The Bonebridge Bone Conduction Hearing Implant: indication criteria, surgery and a systematic review of the literature

BackgroundHearing aids and implants employing bone conduction (BC) stimulation have a long tradition in the treatment of conductive or mixed hearing loss, with their indications being extended in the 2000s to include single-sided deafness (SSD). Existing percutaneous bone conduction implants (BCI) provide significant audiological gain but are associated with a high rate of complications. This has led to the development of passive transcutaneous BCIs; however, audiological benefit may be compromised. An active transcutaneous BCI, the Bonebridge, was recently introduced and first implanted in 2011 as part of a clinical trial. Objective of reviewTo introduce and assess the safety and effectiveness of the Bonebridge for individuals with conductive or mixed hearing loss, and SSD. Type of reviewSystematic review. Search strategyThe Cochrane Library, PubMed and OVIDSP (MEDLINE) and EMBASE were searched to identify papers on the Bonebridge published as of June 2014. No exclusion criteria were set on publication language, study design or reported outcomes. The literature found was supplemented by presentations from relevant conferences. Evaluation methodStudy selection, data extraction and study quality assessment were carried out by a single reviewer with any uncertainties resolved with consulting a second reviewer. Studies were synthesised narratively and results were tabulated. ResultsA total of 29 studies, 17 published and 12 presentations, were identified. The highest quality evidence was from three single-arm trials. In those assessing the safety of implantation, 6 of 117 patients experienced a minor adverse event with superficial revision surgery being required in one case. Studies demonstrated improved hearing thresholds and speech recognition with the Bonebridge when compared to no aiding in adults and children with either type of hearing loss. This was reflected in high device satisfaction rates. Data collected in the second year of device use further suggest the benefit to remain constant. ConclusionThe transcutaneous BCI system Bonebridge provides a valuable and stable audiological benefit to patients suffering from conductive or mixed hearing loss and SSD. With its active transcutaneous design, the Bonebridge offers a lower complication rate to percutaneous systems and higher and more reliable hearing gain compared to other transcutaneous or percutaneous systems. Moreover, the fast activation of the implant system enables the recipient of the system to benefit in a short time frame postoperatively from the intervention.