Abstract: Objective To explore the facial nerve functional recovery law after resection of acoustic neuroma .And studied the influence of tumor size on postoperative facial nerve function. Methods According to the House-Brackman (HB) facial nerve function classification methods, grading 89 patients with acoustic neuroma after microsurgical resection with the retrosigmoid approach and facial nerve preservation. They were observed, follow-up with call and retrospectively analyzed. Choosing immediately , 15 days, 45 days , 3 months, 6 months, 12 months and more than 12 months after operation for the point .To explore the rule of the postoperative facial nerve functional recovery. And according to the tumor diameter < 30 mm, 30 ~ 40 mm, and ≥40mm divided into three groups. Compared the patients facial nerve function in different groups with early postoperative (within 15 days) and long-term (more than 12 months). Results The facial nerve function worst in 15 days after operation (excellence rate was 52.81%), but in postoperative 3 months most returning (excellence rate reached 80.90% ), for the most part can be restored to excellence in postoperative 12 months (excellence rate was 91.01% ), and the facial nerve recovery more smoothly after postoperative 12 months. Patients whoes tumor diameter < 30 mm have better excellence in early postoperative (rate was 82.61%) and long-term (rate was 100%). Tumor size has remarkable effect on facial nerve function in the early postoperative (χ2 = 23.34, P = 23.34, P < 0.05), and long-term (χ2 = 14.46, P = 14.46, P < 0.05) . And they are correlation, the early stage (r = 0.476, P = 0.000, P < 0.05) and long-term (r = 0.379, P = 0.000, P < 0.05) . The tumor more larger ,the postoperative facial nerve function in the early and long-term more poorer. Conclusion The retrosigmoid approach and facial nerve preservation in patients who have acoustic neuroma ,the facial nerve function in early postoperative (within 15 days) may appear deterioration, but most can be recovery in postoperative 3 months, and almost all can be recovery in 12 months. The postoperative facial nerve function closely related with the size of the tumors not only in the early postoperative (within 15 days) but also in the long-term (> 12 months), which is one of the important factors influencing the postoperative facial nerve function.

Key words: Neuroma,Acoustic, Facial Nerve, Microsurgery, Recovery of Function, Follow-Up Studies