2026 Proffered Presentations
S079: PROGNOSTIC IMPACT AND CLINICAL PROFILE OF A LARGE COHORT OF HIGH-RIDING JUGULAR BULBS IN VESTIBULAR SCHWANNOMA SURGERY: A MULTI-INSTITUTIONAL ANALYSIS OVER THREE DECADES
Kaasinath Balagurunath, BA1; Sabrina Heman-Ackah, MD, DPhil, Oxon, MSE1; Rania A Mekary, PhD, MSc, MS2; C. Eduardo Corrales, MD3; Timothy Smith, MD, PhD, MPH3; 1Brigham and Women's Hospital; 2School of Pharmacy, Massachusetts College of Pharmacy and Health Sciences (MCPHS) University; 3Co-Senior Author, Brigham and Women's Hospital
Introduction: High-riding jugular bulb (HRJB) is a rare anatomical variant encountered during vestibular schwannoma (VS) surgery which can complicate excision, particularly during drilling of the internal auditory canal (IAC) or internal-auditory-meatus (IAM). Large-scale, multi-institutional data examining patients with HRJB remain scarce. This study addresses this gap through comprehensive analysis from three large tertiary care centers in New-England, over a 35-year period.
Objectives: To characterize clinical and demographic features, operative approaches, and postoperative outcomes in patients with HRJB compared to those without, and to evaluate the prognostic significance of HRJB on postoperative complications and functional outcomes.
Methods: We retrospectively analyzed 2,139 patients undergoing VS resection from 1990 to 2025 across three tertiary institutions within the MGB system. Patients were stratified by the presence of HRJB (n=59) or absence (n=2080). Baseline demographics, lesion characteristics, operative approach, laboratory parameters, and postoperative complications were compared. To mitigate inflated type-I error due to multiple testing, no T-tests or chi-square tests were performed. Multivariate logistic regression adjusting for confounders (age, GTR, lesion-size, operative approach, BMI, tobacco history, cystic lesion, nutrition status) was utilized to assess the independent prognostic impact of HRJB.
Results: Patients with HRJB were older (mean age 54.12 ± 11.43 years vs. 49.50 ± 13.19 years) and predominantly female (72.9% vs. 54.9%). Lesion size was larger in the HRJB group (25.30 ± 5.85 mm) compared to controls (23.06 ± 10.24 mm). The majority in both cohorts underwent retrosigmoid craniotomy (76.3% HRJB vs. 76.1% non-HRJB). Gross total resection (GTR) was achieved more frequently in HRJB patients (64.4% vs. 48.6%), possibly reflecting surgical selection or tumor characteristics.
Baseline functional assessments showed a higher proportion of HRJB patients with moderate disability (mRS 3 in 33.9% vs. 22.2%) and elevated baseline Barthel scores (61–99 in 37.3% vs. 25.0%), indicating a different preoperative status.
Postoperatively, the HRJB cohort exhibited increased CSF leak rates (11.9% vs. 5.6%) and a higher incidence of peri-tumoral radiographic changes (diffusion restriction, T2 hyperintensity, parenchymal shrinkage, or encephalomalacia, 33.9% vs. 23.8%). Hydrocephalus rates were similar between groups (13.6%). Recurrence rates trended lower in the HRJB group (6.8% vs. 10.6%), which may correlate with the higher GTR rate.
Multivariate logistic regression confirmed that HRJB was an independent risk factor for postoperative CSF leak (Odds Ratio [OR] 12.33; 95% Confidence Interval [CI] 1.55–98.18; p=0.018). No significant associations were found between HRJB and hydrocephalus (OR 0.69; p=0.786), radiographic recurrence (OR 0.00; p=0.999), or poor functional outcome (OR 1.03; p=0.976). Other confounders accounted for included age, GTR, lesion size, operative approach, BMI, tobacco use, cystic-changes, nutrition status, HRJB.
Conclusions: This largest-to-date multi-institutional study elucidates the distinct clinical profile and surgical risks associated with HRJB in VS . Patients with HRJB tend to be older, female, and present with larger tumors. HRJB elevates the risk of postoperative CSF leak. We believe this could be due to an increased risk of mastoid air cell entry, impairment of the surgeon’s ability to create watertight closure along the sigmoid sinus margin, or alterations in venous outflow dynamics/pressures adjacent to the dura.
