大鼠腹主动脉瘤残余应力分析

目的 用测量张开角的方法研究大鼠腹主动脉瘤模型的应力分布，研究腹主动脉瘤壁的顺应性和临床预测腹主动脉瘤的破裂风险。方法 用猪弹力蛋白酶灌注Wistar大鼠腹主动脉建立梭形肾下腹主动脉瘤模型，测量并对比腹主动脉瘤动脉环和正常腹主动脉环的蠕变速度，残余应力，对比腹主动脉瘤不同部位的残余应力，动脉环内径和瘤壁厚度。结果 梭形腹主动脉瘤模型建立的成功率90%，腹主动脉瘤动脉环蠕变速度较正常腹主动脉快，腹主动脉瘤入口和出口的残余应力值最大，内径和瘤壁厚度最小，结论 残余应力可以量化腹主动脉瘤瘤壁的顺应性，用测量残余应力的方法发现腹主动脉瘤的顺应性较正常主动脉小，腹主动脉瘤入口和出口附近应力最大，但保护作用最小，是可能破裂的部位。

Residual strain in abdominal aortic aneurysms

Objective To study the stress distribution and the elasticity of abdominal aortic aneurysms (AAA) rat by opening angle along the aorta, calculate rupture risk of AAA clinically.Methods Perfusion of the Wistar rats infrarenal aorta with porcine pancreatic elastase (PPE) induced the fusiform infrarenal AAA models. The creep velocity and residual strain of the aorta ring between the AAA and the control group were measured and compared. Residual strain, inner radius and wall thickness of different parts in AAA were compared.Results 90% animals developed AAA in PPE induced group. The creep velocity of AAA was higher than that in the control group. In the inlet and outlet of AAA, the residual strain was highest,inner radius the smallest and wall thickness the most thin.Conclusion The residual strain could quantitate the elasticity of AAA and calculate the rupture and growth way of AAA.