Endovascular Treatment for eXtra-Large Ischemic Stroke

Inclusion Criteria: 1. Age 18 years or older, and modified Rankin scale score = 0 or 1 in patients 80 years or older; 2. Acute ischemic stroke within 6 hours from last known well to randomization, or with negative MRI-FLAIR (no change on FLAIR sequence and presence of infarct on MRI-DWI) if \> 6 hours or unknown last known well time; 3. Occlusion of the internal carotid artery, M1 or M2 segment of the middle cerebral artery confirmed by CTA/MRA/DSA; 4. Baseline ASPECTS score of 0-2 or infarct core volume ≥100ml; 5. The patient or patient's representative signs a written informed consent form. Exclusion Criteria: 1. CT or MR evidence of hemorrhage; 2. Evidence of mass effect with ventricular effacement, midline shift or herniation on baseline imaging; 3. Vessel tortuosity where it is expected that the thrombectomy device will not be able to reach the occlusion site or result in unstable access; 4. History of bleeding disorders, severe heart, liver or kidney disease, or sepsis; 5. Currently participating in another investigational drug study; 6. Any terminal illness with life expectancy less than 6 months.