Endovascular Therapy for Large Core Patients With Uncertain Response to Thrombectomy

Inclusion Criteria: 1. Signs and symptoms consistent with an acute anterior circulation ischemic stroke and associated brain imaging 2. Baseline NIHSSS is ≥10 and remains ≥10 immediately prior to randomization 3. Treatment can be initiated within 24 hours of stroke onset or time last known well and within 120 minutes of completion of qualifying imaging 4. Functionally independent prior to stroke onset 5. Patient/ Legally Authorized Representative has signed the Informed Consent form. Exclusion Criteria: 1. Other serious, advanced, or terminal illness (investigator judgment) or life expectancy is less than 6 months. 2. Pre-existing medical, neurological or psychiatric disease that would confound the neurological or functional evaluations 3. Pregnant 4. Unable to undergo a contrast brain perfusion scan with either MRI or CT 5. Known allergy to iodine that precludes an endovascular procedure 6. Treated with tPA or TNK \>4.5 hours after time last known well 7. Seizures at stroke onset if it precludes obtaining an accurate baseline NIHSS 8. Baseline blood glucose of \<50mg/dL (2.78 mmol) or \>400mg/dL (22.20 mmol) 9. Baseline platelet count \< 50,000/uL 10. Severe, sustained hypertension (SBP \>185 mmHg or DBP \>110 mmHg) 11. Current participation in another investigational drug or device study 12. Presumed septic embolus; suspicion of bacterial endocarditis 13. Any other condition that, in the opinion of the investigator, precludes an endovascular procedure or poses a significant hazard to the subject if an endovascular procedure was performed. NEUROIMAGING Exclusion: 1. Evidence of intracranial tumor (except small meningioma) acute intracranial hemorrhage, neoplasm, or arteriovenous malformation 2. Significant mass effect with midline shift 3. Evidence of internal carotid artery dissection that is flow limiting or aortic dissection 4. Intracranial stent implanted in the same vascular territory that precludes the safe deployment/removal of the neurothrombectomy device 5. Acute symptomatic arterial occlusions in more than one vascular territory confirmed on CTA/MRA (e.g., bilateral MCA occlusions, or an MCA and a basilar artery occlusion).