Predictive factors influencing facial nerve outcomes in surgery for small-sized vestibular schwannoma

Conclusion: The most important predictive factor of facial nerve outcome in surgery for small-sized vestibular schwannoma (VS) is the adhesion between the tumor and the facial nerve. Objectives: To compare the facial nerve outcomes between middle cranial fossa (MCF) and translabyrinthine (TL) approaches, and to analyze the preoperative and intraoperative factors influencing facial nerve outcome after small VS surgery in our neurotologic department. Methods: A total of 29 patients were retrospectively analyzed, with 16 in the MCF group and 13 in the TL group. Facial function was serially evaluated according to the House-Brackmann classification at 7 days, 1 month, 3 months, 6 months, and 1 year postoperatively. The effects of variables such as the surgical approach, tumor size, nerve origin, extrameatal extension, intraoperative tumor adhesion to the facial nerve, and facial nerve displacement were determined. Results: Early and late facial nerve outcomes showed no significant correlation with surgical approach, tumor origin, tumor size, extrameatal extension, or facial nerve displacement pattern. However, a significant correlation was observed with tumor adhesion to the facial nerve and facial nerve outcomes.