Comparison of retrosigmoid and middle fossa approaches for vestibular schwannoma

Abstract

Problem: Hearing preservation during acoustic tumor removal is generally attempted using 1 of 2 approaches: the middle fossa or retrosigmoid. This study evaluates hearing and facial nerve preservation rates using the retrosigmoid approach and compares the postoperative results with those reported in the literature using the middle fossa technique. This comparison was conducted to determine which approach offers an opportunity for the best patient outcome. Methods: Hearing preservation was attempted in 46 patients with vestibular schwannomas. Tumor size ranged from 0.5 to 2.5 cm. A retrosigmoid approach and direct eighth nerve monitoring (DENM) was used for all patients. Outcome measures of hearing preservation, facial nerve function, and cerebral spinal fluid leak were evaluated and compared to those reported using the middle fossa approach. Results: Hearing was preserved in 71% of patients with tumors 1 cm or smaller and 32% of patients with tumors between 1 and 2.5 cm. Facial nerve preservation rates were 94% (HB 1–2) for tumors smaller than 2 cm. Conclusion: The retrosigmoid approach with DENM provides rates of hearing preservation comparable to those reported for the middle fossa approach for the resection of vestibular schwannomas. Facial nerve function, both short-term and long-term, appears to be better with the retrosigmoid approach. Significance: Resection of vestibular schwannomas via either the retrosigmoid approach, the use of DENM, or the middle fossa approach provides comparable results for hearing preservation. However, facial nerve function appears to be better preserved with the retrosigmoid approach. Support: None reported.