Intra-arterial Recombinant Human TNK Tissue-type Plasminogen Activator (rhTNK-tPA) Thrombolysis for Acute Large Vascular Occlusion After Successful Mechanical Thrombectomy Recanalization (ANGEL-TNK)

Inclusion Criteria: Clinical Inclusion Criteria: Age >18 years; NIHSS ≥2; Onset of symptoms to baseline CT imaging time: 4.5 to 24 hours, including wake-up stroke and unwitnessed stroke; Time of onset of symptoms is defined as "last known well" (LKW); Pre-stroke mRS score 0-1; Signed informed consent from patient or their health care proxy. Neuroimaging Inclusion Criteria: CTA/MRA proven intracranial artery occlusion: Intracranial Internal Carotid Artery (ICA)、M1 of Middle cerebral artery (MCA)、dominant M2 of MCA; ASPECTS ≥6 on non-contrast CT (NCCT) scan or DWI MRI; CT perfusion or MR perfusion: ischemic infarct core <70ml, mismatch ratio≥1.2, mismatch volume ≥15ml; Treated with MT resulting in an eTICI score 2b50-3 at end of the procedure. Patients with an eTICI score 2b50-3 on the diagnostic cerebral angiography before the onset of MT are also eligible for the study. Exclusion Criteria: Clinical Exclusion Criteria: IV thrombolysis used on admission; Contraindications to intravenous thrombolysis; Balloon angioplasty, permanent stenting and other situations during the endovascular procedure that require antiplatelet therapy or anticoagulant within the first 24h; IV heparin (heparinized saline allowed); Females who are pregnant, or those of child-bearing potential with positive urine or serum beta Human Chorionic Gonadotropin (HCG) test; Brain tumor (with mass effect); Known hereditary or acquired hemorrhagic diathesis, coagulation factor deficiency Known coagulopathy, INR>1.7 or use of novel anticoagulants < 48h from symptom onset Platelets < 50*109/L; Suspicion of septic emboli or endocarditis Renal Failure as defined by a serum creatinine > 2.5 mg/dl (or 220μmol/l) or glomerular Filtration Rate [GFR] < 30ml/min; Patient who requires hemodialysis or peritoneal dialysis, or who has a contraindication to angiogram for whatever reason; Suspicion of aortic dissection; Parenchymal organ surgery and biopsy were performed in the past one month; Any active bleeding or recent bleeding (gastrointestinal bleeding, urinary bleeding, etc.) in the past 1 month; History of life-threatening allergy (more than rash) to contrast medium; SBP >185 mmHg or DBP >110 mmHg refractory to treatment; Serious, advanced, terminal illness with anticipated life expectancy < 6 months; Participation in another randomized clinical trial that could confound the evaluation of the study; Other circumstances that the investigator considers inappropriate for participation or may pose a significant risk to patients (e.g. inability to understand and/or comply with study procedures and/or follow-up due to mental disorders, cognitive or mood disorders). Specific Neuroimaging Exclusion Criteria Midline shift or herniation, mass effect with effacement of the ventricles Evidence of acute intracranial hemorrhage on CT/MRI Acute bilateral strokes or multiple intracranial vessel occlusions Isolated extracranial ICA occlusion or tandem carotid / MCA occlusion Dissection of occluded artery on DSA after thrombectomy