Cochlear implantation under local anesthesia in 117 cases: patients' subjective experience and outcomes

To report the outcomes and the patients' subjective experience of cochlear implantation (CI) performed under local anesthesia (LA). To describe a new form of intraoperative cochlear monitoring based on the patients subjective sound perception during CI.

In this retrospective case-cohort study, 117 patients underwent CI under LA with (n = 58) or without conscious sedation (n = 59). Included were primarily elderly patients with elevated risks for general anesthesia and recently patients with residual hearing eligible for electro-acoustic stimulation (EAS) (n = 27), in whom hearing could be monitored during the electrode insertion. A 500 Hz test tone was presented and the patient reported  of subjective changes in loudness, leading to a modification of the insertion. A questionnaire was sent to all patients in which they assessed their subjective experience.

All patients were successfully operated under LA without the need to intraoperatively convert to general anesthesia. 90% of the patients reported that the surgery was a positive experience. The vast majority, 90% of patients were satisfied with the overall treatment and with intraoperative pain management and 84% of the patients would opt for local anesthesia again. Cochlear monitoring by the patients' subjective sound perception enabled for atraumatic insertions as all EAS patients could hear the test tone up to the end of the surgery.

CI under LA was well tolerated and recommended by the vast majority of patients. In addition, it offers the possibility to monitor the patients' hearing during the electrode insertion, which may help to prevent insertion trauma.