State of acute endovascular therapy: report from the 12th thrombolysis, thrombectomy, and acute stroke therapy conference.

Abstract

Acute endovascular therapy for ischemic stroke is at a pivotal juncture. Until recently, on the basis of randomized trials comparing devices, we knew that endovascular treatment options were effective in quickly restoring blood flow and that successful early recanalization was associated with better functional outcome when compared with sustained occlusion.1,2 We did not have randomized evidence that available acute endovascular therapy improved patient outcomes; the 3 initial randomized controlled trials of endovascular recanalization treatment published in February of 2013—the Phase II Mechanical Retrieval and Recanalization of Stroke Clots Using Embolectomy (MR RESCUE), Phase III Interventional Management of Stroke (IMS) III, and Local Versus Systemic Thrombolysis for Acute Ischemic Stroke (SYNTHESIS) trials—failed to demonstrate improved clinical outcomes.3–5 Many factors may have contributed to the failure of these 3 initial trials to show endovascular benefits. These trials were performed during a period of rapid evolution of imaging and treatment options, and used intra-arterial thrombolysis, or first-generation device therapies at best, with little use of newer generation devices, such as stent retrievers, demonstrated to achieve significantly higher rates of recanalization.1,2 Patients with mild or moderate stroke severity may have been less likely to benefit from endovascular reperfusion based on IMS III and Prolyse in Acute Cerebral Thromboembolism (PROACT) II post hoc analyses and others.3,6,7 The power of these trials was diluted by including subjects without intracranial vessel occlusions, and post hoc analyses of IMS III suggested a potential treatment effect among stroke patients with baseline computed tomographic (CT) angiographic occlusions.8 Larger vessel occlusions, which are more resistant to recanalization by intravenous recombinant tissue-type plasminogen activator (r-tPA), such as intracranial internal carotid artery (ICA) location or occlusions >8 mm, may have been more likely to show a treatment effect …