Introduction

Since 2005 the Floating Mass Transducer (FMT) of the Vibrant Soundbridge (VSB) can be coupled directly or indirectly to the round window. Indirect coupling can be done via fascia, Tutopatch (TP), Round Window Coupler (RWC), Round Window Soft Coupler (RWS), or the CMD Hannover Coupler (HCV2). The aim of the study is (1) analyzing the safety of the RW vibroplasty and (2) the evaluation of the coupling efficiency.

Material and Methods

Inclusion criteria was a bone conduction threshold (BC) within the indication limit for RW vibroplasty +10 dB and within the measurement limit. Safety analysis included revision and explantation rates. The audiological results included BC and the coupling efficiency (CEF, in situ measurement - BC). The results were analyzed pre- and postoperatively after 2 month (2m), 2.7 (2y) and 5.4 (5y) years. The average is given as PTA₄.

Results

The audiological analysis (n=56) showed a significant change in mean BC at 2y in groups HCV2 (n=12) and RWS (n=8) by 8.14 dB and 5.9 dB, respectively. Regarding safety analysis (n=76), 9 patients were explanted (n=3 deficit, n=2 implant defect, n=2 infections, n=2 cholesteatoma), 6 of whom received VSB reimplantation (n=5 RW vibroplasty) and the others acoustic implants (BAHA, Bonebridge, CODACS). Revisions (n=4) were caused by deficit (n=2) and medical reasons (n=1 related, n=2 non-related). A significant improvement in CEF was found at 5y for group RWC (n=14) at 4 and 6 kHz. A CEF of > 35dB was found in 5 subjects (n=4 TP, n=1 HCV2) with a BC of 16.5 dB HL. No significant differences were found between the groups in terms of safety or CEF.

Discussion

The RW vibroplasty is a safe procedure. The coupling efficiency becomes more important the further the hearing loss progresses.

The work of Ms. Knölke is sponsored by MED-EL. The authors received travel support by MED-EL to conferences. The authors disclose no conflicts of interest.