Impressively rare coexistence of vertebral arteria lusoria and unilateral internal carotid agenesia

Anatomical variants of the cervicocranial vasculature are rare and usually incidental findings. However, their identification is crucial due to their association with other neurovascular pathologies and their profound impact on surgical planning. We report the case of an 84 year-old patient who underwent computed tomography angiography for a suspected stroke. The study incidentally revealed the coexistence of two extremely rare vascular anomalies: agenesis of the left internal carotid artery and a right vertebral artery with a retroesophageal course. This exceptional finding emphasizes the fundamental role of modern imaging techniques in the diagnosis of these entities, which is essential for a correct interpretation of the patient's symptoms, preventing iatrogenic complications during interventional procedures, and understanding altered cerebral hemodynamics.