Stent Retrievers for the Treatment of Acute Ischemic Stroke

IMPORTANCE: Stent retrievers are a promising alternative for the treatment of acute ischemic stroke (AIS). Several recently completed clinical trials have examined the use of stent retrievers with intravenous recombinant tissue plasminogen activator (rtPA) compared with rtPA alone. OBJECTIVE: To conduct a systematic review and meta-analysis of randomized clinical trials to quantify the benefits and risks of using stent retrievers in addition to rtPA for the treatment of AIS. DATA SOURCES: The MEDLINE, EMBASE, and Cochrane Library of Clinical Trials databases were searched from inception to July 2015 for the keywords stent*, retriev*, Solitaire, Trevo, Revive, and stroke. Trial registries were also searched. A total of 326 publications were identified and 213 potentially relevant records were screened. STUDY SELECTION: Randomized clinical trials that examined stent retrievers with rtPA vs rtPA alone were included in the meta-analysis. DATA EXTRACTION AND SYNTHESIS: Two independent reviewers extracted study data and performed quality assessment using the Cochrane Risk of Bias Tool. DerSimonian and Laird random-effects models were used to estimate relative risks (RRs), risk differences (RDs), and numbers needed to treat. MAIN OUTCOMES AND MEASURES: The primary outcome was the proportion of patients achieving functional independence (defined as a score of 0-2 on the modified Rankin Scale, with 0 indicating no disability and 6 indicating death) at 90 days. Risks of all-cause mortality, intracranial hemorrhage, and parenchymal hematoma at 90 days were also assessed. RESULTS: Five randomized clinical trials met our inclusion criteria (n = 1287 patients). Patients randomized to stent-retriever therapy with rtPA had significantly improved rates of functional independence at 90 days compared with those randomized to rtPA alone (RR, 1.72; 95% CI, 1.48-1.99; RD, 0.19; 95% CI, 0.13-0.25). When data were pooled across trials, the effect of stent-retriever therapy on all-cause mortality at 90 days was inconclusive (RR, 0.82; 95% CI, 0.60-1.11; RD, -0.04; 95% CI, -0.08 to 0.1). There were similarly no detectable differences in the risks of intracranial hemorrhage (RR, 1.15; 95% CI, 0.67-1.97; RD, 0.00; 95% CI, -0.02 to 0.03) or parenchymal hematoma (RR, 1.18; 95% CI, 0.71-1.94; RD, 0.01; 95% CI, -0.01 to 0.04), although the 95% CIs were wide. Fixed-effects sensitivity analyses produced similar results for all outcomes. CONCLUSIONS AND RELEVANCE: The use of stent retrievers in conjunction with rtPA vs rtPA alone is associated with significant improvement of functional independence 90 days after AIS.