Citations

In this video, the authors present the microsurgical treatment of a superior petrosal dural arteriovenous fistula (dAVF) associated with a symptomatic hemorrhagic brainstem cavernous malformation in a 38-year-old male. The patient underwent a retrosigmoid craniotomy for cavernoma evacuation and fistula disconnection. Intraoperative indocyanine green angiography revealed cortical venous reflux not evident on catheter angiography, prompting reclassification to a higher-grade fistula. Postoperatively, the patient returned to neurological baseline, and follow-up imaging confirmed complete fistula obliteration, cavernoma resection, and new appearance of a developmental venous anomaly (DVA). This case highlights the dynamic nature of dAVF venous drainage and illustrates the rare co-occurrence of dAVF, DVA, and brainstem cavernoma. The video can be found here: https://stream.cadmore.media/r10.3171/2025.7.FOCVID2553

BACKGROUND AND OBJECTIVES: Surgery in NF2-related schwannomatosis (NF2-SWN) vestibular schwannoma (VS) carries a higher risk of facial nerve damage, hearing loss, and partial resection, than in sporadic cases. Radiosurgery is also associated with higher failure compared with sporadic schwannomas. Nowadays, bevacizumab (BEV) is frequently considered in the NF2-SWN population. However, some patients experience progression despite treatment. Among other surgical risks, in BEV-treated patients, hemorrhage and impaired healing are specific considerations. These concerns have led manufacturers to recommend stopping BEV 6 to 8 weeks preoperatively. The aim of our multicentric study was to assess the perioperative bleeding risk and postoperative outcomes in NF2-SWN patients undergoing VS surgery after preoperative BEV treatment. METHODS: Our retrospective analysis included medical and surgical records along with imaging reviews from 4 high-volume tertiary academic referral centers for NF2-SWN and VS. RESULTS: A total of 21 patients met the inclusion criteria. VS had a mean volume of 13.2 ±7.6 cm 3 corresponding to 1 KOOS III and 20 KOOS IV. BEV was stopped at a mean of 5.8 ± 4.0 months before surgery with a total mean treatment duration of 33.7 ± 20.7 months and a monthly dose of 10.2 ± 4.1 mg/kg. Intraoperatively, the tumor was assessed to be bloody by the operating surgeons in 7 patients. Late BEV discontinuation and high cumulative dose independently predicted perioperative bleeding and longer surgery duration. No other complication such as wound dehiscence was reported. CONCLUSION: Our findings suggest that a higher cumulative BEV dose (∼600 mg/kg) and a longer interval between BEV discontinuation and surgery (∼8 months) are associated with a modest but statistically significant increase in intraoperative bleeding risk. Based on these observations, a BEV-free window between 6 weeks and 6 months (depending on the clinical scenario) before tumor resection seems optimal, particularly for patients with high cumulative exposure.

Importance In the literature, there is a lack of data reporting tumor control rates after radiotherapy in actively growing vestibular schwannomas (VS). Data for this rarely studied population are needed. Objective To estimate tumor control rates in radiologically growing VS treated with first-line radiotherapy. Design, Setting, and Participants This international, multicenter cohort study used prospectively collected data from patients with growing unilateral VS treated first-line with radiotherapy between January 2000 and December 2023 from 8 tertiary referral skull base units. The data were analyzed in June 2025. Exposures Radiotherapy as an initial treatment for VS. Main Outcomes and Measures The primary outcome was treatment failure, ie VS growth postradiotherapy, which was predefined as an increase in maximum intracranial tumor diameter (ICTD) of 3 mm or greater within the first 2 years after radiotherapy or 2 mm or greater thereafter. Secondary outcomes were treatment failure based on different definitions of VS growth: (1) an increase in ICTD of 2 mm or greater, (2) an increase in ICTD of 3 mm or greater, and (3) conversion to surgery. Results A total of 1883 patients (975 female individuals [51.8%]; median age at diagnosis, 63 years [IQR, 53-71 years]) were included in the study. Using the primary definition of treatment failure (an increase in ICTD of ≥3 mm within the first 2 years postradiotherapy or ≥2 mm thereafter), the Kaplan-Meier estimate yielded a 10-year tumor control rate of 76.1% (95% CI, 72.7%-79.2%). For secondary outcome definitions, 10-year tumor control rates were 60.1% (95% CI, 57.5%-64.3%) for an ICTD increase of 2 mm or greater, 78.3% (95% CI, 75.0%-81.2%) for an increase of 3 mm or greater, and 92.6% (95% CI, 90.4%-94.3%) for conversion to surgery. Neither pretreatment tumor size nor tumor location (intracanalicular vs extracanalicular) were significantly associated with treatment failure. Conclusions and Relevance The results of this cohort study provide tumor control outcomes for radiologically growing VS treated with radiotherapy using several clinically relevant definitions of growth. By focusing exclusively on this rarely isolated subgroup, the findings offer targeted data to potentially inform treatment expectations and future research.

BACKGROUND AND OBJECTIVE: In skull base surgery, endoscopic endonasal approaches require precise evaluation of the area of exposure and the maneuverability provided by each approach. Current neuroanatomical methodologies for quantifying these parameters primarily rely on computed tomography (CT) scans and neuronavigation systems, which entail significant financial investment. The aim of this study was to develop and validate an innovative, cost-effective methodology using an endoscopic photogrammetric model to measure the exposure area and maneuverability in endoscopic endonasal approaches, offering an accessible alternative to existing techniques. METHODS: Six cadaveric specimens were used to validate the accuracy of endoscopic photogrammetric measurements by comparing them with direct measurements. Subsequently, the exposure area, angle of attack, and surgical freedom were analyzed for 3 endoscopic approaches to the parasellar region: contralateral transmaxillary, single-nostril, and double-nostril approaches. RESULTS: Photogrammetric measurements demonstrated a high level of concordance with direct cadaveric measurements, with a mean difference of 0.02 mm as shown in the Bland-Altman plot. In addition, measurements obtained in comparative analysis describing the exposure area and maneuverability of 3 endoscopic approaches were congruent with those reported in existing literature derived using CT scans and neuronavigation systems. CONCLUSION: To our knowledge, this study is the first to validate endoscopic photogrammetric models as a measurement tool in neuroanatomy. Performing direct measurements on 3D models might eliminate the necessity of expensive CT and neuronavigation systems for volumetric quantification. Our cost-effective methodology allows for the widespread democratization of anatomical quantification within skull base neuroanatomy.

Abstract Professor Albert J. Rhoton Jr., MD, is renowned for his groundbreaking dissections, marking a monumental achievement in the field of neuroanatomy. Alongside his anatomical contributions, he also passed on his knowledge and skills to numerous fellows, leaving behind a profound legacy. Despite the widespread recognition of his influence, little quantitative work has been done to characterize the scholarly impact of his alumni. Data were collected on Rhoton fellows, including fellowship years, country of origin, current institutions, and titles, practice settings, and leadership roles. Scholarly productivity was evaluated by assessing publication counts, including publications before and after the fellowship, and publications focused on surgical anatomy. Additionally, H-indices and citation counts were recorded. Other variables analyzed included ownership of a surgical anatomy laboratory, and participation in organizing hands-on courses. We analyzed 118 alumni from diverse countries. There was a significant increase in publication output following the fellowship, with publications rising from an average of 7 to 76 (p < 0.001). Fellows from high-income countries had higher research productivity than those from middle-income countries, with greater average H-index (p = 0.003), publication count (p = 0.01), and citation score (p = 0.003). Overall, 65% of fellows pursued academic practice, with 18% owning a laboratory and 30% involved in hands-on courses. Dr. Rhoton's mentorship has shaped a generation of neurosurgeons who continue his legacy. His fellows have established careers worldwide, leading in academia, professional organizations, and surgical training. Their global impact underscores the lasting value of structured mentorship in neurosurgery.

OBJECTIVE Calcium phosphate cement (CPC) use has been previously described as a strategy to reduce the rates of pseudomeningocele and CSF leakage following skull base surgery. The authors aimed to present their institutional experience with CPC in retrosigmoid craniotomy and perform a systematic review of the literature to determine the effectiveness of CPC in reducing postoperative complications, including pseudomeningocele and craniotomy-site CSF leakage. METHODS A retrospective single-institution cohort study of patients who underwent retrosigmoid craniotomy with and without CPC cranioplasty from January 2017 to April 2024 was performed. A systematic literature review and meta-analysis of CPC use in retrosigmoid craniotomy was also performed. RESULTS Of 336 patients who underwent retrosigmoid craniotomy, 193 (57%) were female and the median age at surgery was 55 years (range 18–81 years). The median follow-up duration was 23 months (range 3–80 months). CPC was used to seal the edge of the craniotomy in 66 patients (20%). Among all patients, 50 (15%) experienced a postoperative complication, and 28 (8%) were wound-specific complications. Patients in the non-CPC group experienced significantly more postoperative wound-specific complications than those in the CPC group (10% vs 0%, p = 0.002). Specifically, pseudomeningocele occurred in 0 patients (0%) in the CPC group compared with 24 patients (9%) in the non-CPC group (p = 0.006), which progressed to CSF leaks at the craniotomy site in 6 patients (p = 0.60). Additionally, no patients (0%) in the CPC group experienced wound infection, dehiscence, or breakdown compared with 10 patients (4%) in the non-CPC group (p = 0.22). Five patients (8%) in the CPC group reported prolonged mild incisional pain at the craniotomy site, and there were no instances of major complications related to the CPC. In the meta-analysis, 10 studies met the inclusion criteria, yielding a total of 2166 patients (including the current study), 1101 of whom received CPC. In the pooled analysis, CPC was significantly associated with lower risk of CSF leakage at the craniotomy site (OR 0.23, 95% CI 0.13–0.42; p < 0.01) and lower risk of infection (OR 0.17, 95% CI 0.08–0.38; p < 0.01). CONCLUSIONS CPC use in retrosigmoid craniotomies could be a safe and effective strategy to reduce the incidence of pseudomeningocele and craniotomy-site CSF leakage, leading to lower rates of wound-related complications and infection.

BACKGROUND AND OBJECTIVES: Stereotactic radiosurgery (SRS) is increasingly used as a primary treatment modality for intracranial meningiomas. We aim to describe clinical outcomes after single-fraction SRS for sporadic intracranial meningiomas. METHODS: A prospectively maintained database was reviewed for patients with sporadic meningiomas who underwent SRS (Gamma Knife) as primary treatment modality from April 1997 to February 2022. Primary outcomes included progression-free survival (PFS) and treatment-related complications. RESULTS: Six hundred sixteen patients (653 tumors) underwent SRS with median follow-up of 6.3 years (interquartile range [IQR] 3.1-10.5 years). The median tumor volume was 4.5 cm 3 (IQR 2.0-8.0 cm 3 ). The median margin dose was 15.0 Gy (IQR 14.0-16.0). In-field progression was noted in 7 tumors (1.1%) and marginal progression in 2 tumors (0.3%) for a raw failure rate of 1.4%. PFS estimates at 5, 10, and 15 years were 99.8%, 99.0%, and 93.2%, respectively. Factors associated with reduced PFS on univariable analysis included older age (hazards ratio [HR] 1.14, 95% CI, 1.05-1.22, P < .001), male sex (HR 5.44, 95% CI, 1.45-20.4, P = .010), increasing tumor volume (HR 1.06, 95% CI, 0.99-1.13, P = .028), and lower tumor margin dose (HR 0.65, 95% CI, 0.43-0.97, P = .006). Treatment-related complications were noted in 56 patients (9.1%), of which 45 (7.3%) were temporary, 5 (0.8%) were minor, and 6 (1.0%) were permanent and/or required intervention. Radiosurgical parameters associated with treatment-related complications included increased number of isocenters (odds ratio [OR] 1.09, 95% CI, 1.04-1.14, P < .001), higher 12-Gy volume (OR 1.06, 95% CI, 1.03-1.09, P < .001), larger tumor volume (OR 1.06, 95% CI, 1.02-1.10, P < .001), and lower maximal dose (OR 0.90, 95% CI, 0.82-0.98, P = .11). CONCLUSION: SRS is effective as a primary treatment modality for sporadic, small-volume to medium-volume intracranial meningiomas. Pre-emptive SRS should be discussed as a safe management strategy compared with observation alone for incidentally discovered meningiomas.

OBJECTIVE The objective of this study was to develop a deep learning model for automated pituitary adenoma segmentation in MRI scans for stereotactic radiosurgery planning and to assess its accuracy and efficiency in clinical settings. METHODS An nnU-Net–based model was trained on MRI scans with expert segmentations of 582 patients treated with Leksell Gamma Knife over the course of 12 years. The accuracy of the model was evaluated by a human expert on a separate dataset of 146 previously unseen patients. The primary outcome was the comparison of expert ratings between the predicted segmentations and a control group consisting of original manual segmentations. Secondary outcomes were the influence of tumor volume, previous surgery, previous stereotactic radiosurgery (SRS), and endocrinological status on expert ratings, performance in a subgroup of nonfunctioning macroadenomas (measuring 1000–4000 mm 3 ) without previous surgery and/or radiosurgery, and influence of using additional MRI modalities as model input and time cost reduction. RESULTS The model achieved Dice similarity coefficients of 82.3%, 63.9%, and 79.6% for tumor, normal gland, and optic nerve, respectively. A human expert rated 20.6% of the segmentations as applicable in treatment planning without any modifications, 52.7% as applicable with minor manual modifications, and 26.7% as inapplicable. The ratings for predicted segmentations were lower than for the control group of original segmentations (p < 0.001). Larger tumor volume, history of a previous radiosurgery, and nonfunctioning pituitary adenoma were associated with better expert ratings (p = 0.005, p = 0.007, and p < 0.001, respectively). In the subgroup without previous surgery, although expert ratings were more favorable, the association did not reach statistical significance (p = 0.074). In the subgroup of noncomplex cases (n = 9), 55.6% of the segmentations were rated as applicable without any manual modifications and no segmentations were rated as inapplicable. Manually improving inaccurate segmentations instead of creating them from scratch led to 53.6% reduction of the time cost (p < 0.001). CONCLUSIONS The results were applicable for treatment planning with either no or minor manual modifications, demonstrating a significant increase in the efficiency of the planning process. The predicted segmentations can be loaded into the planning software used in clinical practice for treatment planning. The authors discuss some considerations of the clinical utility of the automated segmentation models, as well as their integration within established clinical workflows, and outline directions for future research.

AbstractObjectiveTo examine associations with changes in quality‐of‐life (QOL) outcomes following treatment of vestibular schwannoma (VS) using stereotactic radiosurgery (SRS).Study DesignProspective longitudinal study.SettingTertiary academic center.MethodsPatients who were treated for sporadic VS using SRS from 2015 to 2022 were included. QOL outcomes were measured using the disease‐specific Penn Acoustic Neuroma QOL (PANQOL) scale.ResultsSeventy‐nine patients with pre‐SRS and at least one post‐SRS PANQOL assessments were available for analysis. The mean change in total PANQOL scores was −2 (SD 13) on a 100‐point scale. The mean duration between assessments was 4.6 years (SD 2.0). Age at SRS, sex, and SRS treatment doses were not significantly associated with changes in total PANQOL scores. Total PANQOL scores improved a mean of 4 points for patients with tumors confined to the internal auditory canal but declined a mean of 5 points for patients with tumors extending into the cerebellopontine angle (P = .01); however, these changes did not exceed the minimum clinically significant threshold of 11 points. The correlation coefficient between treated tumor volume at SRS and change in total PANQOL scores was −0.30 (P = .007). Changes in PANQOL total (P = .5) and hearing domain (P = .3) scores for patients who maintained serviceable hearing or progressed to nonserviceable hearing did not significantly differ.ConclusionTumor extent and treated volume at SRS had a statistically significant but likely not clinically important impact on total PANQOL scores. Progression to nonserviceable hearing did not have a significant impact on PANQOL total or hearing domain scores.

To address the limitations of existing instruments, the authors developed the Vestibular Schwannoma Quality of Life (VSQOL) Index. The Index captures the multifaceted impacts of vestibular schwannoma (VS) on daily life across eight categories: hearing problems; dizziness and imbalance; pain, discomfort, and tinnitus; problems with face or eyes; impact on physical, emotional, and social well-being; difficulty with thinking and memory; satisfaction or regret; and impact on employment. Initially developed in English, this digital supplement of the Journal of Neurosurgery presents translations of the VSQOL Index to Simplified Chinese, Spanish, Japanese, Arabic, French, and Norwegian. These translations aim to improve access to VS quality of life (QOL) research globally with enhanced racial, ethnic, and geographic representation. The goal is to comprehensively evaluate the impact of VS diagnosis and management on well-being and QOL by offering the VSQOL Index in patients’ native, or first-learned, languages. The English version and these translations may be used for noncommercial research, clinical, or educational purposes without written permission from the authors. Investigators interested in translating the VSQOL Index to other languages should contact the corresponding author for translation methodology instructions.