Which approach is better for the protection of vestibular receptors in cochlear implant surgery: Round window or standard cochleostomy?

Abstract

Objectives: This study aims to compare electrode insertion techniques in cochlear implantation (CI) as the standard cochleostomy approach (SCA) versus the round window approach (RWA) on five vestibular end-organ functions and vertigo in the pre- and postoperative period. Patients and Methods: In total, 51 patients (22 males, 29 females; mean age 38.2 years; range 16 to 70 years) with normal vestibular function and operated with single-sided CI were included in this study between January 2015 and December 2019. Of the patients, 30 were operated with the RWA and 21 with the SCA. All of the patients were evaluated with the Dizziness Handicap Inventory (DHI) and a complete vestibular test battery including the video head impulse test (vHIT), cervical vestibular-evoked myogenic potential (cVEMP), and ocular vestibular-evoked myogenic potential (oVEMP) at one week preoperatively and one month postoperatively. Results: Patients in the RWA group had a statistically significantly better protected vestibular functions and fewer subjective vertigo symptoms in the postoperative period (p<0.05). Deterioration in at least one of the five vestibular end-organ functions was observed in eight of 21 patients (38.09%) in the SCA group, compared to three of 30 (10%) in the RWA group. A significant correlation was detected between the vestibular tests and DHI in both groups (r=0.686, p=0.001 in the SCA group and r=0.630, p<0.001 in the RWA group). Conclusion: Our study results suggest that RWA for CI may minimize damage to vestibular receptor functions and vertigo symptoms than SCA.