Aneurysms of Proximal(A1) Segment of Anterior Cerebral Artery

Ahn, Jea Keun; Park, Young Sup; Park, Sung Chan; Cho, Kyung Keun; Lee, Kyung Jin; Choi, Chang Rak

Abstract

Aneurysms located on the proximal(A1) segment of the anterior cerebral artery are known for their rarity. In this study, eight patients, all with aneurysms arising from the proximal(A1) segment of the anterior cerebral artery, were selected from 625 patients who underwent surgical treatment under the diagnosis of cerebral aneurysm. Each cases were reviewed as an attempt to investigate the demographic and clinical features of these patients. The incidence of A1 aneurysm was 1.3%. Multiple aneurysms occurred in one(12.5%) out of the 8 cases and the bleeding was from the A1 aneurysm. The mean age of the eight patients was 56.8 years: there were six women and two men. The aneurysms were classified according to the mode of origin of the aneurysm in relation to the A1 segment: in 4 of the 8 cases, the aneurysms were found to be originated from the junction of the A1 segment and a perforating artery: in which the remaining 4 cases, they are from the A1 segment directly. Computerized tomography(CT) of these aneurysms revealed subarachnoid hemorrhage extending to the surprasellar and sylvian cisterns similar to that of the posterior communicating artery aneurysm or the internal carotid artery bifurcation aneurysm. Bleeding which extends to the interhemispheric cisterns or septum pellucidum, while frequently occurrs during the rupture of anterior communicating artery aneurysm, are rare in these cases. Because there are many differences between the findings in author's series and these in the literature, coordinated studies are necessary to define the demographic and clinical features of A1 aneurysm in Korea.