Dural Artery from Supraclinoid Internal Carotid Artery to Anterior Clinoid Process: Origin, Course, and Clinical Implications.

Background: Dura of the anterior clinoid process (ACP) is presumably supplied by the ophthalmic and external carotid artery branches. There is a less recognized artery described by Yasargil that arises directly from the supraclinoid internal carotid artery (ICA) and supplies the ACP dura. We studied the origin and course of this direct branch in patients in whom the carotid cistern was dissected for lesions not involving the carotid cistern and ACP dura. The management implications of this arterial twig have been described.

Methods: Thirty patients operated through the transsylvian route for suprasellar lesions were included. The arterial branch from the supraclinoid ICA to the clinoidal dura was dissected and studied under high magnification.

Results: A thin solitary artery could be delineated in 21 patients. In 14 patients, it originated from the dorsomedial surface of the ICA at its bifurcation close to the A1 origin. In the remaining 7, it was seen arising from the dorsomedial surface of the ICA, 2-4 mm proximal to bifurcation. The artery coursed from medial to lateral and pierced the clinoidal dura, 1-3 mm lateral to the entry of the carotid artery. The artery had no branches.

Conclusions: The knowledge of this arterial twig to the clinoidal dura is important as this supply may be responsible for feeding the tumor arising from the dura arising from the anterior clinoid, making preoperative embolization impossible. In addition, the tumor may grow along with this vessel and infiltrate the adventitia of the ICA at the origin of this vessel.