Step-by-step approach to the suprasellar region. The bone covering the right paraclinoidal internal carotid artery (ICA) has been completely removed up to the level of the optic strut. The optic canal has been decompressed in 180- to 270-degree fashion up to the orbital apex, including all of the medial wall, most of the roof, and part of the floor of the optic canal. The floor cannot be removed completely because it is formed by the optic strut, and the lateral wall is formed by the anterior clinoid process, which is not accessible from the endonasal route. This extensive exposure of the ICA and optic canal dura is required to facilitate wide access to the optic-carotid cistern once the dura is opened. (Image courtesy of JC Fernandez-Miranda)