SS06: ACTIVE MIDDLE EAR IMPLANTS AND MHL

INCUS VIBROPLASTY VERSUS ROUND WINDOW VIBROPLASTY; HANNOVER RESULTS

Lenarz T

Dept. of Otorhinolaryngology, Medical University of Hannover, Germany.

The objective of this paper is a retrospective evaluation of audiological results with the application of the implantable hearing device Vibrant Soundbridge (VSB) on the round window membrane for treatment of mixed hearing loss (MHL) and with the conventional application of VSB on incus for treatment of sensory neural hearing loss (SNHL).

Two patient groups with SNHL (n=45) and MHL (n=15) were recruited for this study. The median duration of wearing  the implants was 9.7 years for the SNHL-group and 2.1 years for the MHL-group. Audiological tests consisted of pure tone audiometry, free-field audiometry, speech audiometry, speech-in-noise and multi  frequency tympanometry were performed pre-and postoperatively.

Patients with SNHL showed a median functional gain of about 27 dB in the free field test. When using the unaided AC-thresholds in the MHL-group a median functional gain of about 48 dB were measured and with respect of bone-conduction thresholds the functional  gain was about 24 dB. The improvement of the speech discrimination score at 65 dB SPL for the first and second groups was about 40% and 65%