Hearing and Facial Nerve Function Preservation in Small Vestibular Schwannoma Surgery via the Middle Cranial Fossa Approach

Object: To present our experience on hearing and facial nerve function preservation in microsurgical treatment of small vestibular schwannomas (VSs) via the middle cranial fossa approach.

Methods: We performed a retrospective analysis of 83 cases of small VSs that underwent surgery via middle cranial fossa approach for hearing and facial nerve preservation between May 2016 and August 2018.

Results: The patients consisted of 38 men and 45 women, aged 20 to 72 years. Total excision of the tumor was 75/83 cases (90.4%), subtotal resection was 5/83 cases (6.0%), and nearly total resection was 3/61 (3.6%). Tumor size ranged from 0.3 to 2.1 cm.

Six patients presented with Class A hearing preoperatively. Among these, 4 patients (66.7%) maintained Class A postoperatively, 1 (16.7%) deteriorated slightly to Class C, and 1 (16.7%) deteriorated to Class D postoperatively. Twenty patients presented with Class B hearing preoperatively. Of these, 10 (50%) remained in Class B, 2 (10.0%) deteriorated to Class C, and 8 (40.0%) deteriorated to Class D. Thirty-four patients had Class C hearing preoperatively. Of these, 1 (2.9%) improved to Class A, 2 (5.9%) improved to Class B, 13 (38.2%) remained in Class C, and 18 (52.9%) deteriorated to Class D postoperatively. Twenty-three patients presented with Class D hearing preoperatively. All of them remained Class D postoperatively. Overall, 26 patients presented with useful (Class A or B) hearing preoperatively and 14 (53.8%) remained useful (Class A or B) hearing after operation. Facial nerve function was House–Brackmann (HB) Grade I in 78 patients preoperatively. Postoperatively, facial nerve function was HB Grade I or 2 in 70 (89.7%) patients, Grade III in 3, and Grade IV in 4, Grade V in 1 at follow-up of no longer than 6 months. One (1.2%) patient developed transient cerebrospinal fluid leaks, which was cured by conservative treatment.

Conclusion: The middle cranial fossa approach is an effective and relatively safe option for the resection of small VSs with hearing and facial nerve preservation. Early intervention, extensive exposure, facial and cochlear nerve monitoring, meticulous manipulation, and maintenance of clear tumor–neural interface are the guarantees of good efficacy.

No conflict of interest has been declared by the author(s).