Assess the safety and efficacy of the Q Revascularization System to remove thrombi and emboli from the neurovasculature in patients experiencing an acute ischemic stroke

Inclusion Criteria:

• Age 18 years or older.
• Pre-stroke independent functional status in activities of daily living with mRS 0-1.
• A disabling stroke defined as NIHSS ≥ 6
• In USA thrombolytic therapy (IV tPA) received within 3 hours of onset/ last known well, in Europe treatment with IV tPA received within 4.5 hours from onset/ last known well OR ineligibility for thrombolytic therapy
• Endovascular treatment intended to be initiated < 8 hours from onset of symptoms or last known well time
• Confirmed symptomatic large vessel occlusion of the intracranial internal carotid artery, middle cerebral artery, M1, M2, basilar or intracerebral vertebral artery by baseline neuroimaging CTA/MRA and angiographic imaging with a mTICI Score 0-1
• For strokes in the anterior circulation the following imaging criteria should also be met: MRI criterion of volume of diffusion restriction visually assessed ≤50 mL OR CT criterion of ASPECTS 6 to 10 on baseline CT or CTA-source images or, significantly lowered cerebral blood volume (CBV) ≤50 mL
• For strokes in the basilar or vertebral artery, the following imaging criterion should also be met: pc-ASPECTS score 8 to 10 on baseline CT, CTA-source images, or MRI
• Signed informed consent from subject, acceptable person responsible (e.g. LAR) and/or according to County specific regulatory requirements and local ethical committee or review board requirements

Exclusion Criteria:

• CT or MRI evidence of intracranial hemorrhage on presentation
• CT or MRI showing mass effect or intracranial tumor (meningioma > 2 cm in diameter).
• Previous stroke within the past 3 months
• Rapidly improving neurological status as determined by Investigator/Neurologist
• Renal failure/insufficiency with >3.0 mg/dL creatinine prior to procedure
• Severe, sustained hypertension resistant to treatment (SBP >185 mmHg or DBP >110 mmHg)
• Use of warfarin anticoagulation with International Normalized Ratio (INR) > 3.0 at the time of the procedure or any known hemorrhagic or coagulation deficiency
• For patients who have received a direct thrombin inhibitor within the last 48 hours; partial thromboplastin time (PTT) > 2.0 times the normal prior to procedure
• Platelet count < 50,000 mm3
• Cerebral vasculitis or evidence of active systemic infection
• Suspicion of aortic dissection, presumed septic embolus, or suspicion of bacterial endocarditis
• Clinical symptoms suggestive of bilateral stroke or occlusions in multiple vascular territories (e.g., bilateral anterior circulation, or anterior/posterior circulation)
• Seizure due to stroke
• Pregnancy
• Severe contrast allergy or absolute contraindication to iodinated contrast
• Presence of a carotid artery stenosis or occlusion requiring balloon angioplasty or stenting at time of the procedure
• Difficult endovascular access or difficult aortic arch or severe neurovascular tortuosity that will result in an inability to deliver endovascular therapy
• Evidence of dissection in the carotid or target artery for treatment
• Clinical history, past imaging or clinical judgment suggests that the intracranial occlusion is chronic
• Active participation in another study involving an investigational drug or device
• A severe or fatal comorbid illness that will prevent improvement or follow-up or that will render the procedure unlikely to benefit the patient
• Unwillingness to complete follow up visits