Diagnosing common carotid artery agenesis using duplex ultrasound.

The complete absence of a common carotid artery, also known as common carotid artery (CCA) agenesis, is a well-described yet extremely rare congenital anomaly. Most carotid system anomalies are related to origins of the external or internal carotid arteries. All such anomalies are typically asymptomatic unless associated with a concomitant arterial lesion that results in a workup for symptomatic intracerebral pathology or a focal neurological deficit. The literature is scant on the topic, being limited to singular case reports. We report 3 cases of CCA agenesis and provide the readers with insightful data on the available literature.