Safety and Efficacy of Selective Intra-Arterial Cooling Infusion Combined With EVT in Acute Ischemic Stroke

This is a multicenter, randomized, controlled, subject- and assessor-blinded clinical trial. The research objective is to evaluate the safety and efficacy of selective intra-arterial cooling infusion combined with endovascular therapy in the treatment of acute anterior circulation large vessel occlusion stroke. This trial aims to enroll 258 subjects. Patients assigned to the control group will receive best medical management (BMM) and endovascular therapy (EVT). Those in the selective intra-arterial cooling infusion group (IA-SCI group) will undergo selective intra-arterial cold saline infusion, in addition to BMM and EVT. Subjects will be interviewed face-to-face at randomization, 24±6 hours, 48±6 hours after randomization, 7±2 days/discharge. Telephone interviews/ face-to face interviews will be performed at 30±3 days and 90±7 days after randomization. The primary outcome is the distribution of Modified Rankin Score at 90±7days after randomization.

Inclusion Criteria 1. Age ≥18 and ≤80. 2. Clinical signs consistent with AIS-LVO in the anterior circulation (intracranial segment of internal carotid artery, M1 segment of middle cerebral artery (MCA) demonstrated by computed tomography angiography (CTA) / magnetic resonance angiography (MRA)/ digital subtraction angiography (DSA)). 3. National Institutes of Health Stroke Scale (NIHSS) score (at screening) ≥6 and ≤25. 4. Modified Rankin Scale (mRS) score ≤1 before stroke onset. 5. Arterial puncture performed within 24 hours of symptom onset or last known well (LKW). 6. Written informed consent obtained from the patients or legally authorized representatives. For patients admitted to the hospital within 6 hours of symptom onset, an Alberta Stroke Program Early CT Score (ASPECTS) ≥6 is required. For those admitted between 6 and 24 hours, the neuroimaging criteria of the DAWN or DEFUSE-3 trials are applied. Exclusion Criteria 1. Baseline CT/MRI reveals the presence of acute infarction in multiple vascular territories. 2. CTA/MRA/DSA confirms the presence of arterial dissection. 3. Evidence of intracranial hemorrhage or hemorrhagic transformation before thrombectomy. 4. Known allergies or intolerances to antiplatelet agents, anticoagulants, iodinated contrast, or anesthetics. 5. Severe infection (e.g., sepsis) or multiple organ failure. 6. Known hereditary or acquired hemorrhagic diathesis; coagulation factor deficiency; recent oral anticoagulant therapy with international normalized ratio (INR)\>3. Exception: Time elapsed since the last use of a novel oral anticoagulant ≥48 hours plus a normal activated partial thromboplastin time (APTT). 7. Baseline platelet count \185 mmHg or diastolic BP \>110 mmHg). 10. Previous New York Heart Association (NYHA) functional classification \>I. 11. Coronary artery stenosis \>70% or history of coronary artery bypass grafting. 12. Undergoing hemodialysis or peritoneal dialysis; severe renal insufficiency with a glomerular filtration rate \220 mmol/L (2.5 mg/dL). 13. Known intracranial aneurysm or cerebral arteriovenous malformation. 14. Malignant brain tumor or central nervous system infection. 15. Pre-existing neurological or psychiatric diseases that could confound the neurological or functional evaluations (e.g., dementia or mental illness) 16. Pregnant or lactating at admission. 17. Anticipated life expectancy \