PLAT and Stroke: However, the benefit of IV r-tPA for patients with severe stroke due to large artery occlusion is variable, due largely to failure of early recanalisation (generally less than 30% for carotid, proximal middle cerebral artery or basilar artery occlusion).16 More importantly, there is a good clinical outcome in only ~25% of patients (at best) with proximal anterior circulation or basilar artery occlusion.17 Important independent risk factors predicting poor outcome post intravenous thrombolysis are the length18–22 and location23 24 of the arterial thrombus.