Objective: The objective of this study was to evaluate hearing outcomes following middle fossa (MF) or retrosigmoid (RS) craniotomy for vestibular schwannoma (VS) removal with the goal of hearing preservation.
Design: This is a retrospective series.
Setting: This study was set at a skull base referral center.
Participants: In this study, 377 sporadic VS patients underwent primary microsurgery for VS from 2002 to 2012 using the MF (n = 305) or RS (n = 72) approaches.
Main outcome measures: The main outcome measures were change in pure-tone average (PTA) and word recognition score from pre- to postoperative and surgical complications.
Results: Preoperative hearing did not differ between approaches. Tumors were larger in the RS group (mean = 1.78 cm) than the MF group (mean = 0.97 cm) (p ≤ 0.001). Mean times to last audiometric follow-up were MF 1.0 year and RS 0.7 years. Mean decline in hearing from preoperative to last follow-up was greater in the RS group (55.5 dB in PTA and 45.6% in discrimination) than the MF group (38.9 dB and 31.7%) (p ≤ 0.011 and 0.033, respectively). The effect of surgical approach on hearing outcome remained after controlling for tumor size. Facial nerve outcomes and cerebrospinal fluid leak rates were not significantly different.
Conclusion: Loss of hearing was greater with the RS approach than the MF approach, even when accounting for differences in tumor size. Postoperative facial nerve function and other complications did not differ between approaches.
Keywords: acoustic neuroma; hearing preservation; middle fossa craniotomy; retrosigmoid craniotomy; vestibular schwannoma.