Commentary

Removal of the anterior clinoid process improves exposure of the parasellar and suprasellar regions and of the area in front of the upper brain stem. However, the extent of this exposure has not been quantified. The authors did so in 10 cadaveric specimens and concluded that the narrow space between the carotid artery and oculomotor nerve is almost doubled by drilling away the entire anterior clinoid process. When dealing with tumors in this area, surgeons often must use multiple avenues to access this region because a single path may have an unanticipated impediment. In the case of the carotico-oculomotor triangle, the posterior communicating artery, anterior choroidal artery, and their perforating branches can be draped over and pushed laterally by a suprasellar tumor. Enlarging the space between the optic nerve and the carotid artery can be achieved by opening the optic nerve sheath and mobilizing the optic nerve, providing a different trajectory to this area.