Long-term hearing performance and soft tissue outcomes of Baha@ Attract system in patients with bilateral congenital microtia in a single center

Abstract： Background: Baha Attract System was designed as non-skin penetrating bone conduction implant to minimize skin complication. However, there were insufficient studies on its long-time acoustic outcome and safety in microtia patients with auricle reconstruction surgeries, who have thinner retroauricular subcutaneous layer and theoretically vulnerable skin at the implant side. Objectives: To analysis the long-term hearing performance and soft tissue complications of Baha@ Attract System in microtia population. Study Design & setting: A prospective cohort study at single tertiary referral center. Patients: Twenty Mandarin-speaking patients with congenital bilateral microtia who were underwent Baha@ Attract implantation with or without auricle reconstruction surgeries simultaneously. Main Outcome Measure(s): Comparative analysis of audiological test results including hearing thresholds and speech recognition in quiet and in noise were pre- and post-operatively performed. subjective benefit as measured with the SSQ Scale. Soft tissue outcomes were monitored and documented. Results: The mean follow-up time was 36.11±3.30 months. Significant and stable improvements in hearing threshold and speech understanding in noise and quiet were demonstrated with aided condition. Subject evaluation revealed high level of patients’ satisfaction with the amplification in all the subscales. Adverse events including skin necrosis increased after one year post-operatively. Soft tissue evolution including sin thinning, erythema, epidermis atrophy, soft tissue atrophy, skin necrosis was seen or once developed in most of the participants. However, prevalence of severe soft tissue complication was not higher to non-microtia population. Conclusions: Baha@ Attract System provides favorable and stable hearing improvements for microtia patients. Combining plastic surgeries with implantation will not increase the prevalence of soft tissue complication. However, long-term soft tissue problems should be highly aware of even after one year post implantation. Key words: Baha Attract, microtia, hearing, soft tissue, skin necrosis