Does the Evidence Support Use of the Baha Implant System (Baha) in Patients with Congenital Unilateral Aural Atresia?

Purpose: To determine if the evidence supports the recommendation of Baha implant systems (Bahas) over unaided conditions in persons with conductive hearing loss due to congenital unilateral aural atresia (CUAA), and if laboratory measures predict patient benefit and satisfaction. Research Design: A systematic review. Methods: The authors constructed and submitted search strings to PubMed and other electronic databases to identify studies in peer-reviewed journals that were at an appropriate level of evidence (systematic reviews, randomized controlled trials, or nonrandomized intervention studies); used outcome measures assessing audibility, localization, or speech-recognition in noise; included patients with CUAA using Bahas; and had intrepretable data. References of all retrieved articles were also hand searched for relevant studies. Evaluation forms were completed by the authors for each of the included studies at all phases of the review including quality assessment and data extraction. Results: The authors reviewed 88 retrieved titles and excluded four that had no relevance to the topic and 67 that were duplicates. Abstracts were reviewed for the remaining 17, and six nonrelevant studies were excluded. The remaining 11 articles were retrieved for full-text review; only three studies met inclusion criteria and were analyzed further. The three studies were not appropriate for a meta-analysis due to limited data, too few participants, and insufficient presentations of results. Qualitative analysis revealed inconsistent findings across audiometric measures, and few significant differences were noted with and without Bahas, yet most participants believed that Bahas improved their quality of life. Laboratory measures did not always predict patient benefit and satisfaction with Bahas. Conclusions: Results were limited for this narrow population having CUAA and the specific criteria used for this review. Audiologic measures generally failed to predict patients' success and/or satisfaction with their Bahas, but most of the included studies showed that patients perceived some benefits. Ideally, clinical decision making should include the highest levels of scientific evidence. However, when evidence is unavailable or does not support a clear-cut recommendation for a particular treatment across patients, as seems to be the case for the use of Bahas with CUAA, then clinicians must rely more heavily on clinical expertise and individual patient preferences in guiding clinical decision making.