A Cohort Study of Hearing Outcomes Between Middle Fossa Craniotomy and Transmastoid Approach for Surgical Repair of Superior Semicircular Canal Dehiscence Syndrome.

Objective: To compare postoperative hearing outcomes between transmastoid and middle fossa craniotomy (MFC) approaches for surgical repair of superior semicircular canal dehiscence syndrome (SCDS) in a tertiary referral center. Study Design: Historical cohort study. Setting: Tertiary referral center. Patients: Twelve consecutive SCDS cases who underwent transmastoid plugging of the superior canal; “controls” were 18 audiogram-matched patients who underwent MFC plugging and resurfacing. Main Outcome Measures: Differences between preoperative, 7-day postoperative, and long-term (>6 wk) postoperative air and bone conduction, speech discrimination scores (SDS), and pure-tone averages (PTA) in TM cases versus MFC controls. Methods: MFC controls were selected by matching preoperative bone conduction (BC) pure-tone thresholds from the TM cases within 10-dBs NHL in ≥80% of recorded frequencies. Wilcoxon signed-rank tests were performed to compare primary outcomes between matches, with a Bonferroni corrected p value of 0.004 (n = 13 variables measured at each time period). Results: No statistically significant differences were found in long-term postoperative air conduction and BC thresholds at any frequency both during the immediate postoperative period as well as at long-term follow-up (p > 0.004). Similarly, there were no differences in long-term SDS or PTA (p > 0.004). Conclusions: In this pilot study, there were no long-term significant differences in hearing outcomes between the two repair techniques for SCDS. We recommend continuing with the established practice for recommending surgical repair based on individual patient characteristics and preferences in managing both vestibular and auditory function.