Previously unreported variant collateral supply in an acute stroke patient with anomalous common and internal carotid artery anatomy undergoing mechanical thrombectomy

Agenesis of the common carotid and internal carotid arteries are rare entities. Approximately 100 cases of internal carotid artery (ICA) agenesis are reported in the literature, and even fewer cases of common carotid agenesis. The collateral supply in such cases is well described and typically follows one of only a small number of variations. Lie classically described six major pathways of collateral supply in ICA agenesis (Congenital Anomalies of the Carotid Arteries. Excerpta Medica, Amsterdam, 1968; 35). Vasovic et al. in a comprehensive review of all published cases of common carotid agenesis have similarly described the typical variations in collateral supply seen in this setting. Neither described the anatomy presented here.