Afferent artery and the site of neck of anterior communicating aneurysms.

The relationship between the afferent artery and the site of aneurysmal neck and hemodynamics in the anterior part of the circle of Willis was investigated from surgical and angiographic findings in 213 patients with anterior communicating artery aneurysms. An afferent artery was limited to the dominant A1 in about 95% of them. The neck of an aneurysm was more than three times greater at the bifurcation of the dominant A1 and the anterior communicating artery than at the bifurcation of the non-dominant A1 and the anterior communicating artery.