Let us concede upfront that there is controversy surrounding the proposal: there is sufficient evidence to support intra-arterial (IA) therapy of ischemic stroke. Thus, rather than relying on a selective review of the available evidence to formulate a personal opinion on a controversial topic, it is preferable and less biased to examine where majority expert opinion lies on this matter. Also, we should first define IA stroke therapy. Although IA stroke therapy typically begins with mechanical clot retrieval, it frequently incorporates thrombolytic agents, antithrombotics and platelet inhibition. As a result, there is no standard IA stroke therapy or even standard criteria for device selection, and it is routine to make interventional decisions ‘on the table’. This reflects the complex technical heterogeneity of acute stroke arterial recanalization and further complicates the design of any potential randomized clinical trial (RCT) of IA therapy. It should thus be pointed out that PROACT II (Prolyse in Acute Cerebral Thromboembolism Trial II),1 the only completed RCT of IA stroke therapy, prohibited mechanical clot manipulation, included a novel heparin regimen, did not include antiplatelet agents and allowed 2 h for pro-urokinase infusion, thus representing a very conservative IA approach compared with current regimens.

The most comprehensive review of the evidence related to IA stroke therapy is a meta-analysis published in 2010 in Stroke2 which concluded: “Formal meta-analysis suggests that IA fibrinolysis substantially increases recanalization rates and good and excellent clinical outcomes in acute ischemic stroke. Increased hemorrhage frequencies are not associated with any increase in mortality. For excellent clinical outcomes, the benefit per 100 patients treated is 17 within <3 h of intravenous tissue plasminogen activator (IV tPA), 13 with IA fibrinolysis, and 7 within 3 to 4.5 h of IV tPA. Accordingly, indirect comparison suggests that the benefit of IA lysis is somewhat similar to early, …