The Association Between Postoperative Prophylactic Antibiotics and Severe Infections After Cochlear Implantation: A Retrospective Cohort Study.

Objective: To investigate the association between postoperative antibiotic prophylaxis and the risk of infections leading to implant explantation or hospitalization, with a follow-up of up to 12 years.

Study design: Retrospective cohort study.

Setting: Tertiary medical institution.

Patients: Adult patients (≥18 yr) receiving cochlear implant surgery between 2010 and 2022.

Intervention: Postoperative oral prophylactic antibiotic treatment for 4 to 10 days.

Main outcome measures: The medical records of patients receiving cochlear implants were assessed (n = 927). Two groups were formed: group A, receiving postoperative oral antibiotic treatment (period: 2010-2015) (n = 526), and group B, not receiving postoperative oral antibiotic treatment (period: 2016-2022) (n = 401). The two groups were compared regarding infections leading to hospitalization or explantation, and baseline characteristics.

Results: In total, 28 patients (3.0%) had infections requiring explantation or hospitalization. Of these, 13 were explantations (1.4%). The infection rate in group A was 2.9%, compared with 3.2% in group B, with an odds ratio of 1.2 in group B (p = 0.646). Group B had a 2.2 odds ratio of explantation caused by infection compared with group A (p = 0.179). We observed a significant correlation between severe infections in patients previously having otologic surgery (7.7%, p = 0.011) and in patients with previous issues of chronic otitis (16.7%, p = 0.005).

Conclusion: Occurrence of postoperative infection leading to explantation and hospitalization was not significantly associated with the use of postoperative antibiotic prophylaxis. However, infections were higher in patients not receiving antibiotic prophylaxis, despite having a lower risk of postoperative infection.