Residual hearing preservation after cochlear implantation: Comparison between straight and perimodiolar implants

Objective Investigate whether perimodiolar cochlear implants provide a better preservation of residual hearing than straight implants. Study Design and Setting Longitudinal, observational, and comparative study in tertiary center in Mexico City. Forty-eight patients who underwent cochlear implant surgery were included and were divided into two groups depending on whether they received a straight or a perimodiolar implant. The residual hearing of the operated ear was measured audiometrically before and after surgery. Variables analyzed were pure-tone average threshold at 125, 250, and 500 Hz and residual hearing at frequencies from 125 to 8000 Hz. Residual hearing was considered as preserved when audiometric changes were less than 10 dB HL in each variable. Results No statistically significant difference was found in the preservation of residual hearing between the two groups or between individual devices ( P > 0.05 in all variables). Conclusion Straight and perimodiolar cochlear implants seem to preserve residual hearing at similar rates across frequencies.