Predictive factors for short‐ and long‐term hearing preservation in cochlear implantation with conventional‐length electrodes

Objectives/Hypothesis The aims of this study were to investigate short‐ and long‐term rates of hearing preservation after cochlear implantation and identify factors that impact hearing preservation. Study Design Retrospective review. Methods Patients undergoing cochlear implantation with conventional‐length electrodes and air‐conduction thresholds ≤80 dB HL at 250 Hz preoperatively were included. Hearing preservation was defined as air‐conduction thresholds ≤80 dB HL at 250 Hz. Results The sample included 196 patients (225 implants). Overall, the rate of short‐term hearing preservation was 38% (84/225), with 18% (33/188) of patients preserving hearing long term. Multivariate analysis showed better preoperative hearing was predictive of hearing preservation at short (odds ratio [OR]: 0.93, 95% confidence interval [CI]: 0.91‐0.95, P < .001) and long‐term follow‐up (OR: 0.94, 95% CI: 0.91‐0.97, P < .001). Lateral wall electrodes and mid‐scala electrodes had 3.4 (95% CI: 1.4‐8.6, P = .009) and 5.6‐times (95% CI: 1.8‐17.3, P = .003) higher odds of hearing preservation than perimodiolar arrays at short‐term follow‐up, respectively. Long‐term data revealed better hearing preservation for lateral wall (OR: 7.6, 95% CI: 1.6‐36.1, P = .01), but not mid‐scala (OR: 3.1, 95% CI: 0.4‐23.1, P = .28), when compared to perimodiolar electrodes. Round window/extended round window (RW/ERW) approaches were associated with higher rates of long‐term hearing preservation (21%) than cochleostomy approaches (0%) (P = 0.002) on univariate analysis. Conclusions Better preoperative residual hearing, lateral wall electrodes, and RW/ERW approaches are predictive of higher rates of long‐term functional hearing preservation. Level of Evidence 4. Laryngoscope, 128:482–489, 2018