Theoretical study of the effect of stress-dependent remodeling on arterial geometry under hypertensive conditions
Theoretical study of the effect of stress-dependent remodeling on arterial geometry under hypertensive conditions
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DOI：
10.1016/s0021-9290(97)00032-8
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发表时间：
1997-08-01
影响因子：
2.4
通讯作者：
Rachev, A
中科院分区：
文献类型：
--
作者：
Rachev, A
在理论模型的基础上，对动脉几何重构进行了研究。持续高血压通过血压的阶梯升高来模拟。该动脉被认为是由非线性弹性不可压缩材料组成的厚壁双层管道。基本假设是，动脉以这样一种方式重塑其零应力构型，即在高血压条件下动脉壁中的应变和应力分布与在正常血压条件下相同。利用这一假设，提出了一种确定高血压动脉零应力构型几何尺寸的方法。为了保证解的唯一性，对重塑过程施加了两个条件：(A)无载荷状态下动脉的内径保持不变；(B)在零应力配置下，高血压动脉内层和外层的厚度之比是已知的。该模型预测，动脉壁重构导致：(1)在非负荷状态和生理状态下动脉壁厚度均增加；(2)高压下高血压血管内径较正常血压下正常血压动脉内径增大；(3)当未负荷动脉段被径向切断时，开放的结构仍然包含残余应变和应力。这些结果与已发表的实验结果一致。推测在空载和张开状态下，残余应力的来源是应力调制生长。(C)1997年爱思唯尔科学有限公司。
Remodeling of arterial geometry was studied on the basis of a theoretical model. Sustained hypertension was simulated by a step increase in blood pressure. The artery was considered to be a thick-walled two-layer tube made of nonlinear elastic incompressible material. The basic hypothesis is that the artery remodels its zero-stress configuration in such a way that the strain and stress distributions in the arterial wall under hypertensive conditions are the same as under normotensive conditions. Using this hypothesis, a method for determining the geometrical dimensions of the zero-stress configuration of the hypertensive artery was proposed. To ensure uniqueness of the solution, two side conditions on the remodeling process are imposed: (a) the inner radius of the artery in the unloaded state remains unchanged; and (b) the ratio between the thickness of the inner and outer layer of the hypertensive artery in the zero-stress configuration is known. The model predicts that the arterial wall remodeling causes: (i) an increase of the well thickness both in the unloaded and physiological states; (ii) an increase of the inner diameter of the hypertensive vessel under high pressure compared to the diameter of the normotensive artery under normal pressure; (iii) the opened-up configuration which arises when the unloaded arterial segment is cut radially still contains residual strains and stresses. These results are consistent with published experimental findings. It is speculated that the origin of residual stresses that exist in the unloaded and opened-up configurations is the stress-modulated growth. (C) 1997 Elsevier Science Ltd.