Clinical Analysis Of The Timing Of Using Embolic-protected Devices For Carotid Artery Stenting

Purpose:This study was designed to analysis of carotid plaques nature and predict the harmful emboli shedding in CAS according to carotid artery high-resolution MRI scans. To calculate the incidence of harmful emboli through combined with patients’ risk factors and captured the emboli in CAS to provide reliable basis for reasonable use of the embolic-protected device.Methods:A total of195consecutive patients who underwent CAS between October2010and December2013in Provincial Hospital affiliated to Shandong University were enrolled. In order to define the nature of the carotid artery plaque (Stable plaque or vulnerable plaque), all patients were scaned by carotid artery Magnetic Resonance Imaging before CAS. Intraoperative EPDs were used in all patients. The size and number of emboli in EPDs were assigned to four grades (grad A=no emboli;grad B=the emboli diameter<2mm, n≤2;grad C=the emboli diameter<2mm,n≤3;grad D=the emboli diameter≥2mm,n≥1).According to the collected emboli of patients, all patients were divided into two groups:Harmless emboli group(group W:grade A and B)and Harmful emboli group (group Y: grade C and D). We compared demographic characteristics, medical history, and angiographic findings of each group to get the risk factors of the harmful emboli. we got the incidence of the harmful emboli according to statistical data that vulnerable plaque with different amounts of risk factors.Results:The carotid artery high-resolution MRI detection:the plaques of116cases (59.5%) in all patients were stable plaques, and those of79(40.5%) cases were vulnerable plaques. Intraoperative EPDs were used in all patients. After CAS,58cases patients were included Y group and137cases patients were included W group. Logistic Regression analysis showed that advanced age (P=0.0465), smoking (P=0.0172), lesion length (P=0.0475) and preoperative TIA attack≥3(P=0.0102) were risk factors of harmful emboli shedding. However, we also found:2cases (3.4%) of the harmful emboli came from stable plaques,56cases (96.6%) harmful emboli came from vulnerable plaques. AS vulnerable plaques with zero risk factor, the incidence of the harmful emboli was44%. AS vulnerable plaques with one risk factor, the incidence of the harmful emboli was68.1%. AS vulnerable plaques with two risk factors, the incidence of the harmful emboli was72.2%. AS vulnerable plaques with three risk factors, the incidence of the harmful emboli was74.5%. AS vulnerable plaques with four risk factors, the incidence of the harmful emboli was84.6%.Conclusion:The incidence (1.7%) of harmful embolus was low for stable plaques in CAS. In CAS, the vulnerable plaques with more risk factors, the greater probability of harmful emboli shedding. We don’t to use EPDs if the carotid plaque was the stable plaque. We recommend to use EPDs if the carotid plaque was vulnerable plaque.