Congenital Absence of the Left Common Carotid Artery in a Patient with a Right-Sided Aortic Arch: A Case Study

Abstract

Absence of a common carotid artery (CCA) is an extremely rare congenital anomaly. The first documented case was in 1787 during a postmortem examination. The incidence of agenesis of the CCA is unknown with fewer than 25 cases reported in literature. Agenesis of the CCA is commonly associated with separate origins of the internal carotid artery (ICA) and external carotid artery (ECA) and is usually an incidental finding on imaging studies and can pass unnoticed or misdiagnosed. Such an anomaly is typically asymptomatic unless associated with an accompanying arterial lesion that results in a work-up for symptomatic intracerebral pathology, a focal neurological deficit, or during autopsy. Although absence of the CCA is usually asymptomatic, transient ischemic attacks, hemiplegia, and intracranial hemorrhage may occur.