Absent internal carotid artery during neck exploration for penetrating trauma.

Congenital absence of the internal carotid artery (ICA) is an extremely rare vascular anomaly. Although typically asymptomatic, its presence can complicate the surgical management of penetrating neck injuries. We present the case of a 23-year-old man with active hemorrhage from a right-sided neck stab wound. Intraoperative neck exploration failed to identify the right ICA. Subsequent intraoperative angiography and postoperative computed tomography angiography confirmed a congenital absence of the right ICA and the corresponding carotid canal. Surgeons must be aware of rare vascular variants such as ICA agenesis, because they can mimic traumatic injury or vascular occlusion during emergent neck explorations.