Early Outcomes With a Slim, Modiolar Cochlear Implant Electrode Array.

OBJECTIVE To describe outcomes from cochlear implantation with a new, slim modiolar electrode array. STUDY DESIGN Retrospective cohort study. SETTING Tertiary referral centers. PATIENTS Adult cochlear implant candidates. INTERVENTIONS Cochlear implantation with CI532 (Cochlear Corp). MAIN OUTCOME MEASURES Pre- and postoperative speech perception scores, operative details, and postoperative computed tomography (CT) reconstructions of array location. RESULTS One hundred seventeen patients are implanted to date. There were eight tip rollovers identified with intraoperative x-ray and resolved with reinsertion. An additional rollover was identified on postoperative CT. CT reconstructions in 17 of 23 patients showed complete scala tympani placement with a wrap factor of 58% (range 53-64%) and a mean insertion angle of 406 degrees (range 360-452 degrees). Three implants demonstrated array translocation with electrodes in the scala vestibuli. Consonant-nucleus-consonant word scores improved from 10% preoperatively to 48% at 3 months postoperatively. Pure-tone thresholds were preserved postoperatively in 37 to 52% of patients across frequencies from 250 to 4000 Hz. Functional pure-tone thresholds (≤80 dB) were recorded in 9 to 25% of patients. CONCLUSION CI532 array insertion results in consistent scala tympani location and provides expected audiologic performance. Initial hearing preservation results are not consistent with current electro-acoustic arrays.