Remote limb ischemic preconditioning is neuro-protective and anti-inflammatory for ischemia- reperfusion injury. As the extent of its effect is unknown, the investigators will use clinical outcome, serum biochemical markers and diffusion-weighted magnetic resonance imaging (DW-MRI)to determine the extent of its neuro-protective and anti-inflammatory effect.

BACKGROUND: Brain ischemia and injury contributed to perioperative morbidity and mortality in Carotid Artery Stenting. Remote ischemic preconditioning (RIPC) is a phenomenon whereby brief periods of ischemia followed by reperfusion in one organ provide systemic protection from prolonged ischemia. To investigate whether remote preconditioning protects the brain injury in patients undergoing elective Carotid Artery Stenting, a randomized trial will be performed in current study.

DESIGNING 60 patients will be randomized to Carotid Artery Stenting with RIPC group or conventional Carotid Artery Stenting group (control). RIPC consisted of five 5-min cycles of right upper arm ischemia/reperfusion, which was induced by an automated cuff-inflator placed on the right upper arm which was inflated to 200 mmHg for 5mins followed by deflating the cuff for 5mins. Cerebral injury was assessed by S-100b, NSE, hs-CRP and MMSE test in different time points.

Inclusion Criteria:Patients referred for elective Carotid Artery Stenting were participate in the study at the time of scheduling for operation.

1. Symptomatic patient, as evidenced by transient ischemic attack (TIA), amaurosis fugax, minor or non-disabling stroke(in the hemisphere supplied by the target vessel), within 180 days of the randomization date.

2. Discrete lesion located in the internal carotid artery(ICA), and the degree of carotid stenosis ≥50% defined as:

   Stenosis ≥70% by ultrasound. Stenosis ≥50% by angiography (based on NASCET Criteria)

3. Appropriate for carotid stenting. Candidates for Carotid Artery Stenting meet all other inclusion requirements.

Exclusion Criteria:

1. Evolving stroke
2. Untoward reaction to anesthesia
3. Intolerance or allergic reaction to associated medications, including aspirin(ASA) and clopidogrel.
4. Prior major ipsilateral stroke that may confound study endpoints.
5. Severe dementia.
6. Hemorrhagic transformation of an ischemic stroke within the past 60 days.
7. Chronic atrial fibrillation.
8. MI within previous 30 days.
9. High risk surgical candidate defined as the CREST test.
10. Bilateral upper limb arteries are severe stenotic or occlusion.