Amnis Therapeutics Thrombectomy Device-First in Man (FIM) Safety and Performance Study

Inclusion Criteria: 1. Aged18-85years. 2. Subject who is contraindicated or failed (when the physician withdraws the tPA per physician discretion) intravenous tissue plasminogen activator (t-PA) therapy given at local institutions or within national practice. Failed means that the physician does not continue with IV tPA after thrombolysis; there is still an occlusion with TICI that is \</= 1 as the relevant inclusion criteria. 3. Subject is able to be treated within 8 hours of stroke symptoms onset with minimum of one deployment of the Amnis Thrombectomy Device. 4. NIHSS score ≥8. 5. Pre-stroke mRS (modified Rankin Scale) score of 0 to 1. 6. Thrombolysis in cerebral infarction (TICI) ≤1 and causative occlusion of the M1 or M2 portion of the MCAs, anterior cerebral arteries, vertebral arteries, basilar artery ,or posterior cerebral arteries (P1 o rP2), confirmed by CT or MR angiography that is accessible to the Amnis thrombectomy device (i.e. according to IFU; 2-5.5 mm). 7. ASPECTS of ≥6 based on CT or MRI that was performed within 60 min prior to the start of endovascular procedure. 8. Subject or subject's legal guardian where regulations permit, signs the Patient Informed Consent and agrees that subject will attend follow-up visits. Exclusion Criteria: 1. Rapid neurological improvement prior to or at time of treatment suggesting resolution of signs/symptoms of stroke. 2. Estimated time of symptom onset. 3. Baseline NIHSS score \<8. 4. BaselineNIHSS score ≥30 or state of coma. 5. Baseline pre-stroke mRS score \>1. 6. Baseline Thrombolysis in cerebral infarction (TICI) \> 2a. 7. Known serious sensitivity to radiographic contrast agent. 8. Arterial tortuosity, pre-existing stent and/o rother arterial disease that would prevent the device from reaching the target vessel. 9. Evidence of a moderate/large core defined as extensive early ischemic changes of Alberta Stroke Program Early CT score (ASPECTS) \<6. Co-morbid conditions: 10. Elevated blood pressure(systolic\>185 mm Hg or diastolic \>110 mm Hg) 11. Use of warfarin anticoagulation with INR \>3.0. 12. Platelet count \<30,000/mm³. 13. Blood glucose concentration \<50 mg/dL (2.7 mmol/L). 14. CT/MRI imaging demonstrate smultilobar infarction (hypodensity \>1/3 cerebral hemisphere). 15. CT or MRI evidence of mass effect, signs of hemorrhage, arteriovenous malformation or aneurysm or intra-cranial tumor (except small meningioma). 16. Angiographic evidence of carotid dissection, complete cervical carotid occlusions or vasculitis. 17. Clinical Symptoms or CT/MRI imaging suggest subarachnoid hemorrhage. 18. Imaging evidence that suggests, in the opinion of the investigator, the subject is not appropriate for mechanical thrombectomy intervention (e.g. inability to navigate to target lesion, moderate/large infarct with poor collateral circulation, etc.). General - related to the protocol or device: 19. Known sensitivity to nickel, titanium metals or their alloys. 20. Subject who requires hemodialysis or peritoneal dialysis, or who has a contraindication to an angiogram for whatever reason. 21. Current participation in another investigational drug or device study. 22. Female who is pregnant or lactating or has a positive pregnancy test at time of admission. 23. Subject currently uses or has a recent history of illicit drug(s) or abuses alcohol (defined as regular or daily consumption of more than four alcoholic drinks per day). 24. Subject has a life expectancy of \<90 days. 25. Subject with a comorbid disease or condition that would confound the neurological and functional evaluations or compromise survival or ability to complete follow-up assessments.