Development of a new reinforced electrode for cochlear implantation in mastoid cavities

Patients with chronic otitis media often suffer from severe combined hearing loss after many years of illness and often multiple operations, which cannot be adequately compensated with conventional or bone conduction hearing aids. In these cases, cochlear implantation is the most effective rehabilitation method. Unfortunately, this can lead to electrode extrusion through the skin and cartilage covering in the mastoid cavity, which can usually only be solved by revision surgery.

In the present study, the mechanical properties of CI electrodes, which favor electrode extrusion, were analyzed to develop an optimized concept and an adapted electrode design.

To investigate the mechanical force effects of CI electrodes, an anatomical model of a temporal bone with a mastoid cavity was created, and systematic experiments were carried out on electrodes.

In the second step of the experiments, different models of electrode dummies were produced that had a central deformation element of different lengths. Systematic analyzes of these models showed that almost complete elimination of the tangential spring forces could be achieved. Two patients with mastoid cavities were successfully supplied with electrodes of this type as "custom-made-device" CIs.

In summary, it was shown that the chosen design of electrodes with a malleable metal reinforcement significantly reduced the potential tangential spring forces. After successful clinical application, it can be expected that this new electrode design will lead to an improvement for patients with demanding anatomical conditions, such as mastoid cavities.

IZKF Würzburg, Clinician Scientist Programm, #Z-2/CSP-4, Beethovenstrasse 1a, 97080 Würzburg

Publication History

Article published online:
24 May 2022