Surgical and audiological outcomes of a fully implantable middle ear implant: early results from a retrospective multicentre study

PURPOSE

This paper reports the surgical and audiological outcomes of a large series of patients who received a fully implantable middle ear implant (MEI): carina (Cochlear, Australia).

METHODS

This is a multicentre retrospective study involving three tertiary referral centres. Patient data were collected for the first 42 consecutive patients who were fitted with the MEI between 2014 and 2019 (Sheffield from February 2017 to January 2019; São Paulo from April 2015 to September 2017; Porto from December 2014 to May 2017). The main outcome measures included surgical results, free field speech testing with speech recognition thresholds (SRT) and audiological gain.

RESULTS

There was one major complication due to infection resulting in a brain abscess and explantation of the device. Three other patients had minor skin infections; no other complications were reported. Results show a functional gain of 19.5 dB (p < 0.05) with the MEI versus unaided condition. SRT improved from 57.4 dB to 44.6 dB with the MEI (p < 0.05).

CONCLUSIONS

This fully implanable active MEI offers a reliable option for patients with moderate-to-severe sensorineural or mixed hearing losses especially for those do not tolerate or cannot use conventional hearing aids. It provides significant improvement in hearing as shown in the audiological outcomes. The surgery is relatively straightforward but there is a steep learning curve. The devices are well tolerated by all patients.

The first results of a totally implanted active middle ear device

PURPOSE

The aim of this study was to assess the first outcomes of a fully implantable active middle ear device.

METHODS

Retrospective observational nonrandomized group study.

SETTINGS

Private hospital. Fifteen patients underwent device implantation between December 2014 and June 2017. The pre-operative and post-operative air conduction (AC) and bone conduction (BC) thresholds were evaluated. The functional gain, speech perception in silence and in noise, and localization abilities were also analyzed.

RESULTS

Sixteen active middle ear implantations were performed. Post-operatively, the mean pure tone thresholds were 50.5 dB ( ± 12.64) for BC and 64.9 dB ( ± 15.36) for AC. No differences were found between the post-operative and pre-operative audiometric thresholds before activating the system (p > 0.05). Post-operatively, the mean thresholds in the free field after the device was activated were 46.8 dB, 45.75 dB, 42.6 dB, and 43.38 dB at 1, 3, 6, and 12 months, respectively. The global results of speech understanding in silence were 50.7 dB, 47.18 dB, 42 dB, and 42 dB for 1, 3, 6, and 12 months, respectively. Patients with mixed hearing loss had better results than those with sensorineural hearing loss. Speech discrimination in noise and localization was improved.

CONCLUSIONS

Despite the small number of patients, our results confirmed that this fully implantable active middle ear device is a viable treatment for patients with moderate-to-severe sensorineural hearing loss who cannot or do not want to use traditional hearing aids for clinical or cosmetic reasons.

Otologics active middle ear implants

This article describes outcomes for the Otologics active middle ear implant for the semi-implantable and fully implantable (Carina, Otologics LLC, Boulder, CO) devices. Inclusion and exclusion criteria are reported in detail for surgical and audiologic management. Results from the clinical trial demonstrated no change for unaided air and bone conduction thresholds and no significant change in monosyllabic word scores or sentences in noise. Experiments are reported for conductive and mixed types of hearing losses in animal and human cadaveric models. These devices are in their infancy, and further study is needed to better identify candidates and develop appropriate expectations.