Measurement of Critical Structures around Paraclinoidal Area : A Cadaveric Morphometric Study

Area of Science:

• Neurosurgery
• Anatomy
• Surgical Technique

Background:

• Anterior clinoidectomy is a key surgical approach for accessing the parasellar region.
• Quantitative data on the space enhancement provided by anterior clinoidectomy is limited.

Purpose of the Study:

• To measure anterior clinoid process dimensions.
• To quantify the exposure improvement in the parasellar space after extradural anterior clinoidectomy.
• To assess correlations between paraclinoidal structures.

Main Methods:

• Eleven formalin-fixed Korean adult cadaveric heads underwent bilateral frontotemporal craniotomies.
• Measurements of the C6 segment of the internal carotid artery and optic nerve length were taken before and after anterior clinoidectomy.
• Anterior clinoid process dimensions and relationships among paraclinoidal structures, including the ophthalmic artery, were assessed.

Main Results:

• The mean intradural anterior clinoid process basal width was 10.82 mm and height was 7.61 mm.
• Anterior clinoidectomy increased C6 segment length by 49% and optic nerve length by 97%.
• Distances from the optic strut to the falciform ligament, distal dural ring, and ophthalmic artery origin were 6.69 mm, 9.36 mm, and 5.99 mm, respectively.

Conclusions:

• Anterior clinoidectomy substantially increases surgical exposure of critical neurovascular structures.
• This technique is essential for surgeons managing lesions in the complex parasellar area.