Step-by-step approach to the suprasellar region. The superior intercavernous sinus has been transected and the diaphragma sellae and pituitary gland are being displaced inferiorly to facilitate identification of the pituitary stalk. The suprasellar space is divided in an infrachiasmatic region, where the superior hypophyseal arteries (SHAs) are located, and suprachiasmatic space, where the anterior communicating artery complex is located. When the dural opening stops at the limbus of the sphenoid dural fold, the suprachiasmatic space is not readily exposed. The left SHA gives off the following branches: descending or diaphragmatic, infundibular anastomotic, and to the optic nerve. The left-sided SHA gives only the infundibular anastomotic and to the optic nerve. Note the rich anastomotic network formed by both SHAs at the tuberoinfundibular area. (Image courtesy of JC Fernandez-Miranda)