Long-term Audiological Benefit with an Active Transcutaneous Bone-Conduction Device: a Retrospective Cohort Analysis

PURPOSE:To evaluate long-term audiological, surgical and safety outcomes of a complex patient cohort treated with an active transcutaneous bone-conduction device (tBCD). METHODS:This retrospective, monocentric cohort analysis involves 31 adults with conductive (CHL) and mixed hearing loss (MHL). For outcome analysis, study results were divided into short-term follow-up data (< 12 months) and long-term follow-up data (> 12 months). RESULTS:31 patients with a total person-time of 90.4 years and an average number of 3.2 ± 1.5 preoperatively performed surgeries on the implanted side were investigated. Mean BCD-aided PTA4 thresholds were significantly lower than unaided PTA4AC before surgery (64.7 ± 16.1 dB HL; CHL 50.6 ± 10.6 dB HL; MHL 72.8 ± 12.8 dB HL) and did not change between short-term (42.3 ± 13.1 dB HL; CHL 35.8 ± 6.8 dB HL; MHL 45.2 ± 14.3 dB HL) and long-term (43.4 ± 10.0 dB HL; CHL 35.8 ± 4.3 dB HL; MHL 48.1 ± 9.6 dB HL) follow-up periods. Speech intelligibility in the Freiburg monosyllables test at 65 dB improved significantly, from 16.3 ± 21.5% (CHL 26.8 ± 19.0%; MHL 8.7 ± 20.5%) in the unaided condition to 82.7 ± 15.5% (CHL 90.0 ± 12.2%; MHL 79.4 ± 16.3%) in the short-term and 85.5 ± 13.2% (CHL 93.8 ± 7.9%; MHL 79.5 ± 13.3%) BCD-aided in the long-term follow-up periods. Ten minor procedure-related and 6 implant-related (5 minor, 1 major) AEs occurred over the total follow-up period. CONCLUSION:The device provides satisfactory audiological and speech benefit over long-term follow-up periods, up to 7 years. Explant rates were very low, while the overall rate of manageable AEs was high in this complex patient cohort. The device is considered a safe and effective option in the long-term hearing rehabilitation of patients with CHL and MHL.