Absence of right posterior communicating artery

The circle of Willis represents a vascular network located at the base of the skull in the interpeduncular fossa. The anterior cerebral artery forms the anterior section of the circle of Willis from the right and left sides. The anterior cerebral arteries from both sides are joined by the anterior communicating artery. In the posterior part, the basilar artery separates into the right and left posterior cerebral arteries, and their connection to the ipsilateral internal carotid artery is provided via a posterior communicating artery. The posterior communicating artery, which represents a significant element of the circle of Willis, functions as a collateral channel for maintaining the blood flow. In this study, the presence of an anatomical variation was determined in the right posterior communicating artery while performing the routine cadaver dissection. It was determined that the right posterior communicating artery was absent in a male cadaver. Since the posterior communicating artery represents one of the elements of the circle of Willis maintaining the cerebral blood flow in case of the failure of principle conduits, information on its anatomical variations is clinically important.