REal-World Analyses of Stroke - Thrombus Occlusion REtrieval

Cohort I: Inclusion Criteria: 1. Patient is ≥ 21 and ≤ 85 years of age. 2. Patient has a pre-morbid mRS ≤ 1. 3. Neuroimaging (CT/CTA and/or MR/MRA collected at no more than 90 minutes prior to groin puncture) demonstrates large vessel proximal occlusion (distal ICA through MCA bifurcation). 4. Patient has an NIHSS score ≥ 5 at time of intervention. 5. Symptom onset is within 8 hours of when groin puncture can be achieved. 6. Patient will undergo treatment via femoral access and the decision to use femoral access has been made by the treating physician outside the context of the RESTORE study and prior to study enrollment. 7. Patient will be treated using the direct aspiration as first line treatment technique and the decision to use this technique and the study device has been made by the treating physician outside the context of the RESTORE study and prior to study enrollment. 8. Patient or patient's legally authorized representative (LAR) has provided written informed consent. 9. Patient is considered by the treating physician to be available for and able to complete all follow-up visits with a trained site investigator. Exclusion Criteria: 1. Inability to obtain written informed consent. 2. Patient is \< 21 or \> 85 years of age. 3. Patient has a pre-morbid mRS ≥ 2. 4. More than 8 hours have passed since symptom onset. 5. Severe unilateral or bilateral carotid artery stenosis or dissection requiring stent treatment. 6. Presence of a pre-existing large territory infarction. 7. Absent femoral pulses or other condition preventing femoral access. 8. Patient has vascular anatomy/tortuosity or other vascular disease preventing access to the target occlusion or that will likely result in unstable access. 9. Patient is pregnant. 10. Known or suspected pre-existing/chronic large vessel occlusion in the symptomatic territory. 11. Patient has known, untreatable hypersensitivity to contrast dye, iodine or any component of the treatment device that cannot be medically controlled. 12. The intracranial occlusion is suspected to be chronic based on past imaging, clinical history, or clinical judgment. 13. Patient has a severe or life-threatening comorbidity that could confound study results, or that will render the procedure unlikely to benefit the patient. 14. Patient is unable to complete scheduled follow-up assessments due to comorbidities, geographical limitations, or a life expectancy of less than 3 months. 15. Patient is enrolled in another device or drug study in which participation could confound study results. 16. Imaging (CT or MR) exclusion criteria: * Presence of intracerebral hemorrhage as evidenced on initial imaging * Ischemic changes in the posterior circulation territories (including the vertebra-basilar and posterior cerebral arteries) * Significant mass effect with midline shift * Evidence of intracranial tumor * Baseline ischemic core lesion \>50 cc * Involvement of \> 1/3 of the middle cerebral artery territory * ASPECTS \<6 (hemispheric sulcal effacement and/or loss of grey-white differentiation alone are not contraindications for treatment) Cohort II: Inclusion Criteria: 1. Neuroimaging (CT/CTA and/or MR/MRA) demonstrates intracranial vessel occlusion. 2. Symptom onset is within 24 hours of when arterial access puncture can be achieved. 3. Patient will be treated using an FDA-cleared/approved and market-released MicroVention mechanical thrombectomy device as the initial, primary treatment device and the decision to use this device has been made by the treating physician outside the context of the RESTORE study and prior to study enrollment. Note: For the purposes of this protocol, ancillary/accessory devices such as balloon guide catheters and other access devices are not considered primary treatment devices. Further, devices used for rescue following attempt of a different primary treatment device are not considered initial primary treatment devices. 4. Patient or patient's legally authorized representative (LAR) has provided written informed consent within 48 hours of procedure. Exclusion Criteria: 1. Inability to obtain written informed consent within 48 hours of procedure. 2. Patient is enrolled in another device or drug study in which participation could confound study results.