Multichannel Cochlear Implantation in Radical Mastoidectomy Cavities

Abstract

OBJECTIVE: We report on our experience in cochlear implantation in patients with radical mastoidectomy cavities. STUDY DESIGN, SETTING, AND METHODS: Retrospectively, records of patients from the Department of Otolaryngology, University of Parma between December 1991 and March 2000 were reviewed, and 6 postlingually deafened adults who received a cochlear implant in a radical cavity were identified. Speech performances were evaluated in terms of bisyllabic word and sentence recognition and common phrase comprehension. RESULTS: To date, with a follow-up of 1 to 9 years, no patient has experienced extrusion of electrodes or other local or intracranial complications. Mean bisyllabic word and sentence recognition scores were 74% and 80%, respectively. Mean comprehension score for common phrases was 86%. CONCLUSION: By obliterating and isolating the radical mastoidectomy cavity from the outer environment, patients who previously had undergone radical surgery of the middle ear can be safely implanted with satisfactory hearing results. Multichannel cochlear implantation (CI) is a treatment accepted worldwide for patients with total or profound deafness. In the presence of normal temporal bone anatomy, CI surgery is a safe and relatively simple procedure with a low complication rate. 1–3 However, some conditions, such as malformations of the middle or inner ear, cochlear ossification, chronic otitis media, and previous middle ear surgery, represent a technical challenge to CI surgeons. Patients with a bilateral radical mastoidectomy cavity who are otherwise suitable for implantation represent a certainly more problematic group to manage than the “standard” CI patients. Under these circumstances, various potential problems must be considered: extrusion of the electrode array by breakdown of the thin epithelial lining of the mastoid cavity, risk of recurrent cholesteatoma, and possibility of spreading of inflammation to the implant with potential labyrinthitis and meningitis. During recent years various surgical strategies have been proposed in the literature to avoid such complications. Many surgeons suggested overcoming these problems by performing an obliterative technique, 4–6 whereas others preferred to maintain the benefits of an open technique 7 or to rehabilitate the cavity 8 ; it has also been suggested that the cavity be bypassed via a middle cranial fossa approach. 9 We describe the experience at the CI Center of the University of Parma in managing 6 CI patients with radical mastoidectomy cavities.