Carina implantation in patients with mixed hearing loss: Influence of coupling site on speech comprehension

Introduction In patients with mixed hearing loss after multiple tympanoplasty and poor middle ear ventilation, fitting of conventional hearing aids is often failed due to the high hearing threshold . From an audiological point of view, implantable hearing aids provide a sufficient treatment option in these patients. In patients with medium to high-grade inner ear component, the fully implantable hearing aid Carina can close the supply gap because of its power characteristics.

Patients and methods Carina implantation was performed in 35 patients between 2017 and 2019. The actuator was coupled to the incus (n = 7), the stapes head (n = 10), the stapes footplate (n = 10) or the round window (n = 8) depending on the middle ear pathology. A simultaneous fat obliteration was performed in 9 patients with radical cavities. Speech comprehension was determined 6 months after implantation using Freiburger monosyllabic test in free field condition at 65 dB and 80 dB.

Results A cochlear depression was not observed in any patient after 6 months. Patients with incus coupling offered a worse speech comprehension at 65 dB (53 ± 23%) than patients with coupling to the stapes head (58 ± 13%), stapes footplate (63 ± 17%), and round window membrane (68 ± 13%). Fat obliteration of the ear had no effect on speech comprehension (64 ± 13% vs. 59 ± 17%).

Conclusion Carina implantation provides an effective method of hearing rehabilitation in patents with mixed hearing loss. Coupling site of the actuator seems to have an effect on speech comprehension. Up to now, long-term results are still missing to evaluate the stability of the different coupling techniques.

Poster-PDF A-1493.PDF

Publication History

Article published online:
10 June 2020