Vestibular schwannoma: predictive factors of long-term postoperative neurological outcome

Introduction: Vestibular schwannoma (VS) is a slow-growing, benign tumor that is usually diagnosed when symptoms develop. Surgical management aims to reduce long-term sequelae (LTS) associated with late diagnosis. Objective: Identify predictive factors of LTS after VS surgery and clinical outcome measured by modified Rankin scale (mRS). Methods: This cohort study included patients submitted to VS surgery from 1999 to 2014, with a mean follow-up of 6.4 +/- 4.5 years. Disability was assessed across the mRS the primary outcome was defined by scores 3 to 6, which implied poor outcome in neurological recovery. Predictive factors were identified through multivariate logistic regression. Results: A total of 101 patients were included in this study. Fifty-one (50.49%) presented mRS >= 3 on the late postoperative period. Men comprise 22.8%, and the mean age was 47.1 +/- 16.0 years (range19-80). Patients with mRS >= 3 presented larger tumors (3.7 +/- 1.1 cm vs. 3.2 +/- 1.0 cm, p < .001), less total resection (50% vs. 76.7%, p < .010) and more neurofibromatosis II(NFII) (84.9% vs. 64.3%, p = .023). On multivariate analysis NFII, tumor size and type resection were predictive of degree of autonomy (mRS >= 3: NF II (OR 3.5, 95% CI 1.08-11.36, p = .036) and tumor size (each 1 cm, OR1.51, 95% CI 0.96-2.38, p = .050). Conclusion: Tumor size, presence of NFT II, type of surgical approach and number of surgeries were identified as predictive factors of functional sequelae in long-term follow-up after VS surgery.