A, The inset shows the small right frontal craniotomy. The frontal lobe has been elevated to expose the right optic nerve and chiasm as shown in the inset. This approach is most commonly selected for lesions situated between and behind the optic nerves in the chiasmatic cistern. The dura has been removed from the upper surface of the planum sphenoidale, optic canal, and anterior clinoid process. In most cases for which this approach is selected, there is no need to expose the sphenoid sinus or remove the anterior clinoid process. B, The subfrontal exposure has been converted into a transfrontal-transsphenoidal approach to the sellar region by removing the roof of the sphenoid sinus. The anterior sellar wall is seen through the opening in the planum sphenoidale. The superior hypophyseal artery arises from the supraclinoid carotid and passes to the pituitary stalk. C, The optic nerve has been displaced laterally to show the origin of the ophthalmic artery. The anterior sellar wall has been removed to expose the anterior surface of the pituitary gland. D, The pituitary gland has been displaced to the left to open the space between the lateral surface of the pituitary gland and the medial surface of the intracavernous carotid. The inferior hypophyseal artery, which arises from the meningohypophyseal trunk of the intracavernous carotid, passes to the capsule of the posterior lobe. (Images courtesy of AL Rhoton, Jr.)