Related Experiment Video
Updated: Oct 1, 2025
Enhancing Electrode Location Assessment in Cochlear Implantation via Computed Tomography Image Fusion
Published on: January 17, 2025
Cochlear Implant Electrode Misplacement: A Case Series and Contemporary Review
Timothy J Shin1, Douglas J Totten, Brady J Tucker
1Department of Otolaryngology-Head and Neck Surgery, Indiana University School of Medicine, Indianapolis, Indiana.
Objective:
To determine root causes leading to misplaced cochlear implant (CI) electrode arrays and discuss their management using a case series and contemporary literature review.
Study Design:
Retrospective case review and contemporary literature review.
Setting:
Single tertiary-referral center.
Patients:
Adult and pediatric patients who were diagnosed with a misplaced CI electrode array, excluding tip-foldover. Literature review was performed via a MEDLINE database PubMed query. All articles that described at least one case of extracochlear electrode array misplacement were included; partial insertions and extrusions were excluded.
Main Outcome Measure:
Extracochlear misplacement.
Results:
A total of 61 cases were reviewed, including 4 new cases and 57 cases from 29 previously published articles. We discuss management of CI arrays in the carotid canal, the vestibule, and the modiolus. The rate of CI misplacement is estimated to be 0.49%. The most frequent location of misplacement CI was the vestibular system (50.8%) followed by the internal carotid canal (11.5%). Normal cochlear anatomy was noted on preoperative computer tomography (CT) in 59.0% of patients; abnormalities were noted in 27.9%. The most common technical issue was misidentification or poor visualization of the round window.
Conclusion:
CI electrode misplacement is rare but can cause postoperative complications and may result in permanently diminished CI performance and hearing outcomes, even after revision surgery. Failure to identify the round window is the most common reason for CI misplacement, despite most patients having normal cochlear anatomy. Surgical strategies to localize the round window and basal turn are imperative for proper electrode placement.
Level Of Evidence:
4.
