Randomized controlled trials of endovascular therapy for acute ischemic stroke with medium or distal vessel occlusion: a study level metaanalysis

INTRODUCTION: A decade ago, endovascular therapy (EVT) for acute ischemic stroke (AIS) with large vessel occlusion (LVO) has been established as standard of care. It is still a matter of debate whether EVT is better and safe for patients with more distal occlusions (DMVO). Three randomized controlled trials investigated the role of EVT on top of best medical treatment (BMT) for patients with DMVO. METHODS: In a narrative review we present the results of 3 randomized controlled trials (RCT), (DISTAL, ESCAPE MeVO, DISCOUNT) of EVT plus BMT versus BMT alone. In addition, we performed a study level meta-analysis with a random-effects model for three endpoints: independent outcome, symptomatic intracranial hemorrhage (sICH) and death. RESULTS: There was neither a significant effect of EVT plus BMT versus BMT alone on functional outcome (RR 0.92, 95% CI 0.80-1.06, p = 0.272), nor did the odds of death differ (OR 1.23, 95% CI 0.76-1.99, p = 0.409). The odds for sICH were more than twice as high with EVT (OR 2.38, 95% CI 1.35-4.20, p = 0.003). CONCLUSION: At present EVT for medium and distal vessel occlusions in AIS patients is not a standard of care. With equipoise for EVT in DMVO now an unbiased and rapid randomization into new and differently designed RCT should be a top priority.