Mechanical thrombectomy with or without thrombolysis: A meta-analysis of RCTs

Background: Mechanical thrombectomy (MT) is effective in treating ischemic strokes due to large vessel occlusion. However, the risk-benefit ratio of intravenous thrombolysis (IVT) prior to MT is still unclear. Aim of the study was to provide a pooled analysis of only randomized controlled trials (RCTs) comparing direct MT (dMT) vs bridging treatment (IVT+MT). Methods: PubMed, EMBASE and Cochrane Central were searched only for RCTs comparing IVT+MT vs dMT in ischemic stroke patients. Primary endpoint was functional independence at 90 days (mRS<3), while secondary endpoints were represented by successful recanalization (TICI>2a), mortality at 90 days and symptomatic intracranial hemorrhage (sICH). Odds ratios for endpoints were pooled with meta-analysis and compared between reperfusion strategies. Results: The pooled analysis comprised 5 studies (n. patients = 1657). The rates for the primary endpoint were 39% and 34.5% for dMT and IVT+MT, respectively (OR 1.06; 95%CI 0.80-1.40). For the secondary endpoints, we did not observe significant differences between groups, even if the rate of successful recanalization was higher in IVT+MT treated patients (OR: 0.58; 95%CI 0.26-1.30;p(heterogeneity) = 0.002), without a significant increase in sICH rates (4.3% vs 5.5%; OR: 0.96; 95%CI 0.43-2.13;p(heterogeneity) = 0.26). Finally, mortality rates were 19.8% and 15.9% for dMT and IVT+MT, respectively. Conclusions: In this meta-analysis including only RCTs, dMT and bridging treatment were substantially equivalent for good functional outcome. IVT+MT was associated to higher rates of successful recanalization, even if not significant. Therefore, further adequately powered RCTs comparing dMT vs IVT+MT are warranted.