Isamu Ezuka

The simple indicator for revascularization of acute middle cerebral artery occlusion using angiogram and ultra-early embolectomy

BACKGROUND The purpose of the study was: (1) to find a clinical indicator for revascularization of acute middle cerebral artery (MCA) occlusion using angiograms of 100 patients examined immediately after onset and treated medically and (2) to investigate 10 ultra-early MCA embolectomies. METHODS Quantity of collateral circulation, based on time required for conduction of contrast media to the insular portion of the MCA from the anterior cerebral artery, MCA conduction time (MCT) was graded as: Grade 1: In the arterial phase, there was conduction not only to the insular portion of the MCA but also to proximal M2; Grade 2: Conduction to the insular portion was present in late arterial phase; Grade 3: Conduction was present in capillary phase; Grade 4: Conduction was present in venous phase; Grade 5: No conduction was seen. The results of embolectomy are discussed. RESULTS MCT can predict the extent of resultant low-density area on computed tomographic scan. For Grades 3, 4, or 5, embolectomy could be considered superior to medical treatment, if the low-density area was localized in the basal ganglia or centrum semiovale after surgery. Consequently, embolectomy was effective in four cases recanalized within 6 hours of onset. Except for one Grade 5 case, the remaining nine cases showed neither lethal hemorrhagic infarction nor brain edema. Overall outcome was significantly better than cases treated medically (p < 0.05), but some cases did not recover from hemiparesis due to infarcts in the area of the lenticulostriate arteries. CONCLUSIONS MCT helps to predict the applicability of revascularization of acute MCA occlusion. Efficacy of embolectomy depends on revascularization within 6 hours of onset. Even after complete MCA flow restoration, infarcts in the area of the lenticulostriate arteries cannot always be prevented.