Endovascular Therapy Versus Medical Therapy Alone for Basilar Artery Stroke: A Systematic Review and Meta-Analysis Through Nested Knowledge.

Background: Endovascular thrombectomy (EVT) is an effective treatment for acute ischemic stroke attributable to the anterior circulation large-vessel occlusion. Randomized trials of patients with posterior circulation large-vessel occlusion (PC-LVO) have failed to show a benefit of EVT over medical therapy (MEDT). We performed a systematic review and meta-analysis to understand better whether EVT is beneficial for PC-LVO. Methods: Using the Nested Knowledge AutoLit living review platform, we identified randomized control trials and prospective studies that reported functional outcomes in patients with PC-LVO treated with EVT versus MEDT. The primary outcome variable was 90-day modified Rankin scale score of 0 to 3, and secondary outcome variables included 90-day modified Rankin scale score of 0 to 2, 90-day mortality, and rate of symptomatic intracranial hemorrhage. A separate random effects model was fit for each outcome measure to calculate pooled odds ratios. Results: Three studies with 1248 patients, 860 in the EVT arm and 388 in the MEDT arm, were included in the meta-analysis. The favorable outcome rate (modified Rankin scale score of 0-3) in patients undergoing EVT was 39.9% (95% CI, 30.6%-50.1%) versus 24.5% in patients undergoing MEDT (95% CI, 9.6%-49.8%). Patients undergoing EVT had higher modified Rankin scale score of 0 to 2 rates (31.8% [95% CI, 25.7%-38.5%] versus 19.7% [95% CI, 7.4%-42.7%]) and lower mortality (42.1% [95% CI, 35.9%-48.6%] versus 52.8% [95% CI, 33.3%-71.5%]) compared with patients undergoing MEDT, but neither result was statistically significant. Patients undergoing EVT were more likely to develop symptomatic intracranial hemorrhage (odds ratio, 10.36; 95% CI, 3.92-27.40). Conclusions: EVT treatment of PC-LVO trended toward superior functional outcomes and reduced mortality compared with MEDT despite a trend toward increased symptomatic intracranial hemorrhage in patients undergoing EVT. Existing randomized and prospective studies are insufficiently powered to demonstrate a benefit of EVT over MEDT in patients with PC-LVO.