Introduction

Neurointerventionalists and other believers in intra-arterial thrombolysis (IAT) were disappointed to learn that the Interventional Management of Stroke (IMS) III trial was halted at a prespecified endpoint. Already there are a number of articles citing rationales for failure of bridging therapy to demonstrate what would seem like an intuitive benefit over intravenous tissue plasminogen activator (tPA) monotherapy.1 There are genuine questions relating to patient selection and device availability as to the ability of IMS III to demonstrate a positive effect. In this brief comment we explore an area not necessarily well-known to the broader neurointerventional community that might confound any bridging trial.

At the most basic level, acute ischemic stroke is caused by the lack of cerebral blood flow. This leads to neurologic dysfunction and brain tissue injury. Hence, prompt restoration of blood flow is the most logical therapeutic approach. Reperfusion remains the only proven method to treat large vessel stroke, and the criticality of recanalization is well-known to neurointerventionalists and is an active part of clinical practice.2 ,3

IMS III was a ‘bridging’ trial; patients were first treated with intravenous tPA, then randomized to mechanical recanalization versus no additional therapy. ‘Bridging’ had been shown to benefit patients.4 ,5 The rationale was to maximize chances for rapid clot lysis, restoring blood …