells in vivo and especially common in tumors contacting the lateral ventricle. These results provide a mechanistic origin for CD32+ macrophages that predominate in the microenvironment of the most aggressive GBM tumors. IL-8 and CD32+ macrophages should now be explored as targets in combination with GBM immunotherapies, especially for patients whose tumors present with radiographic contact with the ventricular-subventricular zone stem cell niche.

Global Economic Evaluation of the Reported Costs of Deep Brain Stimulation.

INTRODUCTION: Despite the known benefits of deep brain stimulation (DBS), the cost of the procedure can limit access and can vary widely. Our aim was to conduct a systematic review of the reported costs associated with DBS, as well as the variability in reporting cost-associated factors to ultimately increase patient access to this therapy. METHODS: A systematic review of the literature for cost of DBS treatment was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed and Embase databases were queried. Olsen & Associates (OANDA) was used to convert all reported rates to USD. Cost was corrected for inflation using the US Bureau of Labor Statistics Inflation Calculator, correcting to April 2022. RESULTS: Twenty-six articles on the cost of DBS surgery from 2001 to 2021 were included. The median number of patients across studies was 193, the mean reported age was 60.5 ± 5.6 years, and median female prevalence was 38.9%. The inflation- and currency-adjusted mean cost of the DBS device was USD 21,496.07 ± USD 8,944.16, the cost of surgery alone was USD 14,685.22 ± USD 8,479.66, the total cost of surgery was USD 40,942.85 ± USD 17,987.43, and the total cost of treatment until 1 year of follow-up was USD 47,632.27 ± USD 23,067.08. There were no differences in costs observed across surgical indication or country. CONCLUSION: Our report describes the large variation in DBS costs and the manner of reporting costs. The current lack of standardization impedes productive discourse as comparisons are hindered by both geographic and chronological variations. Emphasis should be put on standardized reporting and analysis of reimbursement costs to better assess the variability of DBS-associated costs in order to make this procedure more cost-effective and address areas for improvement to increase patient access to DBS.

"Home Field Advantage": The Presence of a "Home" Neurosurgical Residency Training Program is Associated With Improved Match Outcomes.

BACKGROUND AND OBJECTIVES: Competition for neurosurgical residency training positions remains fierce. The support provided by applicants' home neurosurgery residency training programs (NRTP) is suspected to play a key role in the National Resident Matching Program (NRMP) process. We sought to evaluate the impact of the presence of an Accreditation Council for Graduate Medical Education-accredited NRTP at medical students' home institutions has on NRMP match outcomes. METHODS: Our cross-sectional observational study examined all US allopathic senior student Electronic Residency Application Service applications to a single NRTP from 2016 to 2022. RESULTS: We analyzed a total of 1650 Electronic Residency Application Service applications to a single NRTP, of which 1432 (86.8%) were from schools with an Accreditation Council for Graduate Medical Education-accredited NRTP (NRTP+) and 218 (13.2%) were from schools without a residency (NRTP-). NRTP+ applicants matched a higher rate on both pooled analysis (80.8% vs 71.6%, P = .002) and paired analysis (P = .02) over the seven-cycle study period. This difference was present before (82.4% vs 73.9%, P = .01) and after (77.2% vs 65.6%, P = .046) the COVID-19 pandemic. Cohorts were overall similar; however, NRTP+ applicants had more publication experiences (19.6 ± 19.0 vs 13.1 ± 10.2, P < .001) and were more likely to complete a research gap year (RGY) (25.8% vs 17.0%, P = .004). Completing a RGY was associated with an increased likelihood of matching for NRTP+ applicants but not for NRTP- applicants: NRTP+: 84.9% vs 78.1% (P = .0056); NRTP-: 70.3% vs 70.9% (P = .94). CONCLUSION: The presence of a NRTP at a medical student's home institution is associated with improved NRMP match outcomes. This held true both before and after the COVID-19 pandemic. Applicants from schools with a NRTP had more publication experiences and were more likely to complete a RGY. Completion of a RGY is associated with an increased likelihood of matching only for students with an affiliated NRTP.

Cost considerations for vestibular schwannoma screening and imaging: a systematic review.

Vestibular schwannomas (VS) account for approximately 8% of all intracranial neoplasms. Importantly, the cost of the diagnostic workup for VS, including the screening modalities most commonly used, has not been thoroughly investigated. Our aim is to conduct a systematic review of the published literature on costs associated with VS screening. A systematic review of the literature for cost of VS treatment was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The terms "vestibular schwannoma," "acoustic neuroma," and "cost" were queried using the PubMed and Embase databases. Studies from all countries were considered. Cost was then corrected for inflation using the US Bureau of Labor Statistics Inflation Calculator, correcting to April 2022. The search resulted in an initial review of 483 articles, of which 12 articles were included in the final analysis. Screening criteria were used for non-neurofibromatosis type I and II patients who complained of asymmetric hearing loss, tinnitus, or vertigo. Patients included in the studies ranged from 72 to 1249. The currency and inflation-adjusted mean cost was $418.40 (range, $21.81 to $487.03, n = 5) for auditory brainstem reflex and $1433.87 (range, $511.64 to $1762.15, n = 3) for non-contrasted computed tomography. A contrasted magnetic resonance imaging (MRI) scan was found to have a median cost of $913.27 (range, $172.25-$2733.99; n = 8) whereas a non-contrasted MRI was found to have a median cost of $478.62 (range, $116.61-$3256.38, n = 4). In terms of cost reporting, of the 12 articles, 1 (8.3%) of them separated out the cost elements, and 10 (83%) of them used local prices, which include institutional costs and/or average costs of multiple institutions. Our findings describe the limited data on published costs for screening and imaging of VS. The paucity of data and significant variability of costs between studies indicates that this endpoint is relatively unexplored, and the cost of screening is poorly understood.

Gender Differences in Medicare Practice and Payments to Neurosurgeons.

Importance: Despite efforts to promote diversity within the neurosurgical workforce, individuals from underrepresented groups face significant challenges. Objective: To compare practice metrics and earning potential between female and male neurosurgeons and investigate factors associated with gender disparity in Medicare reimbursement. Design, Setting, and Participants: This retrospective cross-sectional study used publicly accessible Medicare data on reimbursements to female and male neurosurgeons for procedural and evaluation and management services delivered in both inpatient and outpatient settings between January 1, 2013, and December 31, 2020. Data were analyzed from December 9, 2021, to December 5, 2022. Main Outcomes and Measures: The primary outcome was the mean annual payments received and charges submitted by female and male neurosurgeons for services rendered between 2013 and 2020. Secondary outcomes included the total number and types of services rendered each year and the number of beneficiaries treated. Univariate and multivariable analyses quantified differences in payment, practice volume, and composition. Results: A total of 6052 neurosurgeons (5540 men [91.54%]; 512 women [8.46%]) served the Medicare fee-for-service patient population. Female neurosurgeons billed for lesser Medicare charges (mean [SE], $395 851.62 [$19 449.39] vs $766 006.80 [$11 751.66]; P < .001) and were reimbursed substantially less (mean [SE], $69 520.89 [$2701.30] vs $124 324.64 [$1467.93]; P < .001). Multivariable regression controlling for practice volume metrics revealed a persistent reimbursement gap (-$24 885.29 [95% CI, -$27 964.72 to -$21 805.85]; P < .001). Females were reimbursed $24.61 less per service than males even after matching services by code (P = .02). Conclusions and Relevance: This study found significant gender-based variation in practice patterns and reimbursement among neurosurgeons serving the Medicare fee-for-service population. Female surgeons were reimbursed less than male surgeons when both performed the same primary procedure. Lower mean reimbursement per service may represent divergence in billing and coding practices among females and males that could be the focus of future research or educational initiatives.

Accuracy and Reliability of Chatbot Responses to Physician Questions.

Importance: Natural language processing tools, such as ChatGPT (generative pretrained transformer, hereafter referred to as chatbot), have the potential to radically enhance the accessibility of medical information for health professionals and patients. Assessing the safety and efficacy of these tools in answering physician-generated questions is critical to determining their suitability in clinical settings, facilitating complex decision-making, and optimizing health care efficiency. Objective: To assess the accuracy and comprehensiveness of chatbot-generated responses to physician-developed medical queries, highlighting the reliability and limitations of artificial intelligence-generated medical information. Design, Setting, and Participants: Thirty-three physicians across 17 specialties generated 284 medical questions that they subjectively classified as easy, medium, or hard with either binary (yes or no) or descriptive answers. The physicians then graded the chatbot-generated answers to these questions for accuracy (6-point Likert scale with 1 being completely incorrect and 6 being completely correct) and completeness (3-point Likert scale, with 1 being incomplete and 3 being complete plus additional context). Scores were summarized with descriptive statistics and compared using the Mann-Whitney U test or the Kruskal-Wallis test. The study (including data analysis) was conducted from January to May 2023. Main Outcomes and Measures: Accuracy, completeness, and consistency over time and between 2 different versions (GPT-3.5 and GPT-4) of chatbot-generated medical responses. Results: Across all questions (n = 284) generated by 33 physicians (31 faculty members and 2 recent graduates from residency or fellowship programs) across 17 specialties, the median accuracy score was 5.5 (IQR, 4.0-6.0) (between almost completely and complete correct) with a mean (SD) score of 4.8 (1.6) (between mostly and almost completely correct). The median completeness score was 3.0 (IQR, 2.0-3.0) (complete and comprehensive) with a mean (SD) score of 2.5 (0.7). For questions rated easy, medium, and hard, the median accuracy scores were 6.0 (IQR, 5.0-6.0), 5.5 (IQR, 5.0-6.0), and 5.0 (IQR, 4.0-6.0), respectively (mean [SD] scores were 5.0 [1.5], 4.7 [1.7], and 4.6 [1.6], respectively; P = .05). Accuracy scores for binary and descriptive questions were similar (median score, 6.0 [IQR, 4.0-6.0] vs 5.0 [IQR, 3.4-6.0]; mean [SD] score, 4.9 [1.6] vs 4.7 [1.6]; P = .07). Of 36 questions with scores of 1.0 to 2.0, 34 were requeried or regraded 8 to 17 days later with substantial improvement (median score 2.0 [IQR, 1.0-3.0] vs 4.0 [IQR, 2.0-5.3]; P < .01). A subset of questions, regardless of initial scores (version 3.5), were regenerated and rescored using version 4 with improvement (mean accuracy [SD] score, 5.2 [1.5] vs 5.7 [0.8]; median score, 6.0 [IQR, 5.0-6.0] for original and 6.0 [IQR, 6.0-6.0] for rescored; P = .002). Conclusions and Relevance: In this cross-sectional study, chatbot generated largely accurate information to diverse medical queries as judged by academic physician specialists with improvement over time, although it had important limitations. Further research and model development are needed to correct inaccuracies and for validation.

Milestones for neurosurgery sub-interns: a novel evaluation tool to quantitatively differentiate residency applicants.

OBJECTIVE: The study objective was to create a novel milestones evaluation form for neurosurgery sub-interns and assess its potential as a quantitative and standardized performance assessment to compare potential residency applicants. In this pilot study, the authors aimed to determine the form's interrater reliability, relationship to percentile assignments in the neurosurgery standardized letter of recommendation (SLOR), ability to quantitatively differentiate tiers of students, and ease of use. METHODS: Medical student milestones were either adapted from the resident Neurological Surgery Milestones or created de novo to evaluate a student's medical knowledge, procedural aptitude, professionalism, interpersonal and communication skills, and evidence-based practice and improvement. Four milestone levels were defined, corresponding to estimated 3rd-year medical student through 2nd-year resident levels. Faculty and resident evaluations as well as student self-evaluations were completed for 35 sub-interns across 8 programs. A cumulative milestone score (CMS) was computed for each student. Student CMSs were compared both within and between programs. Interrater reliability was determined with Kendall's coefficient of concordance (Kendall's W). Student CMSs were compared against their percentile assignments in the SLOR using analysis of variance with post hoc testing. CMS-derived percentile rankings were assigned to quantitatively distinguish tiers of students. Students and faculty were surveyed on the form's usefulness. RESULTS: The average faculty rating overall was 3.20, similar to the estimated competency level of an intern. Student and faculty ratings were similar, whereas resident ratings were lower (p < 0.001). Students were rated most highly in coachability and feedback (3.49 and 3.67, respectively) and lowest in bedside procedural aptitude (2.90 and 2.85, respectively) in both faculty and self-evaluations. The median CMS was 26.5 (IQR 21.75-29.75, range 14-32) with only 2 students (5.7%) achieving the highest rating of 32. Programs that evaluated the most students differentiated the highest-performing students from the lowest by at least 13 points. A program with 3 faculty raters demonstrated scoring agreement across 5 students (p = 0.024). The CMS differed significantly between SLOR percentile assignments, despite 25% of students being assigned to the top fifth percentile. CMS-driven percentile assignment significantly differentiated the bottom, middle, and top third of students (p < 0.001). Faculty and students strongly endorsed the milestones form. CONCLUSIONS: The medical student milestones form was well received and differentiated neurosurgery sub-interns both within and across programs. This form has potential as a replacement for numerical Step 1 scoring as a standardized, quantitative performance assessment for neurosurgery residency applicants.

An immunosuppressed microenvironment distinguishes lateral ventricle-contacting glioblastomas.

Radiographic contact of glioblastoma (GBM) tumors with the lateral ventricle and adjacent stem cell niche correlates with poor patient prognosis, but the cellular basis of this difference is unclear. Here, we reveal and functionally characterize distinct immune microenvironments that predominate in subtypes of GBM distinguished by proximity to the lateral ventricle. Mass cytometry analysis of isocitrate dehydrogenase wild-type human tumors identified elevated T cell checkpoint receptor expression and greater abundance of a specific CD32+CD44+HLA-DRhi macrophage population in ventricle-contacting GBM. Multiple computational analysis approaches, phospho-specific cytometry, and focal resection of GBMs validated and extended these findings. Phospho-flow quantified cytokine-induced immune cell signaling in ventricle-contacting GBM, revealing differential signaling between GBM subtypes. Subregion analysis within a given tumor supported initial findings and revealed intratumor compartmentalization of T cell memory and exhaustion phenotypes within GBM subtypes. Collectively, these results characterize immunotherapeutically targetable features of macrophages and suppressed lymphocytes in GBMs defined by MRI-detectable lateral ventricle contact.

The cost of a plastic surgery team assisting with cranioplasty.

OBJECTIVES: Cranioplasty is a commonly performed neurosurgical procedure that restores cranial anatomy. While plastic surgeons are commonly involved with cranioplasties, the cost of performing a cranioplasty with neurosurgery alone (N) vs. neurosurgery and plastic surgery (N + P) is unknown. METHODS: A single-center, multi-surgeon, retrospective cohort study was undertaken on all cranioplasties performed from 2012 to 22. The primary exposure variable of interest was operating team, comparing N vs. N + P. Cost data was inflation-adjusted to January 2022 using Healthcare Producer Price Index as calculated by the US Bureau of Labor Statistics. RESULTS: 186 patients (105 N vs. 81 N + P) underwent cranioplasties. The N + P group has a significantly longer length-of-stay (LOS) 4.5 ± 1.6days, vs. 6.0 ± 1.3days (p < 0.001), but no significant difference in reoperation, readmission, sepsis, or wound breakdown. N was significantly less expensive than N + P during both the initial cranioplasty cost ($36,739 ± $4592 vs. $41,129 ± $4374, p 0.014) and total cranioplasty costs including reoperations ($38,849 ± $5017 vs. $53,134 ± $6912, p < 0.001). Univariable analysis (threshold p = 0.20) was performed to justify inclusion into a multivariable regression model. Multivariable analysis for initial cranioplasty cost showed that sepsis (p = 0.024) and LOS (p = 0.003) were the dominant cost contributors compared to surgeon type (p = 0.200). However, surgeon type (N vs. N + P) was the only significant factor (p = 0.011) for total cost including revisions. CONCLUSIONS: Higher costs to N + P involvement without obvious change in outcomes were found in patients undergoing cranioplasty. Although other factors are more significant for the initial cranioplasty cost (sepsis, LOS), surgeon type proved the independent dominant factor for total cranioplasty costs, including revisions.

Conditional Recurrence-Free Survival After Surgical Resection of Meningioma.

BACKGROUND: Recurrence after meningioma resection warrants serial surveillance imaging, but little evidence guides the optimal time interval between imaging studies/surveillance duration. OBJECTIVE: To describe recurrence-free survival (RFS) after meningioma resection, conditioned to short-term RFS. METHODS: A retrospective cohort study for adults presenting for meningioma resection from 2000 to 2018 was conducted. The primary outcome was postoperative follow-up RFS. Conditional RFS Kaplan-Meier analysis was performed at 1, 2, 3, 5, and 10 years, conditioned to 6-month and 12-month RFS. RFS probabilities conditioned to 6-month RFS were estimated in subgroups, stratified by World Health Organization grade, extent of resection, and need for postoperative radiation. RESULTS: In total, 723 patients were included. Median age at surgery was 57.4 years (IQR = 47.2-67.2). Median follow-up was 23.5 months (IQR = 12.3-47.8). Recurrence was observed in 90 patients (12%), with median time to recurrence of 14.4 months (IQR = 10.3-37.1). Conditioned to 6-month postoperative RFS, patients had 90.3% probability of remaining recurrence-free at 2 years and 69.4% at 10 years. Subgroup analysis conditioned to 6-month RFS demonstrated grade 1 meningiomas undergoing gross total resection (GTR) had 96.0% probability of RFS at 1 year and 82.8% at 5 years, whereas those undergoing non-GTR had 94.5% and 79.9% probability, respectively. RFS probability was 78.8% at 5 years for non-grade 1 meningiomas undergoing GTR, compared with 69.7% for non-grade 1 meningiomas undergoing non-GTR. Patients with non-grade 1 meningiomas undergoing upfront radiation had a 1-year RFS of 90.1% and 5-year RFS of 51.7%. CONCLUSION: Recurrence risk after meningioma resection after an initial recurrence-free period is reported, with high-risk subgroups identified. These results can inform objective shared decision-making for optimal follow-up.

Association between preoperative hematologic markers and aggressive behavior in meningiomas.

INTRODUCTION: Meningiomas have varying degrees of aggressive behavior. Some systemic hematologic makers are associated with malignancy, but their value in predicting aggressive meningioma behavior is not fully understood. OBJECTIVE: To evaluate the association between preoperative markers such as neutrophil-lymphocyte ratio (NLR), neutrophil-monocyte ratio (NMR), monocyte-lymphocyte ratio (MLR), platelet-lymphocyte ratio (PLR), and prognostic nutritional index (PNI), and diagnostic and prognostic factors including WHO grade, proliferation index, presence of edema on preoperative MRI, and tumor recurrence. METHODS: A retrospective review of patients treated between 2000 and 2019 with a preoperative complete blood count (CBC) differential lab draw before intracranial meningioma resection was conducted. All preoperative steroid dosages were converted to dexamethasone equivalents. Primary outcomes included presence/absence of perilesional edema, WHO grade, Ki-67/MIB-index, and recurrence. Univariate and multivariable regression analyses were conducted. RESULTS: A total of 209 meningioma patients were included. Of these, 143 (68 %) were WHO grade I, 61 (29 %) grade II and 5 (2 %) were grade III. Recurrence was reported in 19 (9.1 %) tumors. No hematologic markers were associated with recurrence. In separate multivariable logistic analyses, no biomarkers were associated with perilesional edema or WHO grade. MLR was associated with higher MIB-index (p = 0.018, OR 6.57, 95 % CI 1.37-30.91). CONCLUSION: Most hematologic markers were not associated with meningioma invasiveness, grade, proliferative index, or aggressiveness. Preoperative MLR was associated with high proliferation index in patients undergoing surgery for intracranial meningioma. Higher MLR could be a surrogate for meningioma proliferation and has potential to be used as an adjunct for risk-stratifying meningiomas.

Comparison of supratentorial meningioma resection outcomes by dural reconstruction technique.

OBJECTIVE: Excision of intracranial meningiomas often requires resection or coagulation of the dura mater. The choice of dural closure technique is individualized and based on surgeon preference. The objective of this study was to determine outcomes following various dural closure techniques for supratentorial meningiomas. METHODS: A retrospective, single-center cohort study was performed for patients who underwent excision of supratentorial meningiomas from 2000 to 2019. Outcomes including operative time, postoperative in-hospital complications, readmission, causes of readmission including surgical site infection, pseudomeningocele, need for shunt surgery, and imaging appearance of pseudomeningocele on long-term follow-up imaging were compared. Univariate and multivariable analyses were conducted. RESULTS: A total of 353 patients who had complete clinical and operative data available for review were included. Of these patients, 227 (64.3%) had nonsutured dural graft reconstruction and 126 (35.7%) had sutured dural repair, including primary closure, artificial dura, or pericranial graft. There was significant variability in using nonsutured dural reconstruction compared with sutured dural repair technique among surgeons (p < 0.001). Tumors with sagittal sinus involvement were more likely to undergo nonsutured closure (n = 79, 34.8%) than dural repair (n = 26, 20.6%) (p = 0.003). There were no other differences in preoperative imaging findings or WHO grade. Frequency of surgical site infection and pseudomeningocele, need for shunt surgery, and recurrence were similar between those undergoing nonsutured and those undergoing sutured dural repair. The mean operative time for the study cohort was 234.9 (SD 106.6) minutes. The nonsutured dural reconstruction group had a significantly shorter mean operative time (223.9 [SD 99.7] minutes) than the sutured dural repair group (254.5 [SD 115.8] minutes) (p = 0.015). In a multivariable linear regression analysis, after controlling for tumor size and sinus involvement, nonsutured dural graft reconstruction was associated with a 36.8-minute reduction (95% CI -60.3 to -13.2 minutes; p = 0.002) in operative time. CONCLUSIONS: Dural reconstruction using a nonsutured graft and sutured dural repair exhibit similar postoperative outcomes for patients undergoing resection for supratentorial meningiomas. Although sutured grafts may sometimes be necessary, nonsutured graft reconstruction for most supratentorial meningioma resections may suffice. The decreased operative time associated with nonsutured grafts may ultimately result in cost savings. These findings should be taken into consideration when selecting a dural reconstruction technique for supratentorial meningioma.

Words matter: using natural language processing to predict neurosurgical residency match outcomes.

OBJECTIVE: Narrative letters of recommendation (NLORs) are considered by neurosurgical program directors to be among the most important parts of the residency application. However, the utility of these NLORs in predicting match outcomes compared to objective measures has not been determined. In this study, the authors compare the performance of machine learning models trained on applicant NLORs and demographic data to predict match outcomes and investigate whether narrative language is predictive of standardized letter of recommendation (SLOR) rankings. METHODS: This study analyzed 1498 NLORs from 391 applications submitted to a single neurosurgery residency program over the 2020-2021 cycle. Applicant demographics and match outcomes were extracted from Electronic Residency Application Service applications and training program websites. Logistic regression models using least absolute shrinkage and selection operator were trained to predict match outcomes using applicant NLOR text and demographics. Another model was trained on NLOR text to predict SLOR rankings. Model performance was estimated using area under the curve (AUC). RESULTS: Both the NLOR and demographics models were able to discriminate similarly between match outcomes (AUCs 0.75 and 0.80; p = 0.13). Words including "outstanding," "seamlessly," and "AOA" (Alpha Omega Alpha) were predictive of match success. This model was able to predict SLORs ranked in the top 5%. Words including "highest," "outstanding," and "best" were predictive of the top 5% SLORs. CONCLUSIONS: NLORs and demographic data similarly discriminate whether applicants will or will not match into a neurosurgical residency program. However, NLORs potentially provide further insight regarding applicant fit. Because words used in NLORs are predictive of both match outcomes and SLOR rankings, continuing to include narrative evaluations may be invaluable to the match process.

Trends in utilization of standardized letters of recommendation in the 2021-2022 neurosurgery application process.

OBJECTIVE: Standardized letters of recommendation (SLORs) were introduced during the 2020-2021 neurosurgery residency application cycle, but suffered from poor interrater reliability and grade inflation. Changes were made to the SLOR template and utilization patterns in response to these shortcomings. The authors examined the second year of SLOR utilization. They hypothesized that grade inflation and interrater reliability would be improved from the first iteration. They also hypothesized that increased numbers of letters by single writers would correlate with broader rating distributions. METHODS: This cross-sectional study analyzed all SLORs submitted to a single neurosurgery residency program over the 2021-2022 cycle. Data from 7 competency domains and the overall rating were recorded and stratified by academic category of the letter writer. Interrater reliability was evaluated using Krippendorff's alpha. The frequency of letters written was evaluated using the Kruskal-Wallis H test. RESULTS: Ninety percent of SLORs rated applicants among the top 25%, but there was a significant decrease in the usage of the top 1% and top 2%-5% ratings. Interrater reliability was poor across all competencies. Writers who completed 1 SLOR rated applicants higher and had a narrower range than those who completed multiple SLORs. CONCLUSIONS: Changes in the format and subsequent utilization patterns of SLORs have slightly decreased grade inflation; however, interrater reliability remains poor. The most wide-ranging evaluators submitted the highest number of SLORs, suggesting that future evaluation and usage of SLORs should emphasize letter-writer characteristics and numbers of SLORs written. Overall, SLORs have been well and broadly accepted with subtle improvements in the second year of utilization.

Matched case-control analysis of outcomes following surgical resection of incidental meningioma.

PURPOSE: The management of incidentally discovered meningioma remains controversial. We sought to compare outcomes following surgical resection of incidental meningioma to a matched cohort of symptomatic meningiomas. METHODS: A retrospective single-center case-control study was conducted for patients undergoing resection of incidental meningioma from 2000 to 2019. A 1:1 case-control matching for incidental and symptomatic meningioma was performed using the following variables: age at initial visit, gender, tumor location/size, and presence of peritumoral edema. Primary outcomes included (1) WHO grading/histopathological subtype/MIB-1 index, (2) extent of resection (gross total resection or subtotal resection), and (3) recurrence. Outcomes were compared between groups using descriptive/bivariate analyses. RESULTS: A total of 91 incidental meningiomas were analyzed. Trauma was the most common reason (n = 19, 21%) to obtain imaging, and tumor size the leading reason to operate (n = 37, 41%). Median time-to-surgery from initial clinical encounter was 5-months (Q1:3, Q3:16.5). More incidental meningioma patients (n = 47, 52%) were privately insured compared to their matched symptomatic cohort (n = 30, 33%) (P = 0.006). Patients with incidental meningioma had significantly higher mean Karnofsky Performance Scale at time-of-surgery (93.2, SD:11.1 vs. 81.4, SD:12.7) (P < 0.001). There were no significant differences in primary/secondary outcomes between the groups. Incidental meningioma was not associated with recurrence on Cox proportional hazards analysis (HR: 0.795, 95%CI: 0.3-2.1, P = 0.637). CONCLUSION: Matched case-control analysis demonstrated no significant differences in clinical, histopathological, and functional outcomes following resection of incidental and symptomatic meningioma. While non-operative management with close follow-up and serial imaging is preferred for incidental meningiomas, those undergoing resection when indicated can anticipate similar safety and efficacy as symptomatic meningiomas.