Endovascular Treatment for Posterior Circulation Ischemic Stroke Post 1 Day （24 Hours）

Inclusion Criteria: 1. Age ≥ 18 years old 2. Baseline NIHSS score of 4 or higher, maintained prior to randomization 3. Stroke onset or more than 24 hours since the last known good state, but within 14 days 4. CTA/MRA/DSA confirmed occlusion of the responsible vessel in basilar artery or intracranial segments of both vertebral arteries (V4) 5. Modified Rankin Scale (mRS) score of 0 or 1 pre-stroke 6. The subject or their legally authorized representative has signed the informed consent form for the study Exclusion Criteria: 1. Hemorrhage on CT or MRI 2. Based on the judgment of the treating physician, the patient is considered unlikely to benefit from the trial (e.g., advanced dementia, severe pre-stroke disability (mRS ≥ 2), or high risk of early mortality) 3. Major comorbidities that may interfere with outcome assessment and follow-up (e.g., severe heart failure, renal failure, etc.). 4. Evidence of vascular recanalization prior to randomization 5. Uncontrolled seizures at the time of stroke onset, if they interfere with obtaining an accurate baseline NIHSS 6. Posterior circulation Acute Stroke Prognosis Early CT score (pc-ASPECTS) \< 6 on non-contrast CT or CT angiography source images or MR with diffusion-weighted imaging 7. Complete cerebellar infarct with significant mass effect and compression of the fourth ventricle,or bilateral thalamic infarction on CT or MRI 8. Baseline platelet count \<50,000/uL 9. Severe, persistent hypertension (systolic blood pressure \> 220 mmHg or diastolic blood pressure \> 120 mmHg) 10. Known hereditary or acquired bleeding disorders, coagulation factor deficiencies, or recent oral anticoagulant therapy with an International Normalized Ratio (INR) \> 3 11. Suspected purulent embolism, with a suspicion of bacterial endocarditis 12. Known allergies to iodine, heparin, anesthetics, or other explicit contraindications to the endovascular treatment procedure 13. Pregnancy 14. Other serious, progressive, or end-stage diseases (as determined by the investigator) or a life expectancy of less than 6 months 15. Attempted use of a neurothrombectomy device to remove the clot prior to randomization 16. Currently participating in a study involving other investigational drugs or devices 17. Evidence of intracranial tumor on CT or MRI (excluding meningioma) 18. CTA/MRA showing excessive tortuosity of the cervical vessels, which may interfere with endovascular treatment 19. Suspicion of aortic dissection based on medical history and CTA/MRA findings 20. Any other conditions that the investigator believes may interfere with the endovascular procedure or pose significant risk to the subject during the procedure