Bilateral Agenesis of Internal carotid artery: A case report with emphasis on neuroimaging features

Abstract

Congenital absence of the internal carotid artery is a rare anomaly, occurring in less than 0.01% of the population [1, 3]. It includes agenesis, aplasia, and hypoplasia of the internal carotid artery [2, 5]. Recognition of these anomalies has important implications during planned surgery, in thromboembolic disease and in the surveillance and detection of associated cerebral aneurysms [2, 3]. It is usually an incidental finding on color Doppler carotid ultra sonography, angiography, computed tomography or magnetic resonance imaging of the head and neck taken for some other indication [2, 6]. Most of the patients are asymptomatic due to the presence of sufficient cerebral circulation supplied by the communicating arteries of the circle of Willis, inter cavernous anastomosis, external carotid artery and by persistent embryologic arteries to the carotid artery territory. Nevertheless, in some cases this anatomic variation may eventually lead to some clinical signs and symptoms [2, 4, 6]. We present a rare case of congenital absence of both internal carotid arteries and its possible implications.