Intra-arterial Alteplase for Acute Ischemic Stroke After Mechanical Thrombectomy

Prior treatment

• Contraindication to rt-PA (except time to therapy).
• Planned use of dual antiplatelet therapy within the first 24 hours after mechanical thrombectomy.
• Previous parenchymal organ surgery or biopsy in the last 1 month;

Other illness

• Preoperative intracranial hemorrhage confirmed by cranial CT or MRI.
• Known genetic or acquired bleeding disposition with anticoagulation factor deficiency.
• Severe allergy to contrast (non-mild rash allergy) or absolute contraindication to iodine contrast.
• Any active bleeding or recent bleeding (gastrointestinal, urinary tract bleeding, etc.) in the last 1 month;
• Anticipated life expectancy \< 6 months (e.g., malignancy, severe cardiopulmonary disease, etc.).
• Any condition that, in the judgment of the investigator, makes the patient unsuitable for this study or where this study may impose a significant risk to the patient (e.g., inability to understand and/or comply with study procedures and/or follow-up due to psychiatric disorders, cognitive or emotional impairment).

Lab values

• Coagulation disorder with INR \> 1.7 or use of new oral anticoagulants (within 48 hours of symptom onset).
• Platelet count \<50X10\^9/L.
• Known severe renal insufficiency with glomerular filtration rate \<30 ml/min or blood creatinine \>220 μmol/L (2.5 mg/dl).

Other

• Angiographic evaluation showing dissection, severe stenosis, or complete occlusion of the carotid artery, which requires the use of carotid artery stents during the endovascular procedure.
• Suspected cerebral vasculitis based on medical history and/or angiographic evaluation.
• Women who are pregnant or breastfeeding.
• Participation in other clinical trials.
• Suspected vascular occlusion as a result of infective endocarditis.
• Suspected aortic dissection.
• SBP \> 185 mmHg or DBP \> 110 mmHg refractory to treatment.

• Aged 18 years or older.
• Clinical diagnosis of acute ischemic stroke.
• Time from symptom onset to randomization within 24 hours, including wake-up stroke or no-witness stroke; the onset time refers to "Last Known Well" (LKW).
• CTA or MRA confirmed occlusion of the intracranial segment of the internal carotid artery, or M1 or M2 segment of the middle cerebral artery; stable eTICI score of 2b50-3 after mechanical thrombectomy, with or without intravenous thrombolysis. Patients with an eTICI score of 2b50-3 on the diagnostic cerebral angiography before mechanical thrombectomy are also eligible for the study.
• Baseline NIHSS of 6-25.
• NCCT/DWI-MRI ASPECTS ≥ 6;
• Pre-stroke mRS score ≤ 1, or mRS \>1 but not related to neurological disease (e.g., amputation, blindness).
• Signed informed consent.