The Importance of a Preinsertion Integrity Device Test of Cochlear Implants

The surgery of a cochlear implant is a complex interdisciplinary procedure with high quality standards to ensure patients safety and implant durability. An integrity test of the device prior to insertion is an additional tool to improve quality standards by detecting potentially malfunctioning implants without burdening the patient.

At the Department of Otorhinolaryngology, University Hospital Frankfurt a. M. (Germany) since 2010 an integrity device test ("pre-insertion telemetry") has been performed prior to the implantation of a cochlear implant. The preinsertion telemetry measures the electrical impedances of the implant electrode contacts in conductive saline solution and thereby confirms regular bidirectional data transmission and electrode integrity. In the case of irregular results with suspected implant malfunction, the device was discarded during surgery and returned to the manufacturer for further technical review. Data and test results of the preinsertion telemetry and from rejected implants (manufacturers' reports) between January 2010 and December 2020 were analyzed.

From 2010 to 2020, 1,926 cochlear implants from three manufacturers were implanted at our institution. All implants had fully functioning bidirectional data transmission. 15 implants had irregular preinsertion telemetry results (electrode circuit failures) and were rejected during surgery. In 13 cases, the manufacturer confirmed implant malfunction. In the last 5 years, only one implant with irregular preinsertion telemetry was detected.

Preinsertion telemetry is strongly recommended as a quick and reliable integrity test of the device to confirm the functionality of a cochlear implant.