Postoperative complications in cochlear implant surgery and their possible risk factors

This is a retrospective analysis of the major and minor complications of cochlear implants, as well as the Risk Factors (RF) involved.

We analyzed the medical records of patients submitted to cochlear implants at public University from 2006 to July 2019, and list here the major and minor complications found, and their risk factors.

There were 193 ears, 100 (51.3%) from females and 93 (48.2%) from males, with a mean age of 23.63 years. In 54 of them (28%), there were alterations seen in the Temporal Bone CT scan, and 44 (22.8%) in the brain MRI. There were 158 (81.9%) insertions performed; 127 (65.8%) of them through the round window. There were 78 complications: 19 (9.8%) major and 56 (29%) minor complications. Among the major complications, there were 3 (1.6%) Surgical Site infections (SS); 5 (2.6%) hematomas/seromas; 5 (2.6%) electrode extrusion; 5 (2.6%) device faults; 1 (0.5%) wrong path. Among the minor complications, there were 6 (3.1%) Acute Otitis Media (AOM); 9 (4.7%) SS infections; 4 (2.1%) facial paresis; 17 (8.8%) vertigos; 9 (4.7%) with tinnitus. The most important RF was age. Patients younger than 2.5 years had more major complications: SS infection (p = 0.018) and electrode extrusion (p = 0.017). There was a higher rate of vertigo in adults (p = 0.003), and it was more often associated with comorbidities (p = 0.008). The insertion route, the presence of changes in CT and MRI and the CI brand used did not impact the number of complications.

Among the minor complications, those involving the vestibular system were the most common, especially in adults with comorbidities. Regarding major complications, there was an emphasis on SS infections, hematomas, seromas, electrode extrusion, especially in children under two years of age. There were implanted device faults (2.6%), with none of the brands evaluated standing out.