The purpose of IMPACT-LVO trial is to investigate the efficacy and safety of early adjunctive intra-arterial combined with intravenous administration methylprednisolone sodium succinate after successful endovascular thrombectomy in anterior circulation large vessel occlusion patients.

This is a multicenter, randomized, double-blind, placebo-controlled trial. Acute ischemia stroke patients with anterior circulation large vessel occlusion within 24 hours from last known well will be screened for this trial. Successful recanalization after mechanical thrombectomy (eTICI 2b-3) patients will be randomized 1:1 to either methylprednisolone sodium succinate group or placebo group. The methylprednisolone sodium succinate group patients will receive intra-arterial methylprednisolone sodium succinate 40mg immediately after the recanalization. Then, intravenous administration with methylprednisolone sodium succinate 2mg/kg in the next 3 days. The placebo group patients will receive intra-arterial and intravenous sterile water for injection.

The shift on modified Rankin Scale score is designed to detect in the present trial. A sample size of n = 178 patients (n=89 per group) is required. The intention-to-treat principle will be applied to the primary analysis, therefore, to safeguard against dilution of the treatment effect associated with an approximate 15% non-adherence rate (due to loss to follow-up, consent withdrawal and other reasons), we planned to enrol n=210 patients (n=105 per group) for this study. The findings of IMPACT-LVO are likely to have a direct impact on clinical practice.

Inclusion Criteria:

• Age 18-80 years old;
• The time from onset to randomization was within 24 hours;
• Large vessel occlusive stroke in the anterior circulation confirmed by CTA/MRA/DSA (Including intracranial segment of internal carotid artery, M1 or M2 segment of middle cerebral artery) and the vessel responsible for the signs and symptoms of acute ischemic stroke;
• NIHSS score >= 6 points
• Alberta Stroke Program Early Diagnosis (ASPECTS) score of NCCT >=3;
• Successful endovascular thrombectomy (eTICI 2b50-3)
• Written informed consent signed by patients or their family members

Exclusion Criteria:

• Intracranial hemorrhage confirmed by computed tomography (CT) or magnetic resonance imaging (MRI);
• Prestroke mRS score >= 2
• pregnant or lactating patients
• Allergy to iodinated contrast media, or methylprednisolone sodium succinate
• Participating in other clinical research;
• Inherited/acquired hemorrhagic diathesis (coagulation factor deficiency) or oral anticoagulation with international normalized ratio (INR) >1.7
• History of major bleeding within the past 1 month (gastrointestinal/genitourinary hemorrhage)
• Chronic hemodialysis and severe renal insufficiency (glomerular filtration rate < 30ml/min/1.73m^2 or serum creatinine > 220μmol/L (2.5mg/dl));
• Terminal illness with life expectancy <6 months;
• Blood glucose < 2.8mmol/L (50mg/dl) or > 22.2mmol/L (400mg/dl);
• Intracranial aneurysm, arteriovenous malformation, or space-occupying brain tumor with mass effect on imaging
• Active systemic infectious disease
• Anticipated inability to complete follow-up
• Intraoperative DSA showed vascular perforation, dissection, and contrast extravasation;
• Puncture to recanalization was more than 90 minutes;
• Total thrombectomy passes >3