Clinical outcomes of 188 patients implanted with Med-El stapes prostheses

PURPOSE: This multicentric, retrospective study aimed to analyze the safety and effectiveness of the mAXIS Stapes Prosthesis, mLOOP Stapes Prosthesis, mZAM Stapes Prosthesis, and mFIX Stapes Prosthesis.

METHODS: Patients underwent stapes surgery and implantation of a mAXIS Stapes Prosthesis, mLOOP Stapes Prosthesis, mZAM Stapes Prosthesis, or mFIX Stapes Prosthesis (MED-EL, Innsbruck, Austria). The clinical data was retrospectively analyzed. Follow-up examination included access to medical records (for adverse events) of the patients, ear microscopy and pure-tone audiometry to determine the post-operative pure tone average of the frequencies 0.5, 1, 2 and 3 kHz (PTA4). The post-operative PTA4 air bone gap (ABG) was used to evaluate the audiological outcome. A post-operative PTA4 ABG ≤ 20 dB was defined as successful rehabilitation. A post-operative minimum and maximum follow-up period was not defined.

RESULTS: 189 patients were implanted with a MED-EL stapes prosthesis mainly as treatment of hearing loss caused by otosclerosis. 188 (186 adults, 2 children; 57 conductive hearing loss (CHL), 131 mixed hearing loss (MHL)) patients were examined for adverse events (AEs). 168 (166 adults, 2 children, 51 CHL, 117 MHL) patients underwent audiological examination. Audiology: 110 (65.5%) patients achieved a post-operative PTA4 ABG ≤ 10 dB. 154 (91.7%) patients achieved a post-operative PTA4 ABG ≤ 20 dB and therefore successful rehabilitation. Individual bone conduction (BC) PTA4 thresholds were stable in 159 (94.6%) patients. AEs: 12 (6.4%, adults only) patients had 13 AEs.

CONCLUSION: Clinical data demonstrated satisfactory audiological results after implantation of the mAXIS Stapes Prosthesis, mLOOP Stapes Prosthesis, mZAM Stapes Prosthesis, and mFIX Stapes Prosthesis. The MED-EL stapes prostheses are safe and effective.

TRIAL REGISTRATION NUMBER: NCT05565339 (clinicaltrials.gov).