Cochlear structures after implantation of a perimodiolar electrode array

Objective: A perimodiolar prototype electrode array has been evaluated on 1 2 human temporal bone specimens, To achieve modiolar proximity, a fine Teno n(TM) positioner is attached to the tip and base of a conventional Nucleus 22 electrode array. Methods: Intracochlear electrode position was examined by macro scopic preparation and confirmed by a cochlear view x-ray after in sertion into human temporal bones. The temporal bones were examined with li ght microscopy for intracochlear trauma after insertion, explantation, and re-implantation of the perimodiolar array. Results: Macroscopic preparation and x-ray confirmed close proximity of the intracochlear electrodes to the modiolar wall. In some bones, electrode insertion and positioning was perf ormed without significant damage to intracochlear structures, but explantat ion caused varying degrees of trauma depending on the explantation techniqu e used. Re-implantation and repeat explantation appeared to destroy most of the intracochlear architecture. Conclusions: The perimodiolar electrode ar ray prototype with Tenon positioner cannot be recommended for clinical use, especially in children in whom the possibility for re-implantation is high .