Long-Term Stability and Safety of the Soundbridge Coupled to the Round Window

Objective: The objective of the study was to demonstrate the long-term outcomes of patients implanted with the active middle ear implant (AMEI) Vibrant Soundbridge (VSB) through coupling the floating mass transducer (FMT) to the round window (RW). Methods: This retrospective study evaluated the short- and long-term clinical performance (audiological outcomes) and safety (revisions/explantations) of the VSB coupled to the RW between 2013 and 2019 at the St. Polten University Hospital, Austria. For the outcome analysis, the sample was divided into a short-term examination group followed up for less than 12 months (<12 months) and a long-term examination group followed up for more than 12 months (>12 months). Cumulative survival outcomes were separately analyzed for subjects with and without cholesteatoma. Results: 46 patients with an average long-term follow-up period of 31.43 months (13-75 months) were investigated. Complications requiring revision surgery were reported in total in seven patients with cholesteatoma (15.2%) and none in subjects without cholesteatoma (0%). Residual hearing was not affected by VSB surgery. Word understanding on the Freiburger monosyllabic speech test improved significantly at 65 dB (P < .0001) and 80 dB (P < .0001), and these outcomes were stable for long-term follow up. Conclusion: The VSB coupled to the RW is a safe implantation method for patients with conductive or mixed hearing loss. Hearing improvement was stable for the long-term follow-up up to 74 months. The revision rates are directly related to the underlying pathology of cholesteatoma (with radical cavity); thus, this special cohort requires additional counseling on potential complications.