Abstract

The posterior cerebral artery pertains to rear brain circulation and irrigates the lower areas of temporal and occipital lobes, as well as the thalamus, hippocampus and mesencephalon. It originates in the bifurcation of the basilar artery and goes around the mesencephalon to the quadrigeminal cistern, where it continues to the rear until it enters the cerebral parenchyma and divides into its terminal branches, the calcarine and parieto-occipital arteries. The aim of this study is to describe the different segments of the posterior cerebral artery (PCA) in chileans and to analyze some anatomical differences found when compared with descriptions in international literature. Twenty hemispheres analyzed were formalin fixed, and their arteries were injected with colored acrylic in order to be anatomized with 6x to 40x magnification using microanatomical techniques. The results were statistically analyzed. The PCA and each of its branches are similar in path and morphology to those described by other authors. Meaningful differences were found in segments' distribution in the arterial groups between right and left hemispheres. When compared with the Zeal and Rhoton (1) study, there are differences in the PCAs' segment lengths, in the prevalence of 3 arterial groups and in the distribution of the arterial groups by origin segment. In 20% of the analyzed hemispheres, the terminal branches of the PCA extended into the calcarine cissure. © 2006 Sociedad de Neurolog Psiquiatry Neurocirugbr.