Objective: To evaluate the long-term safety and efficacy of the Clip coupler attached to the stapes head in patients with unilateral congenital aural atresia (CAA).
Methods: This single-center retrospective study included 16 Mandarin-speaking patients who had unilateral microtia accompanied by CAA. All patients were divided into two groups: the short-term follow-up group (n = 9) and the long-term follow-up group (n = 7). The floating mass transducer of the Vibrant Soundbridge (VSB) was positioned in the stapes head by the Clip coupler. The safety of the VSB was investigated by comparing preoperative and postoperative bone-conduction (BC) thresholds as well as by complications. The effectiveness was evaluated by functional gain (FG), word recognition score (WRS), speech reception threshold (SRT) and signal-to-noise ratio (SNR).
Results: Pre- and post-operative BC thresholds were no different in all patients. And no complications developed. VSB-aided thresholds in the free-field had improved significantly in both short- and long-term follow-up groups. The improvements of WRS were observed in two groups. The monosyllabic VSB-aided WRS in the long-term follow-up group was significantly higher than that in the short-term follow-up group. When speech was from the impaired ear and noise presented to the side of normal ear (SVSBNCL), lower SNRs were found in two groups after VSB implantation. However, there was no statistical difference in aided SNR between the two groups at SVSBNCL status.
Conclusions: Our results show that the FMT connected to the stapes head is a secure and useful device for patients with unilateral CHL/MHL, not only in terms of improved hearing thresholds, but also improved speech intelligibility in quiet and noisy environments.
Keywords: Vibrant Soundbridge; aural atresia; congenital; hearing loss; speech perception; unilateral.