IntraCranial Atherosclerosis Related Large-vessel Occlusion Treated With Urgent Stenting (ICARUS)

Inclusion Criteria: * A relevant clinical deficit defined as a National Institute of Health Stoke Scale (NIHSS) Score of ≥ 6 points for anterior circulation stroke and a NIHSS Score of ≥ 10 for posterior circulation stroke * Anticipated randomization within 24 hours of last seen well (LSW) * Occlusion of the Internal Carotid Artery, the M1 segment, the proximal/dominant M2 segment of the Middle Cerebral Artery, the Basilar Artery or the V4 segment of the Vertebral Artery * Absence of recanalization (thrombolysis in myocardial infarction score of 0 or 1) after up to three endovascular treatment passes * High probability of underlying intracranial atherosclerotic disease based on the assessment of the treating physician * Age ≥ 18 years * Occluded artery amendable to stenting by judgement of the treating physician * Absence of a large infarct core defined as (posterior circulation) Alberta Stroke Program Early CT Score of 6 or above * Informed Consent as documented by signature or fulfilling the criteria for emergency consent procedures Exclusion Criteria: * Acute intracranial haemorrhage * Pre-stroke modified Rankin Scale score of 3 or above * Known, severe comorbidities, which will likely prevent improvement or follow-up (cancer, alcohol/drug abuse or dementia) * Known clotting disease or suspicion of underlying disease which might lead to a hyper coagulant state * In-hospital Stroke * Known contraindications for anti-platelet therapy * Known (serious) sensitivity to radiographic contrast agents, nickel, titanium metals or their alloys * Foreseeable difficulties in follow-up due to geographic reasons (e.g., patients living abroad) * Evidence of an ongoing pregnancy prior to randomization * Radiological confirmed evidence of mass effect or intracranial tumour (except small meningioma) * Radiological confirmed evidence of cerebral vasculitis * Evidence of vessel recanalization prior to randomisation * Participation in another interventional trial which could confound the primary endpoint