Device Failure Most Common Reason for Cochlear-Implant Revision

By Reuters Staff

March 12, 2020

NEW YORK (Reuters Health) - Few patients who undergo cochlear-implant surgery require revision surgery or reimplantation, but when they do, the leading cause is failure of the device itself, according to South Korean researchers.

Because cochlear implants are designed to last a lifetime, the device survival rate is particularly important, Dr. Il Joon Moon of Sungkyunkwan University School of Medicine, in Seoul, and colleagues note in JAMA Otolaryngology Head & Neck Surgery.

The researchers retrospectively reviewed data on 925 patients who underwent such surgery between 2001 and 2019.

After a mean follow-up of 7.1 years, 43 patients (4.6%) required revision surgery. This was due to device failure in 28 of these patients. Flap-associated problems and migration of the devices were the second most common reasons for revision.

The researchers note that most of the revision surgeries were performed near the beginning of the postoperative period. The survival curves dropped right after surgery "and gradually decreased until they reached a plateau at around 5 years."

The overall 10-year survival rate of the surgery was 94.4% and that of the device was 96%. The researchers point out that "our institutional revision rate was slightly lower than had been reported previously, and our cumulative survival rate was higher."

A total of 13 different models of devices were implanted. These came from one of four manufacturers, Cochlear, Med-El, Advanced Bionics and Oticon.

Advanced Bionics had the highest device-failure rate and lowest survival rate, primarily because of voluntarily recalls and also because they were older and had a longer follow-up duration than the devices from other manufacturers. Conversely Med-El had the lowest device failure and revision rates, but also was the most recently employed and had the shortest follow-up.

Nevertheless, say the investigators, no meaningful differences in device failure were found among manufacturers or devices. After excluding recalled devices, the device survival rate after five years was 98.2%. At 10 years it was 97.7% and at 15 years, 94.9%.

The researchers conclude, "By reviewing the reasons for and influencing factors of cochlear implant revision, clinicians can provide realistic counseling to candidates for cochlear implant prior to surgery."

The researchers report no outside funding or conflicts of interest.

Dr. Moon did not respond to requests for comment.

SOURCE: JAMA Otolaryngology Head & Neck Surgery, online March 5, 2020.