Effect of aging on mechanical stresses, deformations, and hemodynamics in human femoropopliteal artery due to limb flexion
Femoropopliteal artery (FPA) reconstructions are notorious for poor clinical outcomes. Mechanical and flow conditions that occur in the FPA with limb flexion are thought to play a significant role, but are poorly characterized. FPA deformations due to acute limb flexion were quantified using a human cadaver model and used to build a finite element model that simulated surrounding tissue forces associated with limb flexion-induced deformations. Strains and intramural principal mechanical stresses were determined for seven age groups. Computational fluid dynamics analysis was performed to assess hemodynamic variables. FPA shape, stresses, and hemodynamics significantly changed with age. Younger arteries assumed straighter positions in the flexed limb with less pronounced bends and more uniform stress distribution along the length of the artery. Even in the flexed limb posture, FPAs younger than 50 years of age experienced tension, while older FPAs experienced compression. Aging resulted in localization of principal mechanical stresses to the adductor hiatus and popliteal artery below the knee that are typically prone to developing vascular pathology. Maximum principal stresses in these areas increased threefold to fivefold with age with largest increase observed at the adductor hiatus. Atheroprotective wall shear stress reduced after 35 years of age, and atheroprone and oscillatory shear stresses increased after the age of 50. These data can help better understand FPA pathophysiology and can inform the design of targeted materials and devices for peripheral arterial disease treatments.
KeywordsFemoropopliteal artery Limb flexion Stress Deformation Hemodynamics Aging
The authors wish to acknowledge the Charles and Mary Heider Fund for Excellence in Vascular Surgery for their help and support. Computational fluid dynamics simulations were carried out within the joint initiative of CINECA and the Lombardy region LISA under the project B-BeST (bringing biomedical simulations to clinical target).
Funding Research reported in this publication was supported in part by National Heart, Lung, and Blood Institute of the National Institutes of Health (Grant Nos. R01 HL125736 and F32 HL124905).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Clowes AW, Reidy MA, Clowes MM (1983) Mechanisms of stenosis after arterial injury. Lab Invest 49:208–215Google Scholar
- Desyatova A, MacTaggart J, Poulson W et al (2017a) The choice of a constitutive formulation for modeling limb flexion-induced deformations and stresses in the human femoropopliteal arteries of different ages. Biomech Model Mechanobiol 16:775–785. doi: 10.1007/s10237-016-0852-8 CrossRefGoogle Scholar
- Desyatova A, Poulson W, Deegan P et al (2017b) Limb flexion-induced twist and associated intramural stresses in the human femoropopliteal artery. J R Soc Interface. doi: 10.1098/rsif.2017.0025
- Mantella LE, Quan A, Verma S (2015) Variability in vascular smooth muscle cell stretch-induced responses in 2D culture. Vasc Cell 7:7. doi: 10.1186/s13221-015-0032-0
- Poulson W, Kamenskiy A, Seas A et al (2017) Limb flexion-induced axial compression and bending in human femoropopliteal artery segments. J Vasc Surg. doi: 10.1016/j.jvs.2017.01.071
- Smouse BHB, Nikanorov A, Laflash D (2005) Biomechanical forces in the femoropopliteal arterial segment. Endovasc Today 4:60–66Google Scholar