Inclusion Criteria- Acute ischemic stroke within 6 hours from symptom onset/last seen well.
- Occlusion (TIMI 0-1) of the basilar artery or distal intracranial carotid artery or middle (M1/M2) or anterior (A1/A2) cerebral artery as evidenced by CTA/MRA/DSA.
- Age ≥18 and ≤80
- No significant pre-stroke functional disability (mRS ≤ 1)
- The possibility to start treatment within 6 hours from onset.
- Informed consent given
Exclusion Criteria- Known hemorrhagic diathesis, coagulation factor deficiency, or oral anticoagulant therapy with INR > 3.0
- Baseline platelet count < 50.000/µL
- Baseline blood glucose of < 50mg/dL or >400mg/dl
- Severe, sustained hypertension (SBP > 220 mm Hg or DBP > 110 mm Hg) NOTE: If the blood pressure can be successfully reduced and maintained below these levels using commonly used medications in China for these purposes (including iv antihypertensive drips), the patient can be enrolled.
- Serious, advanced, or terminal illness with anticipated life expectancy of less than one year.
- History of life threatening allergy (more than rash) to contrast medium
- Subjects who has received iv t-PA treatment beyond 4.5 hours from the beginning of the symptoms.
- Patients with acute stroke within the first 48 hours after percutaneous cardiac, cerebrovascular interventions and major surgery
- Renal insufficiency with creatinine ≥ 3 mg/dl
- Woman of childbearing potential who is known to be pregnant or lactating or who has a positive pregnancy test on admission.
- Subject participating in a study involving an investigational drug or device that would impact this study.
- Cerebral vasculitis
- Patients with a pre-existing neurological or psychiatric disease that would confound the neurological or functional evaluations, mRS score at baseline must be ≤ 1, which includes patients who are severely demented, require constant assistance in a nursing home type setting or who live at home but are not fully independent in activities of daily living (toileting, dressing, eating, cooking and preparing meals, etc.)
- Unlikely to be available for 90 days follow-up (e.g. no fixed home address, visitor from overseas).
- CT or MR evidence of hemorrhage (the presence of microbleeds on MRI is allowed).