Abstract DP128: Endovascular therapy for Medium Vessel Occlusion Stroke: Pooled Analysis of RCTs and Observational Studies

Background: Occlusion of medium vessel arteries (MeVO) with luminal diameters of 0.75–2.0 mm accounts for 25–40% of acute ischemic strokes. The efficacy and safety of thrombectomy for MeVOs remain inconclusive, but a meta-analysis including recently published randomized controlled trials (RCTs) may provide additional data. Objective: To evaluate the clinical outcomes and safety of endovascular treatment in acute ischemic stroke patients with MeVO by pooling data from recent RCTs and high-quality observational studies. Methods: We conducted a systematic review and meta-analysis following PRISMA guidelines. PubMed, Scopus, and Web of Science were searched from January 2013 to March 2025. Eligible studies included RCTs and observational cohorts comparing endovascular treatment plus best medical therapy versus best medical therapy alone in adults with MeVO stroke. Primary outcomes were 90-day functional independence (modified Rankin Scale mRS 0–2), all-cause mortality, and symptomatic intracranial hemorrhage (sICH). Random-effects meta-analyses using the Hartung-Knapp adjustment and REML estimation were conducted. Results: Twenty-eight studies (3 RCTs, 25 observational) involving 8670 patients (EVT+BMT: n=4022; BMT: n=4648) were included. The three recent RCTs—ESCAPE-MeVO, DISTAL, and DISCOUNT—enrolled 1234 patients and demonstrated consistent findings. EVT was not associated with improved functional independence at 90 days (Relative risk (RR) =0.99, 95% Confidence interval (CI): 0.88–1.10) or reduced 90-day mortality (RR=1.23, 95% CI 0.91–1.66), but was associated with an increased risk of sICH (RR=1.55, 95% CI 1.01–2.39). Subgroup and sensitivity analyses confirmed the robustness of these results. Conclusion: Compared with best medical treatment, endovascular treatment in acute ischemic stroke patients with MeVO did not result in any increase in rates of functional independence at 90 days but was associated with a higher risk of sICH.