Outcomes of stent retriever versus aspiration-first thrombectomy in ischemic stroke: A systematic review and meta-analysis

BACKGROUND: There is ongoing debate regarding the optimal first-line thrombectomy technique for large-vessel occlusion. PURPOSE: We performed a systematic review and meta-analysis of comparative studies on stent retriever-first and aspiration-first thrombectomy. DATA SOURCES: We searched Ovid MEDLINE, PubMed, and EMBASE from 2009 to February 2018. STUDY SELECTION: Two reviewers independently selected the studies. The primary end point was successful reperfusion (TICI 2b/3). DATA ANALYSIS: Random-effects meta-analysis was used for analysis. DATA SYNTHESIS: Eighteen studies including 2893 patients were included. There was no significant difference in the rate of final successful reperfusion (83.9% versus 83.3%; OR=0.87; 95% CI, 0.62%-1.27%) or good functional outcome (mRS 0-2) at 90 days (OR=1.07; 95% CI, 0.80 -1.44) between the stent-retriever thrombectomy and aspiration groups. The stent-retriever thrombectomy-first group achieved a statistically significant higher TICI 2b/3 rate after the first-line device than the aspiration-first group (74.9% versus 66.4%; OR= 1.53; 95% CI, 1.14%-2.05%) and resulted in lower use of a rescue device (19.9% versus 32.5%; OR = 0.36; 95% CI, 0.14%- 0.90%). The aspiration-first approach resulted in a statistically shorter groin-to-reperfusion time (weighted mean difference, 7.15 minutes; 95% CI, 1.63-12.67 minutes). There was no difference in the number of passes, symptomatic intracerebral hemorrhage, vessel dissection or perforation, and mortality between groups. LIMITATIONS: Most of the included studies were nonrandomized. There was significant heterogeneity in some of the outcome variables. CONCLUSIONS: Stent-retriever thrombectomy-first and aspiration-first thrombectomy were associated with comparable final reperfusion rates and functional outcome. Stent-retriever thrombectomy was superior in achieving reperfusion as a stand-alone first-line technique, with lower use of rescue devices but a longer groin-to-reperfusion time.