Postoperative Functional Preservation of Facial Nerve in Cystic Vestibular Schwannoma.

[OBJECTIVE] To retrospectively analyze clinical and surgical data of a consecutive series of 26 patients with unilateral cystic vestibular schwannomas.

[METHODS] Tumors were classified as type A (central cyst) and type B (peripheral cyst) and as small (tumor diameter <3 cm) and large (tumor diameter >3 cm). All patients underwent microsurgical removal via retrosigmoid approach. The course of the facial nerve (FN) was classified as anterior, anterior-inferior, anterior-superior, and dorsal to the tumor's surface.

[RESULTS] Mean patient age was 53.5 years. Mean tumor size was 3.2 cm. There were 22 cases classified as type A and only 4 as type B. Total or near-total resection (>95%) was achieved in 16 cases (61.5%), subtotal removal (90%-95%) was achieved in 9 cases (34.6%), and partial removal (<90%) was achieved in 1 case (3.9%). Position pattern of FN was anterior-inferior in 10 cases (38.4%), anterior-superior in 10 cases (38.4%), anterior in 23.2% of 6 cases. At hospital discharge, FN function was House-Brackmann grade I-V in 9 (36%), 10 (38%), 3 (12%), 3 (12%), and 1 (4%) patients; at final follow-up, House-Brackmann grades I, II, III, and IV accounted for 18 (72%), 6 (24%), 1, and 1 cases. During follow-up ranging from 6 months to 10 years, reoperation for growing of residue was never necessary.

[CONCLUSIONS] According to the literature and the results of our series, microneurosurgery of cystic vestibular schwannomas is associated with good outcomes in terms of extent of resection and FN function. In particular, long-term FN function is much more satisfactory than short-term function. In most cases, microsurgery represents the treatment of choice of cystic vestibular schwannomas.