Contact Aspiration Versus Stent Retriever for Recanalisation of Acute Stroke Patients With Basilar Artery Occlusion: The Posterior Circulation ASTER Randomized Trial Protocol

Acute ischemic stroke (AIS) patients with basilar artery occlusion (BAO) present a devastating, life-threatening prognosis. Urgent recanalization with endovascular mechanical thrombectomy is routinely performed in patients with BAO although the level of evidence is lower than that in anterior circulation occlusions (randomization in this population versus medical treatment alone having been impossible in recent studies). Recently, a large retrospective study supports the interest of thrombectomy in this population . Speed and grade of the recanalisation have a major impact on clinical outcome. Favorable outcome at 90 days is strongly associated with the successful recanalization status at the end of the endovascular procedure (OR=4.57, 95%CI=1.24-16.87, P=0.023). First pass effect has been shown to be a strong marker of efficacy of endovascular procedure with significant correlation with clinical outcome. Thrombectomy with Stent retrievers dramatically changed the prognosis of anterior circulation large vessel occlusion strokes and currently used in BAO patients (posterior circulation). Contact aspiration (CA) is currently used in anterior large vessel occlusions (COMPASS trial, Lancet 2019), with similar rates of recanalization and favorable outcomes (Boulanger M, 2019), as well as in BAO patients . However, the benefit of CA compared to SR for the treatment of BAO remains under debate with the superiority of first line CA compared to SR or no difference. Available data are based on retrospective studies with no data from RCT. In this context, a randomized controlled trial is needed to assess the benefit of CA versus SR.