Research on the correlation of A1 segment predomination of anterior cerebral artery associated with anterior communicating artery aneurysms

Objective On the basis of the cerebral angiographic imaging,this study was undertaken to investigate the correlation between the presence of anterior communicating artery(ACoA) aneurysm and the ipsilateral dominant A1 segment of anterior cerebral artery(ACA).Methods Two hundred and nine patients harboring saccular aneurysms demonstrated by digital subtraction angiography were collected for study.There were 66 cases with aneurysms of ACoA.The remaining 143 cases were other intracranial aneurysms and another 66 cases free of intracranial aneurysms were randomly drawn as control.Results Cerebral angiography showed that the dominant A1 segment incidence was 62.1%(41/66) in ACoA aneurysm group,14.7%(21/143) in the group with other intracranial aneurysms and 27.3%(18/66) in the control group.Within patients with ACoA aneurysms,the incidence of the dominant A1 segment was about 4 times higher on the left side than that on the right side.Conclusion Dominant A1 segment of anterior cerebral artery is much more frequently found in patients with ACoA aneurysms.It can be inferred that hemodynamically generated forces at the apex of anterior cerebral artery bifurcation can maybe an important contributing factor in the focal degeneration of the internal elastic membrane leading to ACoA formation.