Gravity Stent-Retriever System For Reperfusion Of Large Vessel Occlusion Stroke Trial

Inclusion Criteria: 1. New focal neurologic deficit consistent with being of acute cerebral ischemia origin. 2. Age 18-85 years old (inclusive). 3. Interventionalists estimate that treatment with the Supernova (first deployment in target vessel) can be achieved within 24 hours of symptom onset. 4. Intravenous thrombolysis may be given as per national guidelines and patients receiving or not receiving intravenous thrombolysis will both be eligible for inclusion in the study. 5. Admission NIH Stroke Scale score of 8-25 6. No known significant pre-stroke disability (pre-stroke mRS 0 or 1). 7. Catheter angiographic confirmation of large vessel occlusion in the intracranial internal carotid artery, the M1 or M2 segments of the middle cerebral artery, or the basilar artery that is accessible to the Supernova device. 8. For strokes in the anterior circulation, the following imaging criteria should also be met: 1. MRI criterion: volume of diffusion restriction visually assessed ≤50 mL, OR 2. CT criterion: ASPECTS 6 to 10 on baseline NCCT 9. Anticipated life expectancy of at least 6 months. 10. A signed informed consent by the patient or a Legally Authorized Representative or independent physician in case of oral consent. Exclusion Criteria: 1. Subject already participating in another study of an investigational treatment device or treatment. 2. Use any other intra-arterial recanalization drug or device prior to the use of Supernova (Supernova is not the first-choice device). 3. Angiographically evident excessive arterial tortuosity precluding device access to the thrombus. 4. For all patients, severe sustained hypertension with SBP \>220 and/or DBP \>120; for patients treated with IV tPA, sustained hypertension despite treatment with SBP \>185 and/or DBP \> 110. 5. Glucose \< 50 mg/dl (2.78 mmol/L) or \> 400 mg/dl (22.20 mmol/L). 6. Known hemorrhagic diathesis. 7. Coagulation factor deficiency or oral anti-coagulant therapy with an international normalized ratio (INR) of more than 3.0. 8. Treatment with heparin within 48 h with a partial thromboplastin time more than two times the laboratory normal. 9. Patients who have received a direct thrombin inhibitor within the last 48 hours; must have a partial thromboplastin time (PTT) less than 1.5 times the normal to be eligible. 10. Platelet count of less than 50,000/ µL. 11. History of severe allergy to contrast medium, nickel, or Nitinol. 12. Intracranial hemorrhage. 13. Significant mass effect with midline shift. 14. Intracranial tumor (apart from small meningioma, ≤ 2 cm in diameter). 15. Stenosis or any occlusion in the deployment site or in a proximal vessel requiring treatment or preventing device access to the thrombus (for example, stenosis or occlusion in the cervical internal carotid artery or common carotid artery). 16. Presence of intracranial atherosclerotic disease requiring rescue therapy (for example, intracranial stenting). 17. Females who are pregnant or breastfeeding. 18. Known current use of narcotic drugs at the time of treatment. 19. Prior recent stroke in the past 3 months. 20. Renal failure with serum creatinine \>3.0 or Glomerular Filtration Rate (GFR) \<30. 21. Known cerebral vasculitis. 22. Rapidly improving neurological status defined as the improvement of greater than 8 points on the NIHSS or improvement to NIHSS of \< 6 prior to the procedure. 23. Clinical symptoms are suggestive of bilateral stroke or stroke in multiple territories. 24. Ongoing seizure due to stroke. 25. Evidence of active systemic infection. 26. Known cancer with metastases. 27. Suspicion of aortic dissection, septic embolus, or bacterial endocarditis. 28. Evidence of dissection in the extra or intracranial cerebral arteries. 29. Occlusions in multiple vascular territories (e.g., bilateral anterior circulation or anterior/posterior circulation). 30. Aneurysm in the target vessel.