Failure and Revision Surgery After Cochlear Implantation in the Adult Population: A 10-year Single-institution Retrospective and Systematic Review of the Literature.

OBJECTIVE

To characterize failure rate and etiology after cochlear implantation; to identify predictors and describe outcomes after implant failure.

STUDY DESIGN

Retrospective chart review and systematic review of the literature using PubMed and Embase.

SETTING

Academic Cochlear Implant Center.

SUBJECT POPULATION

Four hundred ninety-eight devices in 439 distinct adult patients.

INTERVENTIONS

Unilateral or bilateral cochlear implantation.

MAIN OUTCOME MEASURES

Implant failure rate and etiology.

RESULTS

A total of 32 devices (5.9%) failed in 31 patients encompassing the following failure types in accordance with the European Consensus Statement of Cochlear Implants: 17 device failures (53.1%), 11 failures due to performance decrement/adverse reactions (34.4%), and 4 medical reasons (12.9%). There was no significant difference in age, sex, or manufacturer between patients with and without failures. Twenty-five percent of patients with failure leading to explantation had childhood onset of deafness compared to 12.1% of patients with adult-onset hearing loss (OR = 2.42; p = 0.04). Performance decrement/adverse reaction patients had an older average age at implantation compared to device failure patients (mean 68.5 yr 95% CI: 59.9-77.1 vs mean 47.6 yr, CI: 39.9-55.3, p < 0.01). There was no significant difference in time to failure, sex, or device manufacturer between the different types of failures. Twenty-nine patients who experienced CI failure underwent a revision surgery, while the remaining two opted for explantation without reimplantation. One patient who underwent revision surgery subsequently presented with a second failure and underwent a second revision, which was successful.In our systematic review, 815 citations were reviewed, and 9 studies were selected for inclusion. Overall failure rate across all studies was 5.5%. Device failure was the leading cause of failure in the majority (6/9) of studies, accounting for 40.8% of all failures. Medical reasons were the second leading cause at 33.6%, followed by performance decrement/adverse reaction (20.9%) and other (4.8%).

CONCLUSIONS

Cochlear implant failure is a rare phenomenon. Childhood-onset of hearing loss appears to be associated with an increased risk of overall failure. Older patients are at increased risk for performance decrement/adverse reaction. Revision surgery success rates remain very high and patients with failure of any cause should be offered explantation with concurrent reimplantation.