Cochlear Implant in Patients with Incomplete Partition Type III

Background and Objectives：Among inner ear anomaly, incomplete partition type III is a quite rare finding which has pathognomonic computerized tomographic finding with bilateral, dilatation of lateral end of internal auditory canal, and deficient or absent bone between internal auditory canal and the basal turn of cochlea. Patients with incomplete partition type III have various range of hearing impairment and in case of severe hearing loss which cannot get benefit from hearing aids, cochlear implantation is indicated. In cochlear implantation for incomplete partition type III, perilymph gusher and abnormal electrode position is highly cautioned. We analyzed cochlear implantation patients with incomplete partition type III to find common intra-operative finding and complication. Subjects and Method：Temporal bone computerized tomographies of 120 patients who received cochlear implantation between September, 2002 and March, 2008 in our hospital were reviewed：the imaging of 4 patients were consistent with typical incomplete partition type III. We reviewed intra-operative finding and postoperative complications along with hearing outcome. Results：During the operation, perilymph gusher was encountered in all cases, and it was tightly sealed with subcutaneous tissue and fat with fibrin glue. In patient 1, electrodes were abnormally positioned in IAC causing facial nerve stimulation. However, the result of postoperative speech perception was good in the patient, and in the rest of patients, the results were various. Conclusion：The surgeon should be aware of perilymph gusher when cochlear implantation is performed on patients with characteristic temporal bone computerized tomographic findings and who are suspicious of incomplete partition type III. (Korean J Otorhinolaryngol-Head Neck Surg 2009;52:492-7)