Endovascular Therapy for Acute Basilar Artery Occlusion With Large Ischemic Core

Inclusion Criteria 1. Clinical presentation or imaging findings consistent with posterior-circulation ischemic stroke. 2. Basilar artery occlusion confirmed by CT angiography (CTA), MR angiography (MRA), or digital subtraction angiography (DSA). 3. Baseline National Institutes of Health Stroke Scale (NIHSS) score ≥10 before randomization. 4. Age 18-85 years, inclusive. 5. Baseline noncontrast CT, CTA source images, or diffusion-weighted MRI (DWI) demonstrating at least one of the following: * Posterior circulation Alberta Stroke Program Early CT Score (pc-ASPECTS) of 0-5; or * Pons-Midbrain Index (PMI) \>4. 6. Randomization within 24 hours of the estimated time of basilar artery occlusion. * The estimated time of basilar artery occlusion is defined as the sudden onset of stroke symptoms consistent with acute basilar artery occlusion. * For patients with wake-up stroke or an unknown time of symptom onset, the last known well (LKW) time will be used as the reference time; randomization must occur within 24 hours of LKW. 7. Written informed consent provided by the participant or their legally authorized representative. Exclusion Criteria 1. Prestroke modified Rankin Scale (mRS) score ≥3. 2. Pregnancy or breastfeeding. 3. Allergy to contrast agents or nickel-titanium alloy. 4. Current participation in another clinical trial. 5. Systolic blood pressure \>185 mmHg or diastolic blood pressure \>110 mmHg that cannot be controlled with antihypertensive treatment. 6. A hereditary or acquired bleeding diathesis, coagulation factor deficiency, or oral anticoagulant use with an international normalized ratio (INR) \>3.0. 7. Blood glucose \<50 mg/dL (2.8 mmol/L) or \>400 mg/dL (22.2 mmol/L), platelet count \<50 × 10⁹/L, or hematocrit \<25%. 8. Life expectancy \<1 year. 9. Inability to complete the 90-day follow-up, for example because of a lack of a fixed residence or residence overseas that prevents follow-up. 10. A documented history of cerebral vasculitis. 11. A pre-existing neurological or psychiatric disorder that would interfere with clinical assessment. Imaging-Based Exclusion Criteria 12. Intracranial hemorrhage on CT or MRI. Patients with cerebral microbleeds \<5 mm in diameter detected on MRI may be included. 13. Vascular tortuosity, anatomical variation, or arterial dissection on CTA, MRA, or DSA that would make endovascular treatment technically difficult. 14. An intracranial tumor, except for a small meningioma.