Endovascular Treatment for Acute Basilar Artery Occlusion

Inclusion Criteria 1. Symptoms and signs compatible with ischemia in the basilar artery territory； 2. Basilar artery occlusion confirmed by CTA/MRA/DSA； 3. Age of 18 years or older； 4. Time from stroke onset to randomization within 12 hours of estimated time of basilar artery occlusion (defined as the sudden onset of stroke symptoms consistent with acute occlusion of the basilar artery (e.g. not considering any previous minor prodromal symptoms) as adjudicated by two local experienced neurologists). If symptoms of sudden deterioration are not witnessed (e.g. wake-up or unwitnessed strokes) the time that the patient was last known to be without any major neurological deficits (such as moderate or severe weakness, stupor, coma) will be used as the time of stroke onset. 5. Written informed consent; 6. National Institutes of Health Stroke Scale (NIHSS) score ≥10 at the time of neuroimaging Exclusion criteria 1\. Pre-existing dependency with mRS ≥3 for patients\<80 years; premorbid mRS≥1 for patients≥80 years； 2. bilateral mydriasis; 3. Pregnancy; if a woman is of childbearing potential a urine or serum beta HCG test is positive; 4. Severe contrast allergy or absolute contraindication to iodinated contrast; 5. Participation in other clinical trials; 6. Systolic pressure \>185 mmHg or diastolic pressure \>110 mmHg, and cannot be controlled by antihypertensive drugs; 7. Known genetic or acquired bleeding constitution, lack of anticoagulant factors, or oral anticoagulant drugs and INR \> 1.7; 8. Blood glucose \< 2.7 or \>22.2 mmol / L; platelet count \< 50×109 / L, or hematocrit \< 25%; 9. Life expectancy \< 1 year； 10. Patients that cannot complete 90-day follow-up (e.g. no fixed residence, overseas patients, etc.)； 11. Acute ischemic cerebral infarction within 48 hours after major surgery (patients can be enrolled if more than 48 hours); 12. Premorbid cerebrovascular inflammation; 13. Premorbid nervous system disease or mental disorders hindering the assessment of the disease; Imaging exclusion criteria 1. CT/MR shows intracranial hemorrhage (patients with microbleeds on MR can be included if lesion diameter ≤5mm); 2. CTA/MRA/DSA shows the artery is seriously tortuous, variability or dissection, and thrombectomy device cannot reach the target vessel; 3. PC-ASPECTS on CT/CTA-Source Images/MRI-DWI \<6 for patients\<80 years (\<8 for patients ≥80 years); 4. CT or MR shows the cerebellar infarction with obvious space occupying effect and obvious compression of the fourth ventricle; 5. Complete bilateral thalami or bilateral brainstem infarction confirmed by CT/MR; 6. Occlusion of both anterior and posterior circulation confirmed by CTA/MRA/DSA; 7. Intracranial tumors (except small meningiomas).