Effect of Round Window Opening Size on Residual Hearing Preservation in Cochlear Implantation.

Objectives: This study aims to compare the hearing preservation outcomes in cochlear implant surgery following slit versus full opening of the round window membrane.

Setting: Tertiary referral center.

Study Design: Comparative study.

Subjects And Methods: Seventy patients (mean, 26.3 years; range, 2-69 years) who underwent cochlear implantation via the round window approach were included in the study. Thirty-five subjects were prospectively enrolled for cochlear implantation via the open round window technique between August 2018 and January 2019. Thirty-five patients who underwent cochlear implantation from January 2017 to July 2018 via the slit round window opening, frequency matched by sex and age, were retrospectively enrolled. Pre- and postoperative thresholds were obtained. The percentage of hearing preservation was computed with the HEARRING Network formula and classified into complete, partial, and minimal hearing preservation. The results between the groups were compared and analyzed at 6 months postoperatively.

Results: The rate of complete hearing preservation in the open group was statistically significant ( = .030) at 71.4% (n = 25) as compared with 45.7% (n = 16) in the slit group.

Conclusions: The widely opened round window may be an optional technique that surgeons can utilize to improve hearing preservation outcomes.