Intraoperative Evaluation of Cochlear Implant Electrodes Using Mobile Cone-Beam Computed Tomography

Area of Science:

• Otolaryngology
• Medical Imaging
• Neurosurgery

Background:

• Cochlear implantation (CI) requires precise electrode placement for optimal hearing outcomes.
• Intraoperative imaging is crucial for verifying electrode position, especially in cases of cochlear malformation.

Purpose of the Study:

• To assess the utility of mobile cone-beam CT (mCBCT) for evaluating cochlear implant (CI) electrode status during surgery.
• To compare mCBCT with other CT modalities for intraoperative electrode assessment.

Main Methods:

• A retrospective review of 57 patients (64 ears) who underwent CI with intraoperative mCBCT imaging.
• Analysis of electrode location and angular insertion depth using mCBCT scans.
• Comparison of insertion techniques (cochleostomy vs. round window) and electrode types.

Main Results:

• mCBCT successfully confirmed electrode location in six cases with cochlear malformations.
• Complete scala tympani insertion rates were higher with round window/extended round window insertion compared to cochleostomy (p=0.03).
• Angular insertion depths varied significantly between different electrode types (p<0.05).

Conclusions:

• Intraoperative mCBCT provides reliable evaluation of CI electrode placement, comparable to fan-beam CT or c-arm-based CBCT.
• Due to its low radiation dose and widespread availability, mCBCT is a preferred modality for intraoperative assessment of cochlear implant electrode arrays.