Wang Chong, Guo Xiaomei, Kassab Ghassan S
Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, 22908, USA.
J Biomech Eng. 2009 Nov;131(11):111011. doi: 10.1115/1.4000106.
The stress distribution in the vessel wall has an important bearing on vascular function in health and disease. We studied the relationship between the transmural stress distribution and the opening angle (OA) to determine the stress gradient. The simulation of wall stress was based on transmural measurements of strain and material properties of coronary arteries in reference to the zero-stress state. A one-layer model with material constants of the intact vessel was used to calculate the circumferential stress distribution. A sensitivity analysis using both one- and two-layer models (intima-media and adventitia layers) was carried out to study the effect of the OA on the circumferential stress distribution and average circumferential stress. A larger OA always shifts the circumferential stress from the intima-media to the adventitia layer. We report a new observation that the circumferential stress at the adventitia may exceed that at the intima at physiological loading due to the larger OA in the porcine coronary artery. This has important implications for growth and remodeling, where an increase in opening angle may shift excessive stress from the inner layer to the outer layer.
血管壁中的应力分布对健康和疾病状态下的血管功能具有重要影响。我们研究了跨壁应力分布与开口角度（OA）之间的关系，以确定应力梯度。壁应力的模拟基于冠状动脉相对于零应力状态的跨壁应变测量和材料特性。使用具有完整血管材料常数的单层模型来计算周向应力分布。进行了使用单层和双层模型（内膜 - 中膜和外膜层）的敏感性分析，以研究OA对周向应力分布和平均周向应力的影响。较大的OA总是使周向应力从内膜 - 中膜层转移到外膜层。我们报告了一项新的观察结果，即在生理负荷下，由于猪冠状动脉中较大的OA，外膜处的周向应力可能超过内膜处的周向应力。这对生长和重塑具有重要意义，其中开口角度的增加可能会将过多的应力从内层转移到外层。
