SOLITAIRE™ FR With the Intention For Thrombectomy (SWIFT) Study

Inclusion Criteria: * Patient or patient's legally authorized representative has signed and dated an Informed Consent Form * Age22-85 * Clinical signs consistent with acute ischemic stroke * National Institutes of Health Stroke Scale (NIHSS) ≥8and\<30 * Thrombolysis in Myocardial Infarction (TIMI) 0 or TIMI 1 flow in the M1 or M2 of middle cerebral artery, internal carotid artery, basilar or vertebral arteries confirmed by angiography that is accessible to the SOLITAIRETM or MERCI® Device * Patient is able to be treated within 8 hours of stroke symptoms onset with minimum of one deployment of the SOLITAIRETM or MERCI® Device. * Patient who is ineligible or failed intravenous tissue plasminogen activator (t-PA) therapy given at local institutions or within national practice. * Patient is willing to conduct follow-up visits Exclusion Criteria: * NIHSS \> 30 or coma * Neurological signs that are rapidly improving prior to or at time of treatment * Females who are pregnant or lactating * Known serious sensitivity to radiographic contrast agents * Current participation in another investigation drug or device study * Uncontrolled hypertension defined as systolic blood pressure \> 185 or diastolic blood pressure \> 110 that cannot be controlled except with continuous parenteral antihypertensive medication * Use of warfarin anticoagulation with International Normalized Ratio (INR) \> 3.0 * Platelet count \< 30,000 * Glucose \< 50 mg/dL * Arterial tortuosity that would prevent the device from reaching the target vessel * Life expectancy of less than 90 days * Computed tomography (CT) or Magnetic Resonance Imaging (MRI) evidence of hemorrhage on presentation * CT showing hypodensity or MR showing hyperintensity involving greater than 1/3 of the middle cerebral artery (MCA) territory (or in other territories, \>100 cc of tissue) on presentation * CT or MRI evidence of mass effect or intracranial tumor (except small meningioma) * Angiographic evidence of carotid dissection, complete cervical carotid occlusions, or vasculitis