Contact aspiration versus stent retriever for mechanical thrombectomy: ASTER trial

The Contact Aspiration vs Stent Retriever for Successful Revascularization (ASTER) trial was a randomized, open-label, blinded endpoint multicenter study conducted in comprehensive stroke centers across France from October 2015 to October 2016. Patients who presented with acute ischemic stroke and a large vessel occlusion in the anterior circulation (intracranial internal carotid artery, M1 or M2 segments of the middle cerebral artery) within 6 hours of symptom onset were included. Before switching techniques, operators were asked to perform at least 3 attempts with the assigned treatment.

The total number of patients assigned to first-line contact aspiration was 192 whereas first-line stent retriever was assigned to 189 patients. In the intention-to-treat analysis, there were no differences with respect to successful revascularization defined as TICI 2b or 3, NIHSS at 24 hours, mRS at 90 days, and adverse events. Successful revascularization was accomplished in approximately 80% of patients and functional independence in 45-50%.

These results are of particular interest as the corresponding trial in the US, the COMPASS Trial: a Direct Aspiration First Pass Technique (COMPASS), is expected to be publicized soon.