Arterial Recanalization in Acute Stage of Cerebral Infarction

Abstract

It is well-known that recanalization of the occluded arteries in a cerebral infarction is a common phenomenon observed in about 40% of cerebral infarctions caused by an occlusion of angiographically visible arteries. The precise process and clinical significance of the recanalization is, however, not always analyzed satisfactorily. The authors performed a follow-up angiography in 41 patients with a cerebral infarction which had an arterial occlusion in an initial angiography, and disclosed a recanalization of the occluded artery in 18 patients. The clinical and neuroradiological findings in the 18 patients are reviewed. Recanalization occurred within 7 days after a stroke. In well-documented cases, the recanalization seemed to occur around 4 days after the stroke. However, the precise process were not always uniform and there seemed to be several variations such as partial recanalization caused by migration of an embolus and incomplete recanalization due to gradual spontaneous clot lysis. In thrombotic occlusions the recanalization occurred later than in embolic occlusions, and, moreover, it had a tendency to result in incomplete recanalization which showed a residual stenosis in post-recanalized angiography. Computed tomography (CT) disclosed a hemorrhagic infarction in half of the recanalized cerebral infarctions and enhancement effects by an intravenously injected contrast medium were seen in almost all cases. These CT findings tended to appear later than the arterial recanalization itself.