The mid‐M1 segment of the middle cerebral artery is a cutoff clot location for good outcome in intravenous thrombolysis

Abstract

The outcome of acute internal carotid artery or proximal M1 segment of the middle cerebral artery occlusion is generally poor even if treated with intravenous thrombolysis. Alternative revascularization strategies should be considered. Vascular imaging at the admission is required to guide this decision.

Early Reperfusion Rates with IV tPA Are Determined by CTA Clot Characteristics

“…We also confirm a previously reported association between early recanalization and the distance of the clot from the M1 MCA origin. 20,21 Our study has limitations. We restricted our analysis of early reperfusion rates with IV tPA to baseline CTA characteristics.…”

“…For M1 MCA occlusions, we studied an additional clot characteristic by measuring the distance from the M1 MCA origin to the proximal clot interface. 20,21 Distal M1 MCA clots may be exposed to more shear stress at the proximal clot interface due to patent flow in the lenticulostriate arteries compared with proximal clots. Additionally, distal M1 clots are potentially smaller than proximal clots.…”

An endovascular canine stroke model: middle cerebral artery occlusion with autologous clots followed by ipsilateral internal carotid artery blockade

“…18,27 Besides, the occlusion site and the size of thrombus also had a certain impact on the infarct volume. 15,24 In our previous study, we observed that the connections of pial recruitments to MCA could be visualized nearby the distal M1 segment while occluding proximal-MCA with single clot initially. 10 Given above factors, we chose to block M1 segment with two clots followed by ICA blockade.…”

“…15 In studies of Rink et al 2 and Christoforidis et al, 18 coils, other than thrombus, were used to generate stroke models, which called into questions about the physiological relevance of the model and risk of vasospasm or perforation of intracranial arteries. Moreover, considering that ischemic infarct was Canine stroke model with MCAO and ICA blockade Q-Q Zu et al usually caused by thrombi composed of platelets and/or fibrin in humans, the thrombin-induced clot may recapitulate an ideal stroke model.…”

“…10,13 In human strokes, one vessel blockade often results in large or consecutive ischemia lesions. However, segmental occlusion of one single vessel (eg, middle cerebral artery (MCA)) in dogs often cannot produce significant defects 10,14,15 because of compensation due to their leptomeningeal collateral circulation. Abundant collateral blood flow could develop from the distal area to the occluded locus before an irreversible ischemic lesion could happen, 2,10,[16][17][18] which results in a major mismatch between the size of infarct area and the territory of the vessel occlusion.…”