Effect of Remote Ischemic Preconditioning on Cerebral Circulation Time in Patients With Severe Carotid Artery Stenosis (RIP-CCT)

Inclusion Criteria: * age 18 years or older, regardless of gender; * patients with severe carotid stenosis eligible for stenting (70-99% stenosis confirmed by DSA); * non-responsible vessel stenosis \<50% if bilateral carotid stenosis or combined posterior circulation stenosis is present; * first DSA suggestive of ≥ 0.8 seconds difference (CCT on the affected side - CCT on the healthy side); * baseline modified Rankin Scale (mRS) ≤ 2 points. * signed the informed consent form. Exclusion Criteria: * baseline mRS ≥ 3 points; * severe long-segment calcification of the carotid artery, severe distortion of aortic arch branches, anatomical variation of the aortic arch, and etc, which are not suitable for stenting * spontaneous intracranial hemorrhage within 12 months; * previous severe stroke or myocardial infarction within 3 months; * active bleeding and coagulation disorders, which is contraindication to heparin and antiplatelet agents; * a large intracranial aneurysm that cannot be treated simultaneously; * severe insufficiency of vital organs such as the heart, lungs, liver and kidneys, or malignant tumors with an expected survival cycle of less than six months; * total occlusion of carotid artery without obvious cerebral ischemic symptoms * unable to tolerate anesthesia; * severe dementia; * uncontrolled hypertension ; * allergy to contrast media; * pregnancy; * being involved in studies with other drugs or instruments, etc; * contraindications to remote ischemic preconditioning, such as those with more severe soft tissue injuries, fractures or vascular injuries in the upper extremity, or peripheral vascular lesions in the distal upper extremity.