Use of Intraoperative ECochG for Hearing Preservation Cochlear Implant Surgery

Introduction: Hearing and structural preservation have been strongly associated with better outcomes in cochlear implantation (CI), resulting in better word and sentences discrimination scores. Improvements in surgical technique and electrode design have significantly influenced these results. Nevertheless hearing preservation is widely variable among surgeons. In an attempt to improve these results and make them more constant, the use of intraoperative EChoG has recently been proposed as a mean to provide real time feedback of the functional state of the cochlea.

Objectives: to test the potential benefits of intraoperative EChoG to increase the rates of hearing and structural preservation in CI surgery.

Methods: A Pilot, controlled, observational study. A group of 8 CI patients operated with the aid of intraoperative EChoG are compared with a similar group of patients operated using a standard soft surgical technique without the aid of EChoG.

Results: We observed differences between these 2 groups in terms of: insertion time and strategy, electrodes impedance intraoperative and at follow up, intraoperative NRI, hearing preservation intraoperatively and postoperatively (2 months follow up). Additionally EChoG provided valuable information about the position of the tip of the electrode lead during insertion.

Discussion: intraoperative EChoG provides most valuable real-time information for the surgeon affecting significantly the results of CI surgery. We suggest that EChoG be a standard procedure in CI surgery. Additionally it may be used to avoid the use of intraoperative imaging.