Evaluation of Clinical Parameters in FMT-Application of a Vibrant Soundbridge® at the Short Incus Process Compared to Conventional FMT-Application

Background: The application of the Floating Mass Transducer (FMT) of a Vibrant Soundbridge? (VSB?) to the short incus process is intended to reduce both the surgery time and the complication and revision rate compared to other forms of application. In addition to collecting these parameters, the aim of this study is to investigate the primary audiological outcome of patients with an FMT application to the short process compared to the conventional methods. Methods: The present study retrospectively examined a total of n=36 patients who received a VSB? between 01/2015 and 08/2018 at the ENT University Hospital Leipzig. In n=12 patients (group 1) the FMT was coupled to the short process, in n=24 patients (group 2) to other ear structures. The audiological results were evaluated pre- and postoperatively in the pure tone audiogram according to the recommendations of the AAO-HNS (1995) and the intelligibility (Freiburger, monosyllabic) was measured at 65 dB in the speech audiogram. In addition, the revision and complication rates as well as the surgical time were evaluated. Results: The audiological outcome of group 2 was significantly better postoperatively in both the pure tone (p<.001) and speech audiogram (p=.012). The surgery time of group 1 was significantly shorter (p=.002), but with a slightly increased revision rate (p=.519). The complication rate of group 2 was slightly higher, with no statistically significant difference to group 1 (p=.185). Conclusions: The FMT application on the short ambos process does not seem to offer any advantage in terms of audiological outcome, but at the same time is associated with a significantly shorter surgery time. There are no statistically significant differences in revision and complication rates.