Superior hypophyseal artery aneurysm の3例

Abstract

Saccular intracranial aneurysms almost always arise at arterial bifurcations; however, ventral paraclinoid carotid aneurysms arising from the internal carotid artery in the segment between the ophthalmic artery and the posterior communicating artery (“ophthalmic segment”) may have no obvious arterial branches at their origin. The superior hypophyseal arteries usually arise from the ophthalmic segment and pass ventrally and medially beneath the optic nerve to irrigate the optic nerve, pituitary stalk, and the hypophysis. We have documented intraoperatively three cases of saccular aneurysms arising from the superior hypophyseal artery take-off from the internal carotid artery. The age at presentation was 62, 50 and 63 years old, respectively. All three patients were female. Two patients experienced subarachnoid hemorrhage attributable to their superior hypophyseal artery aneurysms. The remaining patient presented with subarachnoid hemorrhage related to another aneurysm, and in the course of evaluation was found to have a second, incidental superior hypophyseal artery lesion. Angiographically, superior hypophyseal artery aneurysms were invariably noted on the inferior medial surface of the internal carotid artery slightly distal to the ophthalmic artery origin. At surgery, exposure of the cervical internal carotid was performed to gain proximal arterial control. The anterior clinoid process and optic canal roof were removed to provide proximal visualization of the neck of the aneurysm. In two cases, the aneurysm was easily obliterated with angled fenestrated clips, the blade of which passed over and then ran parallel to the internal carotid artery. All three patients were discharged without neurological deficit.