Step-by-step approach to the suprasellar region. Close-up view of the surgical anatomy of the optic canal and medial aspect of the optic-carotid cistern. The dura has been transected up to the level of the distal dural ring, allowing for identification of the supraclinoidal segment of the internal carotid artery (ICA). The ophthalmic artery arises in most cases from the upper surface of the supraclinoidal ICA and runs inferior to the optic nerve toward the floor of the optic canal. The superior hypophyseal artery (SHA) arises from the medial aspect of the supraclinoidal ICA in close proximity to the distal dural ring. (Image courtesy of JC Fernandez-Miranda)