Published online by Cambridge University Press: 28 October 2019
When used alone, intravenous and intra-arterial thrombolysis have yielded low recanalization rates of proximal large-vessel occlusions (LVO). The endovascular trials utilizing first-generation devices such as the Merci retriever and the Penumbra aspiration system were essentially neutral and failed to demonstrate superiority of mechanical thrombectomy over IV tPA (MR RESCUE, SYNTHESIS, IMS-III). In 2015, however, six trials – MR CLEAN, EXTEND-IA, SWIFT PRIME, ESCAPE, REVASCAT, and THRACE – led to a fundamental shift in how we acutely manage LVOs today. All six trials compared endovascular thrombectomy (EVT) to IV tPA alone and demonstrated clear superiority of thrombectomy in patients presenting within 6 hours from the time they were last known well (LKW) if they met specific imaging criteria.