Abstract: Objective  To  explore the application of  the surgical technique of cochlear implantation (CI) in patients with facial nerve developmental abnormalities obstructing round window. Methods  A retrospective analysis  of medical history, audiological data, imaging data and surgical methods was conducted on the clinical data of 6 severely or extremely severely deaf patients with facial nerve developmental abnormalities obstructing round window from March 2009 to July 2023. Results  Among the 6 patients, 1 patient underwent oval window implantation, 2 patients underwent retro-facial approach implantation, and 3 patients underwent ear canal or ear canal/posterior combined approach implantation. Six patients were successfully implanted with electrodes. One patient showed no significant change in facial paralysis after surgery compared to before, and the others did not experience facial nerve damage after surgery. all 6 patients experienced complications such as collapse of the posterior wall of the external auditory canal and cerebrospinal fluid ear fistula. Conclusions  When abnormal facial nerve development is found during CI surgery in patients with severe or extremely severe hearing loss, various pathways can be selected based on the shape of the facial nerve to complete cochlear electrode implantation.

Key words: cochlear implantation, abnormal facial nerve development, oval window approach, retro-facial approach, ear canal approach