Internal Carotid Artery Agenesis in a Trauma Patient with Ipsilateral Neck GSWs

A 38-year-old man presented to the emergency room in the trauma bay for multiple ballistic injuries to the right neck. He was hemodynamically stable, protecting his airway, and neurologically intact. Computed tomography angiography (CTA) revealed absent filling the right internal carotid artery from its origin to the circle of Willis, which was intact, as well as absent petrous carotid canal on the right. The patient was diagnosed with right internal carotid artery (ICA) agenesis and discharged in several days. This report demonstrates the importance of an in-depth knowledge of vascular embryology and anatomy. The patient has agreed to have images and case details published.