The Effects of Insertion Speed on Inner Ear Function during Cochlear Implantation: A Comparison Study

Objective: To investigate the insertion speed and its impact on electrode insertion characteristics, hearing preservation and clinical vestibular function in a prospective cohort study with a retrospective control group at a tertiary otology/neurotology centre. Interventions: Hearing-preserving cochlear implantation using systemic and topical steroids in conjunction with a round-window approach, a complete cochlear coverage electrode and two different electrode insertion speeds [60 mm/min (n = 18) vs. 15 mm/min (n = 22)] was performed. Results: The insertion speed had a significant impact on various insertion characteristics as well as hearing preservation and vestibular function. In conclusion, a slow electrode insertion speed appears to facilitate full electrode insertion, reduce the occurrence of insertion resistance as well as promote preservation of residual hearing and vestibular function after cochlear implantation.