A study of arterial variation of Willis circle in 100 human brain in East Azarbaijan, Iran

Abstract

The aim of this study was to evaluate the variation of Willis circles and the arterial branches which participate to make them in 100 male cadavers in East Azarbaijan-Iran The Willis arterial circle of 100 East Azarbaijanian, Iran male cadavers have been exposed, the diameters of the arteries which participate to make the circles, have been measured by caliper and finally photographed and studied by using t-test. In 49% of subjects there have been complete circle of Willis. The posterior communicating arteries (PcomA) of these circles been symmetrical and had 1.5 mm diameter. The difference in comparison with those indicated in Gray's anatomy, was not significant (p>0.05). Twenty eight percent of subjects showed complete circle and symmetrical PcomA but the diameter of posterior communicating arteries were less than 1 mm (considered hypo functional as collateral routes). The difference of this category in comparison with reference been significant (p<0.05). Twelve percent of cadavers showed right or left side hypo plastic PcomA (p<0.05) and 11% showed incomplete circle with absence of right or left PcomA (p<0.05). The difference of these last two groups also been significant. In all of this studied subjects, the anterior communicating artery been existed. The diameter of the arteries, were about 1.5 mm.