Anatomic variations of anterior cerebral artery cortical branches

The anterior cerebral artery (ACA) is a major vessel responsible for the bl ood supply to the interhemispheric region. The ACA segment after the anteri or communicating artery (AComA) origin is called the distal ACA and has cen tral and cortical branches. The cortical branches are distributed in the di fferent regions of the orbital and medial part of the brain. The objects of this study are the anatomical variations found in the distal ACA. In 76 he mispheres the ACA distal branches were injected with latex and dissected un der microscope magnification. Vessel diameters and distances between vessel origins and anterior communicating artery were recorded and analyzed. Micr osurgical dissection was carried out to demonstrate anatomic variations of these vessels. Average diameter of ACA at origin was 2.61 +/- 0.34 mm and a verage diameter of cortical branches diameter ranged from 0.79 +/- 0.27 mm to 1.84 +/- 0.3 mm. Distances between vessel origin and AComA ranged from 7 .68 +/- 3.91 mm (orbitofrontal) to 112.6 +/- 11.63 mm (inferior internal pa rietal). This study found anatomical variation: a single (azygos) ACA was p resent in one case and three in three cases. Crossing branches of the dista l ACA to the contralateral hemisphere were present in 26% of the cases. in some cases a single ACA may supply the posterior hemispheric region through crossing branches. This calls attention to potential bilateral brain infar cts due to a single unilateral ACA occlusion. (C) 2000 Wiley-Liss, Inc.