Blood flow and oxygen transport in descending branch of lateral femoral circumflex arteries after transfemoral amputation : a numerical study

Abstract

This study investigates atherosclerotic development in the descending branch of the lateral femoral circumflex artery (DLFCA) after transfemoral amputation and assesses the effects of blood velocity during exercise on the oxygen transport of the residuum DLFCA. Computational fluid dynamics models of DLFCAs coupled with oxygen transport in both the residuum and the sound contralateral limb were established. The profiles for three blood velocity profiles were applied at the inlet of the residuum DLFCA model. The results show that in comparison with the sound limb, blood velocity in the residuum DLFCA was higher, the number of low-wall-shear-stress (WSS) regions was smaller, the Sherwood number for the arterial wall was smaller, and there were more hypoxia zones. An increase in blood velocity in the residuum DLFCA resulted in increases in WSS and the Sherwood number and reductions in the numbers of low-WSS regions and hypoxia zones. The rate of atherosclerosis in the residuum is lower than that of the sound limb in terms of WSS, whereas the rate of atherosclerosis in the sound limb is lower than that of the residuum in terms of hypoxia. Overall, both WSS and oxygen transport need to be considered in order to precisely predict atherosclerosis development in the lower-limb arteries after amputation. In addition, exercise is beneficial for oxygen transport, with an increase in oxygen flux to the arterial wall, and is helpful for the prevention and control of atherosclerosis in the arteries of the residuum.