Large vessel occlusion in a carotid terminus pure arterial malformation treated with mechanical thrombectomy and early re-occlusion.

Pure arterial malformations (PAMs) are rare arterial anomalies typically considered incidental, and their role in acute large vessel occlusion is not well defined. We describe a case of acute large vessel occlusion occurring in direct anatomical association with a carotid terminus PAM, treated with mechanical thrombectomy and followed by early selective re-occlusion of the malformed segment. Multimodal imaging and clinical history suggested pre-existing hemodynamic compromise and in situ thrombosis with distal embolization. Mechanical thrombectomy across the PAM segment was technically feasible and resulted in distal reperfusion, but durable patency of the malformed tract was not maintained. This case expands the recognized ischemic spectrum of PAM and suggests that selected morphologically complex lesions may behave as hemodynamically unstable substrates rather than incidental vascular variants.