The Prognostic Value of Collateral Blood Flow in Acute Middle Cerebral Artery Occlusion

Recent clinical studies of thrombolysis in acute cerebral ischemia emphasize mostly the efficacy and safety of this kind of treatment [5–7, 11]. The main objective in these studies, designed to find the optimal dose/application form and the best thrombolytic agent in acute stroke, is reeanalization. Another important objective is to determine the therapeutic efficacy by correlating infarction size with recanalization. We doubt that the infarction size depends only on the degree of recanalization achieved by thrombolysis. While vascular collateral systems in the cerebral circulation other than the circle of Willis have long been known [4], their role in maintaining the blood supply to the brain in occlusion of cerebral arteries is not entirely clear [2, 12, 13, 15]. The pial anastomoses among the anterior, posterior, and middle cerebral arteries responsible for leptomeningeal collateral blood supply (LCBS) are known as the “circulus arteriosus intrahemisphaerieus,” or intrahemispheric arterial circle, and can be shown angiographically.