2.1. Patients

A total of 195 patients who underwent CAS in the Affiliated Provincial Hospital between October 2012 and December 2015 were enrolled. The inclusion criteria were as follows: carotid stenosis ≥70%, symptomatic or asymptomatic poor collateral circulation, and age >45 years. The exclusion criteria were as follows: thrombocytopenia, <100×10⁹/L; leucopenia, <4×10⁹/L; neutropenia; cerebral hemorrhage within nearly 3 months; allergic to aspirin or clopidogrel; severe heart or lung disease; and bead-string-like CAS. If the patient newly developed CI, the surgery was routinely delayed for 3 weeks. If the patient did not present with symptom aggravation within 3 weeks and diffusion-weighted imaging (DWI) or computed tomography (CT) showed good absorption of the new lesion or the lesion was significantly reduced than before, the patients could undergo CAS. The study was supervised by the Medical Ethics Committee of Shandong Provincial Hospital Affiliated to Shandong First Medical University, and all the patients or their legal guardians signed the informed consent.