OBJECTIVE: To describe a simplified drill-out technique for insertion of a multichannel electrode in the completely ossified cochlea without radical mastoidectomy and obliteration. STUDY DESIGN: Description of a new surgical technique and case report. SETTING: Temporal bone dissection laboratory and tertiary referral center. PATIENTS: Adult and pediatric cochlear implant (CI) recipients. MAIN OUTCOME MEASURES: Access for circum-modular drill-out and electrode insertion without radical mastoidectomy and adequate function of multichannel CI. RESULTS: Dissection of 10 cadaver temporal bones demonstrated feasibility of this technique. Highlights include facial recess cochleostomy and 8 mm tunnel; elevation of superiorly based tympanomeatal flap; removal of incus, cochleariform process, and tensor tympani; and identification of carotid canal and use of facial nerve monitor. A case report of an 11-year-year old child with total cochlear ossification and previous failure of a short (8 electrode) CI electrode insertion is presented. Complete insertion of a 22-channel electrode was successful and open-set word recognition is commencing. CONCLUSIONS: The canal wall-up drill-out procedure allows complete electrode insertion without mastoid obliteration in patients with obliterated cochleas. Appropriate attention to the carotid artery and facial nerve is essential.
OBJECTIVE: To describe a simplified drill-out technique for insertion of a multichannel electrode in the completely ossified cochlea without radical mastoidectomy and obliteration. STUDY DESIGN: Description of a new surgical technique and case report. SETTING: Temporal bone dissection laboratory and tertiary referral center. PATIENTS: Adult and pediatric cochlear implant (CI) recipients. MAIN OUTCOME MEASURES: Access for circum-modular drill-out and electrode insertion without radical mastoidectomy and adequate function of multichannel CI. RESULTS: Dissection of 10 cadaver temporal bones demonstrated feasibility of this technique. Highlights include facial recess cochleostomy and 8 mm tunnel; elevation of superiorly based tympanomeatal flap; removal of incus, cochleariform process, and tensor tympani; and identification of carotid canal and use of facial nerve monitor. A case report of an 11-year-year old child with total cochlear ossification and previous failure of a short (8 electrode) CI electrode insertion is presented. Complete insertion of a 22-channel electrode was successful and open-set word recognition is commencing. CONCLUSIONS: The canal wall-up drill-out procedure allows complete electrode insertion without mastoid obliteration in patients with obliterated cochleas. Appropriate attention to the carotid artery and facial nerve is essential.