Microsurgical treatment of ventral (paraclinoid) internal carotid artery aneurysms

Eight cases of ventral (paraclinoid) internal carotid artery aneurysms are presented. These aneurysms often challenge the surgeon because (a) they are partially or completely obscured by the optic nerve, internal carotid artery, and anterior clinoid process; (b) there is no proximal internal carotid artery control intracranially; and (c) part of the neck and fundus of the aneurysm is located within the cavernous sinus. These aneurysms, which have been classified as separate from the typical carotid-ophthalmic aneurysm group, are illustrated, and their surgical treatment and problems described.