Mechanical Thrombectomy for Acute Ischemic Stroke A Meta-Analysis of Randomized Trials

Background Acute ischemic stroke is a leading cause of serious disability and death worldwide. Individual randomized trials have shown possible benefits of mechanical thrombectomy after usual care compared with usual care alone (i.e., intravenous thrombolysis) in the management of acute ischemic stroke patients. Objectives This study systematically determined if mechanical thrombectomy after usual care would be associated with better outcomes in patients with acute ischemic stroke caused by large artery occlusion. Methods The authors included randomized trials that compared mechanical thrombectomy after usual care versus usual care alone for acute ischemic stroke. Random effects summary risk ratios (RR) were constructed using a DerSimonian and Laird model. Results Nine trials with 2,410 patients were available for analysis. Compared with usual care alone, mechanical thrombectomy was associated with a higher incidence of achieving good functional outcome, defined as a modified Rankin scale (MRS) of 0 to 2 (RR: 1.45; 95% confidence interval [CI]: 1.22 to 1.72; p < 0.0001) and excellent functional outcome defined as MRS 0 to 1 (RR: 1.67; 95% CI: 1.27 to 2.19; p < 0.0001) at 90 days. There was a trend toward reduced all-cause mortality with mechanical thrombectomy (RR: 0.86; 95% CI: 0.72 to 1.02; p = 0.09). The risk of symptomatic intracranial hemorrhage was similar with either treatment modality (RR 1.06: 95% CI: 0.73 to 1.55; p = 0.76). Conclusions In acute ischemic stroke due to large artery occlusion, mechanical thrombectomy after usual care was associated with improved functional outcomes compared with usual care alone, and was found to be relatively safe, with no excess in intracranial hemorrhage. There was a trend for reduction in all-cause mortality with mechanical thrombectomy.