Preimplant Hearing Threshold: An Important Predictor of Hearing Preservation in Cochlear Implantation With Lateral Wall Electrodes

Objective: To evaluate the outcomes and association factors of long-term hearing preservation (HP) in cochlear implantation with lateral wall (LW) electrode arrays. Study Design: Retrospective case review. Setting: Tertiary academic center. Patients: Thirty-four consecutive ears from 32 patients with a <= 80 dB HL preoperative low-frequency pure-tone average of 250 to 500 Hz were included. Intervention: Cochlear implantation with LW electrode arrays and the intention of achieving HP. Main Outcome Measures: HP classifications according to the HEARRING group and functional HP methods (<= 85 dB HL of pure-tone threshold at 250 Hz) at 1 year postoperatively. Results: Based on the HEARRING classification, complete, partial, and minimal HP was achieved in 7 ears (21%), 12 ears (35%), and 4 ears (12%), respectively. Under functional classification, 14 ears (41%) exhibited functional hearing after surgery. The average threshold shift was 17.1 dB HL (SD = 16.9 dB HL). Among various clinical features, a <= 60 dB HL preimplant pure-tone threshold of 250 Hz was associated with HP outcome in both classifications (OR = 12.95, 95% CI = 1.29-130.01, p = 0.029 in HEARRING classification; OR = 14.36, 95% CI = 1.07-191.40, p = 0.044 in functional classification). The following parameters were not associated with HP (p > 0.05): patient demographics, surgical aspects (insertion route and depth), electrode array size, scalar electrode position, and presence of comorbidity. Conclusion: With LW electrode arrays, HP was achieved in 68% of HEARRRING group patients and 41% of functional classification patients. A <= 60 dB HL preimplant pure-tone threshold of 250 Hz was significantly associated with an increased rate of long-term HP.

Automated summary

The study evaluated the outcomes and association factors of long-term hearing preservation in cochlear implantation with lateral wall electrode arrays. The results showed that with lateral wall electrode arrays, 68% of HEARRRING group patients and 41% of functional classification patients achieved hearing preservation. A preimplant pure-tone threshold of <= 60 dB HL at 250 Hz was significantly associated with an increased rate of long-term hearing preservation.