Efficacy and Safety of Interleukin-6 Receptor Inhibitor Combined With Endovascular Treatment in Patients With Acute Posterior Circulation Large Vessel Occlusion Stroke

Inclusion Criteria: 1. Age 18 years or older, of either sex; 2. Acute ischemic stroke caused by occlusion of the basilar artery; 3. Decide to undergo emergency endovascular treatment; 4. Time from stroke onset to groin puncture within 24 hours; 5. National Institutes of Health Stroke Scale (NIHSS) ≥ 10; 6. Posterior circulation Alberta Stroke Program Early computed tomography score (pc-ASPECTS) ≥ 6; 7. Signed informed consent from the patients or the legally authorized representatives. Exclusion Criteria: 1. Intracerebral hemorrhage, epidural hematoma, subdural hematoma, intraventricular hemorrhage, or subarachnoid hemorrhage; 2. Pre-stroke modified Rankin scale (mRS) score \>1; 3. Known allergy to tocilizumab or excipients; 4. Known allergy to iodinated contrast agents; 5. Anticipated difficulty in completing endovascular treatment due to vascular tortuosity; 6. History of congenital or acquired bleeding disorders, coagulation factor deficiency diseases, or thrombocytopenic diseases; 7. Systolic blood pressure ≥180 mmHg or diastolic blood pressure ≥110 mmHg despite blood pressure control; 8. Neutrophils \< 2 × 10\^9 /L; 9. Platelets \< 100 × 10\^9 /L; 10. Blood glucose \<2.8 mmol/L (50 mg/dL) or \>22.2 mmol/L (400 mg/dL); 11. Serum alanine aminotransferase (ALT) or aspartate aminotransferase (AST) levels \>2 times the upper limit of normal; 12. Known recent or current serum creatinine \>2 times the upper limit of normal or estimated glomerular filtration rate (eGFR) \<60 mL/min; 13. Pregnant, lactating, or planning pregnancy within 90 days; 14. Severe mental disorders or inability to comply with informed consent and follow-up requirements due to dementia; 15. Concurrent malignant tumors or severe systemic diseases with expected survival of less than 90 days; 16. Presence of autoimmune diseases or use of immunosuppressive drugs; 17. Systemic infectious diseases; 18. Participation in another interventional clinical study within 30 days before randomization or currently participating in another interventional clinical study; 19. Any circumstance that, as assessed by the investigators, might result in harm to the patients if study therapy is initiated; 20. Other conditions that the investigator considers might affect compliance or preclude participation in this study.