Acute endovascular recanalization: lessons from randomized controlled trials

The purpose is to review the results and impact of recent positive studies on endovascular stroke treatment in the context of previous negative trials.

Since October 2014, the results of five randomized controlled multicenter trials on the endovascular stroke treatment as adjunct to conservative treatment (largely including intravenous tissue-type plasminogen activator) versus conservative treatment alone have been published. All of these trials largely used stent retrievers as endovascular device and included patients with proven large vessel occlusion (mostly distal internal carotid or proximal middle cerebral artery (M1), short time windows after stroke onset and mostly small infarctions on initial imaging. Over all there was an overwhelming beneficial effect on outcome measured as shift in the modified Rankin Scale score and independent survival, respectively. Moreover, the rate of adverse events, in particular hemorrhage rate, was not increased. These new findings contrast previous studies on endovascular stroke treatment using mostly first generation nonstent retriever devices, longer time windows and different imaging inclusion criteria, which were overall neutral for patient outcome.

Endovascular stroke treatment with stent retrievers is the standard of care in large vessel occlusion. New randomized controlled trials should investigate safety and efficacy in extended indications as advanced time windows or more extensive signs of ischemia on initial imaging. The same applies for new devices apart from stent retrievers.