The Efficacy and Safety of Endovascular Treatment for Acute Mild Basilar Artery Occlusion

Inclusion Criteria: 1. Age≥18 2. Acute ischemic stroke in posterior circulation, the time from stroke onset (or finally found normal) to randomization was within 24 hours 3. Acute basilar artery occlusion confirmed by CTA,MRA,or DSA 4. NIHSS score≥2 points and\<10 points from the onset of the disease to before randomization 5. Posterior circulation large core infarction:NCCT or DWI showed pc-ASPECTS≥6, or Pons-Midbrain Index (PMI)\<3 6. No significant functional disability before stroke (mRS≤2 points) 7. Each patient or their legal representative must provide written informed consent before enrolment Exclusion Criteria: 1. Any sign of intracranial hemorrhage (except microbleeds) on brain imaging prior to randomization 2. Complete cerebellar infarct with significant mass effect, or bilateral thalamic infarction as evidenced by baseline neuroimaging 3. Known or highly suspected chronic occlusion of basilar artery 4. History of contraindication for contrast medium (except mild rash) 5. CTA/MRA/DSA confirmed occlusion of anterior and posterior circulation 6. Severe stenosis, arterial dissection, or excessive tortuosity of the extracranial or intracranial segments of the vertebral artery may result in the inability of interventional instruments to be successfully delivered or positioned 7. Current pregnant or breast-feeding 8. Refractory hypertension (defined as systolic blood pressure\>185 mmHg or diastolic blood pressure\>110 mmHg) that cannot be controlled by drug treatment 9. Known hereditary or acquired bleeding tendency, lack of coagulation factors, or oral anticoagulants with INR\>1.5 10. Blood glucose\<2.8 or\>22.2 mmol/L; Platelet count\<100\*109/L, serum creatinine\>2.0 g/L (177 μ mol/L), or glomerular filtration rate\<30 ml/(min\*1.73 m2) 11. Enrolled in another drug or device trial or expected to participate in another drug or device treatment trial within the following 3 months 12. Acute cerebral infarction occurred within 48 hours after cardio cerebral vascular intervention or major surgery (patients over 48 hours can be included in the group) 13. Patients whose life expectancy is less than 1 year (such as patients with malignant tumor, advanced cardiopulmonary disease, etc.) 14. Central nervous system vasculitis has been diagnosed or clinically suspected 15. Known to have dementia or psychiatric disease unable to complete neurological assessment and follow-up 16. It is known that patients with dementia or mental illness cannot complete neurological function assessment and follow-up 17. Any other condition (in the opinion of the site investigator) that inappropriate to participate this study