Round Window Accessibility Prediction in Cochlear Implant Surgery.

Area of Science:

• Otolaryngology
• Neurosurgery
• Medical Imaging

Background:

• Cochlear implantation (CI) requires clear identification of the round window (RW) via the facial recess, a step that can be surgically challenging.
• Predicting RW accessibility preoperatively is crucial for successful CI outcomes.

Purpose of the Study:

• To evaluate the efficacy of high-resolution computed tomography (HRCT) in predicting round window (RW) accessibility during cochlear implantation (CI) surgery.
• To compare two established methods for assessing RW surgical accessibility using preoperative HRCT scans.

Main Methods:

• Retrospective review of 142 preoperative HRCT scans from patients undergoing CI via posterior tympanotomy.
• Assessment of surgical RW accessibility using two distinct methods (Mandour et al. and Elzayat et al.) based on HRCT findings.
• Comparison of imaging predictions with actual surgical outcomes documented in operative notes and videos.

Main Results:

• Mandour's method predicted difficult RW access with 81.8% accuracy (sensitivity 56.3%, specificity 96.4%).
• Elzayat's method predicted difficult RW access with 72.2% accuracy (sensitivity 50%, specificity 94.5%).
• Combining both methods improved sensitivity to 71.9%; simultaneous prediction of difficulty strongly indicated the need for cochleostomy (P < .001).

Conclusions:

• Preoperative HRCT assessment using Mandour's and Elzayat's methods are reliable tools for anticipating surgical challenges in RW access.
• These imaging-based methods aid surgeons in preparing for potential difficulties and considering alternative surgical techniques for CI.
• Accurate prediction of RW accessibility enhances surgical planning and patient safety during cochlear implantation.