Predictive Factors Influencing Facial Nerve (CNVII) Function after Vestibular Schwannoma (VS) Surgery

Objective: To analyze the impact of various clinical, radiological, intra- and postoperative factors that could influence the short- and long-term CNVII function. Study Design: Retrospective analysis. Material and Methods: This study included 212 patients operated on for sporadic VS (mean size 30 mm, total resection 210, neartotal 2). Correlations and multivariate logistic regression analysis of 19 factors were performed for each early and late CNVII function. Results: The following factors correlated significantly with satisfactory (HB grades: I-III) facial function in the short-term follow-up: female sex (p = 0.006), tumor stage < T4 (p < 0.001), size < 3 cm (p < 0.001), volume < 10 mL (p < 0.001), anterior CNVII displacement (p < 0.05), nimodipine administration (p = 0.012), positive EMG response during final intraoperative stimulation (p = 0.000) and the lack of postoperative complications (p = 0.001). Multivariate analysis found that three factors independently influenced the early outcome: tumor size (p = 0.002), complications (p = 0.011) and sex (p = 0.035). In the long-term follow-up, satisfactory CNVII function correlated significantly with tumor stage < T4 (p = 0.000), size < 3 cm (p = 0.000) and volume < 10 mL (p = 0.001), and also with left-sided location (p = 0.048). The volume (p = 0.005), stage (p = 0.037) and side (p = 0.026) have each shown an independent influence on long-term results. In addition, the use of nimodipine has revealed an independent, positive effect on very good results occurrence (HB grades: I-II, p = 0.03).