Five recent trials have shown the benefit of endovascular treatment in patients with acute ischemic stroke due to large vessel occlusion in the anterior circulation.1–5 There were a lot of commonalities between the trials. The key ones were: most patients had clinically severe ischemic stroke; most patients had small core based on imaging; all patients had neurovascular imaging to detect the presence of proximal vessel occlusion; most patients had an M1±intracranial internal carotid artery occlusion; a stent retriever was used for clot retrieval in the majority of patients.6–8 There were also commonalities in the results: all trials used the modified Rankin Scale (mRS) at 90 days and used shift analysis (EXTEND-IA was a phase IIB study with reperfusion and/or NIH Stroke Scale at 24 h as the primary outcome; however this trial also reported mRS at 90 days as their secondary analysis); all trials showed a statistically significant benefit of endovascular treatment over the control arm. The complication rates (symptomatic intracranial hemorrhage) of endovascular treatment were exceedingly low across all trials.

There were, nonetheless, some differences between these trials. The key differences were: some trials had a lot of focus on speed and workflow (ESCAPE and SWIFT PRIME), some trials used CT perfusion for patient selection (EXTEND-IA and most of the patients …