Background Whether intravenous thrombolysis before mechanical thrombectomy provides additional benefit for functional outcome in acute ischemic stroke remains uncertain. We performed a meta-analysis to compare the outcomes of direct mechanical thrombectomy (dMT) to mechanical thrombectomy with bridging using intravenous thrombolysis (bridging therapy [BT]) in patients with acute ischemic stroke. Methods and Results We performed a literature search in the PubMed, Excerpta Medica database, and Cochrane Central Register of Controlled Trials from January 1, 2003, to April 26, 2021. We included randomized clinical trials and observational studies that reported the 90-day functional outcome in patients with acute ischemic stroke undergoing dMT compared with BT. The 12 included studies (3 randomized controlled trials and 9 observational studies) yielded 3924 participants (mean age, 68.0 years [SD, 13.1 years]; women, 44.2%; 1887 participants who received dMT and 2037 participants who received BT). A meta-analysis of randomized controlled trial and observational data revealed similar 90-day functional independence (odds ratio [OR], 1.04; 95% CI, 0.90-1.19), mortality (OR, 1.03; 95% CI, 0.78-1.36), and successful recanalization (OR, 0.93; 95% CI, 0.76-1.14) for patients treated with dMT or BT. Compared with those in the BT group, patients in the dMT group were less likely to experience symptomatic intracranial hemorrhage (OR, 0.68; 95% CI, 0.51-0.91; P=0.008) or any intracranial hemorrhage (OR, 0.71; 95% CI, 0.61-0.84; P<0.001). Conclusions In this meta-analysis of patients with acute ischemic stroke, we found no significant differences in 90-day functional outcome or mortality between dMT and BT, but a lower rate of symptomatic intracranial hemorrhage for dMT. These findings support the use of dMT without intravenous thrombolysis bridging therapy. Registration URL: https://www.crd.york.ac.uk/prospero/; Unique identifier: 42021234664.
Keywords: functional independence; ischemic stroke; thrombectomy; thrombolysis.