UNILATERAL AGENESIS OF THE INTERNAL CAROTID ARTERY: REVIEW OF LITERATURE AND CLINICAL CONSIDERATION

The development of the internal carotid artery (ICA) begins at the 3-4 mm embryonic stage and acquires its mature shape by the end of the fourth week. Complex reconstruction of the terminal segment of the dorsal aorta and the third aortic arch underlies the formation of primordial ICA. Failure of this process leads to agenesis of the ICA in one of its seven segments with the following absence of the distal part of the vessel.

Due to the plasticity of the cerebral circulation, the majority of people with agenesis of the ICA manage to stay asymptomatic. However, some geometric patterns of the compensatory blood flow are predisposed to failure, resulting in susceptibility to the development of aneurysms, ischemic attacks, and accidental arterial dissections.

The wide-spread use of modern visualizing techniques allowed registration of quite a number of such cases, allowing systematic analysis and clinical evaluation of settled types of the collateral cerebral circulation and clinical tendencies in patients with agenesis of the ICA. Here, we report a case of unilateral agenesis of the ICA and additionally expose the results of systematic clinical analysis of 45 similar patients reported since 2000.