动脉粥样硬化兔斑块易损性的血管内超声评价

目的应用血管内超声（IVUS）技术评价易损斑块的影像学特征。方法30只实验兔给予球囊损伤腹主动脉＋高脂饲料喂养，12周末将实验兔随机分为A、B两组，在A组腹主动脉斑块处转染携带人野生型P53基因的重组腺病毒载体，2周后给予所有兔中国斑点蝰蛇毒（CRVV）和组胺触发，14周末进行体表超声、血管内超声和病理学检查。结果A组斑块破裂率较B组显著增高（P〈0．05）。IVUS示斑块破裂组的血管外弹力膜面积（EEMA）、斑块面积（PA）、管腔面积狭窄百分率（LAS%）及偏心指数（EI）显著大于未破裂组（P〈0．01～0．05）；斑块破裂组的内一中膜厚度（IMT）、收缩期峰值流速（Vp）显著大于未破裂组，而平均回声强度的校正值（AIIc％）显著低于未破裂组（P均〈0．05）。结论应用野生型P53基因转染可导致斑块的不稳定性，IVUS能够准确识别易损斑块，为临床早期发现易损斑块并预测斑块破裂提供了可靠的方法。

Intravascular Ultrasound Evaluation of Vulnerable Plaques in Rabbit Model

Objective To discuss the imaging features of vulnerable plaques with intravascular ultrasound (IVUS)in rabbit model.Methods Thirty rabbits underwent balloon-induced abdominal aortic wall injury and then were fed with a diet of 1% cholesterol.At the end of 12~ th week,thirty rabbits were divided randomly into group A and B and recombinant adenovirus carrying human wild type P53 gene were injected through a catheter into the aortic segments rich in plaques in group A.Two weeks later,all the rabbits underwent pharmacological triggering by Chinese Russell's Viper Venom(CRVV) and histamine.At the end of 14~ th week of the experiment,the abdominal aortae were detected with IVUS and high frequency ultrasound and the aortae were taken out to be observed pathologically.Results Plaque rupture rate in group A was significantly higher than in group B.External elastic membranous area(EEMA),plaque area(PA),lumen area stenosing(LAS%)and eccentric index(EI)in plaque ruptured group were significantly higher than in nonruptured group(P<0.01-0.05).Compared with nonruptured group,IMT and Vp in plaque ruptured group was significantly higher and AIIc% was significantly lower (P<0.05).Conclusions Transfection of human wild type P53 may induce plaque rupture in most atherosclerotic lesions.IVUS can accurately identify vulnerable plaques,which offer a reliable method for the early discovery and rupture prediction of vulnerable plaques.