Trans-Nasion-Complex Approach for Endoscopic Modified Lothrop Procedure: Conception, Anatomy, and Technique

Area of Science:

• Neurosurgery
• Endoscopic Skull Base Surgery
• Anatomy

Background:

• The endoscopic modified Lothrop procedure (EMLP) is crucial for frontal and anterior skull-base lesions.
• Established techniques rely on landmarks like the frontal recess and first olfactory filament (FOF).
• These landmarks may not always be identifiable, necessitating alternative approaches.

Purpose of the Study:

• To introduce and evaluate the trans-nasion-complex approach (TNCA) as a novel technique for EMLP.
• To demonstrate TNCA's feasibility when traditional landmarks for EMLP are unavailable.

Main Methods:

• Anatomical observation of the bony nasion complex using dry skulls.
• Cadaveric dissection of five silicon-injected head specimens via the TNCA.
• Retrospective review of patient outcomes following TNCA for EMLP.

Main Results:

• The nasion complex anatomy and key surgical landmarks for TNCA were detailed.
• A characteristic "mushroom sign" was identified during dissection and surgery.
• Twenty-one patients underwent TNCA without major complications, including those with tumors and chronic rhinosinusitis with nasal polyps (CRSwNP).

Conclusions:

• The trans-nasion-complex approach (TNCA) presents a safe and direct surgical route for EMLP.
• Familiarity with the nasion complex anatomy and the "mushroom sign" is vital for successful TNCA execution.