Endovascular Treatment for Symptomatic Non-acute Carotid Occlusion

This study is a multicenter, prospective, randomized, open-label, blinded-endpoint clinical trial designed to evaluate the safety and potential efficacy of endovascular recanalization strategies in patients with symptomatic non-acute carotid artery occlusion and cognitive impairment. Eligible participants will be randomly assigned to best medical treatment alone, endovascular recanalization without proximal protection plus best medical treatment, or endovascular recanalization with proximal balloon protection plus best medical treatment. The study will assess whether endovascular recanalization improves cognitive function and whether proximal protection reduces procedure-related new ischemic lesions on diffusion-weighted magnetic resonance imaging.

Inclusion Criteria: 1. The age ranged from 18 to 80 years 2. Unilateral carotid artery occlusion confirmed by CTA or DSA (excluding anterior and middle cerebral artery occlusion) 3. Complete 3T-MRI within 1-3 days before operation 4. The time of carotid artery occlusion was more than 24h (confirmed by imaging or according to the patient's condition), and not more than 3 months 5. Ischemic stroke or TIA related to occluded vessels existed in the past 3 months, and the last ischemic event was \> 2 weeks; and there was cognitive impairment, MoCA score ≤ 25 after education correction 6. Imaging confirmed that there was hypoperfusion in the ipsilateral cerebral hemisphere of carotid artery occlusion, which met at least any of the following requirements: ①Head CT perfusion imaging showed low perfusion in the lesion vascular area (CBF decreased by 30% compared with contralateral perfusion) ②ASITN/SIR collateral circulation score based on DSA \< 3 points ③Cerebral infarction with hemodynamic abnormalities confirmed by head MRI (such as watershed infarction) 7. Sign the informed consent form Exclusion Criteria: 1. There was severe neurological dysfunction (mRS ≥ 4) before enrollment 2. The ipsilateral common carotid artery was occluded, or the ipsilateral middle cerebral artery was severely stenosed or occluded 3. Non atherosclerotic occlusion (such as vasculitis, moyamoya disease, etc.) 4. Patients with massive cerebral infarction (infarction volume based on MRI-DWI/ADC is more than 70ml) 5. Untreated intracranial aneurysms, intracranial tumors (except meningiomas) or any intracranial vascular malformations 6. Evidence of cardiogenic embolism 7. Allergic to heparin, aspirin, clopidogrel, statins, metals, anesthetics, contrast agents, or unable to tolerate general anesthesia surgery 8. Any history of intracranial hemorrhage within 30 days (including cerebral parenchyma, ventricle, subarachnoid hemorrhage, subdural or epidural) 9. History of primary cerebral parenchymal hemorrhage 10. There are contraindications to antiplatelet drugs 11. There are coagulation disorders and systemic bleeding 12. Thrombocytopenia (\180mmHg or diastolic blood pressure\>110mmHg) 14. Severe coronary heart disease, severe liver injury (AST or ALT more than 3 times the normal value), liver cirrhosis and severe renal insufficiency (creatinine\>177 μmol/L) were observed 15. Major surgical operations within 30 days or in the next 90 days 16. It is known that patients with dementia, cognitive impairment caused by other reasons or mental diseases cannot complete the assessment of neurological and cognitive functions 17. There are cerebral infarction that clearly involves the key brain areas of cognition, or there are neurological deficits that affect the accuracy of cognitive function assessment, such as severe aphasia, neglect, and audiovisual impairment. According to the judgment of the researchers, the decline of cognitive function is mainly caused by irreversible brain tissue injury 18. The expected survival time of patients with other diseases was less than 2 years 19. Pregnancy or lactation 20. Patients have been included in other studies, which is in conflict with this study