Middle Fossa Approach for Cochlear Implantation

Abstract

To present qualification criteria, surgery, and results of cochlear implantation via the middle fossa approach. A retrospective analysis of medical charts of patients. Cochlear implant program in academic medical center. Six adults after middle ear surgery due to chronic otitis media with bilateral deafness or profound hearing loss. Analysis aimed to identify patients qualified for cochlear implantation via middle fossa approach and to present surgery and result. Qualification criteria, details of surgery and surgical, functional and audiological results. Surgery was completed in four patients and in the remaining two it was stopped because of adhesions and bleeding from the dura. In three patients, there were no postoperative complications and in one individual intracranial hematoma occurred. Postoperative computed tomography showed the intracochlear position of the electrode in all the implanted patients. All of the patients use their implant for 14 to 16 hours daily. One year after the implantation, they had hearing thresholds in the sound-free field of between 25 and 45 dB sound pressure level, number recognition scores between 80 and 100% and monosyllabic words recognition between 30 and 90%. Successful cochlear implantation via middle fossa approach results in satisfactory hearing, bringing deaf people into a hearing environment. However, this approach is technically difficult and provides the risk of intracranial complications. In our opinion this approach should be used in special cases only (e.g., postmeningitis or otosclerotis patients with obliteration of basal turn of cochlea). In analysed group it should not be considered the primary solution.