Study purpose:
A multicenter, prospective, randomized, open-label, blinded-endpoint (PROBE) phase III trial is planned to evaluate the efficacy and safety of intra-arterial thrombolysis (IAT) in patients with acute ischemic stroke caused by medium vessel occlusion (MeVO), compared with best medical management alone.
Eligible participants (aged 18-80 years, baseline NIHSS score 6-25 or 3-5 with disabling deficits, confirmed MeVO within 24 hours of symptom onset) will be randomly assigned 1:1 to the intra-arterial thrombolysis plus best medical management group or the best medical management alone group.
Primary endpoint: proportion of patients with favorable functional outcome (modified Rankin Scale score 0-2) at 90±7 days post-randomization.
Secondary endpoints:
1. Recanalization rate (meTICI ≥ 2b) at 24±12 hours post-randomization; 2. Early neurological improvement (NIHSS score change from baseline) at 7±1 days or discharge; 3. Overall distribution of mRS scores at 90±7 days (shift analysis); 4. Excellent functional outcome (mRS score 0-1) at 90±7 days; 5. Health-related quality of life (EQ-5D-5L) at 90±7 days; 6. Functional independence (Barthel Index score 95-100) at 90±7 days; 7. Symptomatic intracranial hemorrhage (sICH) per Heidelberg criteria within 48 hours; 8. Early neurological deterioration (NIHSS increase ≥ 4 points or any single item increase ≥ 2 points) within 7 days; 9. Any intracranial hemorrhage within 48 hours; 10. Procedure-related complications; 11. All-cause mortality within 90±7 days.
Age 18 to 80 years.
Time from symptom onset or last known well to randomization within 24 hours.
Clinical diagnosis of acute ischemic stroke confirmed by CTA or MRA as being caused by isolated acute medium vessel occlusion, including distal M2/M3 segments of the middle cerebral artery, A2/A3 segments of the anterior cerebral artery, or P1/P2/P3 segments of the posterior cerebral artery. Isolated occlusion is defined as a single symptomatic vessel occlusion; patients with multiple vessel occlusions or uncertain culprit vessel are excluded.
Baseline NIHSS score ≥ 6, or 3-5 with disabling deficits (e.g., motor weakness, aphasia, visual field defects), and NIHSS score ≤ 25 at the time of randomization.
Pre-stroke modified Rankin Scale (mRS) score > 2.
Presence of contraindications to intravenous thrombolysis.
Known allergy to heparin, contrast media, anesthetics, or other definite contraindications to endovascular treatment.
Comorbid severe diseases that may affect outcome assessment, including but not limited to malignancy, severe heart failure, or renal failure, with expected life expectancy < 6 months.