Frequency -Specific Air- Conduction and Bone - Conduction Outcomes after Stapedotomy.

Introduction: The aim of this study was to investigate hearing outcome of stapes surgery, considering the post-operative air and bone conduction (AC&BC) changes, in a frequency specific approach.

Materials and methods: This was a retrospective cohort study. A total of 245 ears (231 patients), who underwent Stapedotomy at our tertiary referral center in a period of 5 years were enrolled in the study. Pure tone audiometry (PTA) was evaluated preoperatively and one month postoperatively. AC, BC, and Air-bone gap (ABG) were documented. Moreover, one-year post-op PTA was also recorded for more than a quarter of the cases.

Results: Overall, significant improvements were observed in AC thresholds with a mean AC gain of 20.44±13.64 dB. At higher frequencies the results were poorer (AC gain of 27 dB at 250 Hz vs 7 dB at 8000 Hz). ABG significantly improved at all frequencies after one month. BC thresholds were typically better after surgery. However, there appears to be a worsening trend in BC thresholds at frequencies higher than 2000 Hz. In 68 patients with 1-year follow-up, BC thresholds were slightly worse (but not statistically significant) at most frequencies, in comparison to the one-month results.

Conclusions: Stapes surgery significantly improves air and bone conduction hearing, particularly at lower frequencies. Nonetheless, there exists a potential for sensorineural hearing loss (SNHL) at high frequencies. However, the changes are insignificant and not within the speech frequencies. Therefore, patients are typically satisfied with the hearing outcome of the surgery.