Management of surgical difficulties during cochlear implant with inner ear anomalies.

Objective: To review the difficulties that can occur during cochlear implant surgery in patients with inner ear abnormalities and the management thereof.

Methods: A retrospective chart review of 316 patients who received cochlear implants was conducted. The data collected included the types of inner ear anomalies, intraoperative findings, and the clinical management strategies. A review of the literature was also performed.

Results: A total of 24 patients with inner ear malformations who underwent 28 total cochlear implant procedures were identified. The anomalies included isolated large vestibular aqueducts in 8 (33.3%) patients, isolated semicircular canal dysplasia in 8 (33.3%) patients, classical Mondini malformation in 7 (29.1%) patients, and cochlear hypoplasia in 1 (4.1%) patient. Four (14.2%) patients exhibited intraoperative cerebrospinal fluid (CSF) gushers. One patient experienced delayed facial nerve paralysis, and an electrode was partially inserted into one patient. In 2 (7.14%) cases, the surgeries were aborted because of difficulties.

Conclusion: Cochlear implantation for inner ear anomalies can be performed safely. Special attention should be given to preoperative imaging to anticipate the potential intraoperative risks that can occur in inner ear anomaly cases. Every surgery should be planned with a safe approach and specific requirements, e.g., regarding electrode type, and the surgeries must be performed by experienced surgeons who are capable of modifying their technique according to the surgical findings.