2026 Proffered Presentations
S228: PREOPERATIVE MICRONUTRIENT-DEFINED MALNUTRITION PREDICTS POOR FUNCTIONAL OUTCOMES FOLLOWING VESTIBULAR SCHWANNOMA RESECTION: A MULTI-INSTITUTIONAL ANALYSIS (1990-2025)
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: Despite established links between nutritional deficiencies and adverse surgical outcomes across various specialties, the prognostic relevance of micronutrient-defined malnutrition in vestibular-schwannoma (VS) has not been explored. This study represents the first large-scale, multi-institutional investigation of the relationship between nutritional status and perioperative and long-term outcomes in patients undergoing resection of VS.
Objectives: To determine the association between preoperative micronutrient-defined malnutrition and clinical, radiographic, and functional outcomes following microsurgical resection of vestibular schwannoma.
Methods: A retrospective cohort study was conducted across three large academic tertiary care centers in New-England. All patients who underwent microsurgical resection of VS between 1990 and 2025 and had available preoperative nutritional laboratory data were included.
Nutritional status was defined as abnormal if deficiencies or imbalances were identified in: vitamin A, D, E, B12, folate, zinc, copper, selenium, or albumin. Baseline demographics, lesion characteristics, surgical approach, and postoperative outcomes were compared between patients with normal vs. abnormal nutrition. Functional outcomes were assessed using the modified Rankin Scale (mRS), Glasgow Outcome Scale–Extended (GOSE), and Barthel Index.
To minimize the risk of Type-I error associated with multiple hypothesis testing, univariate comparisons using t-tests and chi-square tests were avoided. Multivariable logistic regression was used to assess the prognostic impact of malnutrition on key clinical outcomes, adjusting for relevant confounders (age, GTR, lesion size, operative approach, BMI, tobacco use, cystic changes, nutrition status, HRJB).
Results: Among 2,184 patients included (normal nutrition: n=1,812; abnormal nutrition: n=372), malnourished patients exhibited higher rates of smoking history (31.2% vs. 17.8%) and lower albumin levels (3.88 vs. 4.26 g/dL). Body mass index (BMI) was nearly identical between groups, underscoring that traditional anthropometric measures may not fully capture underlying nutritional deficits. Gross total resection (GTR) was achieved less frequently in the malnourished cohort (66.4% vs. 77.9%), suggesting a possible link between nutritional status and surgical complexity or intraoperative decision-making.
Malnutrition was independently associated with significantly worse postoperative functional outcomes (OR: 2.98, 95% CI: 1.44–6.16, p=0.003). This group also experienced increased rates of hydrocephalus (27.4% vs. 10.7%) and recurrence (15.6% vs. 9.5%), although these associations were not statistically significant in multivariable analysis (hydrocephalus OR: 1.25, 95% CI: 0.52-3.03 p=0.62; recurrence OR: 1.65, 95% CI: 0.65-4.2, p=0.29). CSF leak rates were similar between groups (5.4% vs. 5.9%) and the association between malnutrition and postoperative leaks was non-significant on logistic regression (OR: 2.04, 95% CI: 0.58-7.15 p=0.26) suggesting that not all postoperative complications are affected by nutrition status.
Final functional outcomes showed substantial deterioration in the malnourished cohort across mRS, GOSE, and Barthel scores. For instance, 32.8% of malnourished patients had a final mRS of 6 (death or severe disability), compared to 12.9% in the well-nourished cohort. Similar disparities were seen in Barthel Index performance, where malnourished patients were significantly less likely to return to full independence.
Conclusions: Micronutrient-defined malnutrition is a clinically meaningful and previously underrecognized risk factor for poor postoperative functional outcomes in patients undergoing resection of vestibular-schwannoma. These findings underscore the potential value of routine preoperative nutritional assessment and optimization in this population.
