A Multifactorial Analysis of Facial Nerve Results in Surgery for Cerebellopontine Angle Tumors

Preserving the function of the facial nerve remains a paramount objective in acoustic neuroma surgery. This study was undertaken to determine the influence of four independent variables on facial nerve outcome by means of a retrospective review of 111 surgical cases: 1) tumor size; 2) use of intraoperative facial nerve monitoring (IFNM); 3) completeness of tumor resection; and 4) surgical approach used. Partial tumor resection appeared to result in improved facial nerve outcome for patients with large tumors. Results indicated that tumor size did not correlate with facial nerve functional outcome, with no statistically significant differences observed among the three size categories. Facial nerve function was not found to depend on selection of either a translabyrinthine (n=47) or a suboccipital (n—55) surgical approach in that results were similar for both groups. Outcome data showed a trend in support of the use of IFNM, especially for large tumors, even though the differences between monitored and unmonitored groups were not statistically significant. This study describes the independent impact of the four factors generally thought to affect facial nerve outcome and, in addition, recommends the use of data stratification in reporting facial nerve function results.