Long-term follow-up of Bonebridge BCI 601 implantation in microtia patients with aural atresia: Acoustic and subjective benefits

Abstract

Background: This study evaluated the long-term acoustic and subjective outcomes of Bonebridge bone conduction implant (BCI) 601 implantation in Taiwanese patients with microtia and aural atresia (AA). Methods: A total of 41 microtia patients (28 males and 13 females; 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 assessed included 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. Results: The mean age at the time of implantation was 18.9 years (range, 6.3–54.9), and 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, improvements (p < 0.05) in the mean SRT in quiet (from 58.3 ± 7.4 dB HL to 29.4 ± 7.0 dB HL), SRT in noise (from −1.4 ± 7.3 dB signal-to-noise ratio (SNR) to −9.6 ± 5.4 dB SNR), WRS in quiet (from 46.4 ± 26.9% to 93.8 ± 3.1%), and WRS in noise (from 46.7 ± 21.8% to 72.7 ± 19.3%) were found. 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. Conclusion: Bonebridge BCI 601 implantation provided long-term acoustic and subjective benefits for patients with microtia and AA, particularly those with bilateral AA.