Pedersen E M, Yoganathan A P, Lefebvre X P
Department of Cardiovascular and Thoracic Surgery, Skejby Sygehus, Aarhus, Denmark.
J Biomech. 1992 Aug;25(8):935-44. doi: 10.1016/0021-9290(92)90234-r.
The infrarenal abdominal aorta and aortic bifurcation are frequent sites of atherosclerosis. The local hemodynamics are considered to be atherogenetic factors; a detailed description of these flow fields is, therefore, essential to understand their relationship to atherosclerosis. The aim of this study was, therefore, to provide such detailed information using a flow visualization technique in an anatomically realistic flow model of the abdominal aorta and its main branches in which the complex pulsatile flow waveforms and flow rates were simulated for two physiologic flow conditions (rest and exercise). At rest, the particle path lines in the suprarenal abdominal aorta were straight with no visible signs of flow reversal. Vortices were initiated opposite to the main branches. In the infrarenal aorta, large flow separation zones formed at the posterior aortic wall and at the lateral walls in the aortic bifurcation during systolic deceleration, and flow reversal was present during diastole. Under exercise conditions, the particle path lines were straight, and only slight flow reversal was seen. This study emphasizes, that rather than being a straight tube with forward-moving fluid, the abdominal aorta has to be considered as a complex part of the arterial tree. Distinct local hemodynamic qualities of importance for explaining atherogenesis were pointed out. At rest, the suprarenal abdominal aorta had much less complicated flow characteristics than the infrarenal abdominal aorta where the distal, posterior vessel wall and the lateral walls of the bifurcation were sites of flow patterns thought to be associated with atherosclerosis. During exercise, the infrarenal flow patterns changed dramatically away from the flow patterns associated with the induction of atherosclerosis.
肾下腹主动脉和主动脉分叉是动脉粥样硬化的常见部位。局部血流动力学被认为是动脉粥样硬化的诱发因素；因此，详细描述这些流场对于理解它们与动脉粥样硬化的关系至关重要。因此，本研究的目的是在腹主动脉及其主要分支的解剖学真实血流模型中使用流动可视化技术提供此类详细信息，其中针对两种生理血流状况（静息和运动）模拟了复杂的脉动血流波形和流速。在静息状态下，肾上腹主动脉中的粒子迹线是直的，没有明显的血流逆转迹象。在与主要分支相对的位置会产生涡流。在肾下腹主动脉中，在收缩期减速时，主动脉后壁和主动脉分叉处的侧壁会形成大的血流分离区，舒张期存在血流逆转。在运动状态下，粒子迹线是直的，仅可见轻微的血流逆转。本研究强调，腹主动脉不应被视为一个流体向前流动的直管，而应被视为动脉树的一个复杂部分。指出了对于解释动脉粥样硬化形成具有重要意义的独特局部血流动力学特征。在静息状态下，肾上腹主动脉的血流特征比肾下腹主动脉简单得多，肾下腹主动脉远端、后壁和分叉处的侧壁是被认为与动脉粥样硬化相关的血流模式部位。在运动期间，肾下腹主动脉的血流模式发生了显著变化，远离了与动脉粥样硬化诱发相关的血流模式。
