Summary

Mechanical thrombectomy with stent retrievers is now the reference therapy for acute ischemic stroke (AIS) in the anterior circulation in association with thrombolysis. We conducted an extensive systematic review and meta-analysis to evaluate the clinical and angiographic outcomes of stent-retriever thrombectomy in patients with acute anterior circulation stroke. Available literature published to date on observational studies and three randomized trials (MR CLEAN, ESCAPE, and EXTEND-IA) involving the stent-retriever device were reviewed. Successful recanalization and favorable clinical outcome were defined by a TICI ≥ 2b and modified Rankin Scale score of ≤ 2 at 90 days following AIS, respectively. A total of 2067 patients harboring an anterior circulation stroke were treated with a stent retriever: 433 patients from 3 randomized trials involving the device and 1634 patients from observational studies. Mean NIH Stroke Scale score on admission was 16.6, and mean time from onset to recanalization was 300 minutes. Successful recanalization was achieved in 82% (95%CI 77–86, 31 studies). The 90 day favorable outcome was achieved in 47% (95%CI 42–5.2, 34 studies) with an overall mortality rate of 17% (95%CI 13–20, 31 studies). Symptomatic intracerebral hemorrhage was identified in 6% (95%CI 4–8, 32 studies). In patients with AIS caused by a proximal intracranial occlusion of the anterior circulation, stent-retriever thrombectomy is safe and restores brain reperfusion in four of five treated patients, allowing favorable clinical outcome in one of two AIS patients with large vessel occlusion.