Han Hai-Chao
Department of Mechanical Engineering, The University of Texas at San Antonio, Biomedical Engineering Program, UTSA-UTHSCSA, San Antonio, TX 78249, USA.
J Biomech. 2007;40(16):3672-8. doi: 10.1016/j.jbiomech.2007.06.018. Epub 2007 Aug 8.
The stability of arteries under blood pressure load is essential to the maintenance of normal arterial function and the loss of stability can lead to tortuosity and kinking that are associated with significant clinical complications. However, mechanical analysis of arterial bent buckling is lacking. To address this issue, this paper presents a biomechanical model of arterial buckling. Using an elastic cylindrical arterial model, the mechanical equations for arterial buckling were developed and the critical buckling pressure was found to be a function of the wall stiffness (Young's modulus), arterial radius, length, wall thickness, and the axial strain. Both the model equations and experimental results demonstrated that the critical pressure is related to the axial strain. Arteries may buckle and become tortuous due to reduced (subphysiological) axial strain, hypertensive pressure, and a weakened wall. These results are in accordance with, and provide a possible explanation to the clinical observations that hypertension and aging are the risk factors for arterial tortuosity and kinking. The current model is also applicable to veins and ureters.
动脉在血压负荷下的稳定性对于维持正常动脉功能至关重要，而稳定性的丧失会导致动脉迂曲和扭结，进而引发严重的临床并发症。然而，目前缺乏对动脉弯曲屈曲的力学分析。为了解决这一问题，本文提出了一种动脉屈曲的生物力学模型。通过使用弹性圆柱形动脉模型，推导了动脉屈曲的力学方程，发现临界屈曲压力是壁刚度（杨氏模量）、动脉半径、长度、壁厚和轴向应变的函数。模型方程和实验结果均表明，临界压力与轴向应变有关。由于轴向应变降低（低于生理水平）、高血压以及动脉壁减弱，动脉可能会发生屈曲并变得迂曲。这些结果与临床观察结果一致，并为高血压和衰老作为动脉迂曲和扭结的危险因素提供了一种可能的解释。当前模型也适用于静脉和输尿管。
