Clinical features of cochlear implantation in Japan and factors affecting postoperative infection.

OBJECTIVE

This study aimed to evaluate the clinical features in a large cohort of patients who underwent cochlear implantation in Japan, including the number of simultaneous bilateral cochlear implantation, proportion of postoperative infectious complications, and factors associated with postoperative infectious complications.

METHODS

This retrospective cohort study extracted data of 7893 patients who underwent 9427 cochlear implantations from a Japanese national inpatient database between July 2010 and March 2021. We determined the number of cochlear implantations, patient age, number of simultaneous bilateral surgeries, and incidence of infectious complications. The factors associated with postoperative infection were analyzed using a multivariate logistic regression model.

RESULTS

Pediatric cases were predominant until 2016, whereas adult cases surpassed pediatric cases beginning in 2017. The proportion of patients aged > 1 year and 6 months decreased gradually since 2014. The number of simultaneous cochlear implantations increased steadily since 2016. The incidence of postoperative infection was 4.8 %. Postoperative infectious complications were significantly associated with age < 2 years at surgery, inner ear malformations, and medium hospital volumes in pediatric patients. In adults, chronic otitis media and comorbid diabetes mellitus without complications were associated with postoperative infectious complications.

CONCLUSIONS

The trends in patient age and the number of simultaneous surgeries in Japan are consistent with the revised guidelines. The incidence of postoperative infections was 4.8 %. The factors associated with postoperative infection differed between pediatric and adult patients. These findings may help surgeons in the management of cochlear implantation.