Mothership versus drip and ship for thrombectomy in patients who had an acute stroke: a systematic review and meta-analysis

Background The effectiveness of mechanical thrombectomy (MT) in acute ischemic stroke due to large vessel occlusion is time-dependent. While only stroke centers with endovascular capabilities perform MT, many patients who had a stroke initially present to the closest primary stroke centers capable of administering earlier intravenous thrombolysis, and then require to be transferred to a comprehensive stroke center for MT. Purpose To compare the outcomes of this care pathway (drip and ship (DS)) with that whereby patients are directly transferred to a comprehensive stroke center (mothership (MS)). Methods We performed a systematic review and meta-analysis of published studies using several electronic databases to determine whether successful reperfusion (modified Thrombolysis In Cerebral Infarction ≥2b), functional independence at 90 days (modified Rankin Scale score ≤2), symptomatic intracranial hemorrhage, and 90-day mortality differed between those who underwent MT with the DS or the MS treatment pathway. Outcomes were meta-analyzed and the results expressed as adjusted relative risk (aRR) for the primary analysis and unadjusted relative risk (uRR) for secondary analysis. Results Eight studies including 2068 patients were selected, including one study reporting results fully adjusted for baseline characteristics. Patients undergoing MS had better functional independence than those undergoing DS (uRR=0.87, 95% CI 0.81 to 0.93; aRR=0.87, 95% CI 0.77 to 0.98). No difference was found between the treatment pathways in successful reperfusion (uRR=1.05, 95% CI 0.95 to 1.15; aRR=1.00, 95% CI 0.92 to 1.10), symptomatic intracranial hemorrhage (uRR=1.37, 95% CI 0.91 to 2.06; aRR, 1.53, 95% CI 0.79 to 2.98), and 90-day mortality (uRR=1.00, 95% CI 0.84 to 1.19; aRR=1.21, 95% CI 0.89 to 1.64). Conclusions Patients who had an acute ischemic stroke admitted directly to a comprehensive stroke center (MS patients) with endovascular capacities may have better 90-day outcomes than those receiving DS treatment. However, major limitations of current evidence (ie, retrospective studies and selection bias) suggest a need for adequately powered studies. Multicenter randomized controlled trials are expected to answer this question.