Endonasal Access to the Upper Cervical Spine: Part 2-Cadaveric Analysis

Area of Science:

• Otolaryngology
• Neurosurgery
• Anatomy

Background:

• Endonasal approaches to the cervical spine are increasingly utilized.
• Optimizing visualization is crucial for surgical success and patient safety.
• Understanding anatomical limitations and enhancement techniques is essential.

Purpose of the Study:

• To identify factors that enhance endonasal exposure of the upper cervical spine.
• To evaluate the impact of neck positioning and endoscopic tools on visualization.
• To provide data for improved preoperative assessment and surgical planning.

Main Methods:

• Utilized fluoroscopy and endoscopy in ten human cadavers.
• Simulated endoscopic visualization of the upper cervical spine.
• Assessed exposure with projected lines in various neck positions and with different endoscopes.

Main Results:

• Neck extension alone showed a trend towards increased caudal exposure but was not the primary factor.
• Concurrent use of a 30-degree endoscope and neck extension significantly improved exposure.
• Tilting the endoscope against the piriform aperture, using the hard palate as a fulcrum, maximized caudal access.

Conclusions:

• A combination of neck extension and a 30-degree endoscope is key for augmenting endonasal cervical spine exposure.
• Instrument manipulation at the posterior hard palate offers superior access compared to neck positioning alone.
• Findings aid in refining surgical planning for endonasal cervical spine procedures.