Investigating variability in cochlear implant electrode array alignment and the potential of visualization guidance

Background Internal cochlear anatomy is difficult to discern from external inspection, hindering cochlear implant electrode insertion. Methods A user study characterized the repeatability of standard surgical technique and examined the role of visual inspection and guidance cues in reducing electrode array insertion misalignment. Results Without guidance, a large spread in angles of insertion, up to 30°, was observed, highlighting the need for intraoperative guidance. Visual inspection did not significantly improve overall orientation, suggesting the need for alternate intracochlear visualization methods and/or increased training to effectively improve surgeon understanding of the visualized images. Visual cues and guidance software increased repeatability of surgeon performance, reducing one metric of repeatability to ±2°. Conclusions This study establishes a baseline for surgeon variability in cochlear implant insertion and supports the need and lays the groundwork for future intraoperative guidance techniques.