Long-term follow-up of Bonebridge BCI 601 implantation for microtia patients with aural atresia: acoustic and subjective benefits.

Abstract

This study evaluated the long-term acoustic and subjective outcomes of Bonebridge bone conduction implant (BCI) 601 implantation in Taiwanese microtia patients with aural atresia (AA). A total of 41 microtia patients (26 with bilateral AA and 15 with unilateral AA) who received Bonebridge BCI 601 implantation between December 2014 and March 2021 at Chang Gung Memorial Hospital, Linkou, Taiwan, were included in this retrospective study. Acoustic outcomes, including the functional hearing gain (FHG), speech reception threshold (SRT), and word recognition score (WRS), were assessed. Subjective outcomes were assessed using the Chinese versions of four questionnaires: the Abbreviated Profile of Hearing Aid Benefit (APHAB); the Speech, Spatial and Qualities of Hearing Scale; the International Outcome Inventory for Hearing Aids; and the Satisfaction with Amplification in Daily Living. The mean follow-up duration was 6.3 years (range, 2.8-9.1). The mean unaided air conduction pure tone average (PTA4) was 65.3 ± 8.8 decibels (dB) hearing level (HL) and the mean aided sound field PTA4 was 31.1 ± 9.1 dB HL, resulting in a FHG of 34.2 ± 11.7 dB HL (p < 0.05). After Bonebridge implantation, the mean SRT in quiet, SRT in noise, WRS in quiet, and WRS in noise improved from 58.3 ± 7.4 dB HL to 29.4 ± 7.0 dB HL, from -1.4 ± 7.3 dB signal-to-noise ratio (SNR) to -9.6 ± 5.4 dB SNR, from 46.4 ± 26.9% to 93.8 ± 3.1%, and from 46.7 ± 21.8% to 72.7 ± 19.3%, respectively (p < 0.05). Additionally, the bilateral AA group exhibited greater SRT and WRS improvements compared to the unilateral AA group (p < 0.05). All mean subscale scores in the four questionnaires showed improvement after Bonebridge implantation, except for the mean aversiveness to sounds subscale score in the APHAB questionnaire. Bonebridge BCI 601 implantation provided long-term acoustic and subjective benefits to microtia patients with AA, particularly those with bilateral AA.