A navigation-based anatomical study comparing 19 surgical corridors to the orbit and surrounding skull-base regions.

Agosti, Valentini, Mapelli and colleagues performed a quantitative anatomical comparison of 19 microsurgical transcranial, endoscopic endonasal and endoscopic transorbital approaches using five alcohol-fixed cadaveric specimens and neuronavigation. Twenty-six orbital and skull-base subregions were segmented, and both exposure areas and working volumes were quantified.

The results show a complementary pattern between approaches. Endoscopic transorbital approaches provided excellent access to the lateral orbit and selected cavernous regions, while endoscopic endonasal approaches were strongest for medial targets. Microsurgical transcranial approaches, particularly the orbitozygomatic approach with anterior clinoidectomy, retained the largest working volumes and broad spheno-orbital exposure.

Why it matters

This study provides quantitative data that may help move approach selection beyond purely qualitative anatomical descriptions. It is particularly useful for understanding when a minimally invasive endonasal or transorbital corridor offers a true anatomical advantage—and when a transcranial route still provides greater surgical freedom.

Reference

Agosti E, Valentini M, Mapelli K, et al.
Quantitative Anatomic Comparison of Microsurgical Transcranial, Endoscopic Endonasal, and Transorbital Approaches to the Orbit and Surrounding Skull-Base Regions.
Operative Neurosurgery. Published online September 25, 2026.
DOI: 10.1227/ons.0000000000002166
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