Anatomical variations of the anterior communicationg artery complex : a multidetector CT angiographic study

Abstract

The anterior communicating artery complex (ACoA complex) of the circle of Willis is an area with great anatomical diversity, and it forms part of the communicating arterial supply to the brain. As brain tissues are susceptible to cell death due to insufficient blood supply, knowledge on this variability is important in diagnosis and management of any diseases that affect brain circulation. A cross-sectional study was done to measure the prevalence and to describe these variations from reconstructed CT angiographic (CTA) images. All patients who underwent angiographic computed tomography scanning for any reasons in HTAA from January 2009 to August 2015 were selected. A total of 81 CT angiographic images were studied for different types of variations (hypoplasia, aplasia, and duplication of the anterior communicating artery; hypoplasia, and aplasia of the A1 and A2 segments of the anterior cerebral artery; A2 segments of the anterior cerebral artery arising from a common trunk; and the third A2 segment); where A1 segment is the part of the anterior cerebral artery from the internal carotid artery to the anterior communicating artery, and A2 segment is the part of the anterior cerebral artery from the anterior communicating artery to the junction between the rostrum and genu of the corpus callosum. Eleven types of variations were described. The typical pattern (Type 1) of the ACoA complex was seen in 35.8%, and the cases with vascular variations constituted 64.2%, which is higher compared to previous studies. The percentage of the cases presented with variations in the anterior communicating artery was 43.2%, and the most common type of anatomical variation was the aplasia of the anterior communicating artery, accounting for 28.4%. This study has shown that the prevalence of anatomical variations in the ACoA complex is high, and that there can probably be difference of this figure in different populations.