Long-term Stability of the Active Middle-ear Implant with Floating-mass Transducer Technology: A Single-center Study

To examine the long-term results of an active middle-ear implant (AMEI) with floating-mass transducer (FMT) technology.

Prospective cohort study of German-speaking patients implanted with an AMEI between 2006 and 2013.

Single-center study.

Eighty-three patients.

AMEI with FMT technology implantation.

Long-term outcome (27 mo; range, 12-84 mo) for FMT position in correlation with pure-tone audiometry, auditory thresholds for frequency-modulated (warble) tones, vibroplasty thresholds for pure tones, and speech audiometry in quiet and noise.

In 15.6% of patients, a revision surgery was necessary to improve functional performance of the AMEI, and the highest revision rate was found with FMT coupling to the round window not using couplers. A peak number of revision surgeries were observed 3 years after the initial surgery. Stable audiological results (pure-tone audiometry and speech audiometry in quiet and noise) were observed up to 84-month post-surgery. Incus vibroplasty (classic indication) showed a significantly lower functional gain compared with oval and round window vibroplasty. Vibroplasty in combined or conductive hearing loss showed no functional difference between forward and reverse stimulation of the cochlea; however, significantly lower vibroplasty thresholds were detected when using a coupler.

The AMEI with FMT technology can be safely used in treatment of patients with mild-to-severe sensorineural, conductive, or mixed hearing loss. Optimized coupling, especially in incus vibroplasty, has to be developed to achieve enhanced audiological results.