Does electrocautery damage cochlear implants?

OBJECTIVES

1. Evaluate the effects of monopolar cautery on cochlear implant devices. 2) Determine whether voltage fluctuations within the cochlear implant adversely affect the cochlear implant devices

STUDY DESIGN

Two Med-El cochlear implants modified to record voltage difference from the apical and proximal electrodes were implanted into an unembalmed, fresh cadaver. Cautery was applied to the ipsilateral pectoralis major muscle and ipsilateral temporalis muscle at bipolar, monopolar coagulation, and monopolar cut settings of 50 W. The intensity in each modality setting was increased by increments of 10 W to a maximum of 100 W. Integrity testing was performed before, during, and after each cautery setting. Voltage fluctuations were measured during cautery, and maximal voltage changes for each setting were noted. After explantation, devices were returned to the manufacturer for in-depth failure analysis to evaluate for any damage to the devices.

SETTING

Tertiary medical center.

SUBJECTS

Cadaveric study.

METHODS

Basic science laboratory.

RESULTS

No change in impedance or integrity testing occurred at any cautery setting when applied to either to pectoralis major or temporalis. The maximum voltage change was 22 V. Comprehensive device analysis showed no evidence of device damage from the study.

CONCLUSIONS

The cochlear implant devices had no evidence of electrical damage by monopolar cautery, even up to levels of 100 W in the temporalis muscle. The maximum voltage change was 22 V, likely resulting from protecting diodes within the implant. Additional study is necessary, but more flexible recommendations regarding electrosurgery in cochlear implant recipients should be considered.