THE CLINOIDAL SPACE - ANATOMICAL REVIEW AND SURGICAL IMPLICATIONS

This study describes the anatomy of the clinoidal space exposed after the anterior clinoid process (ACP) is removed. Five cadaver heads inje cted with colored latex in the arterial and venous systems were used. Each was cut in half to provide ten specimens for inspection. The bone that covered the medial side of the cavernous and clinoidal internal carotid artery (ICA) was removed. The ACP was removed and its dural la yers were preserved. The removal of the ACP establishes an area called the clinoidal space. In this space, the clinoidal ICA is exposed. Thi s space is delimited by two dural rings that anchors the clinoidal ICA . Most of the clinoidal space is located anterolateral to the artery w here the ACP is found, but there is a small triangular space posterior to the artery and another space anteromedial to it. The clinoidal ICA is completely encased by connective tissue in this space. The crinoid al space is extracavernous, therefore, bleeding occurs only if the con nective tissue layer is broken.