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.