Endoscopic endonasal superomedial orbitectomy: How far is safe and possible?

Area of Science:

• Neurosurgery
• Otolaryngology
• Anatomy

Background:

• The endoscopic endonasal approach (EEA) to the anterior cranial base offers minimally invasive access.
• Lateral surgical exposure is often limited by the lamina papyracea.
• Superomedial orbitectomy can potentially extend this lateral reach.

Purpose of the Study:

• To describe the technique of the endoscopic endonasal transethmoidal supraorbital approach.
• To quantify the coronal plane extension achieved by superomedial orbitectomy during EEA.

Main Methods:

• Thirty superomedial orbitectomies were performed on fresh-frozen head specimens.
• Post-procedure, bifrontal craniotomy allowed measurement of supraorbital EEA width.
• The anterior cranial base was divided into five anatomical zones for measurement.

Main Results:

• Superomedial orbitectomy was feasible without excessive orbital content retraction.
• The widest lateral extension was observed in the inter-ethmoidal zone (mean width 45.4 mm).
• Superomedial orbitectomy added an average of 8 mm to the lateral exposure on each side.

Conclusions:

• Endoscopic endonasal superomedial orbitectomy provides substantial coronal plane extension for EEA.
• The inter-ethmoidal zone offers the greatest lateral surgical exposure with this technique.