Revascularization End Points in Stroke Interventional Trials

Abstract

Background and Purpose-The acute stroke literature lacks a standard convention regarding the critical end point of revascularization. Two distinct parameters may be clinically important: (1) recanalization of the primary arterial occlusive lesion (AOL) and (2) global reperfusion of the distal vascular bed. We sought to determine their relationship in the Interventional Management of Stroke (IMS) Phase I trial of combined intravenous (IV) and intraarterial (IA) recombinant tissue plasminogen activator. Methods-Sixty-one angiograms were reanalyzed using recanalization and reperfusion scores. The AOL Score was defined as: 0ϭno recanalization of the primary occlusion, Iϭincomplete or partial recanalization of the primary occlusion with no distal flow, IIϭincomplete or partial recanalization of the primary occlusion with distal flow, or IIIϭcomplete recanalization of the primary occlusion with distal flow. The Thrombolysis in Myocardial Infarction (TIMI) Score was defined as: 0ϭno perfusion, 1ϭperfusion past the initial occlusion but no distal branch filling, 2ϭperfusion and incomplete or slow distal branch filling, or 3ϭfull perfusion with filling of all distal branches. We compared the 2 scores with one another and with good clinical outcome (modified Rankin Score zero to 2). Key Words: acute Rx Ⅲ acute stroke Ⅲ interventional neuroradiology T hrombolytic revascularization is the only proven, effective way to reverse neurologic deficit in acute ischemic stroke. 1 Newer revascularization strategies are often assessed, at least in part, based on their ability to restore flow. In addition, the U.S. Food and Drug Administration (FDA) assesses devices for revascularization according to their ability to restore blood flow. 2 However, despite attempts to define reporting standards for thrombolysis trials, 3 the acute stroke literature currently lacks a standard convention for describing this critical end point. Trials, studies, and case series have used the terms "recanalization" and "reperfusion," or sometimes both interchangeably, to describe revascularization. Moreover, definitions of each term vary. Results-AOLTwo distinct parameters that may be critical in the assessment of revascularization are (1) recanalization of the primary arterial occlusive lesion (AOL) and (2) global reperfusion of the distal vascular bed. Distinguishing between these parameters may be clinically important. For example, an artery may be completely recanalized, but distal clot embolization may limit distal reperfusion. This may limit significant neurologic recovery and could theoretically increase the risk of hemorrhage as a result of local hyperperfusion in ischemic brain regions. On the other hand, distal reperfusion may be achieved, but the artery may have incomplete recanalization (ie, residual clot at the primary occlusive site) predisposing to a higher rate of reocclusion with subsequent clinical deterioration. 4 Drugs, devices, or combinations may differ in their ability to achieve and maintain recanalization and reperfusion.Heterogeneo...

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Normobaric Hyperoxia Delays Perfusion/Diffusion Mismatch Evolution, Reduces Infarct Volume, and Differentially Affects Neuronal Cell Death Pathways after Suture Middle Cerebral Artery Occlusion in Rats

“…However, it is well recognized that early reperfusion leads to smaller ischemic lesion volumes and good clinical recovery in humans suffering from acute ischemic stroke (Christou et al, 2000). Promising strategies to extend the treatment window include rigorous patient selection based on imaging criteria, intraarterial thrombolysis, combined intravenous and intraarterial thrombolysis, and endovascular approaches to reperfusion (Furlan et al, 2006;Khatri et al, 2005;Smith et al, 2005). However, these approaches have the common disadvantage that they require patient transport to a suitable hospital for advanced neuroimaging before treatment.…”