Quality Control after Cochlear Implant Surgery by Means of Rotational Tomography

Objective: To investigate the intracochlear electrode position in using rotational tomography in adult cochlear implant patients. Study Design: Retrospective. Setting: Tertiary referral center. Patients: Eighteen adult patients being implanted either with a Nucleus straight electrode array or a Contour electrode with a total of 22 implanted ears. Preoperative computed tomography had been without evidence for obliteration, ossification, or malformation of the cochlea. Intervention: Rotational tomography. Main Outcome Measures: The intracochlear electrode position was evaluated with regard to scala tympani, scala vestibuli, and a dislocation from one scala to the other. The intraoperative procedure was compared with the electrode position by analyzing the operating reports. Results: Preliminary results indicate, respectively, that there is a higher incidence of intracochlear trauma in using the Contour electrode array than expected with a more frequent dislocation of electrode arrays from scala tympani to scala vestibuli and that there is a higher rate of scala vestibuli insertions. Conclusions: The impact of these findings may influence further developments of electrode arrays as well as surgical techniques for implantation.