Patient selection for stroke thrombectomy

Six randomized controlled trials have established the substantial benefit of mechanical thrombectomy for acute ischemic stroke patients presenting with large vessel occlusive disease.1–6 Enrolling patients with large clinical deficit in the setting of small completed infarct and rapid, complete, or near complete recanalization, and treatment with the most recent generation of thrombectomy devices, contributed to this success. Efforts to generalize the results of these trials beyond select, experienced centers have focused attention on workflow and developing consensus on patient selection. Optimizing outcomes requires identifying patients most likely to improve and those most likely harmed with reperfusion. Imaging played a central role in selecting patients for these studies but the choice of imaging measures varied among studies. Some designs relied heavily on CT perfusion, multiphase CT angiography, or a combination of modalities, but all endeavored to identify the core (irreversibly infarcted brain), the penumbra (tissue at risk), or both.