Mechanical thrombectomy for emergent large vessel occlusion: a critical appraisal of recent randomized controlled clinical trials

Background and Purpose After numerous attempts to prove efficacy for endovascular treatment of ischemic stroke, a series of recent randomized controlled clinical trials ( RCT s) established fast mechanical thrombectomy ( MT ) as a safe and effective novel treatment for emergent large vessel occlusion ( ELVO ) in the anterior cerebral circulation. Methods We reviewed five recent RCT s that evaluated the safety and efficacy of MT in ELVO patients and captured available information on recanalization/reperfusion, symptomatic intracranial hemorrhage ( sICH ), clinical outcome, and mortality. MT was performed with stent retrievers, aspiration techniques, or a combination of these endovascular approaches. We applied meta‐analytical methodology to evaluate the pooled effect of MT on recanalization/reperfusion, sICH , functional independence (modified Rankin scale score of 0–2) and 3‐month mortality rates in comparison to best medical therapy ( BMT ). Results MT was associated with increased likelihood of complete recanalization/reperfusion ( RR : 2.22; 95% CI : 1.89–2.62; P  < 0.00001) and 3‐month functional independence ( RR : 1.72; 95% CI : 1.48–1.99; P  < 0.00001) without any heterogeneity across trials ( I 2  = 0%). The absolute benefit increase in MT for complete recanalization/reperfusion and functional independence was 44 ( NNT  = 2) and 16 ( NNT  = 6), respectively. MT was not associated with increased risk of 3‐month mortality (15% with MT vs. 19% with BMT ) and sICH (4.6% with MT vs. 4.3% with BMT ), while small heterogeneity was detected across the included trials ( I 2  < 25%). Conclusions MT is a safe and highly effective treatment for patients with ELVO in the anterior circulation. For every six ELVO patients treated with MT three more will achieve complete recanalization at 24 h following symptom onset and one more will be functionally independent at 3 months in comparison to BMT .