Residual Hearing Preservation After Pediatric Cochlear Implantation

Abstract

This study is designed to test the hypothesis that preservation of residual hearing in a pediatric population is possible using standard electrode arrays with full-length insertions. Surgical technique during implantation also is described. Retrospective review of patient medical records. Academic tertiary care center. Thirty-one severely to profoundly hearing impaired pediatric patients with some residual hearing precochlear implantation. Cochlear implantation using a modified "soft surgery" protocol. Preimplant and postimplant pure tone thresholds and pure-tone average were calculated from unaided preoperative and postoperative audiograms from 250, 500, and 1,000 Hz. Hearing preservation rates were determined to be complete (loss of ≤10 dB), moderate (loss of 11-20 dB), marginal (loss of 21-40 dB), or none (loss of >40 dB or no response at the limits of the audiometer). Functional residual hearing rates (defined in this study as at least 1 threshold better than or equal to 75 dB HL for 250, 500, or 1,000 Hz were calculated. Complete hearing preservation was achieved in 14 (45.2%) of 31 patients, whereas 28 (90.3%) of 31 had at least partial hearing preservation (loss of ≤40 dB). The preoperative to postoperative low-frequency pure-tone average had a mean change of 18.5 dB and median change of 20 dB. Of the patients who had preoperative functional hearing, 9 (50.0%) of 18 maintained functional residual hearing postoperatively for at least 1 pitch. Preservation of residual hearing is feasible in pediatric cochlear implant patients using standard-length electrode arrays with full insertions. These data have implications for cochlear implantation in pediatric patients who are at higher risk of progressive hearing loss than adults.