The clinoidal space: anatomical review and surgical implications

Area of Science:

• Neurosurgery
• Anatomical Studies
• Skull Base Anatomy

Background:

• The anterior clinoid process (ACP) is a critical landmark in skull base surgery.
• Understanding the anatomy surrounding the clinoidal internal carotid artery (ICA) is essential for safe surgical approaches.

Purpose of the Study:

• To describe the anatomical features of the clinoidal space after anterior clinoid process (ACP) removal.
• To delineate the boundaries and contents of the clinoidal space, focusing on the clinoidal internal carotid artery (ICA).

Main Methods:

• Dissection of five latex-injected cadaver heads (ten specimens).
• Removal of the anterior clinoid process (ACP) while preserving dural layers.
• Detailed inspection of the exposed clinoidal space and clinoidal internal carotid artery (ICA).

Main Results:

• Removal of the ACP creates a distinct clinoidal space, exposing the clinoidal internal carotid artery (ICA).
• This space is bordered by dural rings anchoring the ICA and contains the artery encased in connective tissue.
• The clinoidal space is extracavernous, with bleeding potential limited to breaches in the connective tissue.

Conclusions:

• The clinoidal space, revealed by ACP removal, offers a unique anatomical perspective on the clinoidal ICA.
• The extracavernous nature of this space and its connective tissue encapsulation are key findings for surgical considerations.