The short-term and long-term efficacy of recanalization therapy needs to be further confirmed by large-sample prospective studies. The comparison of success rate, complication rate and efficacy among the three recanalization modalities also needs to be further explored. The purpose of this cohort study is to observe the success rate, efficacy and safety of recanalization treatment for non-acute occlusion, and to further compare the advantages and disadvantages of CEA, endovascular intervention and hybrid surgery.

Carotid artery occlusion is one of the primary causes of ischemic stroke. When the occlusion time exceeds 30 days, it is commonlly referred to as chronic carotid artery occlusion (CCAO), and patients with carotid artery occlusion over 24 hours are collectively referred as non-acute occlusion. Symptomatic non-acute occlusion patients with definite hemodynamic hypoperfusion still face a high risk of stroke recurrence under drug treatment, with recurrence rates reported to be between 12.3% and 22.7% within 2 years. Currently, the surgical methods for the treatment of carotid artery occlusion are mainly divided into extracranial-intracranial (EC-IC) bypass and recanalization treatment. Recanalization treatment includes CEA, endovascular intervention and hybrid surgery. While the Carotid Occlusion Surgery Study (COSS) and the recently published Carotid or Middle cerebral artery Occlusion Surgery Study (CMOSS) failed to reveal the significant advantages of EC-IC bypass surgery over medical treatment for patients with symptomatic artery occlusion combined with hemodynamic insufficiency, recanalization treatment has been shown to be a promising treatment modality by case-control studies with small sample size. However, the short-term and long-term efficacy of recanalization therapy needs to be further confirmed by large-sample prospective studies. The comparison of success rate, complication rate and efficacy among the three recanalization modalities also needs to be further explored. In addition, about half of non-acute occlusion patients have cognitive impairment, and the role of cerebral hemodynamics in cognitive impairment is still unclear. Therefore, the purpose of this cohort study is to observe the success rate, efficacy and safety of recanalization treatment for non-acute occlusion, and to further compare the advantages and disadvantages of CEA, endovascular intervention and hybrid surgery.

Inclusion Criteria:

1. Older than 18 years old;
2. Sign the informed consent form;
3. Carotid occlusion at least 24h;
4. Patients with clinical localization symptoms: ipsilateral hemisphere ischemia symptoms or ipsilateral eye ischemia symptoms or cognition impairment, with or without anterior circulation blood supply area infarction;
5. DSA confirmed common carotid artery or internal carotid artery (mTICI=0) occlusion;
6. Perfusion imaging confirms the presence of hypoperfusion in the corresponding area(CBF decrease);
7. The optimal medical treatment for patients who still have ischemic symptoms;
8. Routine DWI and ADC sequence examinations are performed before surgery no new infarction;

Exclusion Criteria:

1. Intracranial arteriovenous malformation or aneurysm;
2. Unstable angina, myocardial infarction (MI), or congestive heart failure in the last 6 months;
3. Uncontrolled diabetes mellitus defined as glucose > 300 mg/dL (16.67 mmol/L);
4. Patient is expected to have the ADP antagonist therapy interruption within 3 months after the procedure;
5. Pregnant or in the perinatal period;
6. Severe concomitant disease with poor prognosis (life expectancy < 3 years);
7. Intolerance or allergies to any of the study medications, such as aspirin or clopidogrel;
8. Allergy to iodine or radiographic contrast media;
9. Concomitant vascular conditions precluding endovascular;
10. Patients with large cerebral infarction within 2 weeks;
11. History of ipsilateral vocal cord paralysis;
12. Those with severe skin diseases who are expected to have difficulty healing the incision;
13. Poor functional status before onset (mRS score 4-5 points).
14. The area of infarction in the occluded vascular area exceeds half of the vascular supply area;
15. Already have dementia or psychiatric illness and are unable to complete neurological and cognitive assessments.
16. Any condition that in the surgeon's judgment suggests the patient an unsuitable surgical candidate.

People diagnosed with non-acute carotid occlusion, fulfilled the above eligible criteria in tertiary medical centers in China additionally will be enrolled consecutively.

Please contact the PI