Influence of different tumor resection extent on facial nerve function and tumor recurrence in acoustic neuroma surgery

Abstract

Objective To observe the influence of different tumor resection extent on facial nerve function and tumor recurrence in acoustic neuroma surgery. Methods A total of 118 patients with acoustic neuroma operated by the same surgeon from January 2009 to December 2015 were enrolled retrospectively. All patients were treated via suboccipital retrosigmoid transmeatal approach. The near-total resection strategy was used during operation.Part of the tumors closely adhered to the facial nerveswere not removed forcibly. If there was tumor residue partly, the internal auditory canal was not drilled open. The relationship between facial nerve function or tumor recurrence and tumor resection degree was analyzed. The patients with recurrent tumor were treated with Gamma knife. Results In 118 patients, l patient (0.8%) died during the operation. The follow-up time ranged from 8-90 months. The total resection rate of acoustic neuroma was 19.5%(23/118), the near-total resection rate was 74.6% (88/118), and subtotal resection rate was 5.9%(7/118). The recurrence rate was 16.1%(19/118), in total resection group was 0, in near-total resection group was 15.9%(14/88), in subtotal resection group was 5/7, there was significant difference (χ2= 21.980, P<0.01). The good rate of facial nerve function after procedure was 90.7%(107/118), in total resection group was 73.9%(17/23), in near-total resection group was 95.5%(84/88), in subtotal resection group was 6/7, and there was significant difference between total resection group and near-total resection group (χ2= 14.168, P<0.05). After Gamma knife treatmentthe tumor volume increased again in 3 patients (2.5%) during the follow up period, and they were reoperated. Conclusions After near-total resection of acoustic neuroma, the assisted Gamma knife therapy may effectively control the growth of acoustic neuroma, and significantly improve the retention rate of facial nerve function. For the improvement of the quality of life, it is a feasible treatment scheme in the patients with tumors closely adhered to the facial nerves. Key words: Neuroma, acoustic; Microsurgery; Facial nerve; Neoplasm recurrence, local