Ultra-early Identification of Futile Recanalization After Reperfusion Therapy in Acute Ischemic Stroke Based on Cerebral Autoregulation Monitoring

Inclusion Criteria: 1. Age ≥ 18 2. Diagnosis of acute ischemic stroke caused by anterior circulation large vessel occlusion (intracranial internal carotid artery or M1 segment of the middle cerebral artery). 3. National Institutes of Health Stroke Scale (NIHSS) score ≥ 6 at presentation. 4. Pre-stroke modified Rankin Scale (mRS) score ≤ 1. 5. Symptom onset ≤ 24 hours. 6. For patients with symptom onset within 6 hours: ASPECTS ≥ 6; for patients with symptom onset between 6 and 24 hours: age ≤ 80 years and ASPECTS ≥ 3. 7. Underwent mechanical thrombectomy and achieved successful recanalization (mTICI 2b-3). 8. Patient or legally authorized representative provides written informed consent. Exclusion Criteria: 1. Pre-procedural baseline imaging showing significant intracranial hemorrhagic transformation, intracranial arterial dissection, large chronic cerebral infarction, or intracranial metastasis from malignant tumors. 2. Any degree of stenosis, plaque, dissection, severe tortuosity, or imaging evidence of unstable/vulnerable plaque in the target-side or bilateral common carotid artery or the origin of the internal carotid artery. 3. Known history of carotid sinus hypersensitivity syndrome, severe autonomic dysfunction, sick sinus syndrome, high-grade atrioventricular conduction block, or other malignant arrhythmias. 4. Refractory malignant hypertensive crisis (systolic blood pressure persistently ≥ 200 mmHg despite standardized intravenous antihypertensive therapy, or hemodynamic instability with shock). 5. Known severe allergy to contrast agents or anesthetic drugs, or contraindications to antiplatelet/anticoagulation therapy. 6. Severe systemic active infection, multiple organ failure, or expected survival \< 6 months. 7. Severe hepatic or renal dysfunction (ALT/AST \> 3× upper limit of normal; estimated glomerular filtration rate \< 30 mL/min) or severe coagulation disorders (platelet count \< 40 × 10⁹/L, APTT \> 50 s, INR \> 3.0). 8. Blood glucose \< 2.7 mmol/L or \> 22.2 mmol/L. 9. Heart failure with NYHA class \> II, or persistent systolic blood pressure \< 100 mmHg. 10. Central nervous system infection or intracranial tumor. 11. Unstable vital signs. 12. Severe alcohol dependence or drug dependence. 13. Cognitive impairment or psychiatric disorders that may affect follow-up assessments. 14. Pregnant or breastfeeding women. 15. Participation in another clinical drug or device study within the past 30 days. 16. Local skin damage or other conditions preventing proper placement of monitoring electrodes. 17. Severe agitation or other conditions that interfere with data acquisition. 18. Any other condition judged by investigators to potentially affect study results.