Endovascular Treatment for Stroke Post 1 Day （24 Hours）

Inclusion criteria

• General Inclusion Criteria

• Age≥18 and ≤80
• Baseline NIHSS ≥ 6 and maintained ≥ 6 before randomization
• Stroke onset or more than 24 hours from the last known well state and within 30 days.
• Pre-stroke mRS score of 0 or 1 points
• The subject or their legally authorized representative has signed the informed consent form for the study
• Imaging Inclusion Criteria

• Magnetic Resonance Angiography (MRA), Computed Tomography Angiography (CTA), or Digital Subtraction Angiography (DSA) confirms the occlusion of major intracranial vessels (occlusion of the internal carotid artery and/or the middle cerebral artery M1/M2 segment)
• Meets one of the following imaging evaluation criteria:

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• Assessed by Computed Tomography Perfusion (CTP) or Perfusion Weighted Imaging (PWI) with MRI: Infarct core volume is less than 100 mL and the mismatch ratio is ≥1.2 or the mismatch volume is ≥10 mL.
• Clinical imaging mismatch is defined by MR-DWI or CTP-rCBF images as:

• Infarct volume is less than 30 mL and NIHSS score is ≥10;
• Infarct volume is between 30 mL and 100 mL and NIHSS score is ≥20

Exclusion criteria

• General Exclusion Criteria

• In the judgment of the clinician responsible for treatment, it is considered unlikely to benefit from the trial (e.g., advanced dementia, severe pre-stroke disability (mRS ≥2), high likelihood of early death)
• Major comorbidities that may interfere with the assessment of results and follow-up (e.g., severe heart failure, renal failure, etc.)
• Rapid improvement in neurologic status to NIHSS<6 or evidence of vascular reconstruction before randomization
• Uncontrolled seizures at the time of stroke onset that, if preventing the acquisition of an accurate baseline NIHSS
• Baseline platelet count<50,000/uL
• Severe persistent hypertension (systolic blood pressure >220 mmHg or diastolic blood pressure>120 mmHg)
• Known hereditary or acquired bleeding diathesis, coagulation factor deficiency, or recent oral anticoagulant therapy with an International Normalized Ratio (INR) >3
• Suspected septic emboli, suspected bacterial endocarditis
• Known allergy to iodine, heparin, anesthetics, or other clear contraindications to the endovascular treatment procedure
• Pregnant women
• Other serious, progressive, or terminal illnesses (as judged by the investigator) or life expectancy of less than 6 months
• Attempt to use a neurothrombectomy device to remove the blood clot before randomization
• Currently participating in other studies of investigational drugs or devices
• Any other conditions that, in the opinion of the investigator, would impede endovascular surgery or pose a significant risk to the subject during endovascular surgery
• Imaging Exclusion Criteria

• Intracranial hemorrhage, including parenchymal hemorrhage, ventricular hemorrhage, subarachnoid hemorrhage, and epidural/subdural hemorrhage;
• Evidence of intracranial tumors as shown by CT or MRI (except for small meningiomas);
• CTA/MRA showing excessive tortuosity of the cervical vessels, which may hinder endovascular treatment;
• Suspected aortic dissection based on medical history and CTA/MRA;
• Presence of an intracranial stent in the same vascular area, which would impede the smooth progress of surgery.