Evolution of the reliability of the fully implantable middle ear transducer over successive generations.

OBJECTIVE

To describe the reliability of the fully implantable middle ear transducer after successive technological changes.

STUDY

DESIGN

Prospective, observational, multicenter study.

SETTING

Eight tertiary referral centers.

PATIENTS: One hundred twenty-three adults were implanted with one of the five successive versions of the fully implantable middle ear implant between September 2005 and July 2012.

METHODS

The reliability of each generation 2 years after implantation or at the maximal lifetime was reported by means of survival curves. Only technological failures were considered; non-technological failures were excluded from the analysis of reliability.

RESULTS

One hundred fifty-seven devices were implanted during the period of study. Fifteen explantations were related to non-technological problems (e.g., infections, extrusions, etc.). One hundred forty-two implants were followed in the analysis of reliability. We observed 32 technical failures at 2 years. At the maximal lifetime of follow-up, 46 implants failed. The end of the follow-up was the first of November 2012. Survival rates at 2 years were 0%, 76.1%, 84.2%, 81.8%, and 100% for each of the successive available versions, respectively.

CONCLUSION

The reliability of the fully implantable middle ear implant improved over generations thanks to successive technological modifications that corrected the observed failures. The latest generation seems to be a reliable fully implantable middle ear implant system up to 22 months after implantation. The need to know the reliability of these active middle ear implants incites the creation of a follow-up register including patient's data and device failures to improve patient management.