Fetal and Primitive Type of Circle of Willis with Unilateral Trifurcation of Internal Carotid Artery

Abstract

Circle of Willis is a network of arteries in the base of the brain between the internal carotid artery and the vertebral artery to establish the collateral circulation between these two major arteries. Anomalies in this network may lead to serious clinical conditions like stroke by impairing the vital blood circulation. Normally, the internal carotid artery communicates with the posterior cerebral artery from the basilar artery by a thin posterior communicating artery. The present case however shows a rarity where both anterior cerebral arteries were arising from the left internal carotid artery and the right anterior cerebral artery had a small communication from the right internal carotid artery. In addition, both posterior communicating arteries were large and continued as posterior cerebral arteries with small contribution from the basilar artery. The knowledge of such variations may be useful for neurosurgeons and radiologists during the diagnosis and to plan the treatment regime.