Anatomical variations of origin of the internal carotid artery: Report of two cases and systematic review of the literature.

Abstract

Anatomical variations of origin of the internal carotid artery (ICA) are very uncommon and may pose a diagnostic and therapeutic challenge. We report a case of direct origin of the right ICA from the innominate artery (aplasia of common carotid artery) and a case of duplication of right ICA in healthy patients who performed duplex ultrasound (DUS) for primary cardiovascular prevention screening. In both cases, the ultrasound scan was performed both in a transverse plane and on the longitudinal axis, and in one of the two cases, a computed tomography angiography was performed to confirm the diagnosis. A review of the current literature about anatomical variations of origin of carotid arteries was also performed. The most frequent congenital anomaly is represented by the aplasia of the CCA, followed by the agenesis and by the duplication of the ICA. In most cases, the anomaly is discovered occasionally and symptoms are aspecific. Diagnosis is usually confirmed through a multimodality imaging approach, including DUS of extracranial carotid arteries, magnetic resonance imaging (MRI), and computed tomographic angiography. In most cases, treatment was conservative, with pharmacological therapy aimed at the symptoms. The recognition of such variations is mandatory, particularly when the patient needs a surgical treatment that may involve the vessel with the anatomical variations.