Aim: Stent-retriever (SR) thrombectomy has demonstrated superior outcomes in patients with acute ischemic stroke compared with medical management alone, but differences among SRs remain unexplored. We conducted a Systematic Review/Meta-Analysis to compare outcomes between three SRs: EmboTrap®, Solitaire™, and Trevo®. Methods: We conducted a PRISMA-compliant Systematic Review among English-language studies published after 2014 in PubMed/MEDLINE that reported SRs in ≥25 patients. Functional and safety outcomes included 90-day modified Rankin scale (mRS 0-2), mortality, symptomatic intracranial hemorrhage (sICH), and embolization to new territory (ENT). Recanalization outcomes included modified thrombolysis in cerebral infarction (mTICI) and first-pass recanalization (FPR). We used a random effects Meta-Analysis to compare outcomes; subgroup and outlier-influencer analysis were performed to explore heterogeneity. Results: Fifty-one articles comprising 9,804 patients were included. EmboTrap had statistically significantly higher rates of mRS 0-2 (57.4%) compared with Trevo (50.0%, p = 0.013) and Solitaire (45.3%, p < 0.001). Compared with Solitaire (20.4%), EmboTrap (11.2%, p < 0.001) and Trevo (14.5%, p = 0.018) had statistically significantly lower mortality. Compared with Solitaire (7.7%), EmboTrap (3.9%, p = 0.028) and Trevo (4.6%, p = 0.049) had statistically significantly lower rates of sICH. There were no significant differences in ENT rates across all three devices (6.0% for EmboTrap, 5.3% for Trevo, and 7.7% for Solitaire, p = 0.518). EmboTrap had numerically higher rates of recanalization; however, no statistically significant differences were found. Conclusion: The results of our Systematic Review/Meta-Analysis suggest that EmboTrap may be associated with significantly improved functional outcomes compared with Solitaire and Trevo. EmboTrap and Trevo may be associated with significantly lower rates of sICH and mortality compared with Solitaire. No significant differences in recanalization and ENT rates were found. These conclusions are tempered by limitations of the analysis including variations in thrombectomy techniques in the field, highlighting the need for multi-arm RCT studies comparing different SR devices to confirm our findings.
Keywords: acute ischemic stroke; endovascular treatment; reperfusion; stent retriever; thrombectomy.
What is this article about? The standard treatment for acute stroke involves using minimally invasive stent-retrievers to remove clots. Many studies have reported outcomes for three commonly used stent-retrievers (EmboTrap®, Solitaire™, and Trevo®), but there are few studies comparing these devices directly. In the MASTRO I study, we systematically reviewed studies reporting stroke outcomes with these devices in order to combine and compare findings to determine whether any of them performed better in their ability to improve functional deficits, remove clots successfully or mitigate patient safety, such as hemorrhage in the brain, formation of distal clot fragments, and death. What were the results? We found 51 studies reporting 9,804 patients treated for acute stroke with one of these three devices. When the 51 studies from the three devices were combined and compared, none of them did a significantly better job based on clot removal rates but EmboTrap had significantly better rates of achieving good neurological function than either Trevo or Solitaire. Also, with respect to safety, Solitaire had significantly higher rates of hemorrhage in the brain, and higher rates of death than either EmboTrap or Trevo. The rate of formation of distal clot fragments did not seem to differ among the three devices. What do the results mean? The information from this comparative research review can help physicians with evidence-based decision making on which devices to use when treating acute stroke. It is worth noting that there was a potential for bias in the 51 studies combined in this review due to the high risk of comparing patient groups and treatment approaches that may not be similar, hence we highlight the fact that more randomized trials that control for any differences in study parameters are needed to confirm our results. There are two such randomized controlled trials that are ongoing, and we look forward to including these and any other new studies in future updates to this review in MASTRO II.