Interdural transcavernous approach to the upper clivus. The posterior clinoidectomy has been completed and the dura of the upper clivus and oculomotor triangle has been opened. The interclinoidal ligament forms the medial limit of the oculomotor triangle and serves as a reference for the interdural segment of the oculomotor nerve, located infero-lateral to the ligament. The cisternal segment of the oculomotor nerve runs in between the P1 superiorly and the SCA inferiorly, in close relation with the PComA. The uncus of the temporal lobe is located lateral to the oculomotor nerve. (Image courtesy of JC Fernandez-Miranda)