Predictive Factors of Early Postoperative and Long-Term Facial Nerve Function After Large Vestibular Schwannoma Surgery

OBJECTIVE: The preservation of acceptable facial nerve (FN) function after surgery is the key concern for most patients with vestibular schwannomas (VS). To assess predictive factors of early postoperative and long-term FN function in patients harboring large VS operated with a FN-sparing technique. METHODS: Single-center retrospective cohort study with 169 consecutive large VS operated on between January 2003 and May 2015. Clinical, radiologic, and intraoperative factors were assessed according to FN function. RESULTS: At last follow-up examination, among the 145 patients without preoperative FN palsy, FN function was good (House-Brackmann [HB] grades I or II) in 84% and moderate (HB grade III) in 15% of patients. Only 1 patient presented with poor HB grade IV function. Multivariate logistic regression model showed the mean preoperative VS extrameatal diameter as being an independent predictor of an unfavorable initial FN outcome (odds ratio [OR], 1.062; P = 0.038). Surgical anatomic preservation of the cochlear nerve was associated with better FN outcomes (OR, 0.237; P = 0.012). A history of previous surgery seemed to be related to long-term impaired FN function (OR, 71.405; P = 0.042), as well as early postoperative FN function (OR, 19.068; P = 0.000). No correlation was found between a history of previous Gamma Knife surgery treatment (P = 0.225) or the extent of resection (P = 0.438) and impaired FN outcomes. History of previous surgery was identified as an unfavorable predictive recovery factor of impaired postoperative FN function (P = 0.034). CONCLUSIONS: As long as the extent of resection or additional Gamma Knife surgery have not been identified as predictive risk factors of postoperative FN palsy, we suggest that optimal resection is the main option for patients harboring large VS.