Intraoperative neuromonitoring for removal of large vestibular schwannoma: Facial nerve outcome and predictive factors

Abstract Background Preservation of facial nerve (FN) function is one of the major goals for resection of large vestibular schwannoma (VS) (≥30mm). Little is known about the FN outcome and its predictive factors due to limited data. Objective To explore the predictive factors affecting FN outcome following resection of large VS. Methods 106 Large VS patients underwent surgical resection from 2010 to 2012 via intraoperative neuromonitoring for FN preservation approach. Postoperative FN function evaluation was conducted at the time points of 3–7th day, 3rd month and at the end of the 2nd year. Correlation between tumor size, intraoperative parameters and FN function were examined. Results The ratios of total and subtotal resection were 82.1% and 14.2%, respectively. Acceptable FN function was achieved in 78% patients. Patients with good FN function showed much smaller ( P r =−0.709, P r =−0.709, P r =−0.750, P Conclusion Indicative factors of both immediate and long-term postoperative FN function in large VSs include tumor size, intraoperative train time, start to final FMEP ratios and proximal to distal MRA ratios.