Influences of aortic motion and curvature on vessel expansion in murine experimental aneurysms.
Influences of aortic motion and curvature on vessel expansion in murine experimental aneurysms.
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DOI：
10.1161/atvbaha.110.216481
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发表时间：
2011-02
期刊：
影响因子：
--
通讯作者：
Greve JM
中科院分区：
文献类型：
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作者：
Goergen CJ;Azuma J;Barr KN;Magdefessel L;Kallop DY;Gogineni A;Grewall A;Weimer RM;Connolly AJ;Dalman RL;Taylor CA;Tsao PS;Greve JM
本研究旨在定量比较实验性腹主动脉瘤（AAA）中主动脉曲率和运动与动脉瘤位置、扩张方向和病理生理学的关系。在4.7 T下进行磁共振成像，包括：1）血管几何形状的3D采集和2）量化管腔运动的2D心脏门控采集。在血管紧张素II（AngII）填充的渗透泵植入或输注弹性蛋白酶诱导AAA形成之前和之后，对24周龄雄性小鼠进行成像。AngII诱导的AAA形成于腹主动脉最大弯曲的位置附近，并且扩张的方向与肾上主动脉运动的方向相关。弹性蛋白酶诱导的AAA形成于低血管曲率区域，并且没有可重复的扩张方向。AngII显著增加平均血压（22.7mmHg; p<0.05），而两种模型均显示主动脉循环应变显著降低2倍（p<0.05）。还观察到弹性蛋白降解模式和蛋白酶激活探针荧光信号定位的差异。AngII动脉瘤扩张的方向与运动方向、内侧弹性蛋白夹层和外膜重塑相关。前肾下主动脉运动与弹性蛋白酶诱导的动脉瘤中弹性蛋白降解相关。两种模型的结果表明动脉瘤病理学与主动脉几何形状和运动之间的关系。
The purpose of this study was to quantitatively compare aortic curvature and motion to resulting aneurysm location, direction of expansion, and pathophysiology in experimental abdominal aortic aneurysms (AAAs). Magnetic resonance imaging was performed at 4.7T with: 1) a 3D acquisition for vessel geometry and 2) a 2D cardiac-gated acquisition to quantify luminal motion. Male 24-week-old mice were imaged before and after AAA formation induced by angiotensin II (AngII)-filled osmotic pump implantation or infusion of elastase. AngII-induced AAAs formed near the location of maximum abdominal aortic curvature, and the leftward direction of expansion was correlated with the direction of suprarenal aortic motion. Elastase-induced AAAs formed in a region of low vessel curvature and had no repeatable direction of expansion. AngII significantly increased mean blood pressure (22.7mmHg; p<0.05), while both models showed a significant two-fold decrease in aortic cyclic strain (p<0.05). Differences in patterns of elastin degradation and localization of fluorescent signal from protease-activated probes were also observed. The direction of AngII aneurysm expansion correlated with the direction of motion, medial elastin dissection, and adventitial remodeling. Anterior infrarenal aortic motion correlated with medial elastin degradation in elastase-induced aneurysms. Results from both models suggest a relationship between aneurysm pathology and aortic geometry and motion.