Despite the successful results of acute mechanical thrombectomy in ischemic stroke caused by a proximal intracranial occlusion of the anterior circulation , still a considerable proportion of patients does not recover. This may to a large extent be explained by incomplete microvascular reperfusion (IMR). IMR has been linked to distal microvascular damage or dysfunction as a result of tissue necrosis and cell death (due to late intervention), but also to distal microvascular occlusion caused by pericyte contraction, microtrombi or cellular plugs. This IMR can possibly be restored by pharmacologic management. We hypothesize that periprocedural antithrombotic treatment improves microvascular reperfusion in patients with ischemic stroke undergoing acute mechanical thrombectomy, but whether it improves clinical outcome is unknown.

The purpose of MR CLEAN-MED is to answer the question whether intravenous treatment with acetylsalicylic acid, unfractionated heparin, both or neither, during mechanical thrombectomy is beneficial and leads to better outcomes than the current strategy, which is to postpone this treatment to at least 24 hours after intervention.