Electrode impedance changes after implantation of a dexamethasone-eluting intracochlear array.

Abstract

Postoperative inflammation and the formation of fibrotic tissue around the intracochlear electrode array are often held responsible for negative outcomes in cochlear implant recipients. Here we test the effectiveness of intracochlear delivery of dexamethasone via a drug-eluting electrode array in reducing fibrotic tissue formation, assessed via measurement of both monopolar and four-point electrode impedance. Adult guinea pigs were bilaterally implanted with a dexamethasone-eluting array (left ear) and a standard non-eluting array (right ear). Arrays were electrically stimulated daily for 4 weeks, commencing 1 week after implantation, and impedance measured both before and after stimulation...