Long Term Results With the Vibrant Soundbridge in Patients With Mixed Hearing Loss: a 60-month Longitudinal Study

Introduction:

Active middle ear implants (AMEI) can benefit patients who are unable to use conventional hearing aids (HA) due to medical reasons, discomfort or unsuccessful rehabilitation.

AMEIs provide more hearing gain and consistency compared to middle ear surgery plus conventional hearing aids. Coletti et al. (2013) reported on long-term outcomes of patients implanted at the round window (RW) with the VSB. Brkic et al. (2019) presented a large number of subjects (n = 23) with a 20-year follow-up. The limitations of these studies were their retrospective design.

The best location for the surgeon to place the VSB's floating mass transducer (FMT) depends on various factors. A meta-analysis showed the hearing results at different FMT sites to be similar. None of these studies compared a FMT placed to a FMT clipped.

The impact of the etiology of deafness on a patient's outcome with an AMEI has been poorly studied. Only one study has shown that the difference between inflammatory disease (ID) and non-inflammatory disease (NID) groups was not significant.

The main objective:

Prospectively assess aided hearing benefits in a 60-month, long-term study including conductive and mixed hearing loss adults implanted with the VSB.

Measures are tonal audiometry, pure-tone average (PTA), vocal audiometry in quiet, 50% speech recognition threshold (SRT) in quiet, word recognition in quiet (WRS) at 65 dB sound pressure level (SPL), word recognition in noise (WRSN ; speech at 65 dB SPL and 0°, white noise at 55 dB SPL and 180°. signal-to-noise ratio = 10 dB).

The secondary objectives:

Comparison of the hearing results according to the FMT site (RW/OW to incus/stapes)

Comparison of the hearing results according the type of pathology responsible for the hearing loss (ID to NID).

Plan of the study:

It is a multicentric, prospective, longitudinal study with 6 tertiary references centres with a follow up over a period of 60 months.

Measures will be done on the patient preoperatively and 1, 3, 6, 12 and 60 months post-implantation.

Preoperative measures will be done also with hearing aid (HA) and bone-anchored hearing aid on a headband (HBAHA).

Inclusion criteria

• Adult patient (>= 18 years old) speaking French
• with mixed hearing loss on at least one side
• with a maximum bone conduction (BC) threshold of 45 dB hearing level (HL) at 500 Hz, 50 dB HL at 1000 Hz, 55 dB HL at 1500 Hz, and 60 dB HL at 2000 Hz.
• with a 20 dB minimum air-bone gap (defined as the difference between bone- and air conduction thresholds).
• with stable BC thresholds over the previous 24 months, and no sufficient benefit with the HA.

Exclusion criteria

• fluctuating hearing loss,
• cutaneous disease
• subjects who need an MRI.