Inclusion Criteria- From 18 to 85 years of age.
- Evidence of proximal anterior circulation large vessel occlusion (TIMI 0-1)(TICI 0-1) from CT Angiography. Target vessel occlusion may include the anterior circulation.
- Presented with symptoms consistent with acute ischemic stroke within 8 hours of symptom onset. Patients who presented within 3 hours must be ineligible or refractory to IV rtPA therapy.
- At time of enrollment, neurological deficit resulting in an NIH Stroke Scale (NIHSS) score greater than 10
- Known core infarct volume assessed by CTP, CTA or DWI scans
Exclusion Criteria- History of stroke in the past 3 months.
- Pre-existing neurological or psychiatric disease that could confound the study results such as a pre-stroke mRS score greater than 1
- Known severe allergy to contrast media
- Uncontrolled hypertension (defined as systolic blood pressure greater than 185 mmHg or diastolic blood pressure less than 110 mmHg)
- CT evidence of the following conditions before enrollment:
- Significant mass effect with midline shift
- Evidence of intracranial hemorrhage
- Treated with endovascular therapy for acute stroke
- Life expectancy less than 90 days
- Participation in another clinical investigation that could confound the evaluation of the study