Department of Chemical Engineering, Imperial College London, South Kensington, London SW7 2AZ, UK.
Med Eng Phys. 2012 Jan;34(1):17-27. doi: 10.1016/j.medengphy.2011.06.012. Epub 2011 Jul 20.
As a widely accepted prophylaxis for deep vein thrombosis, the underlying mechanism of compression stocking still remains unclear. In this study, computational fluid dynamics was applied to in vivo data to provide quantitative insight into the hemodynamic response of the deep venous system to static external compression. The geometry and flow information of deep veins before and after compression was acquired from ten healthy volunteers using magnetic resonance imaging. Our results indicated that application of the compression stocking led to a small reduction in blood flow rate but a significant reduction in cross-sectional area of the peroneal veins in the calf, resulting in an increase in wall shear stress (WSS), but the individual effects were highly variable. The mean volume reduction of the deep veins was 58%, while the time-averaged WSS showed an average increase of 398% after compression (median 98%). The analysis also showed a strong linear correlation between the time-averaged WSS and mean blood velocity, suggesting that flow in the deep veins under the level of compression examined here can be approximated by Poiseuille's law despite local geometric variations. It is hoped that quantitative analysis of WSS in the deep venous system will aid in the future design and optimisation of the compression stocking.
作为一种广泛接受的深静脉血栓预防措施，压缩袜的潜在机制仍不清楚。在这项研究中，计算流体动力学被应用于体内数据，以提供对深静脉系统对静态外部压缩的血流动力学反应的定量见解。使用磁共振成像从十名健康志愿者中获得了深静脉在压缩前后的几何形状和流动信息。我们的结果表明，应用压缩袜会导致血流速度略有降低，但小腿腓静脉的横截面积显著降低，导致壁面切应力（WSS）增加，但个体影响差异很大。深静脉的平均体积减少了 58%，而压缩后平均壁面切应力（WSS）平均增加了 398%（中位数为 98%）。分析还表明，平均壁面切应力（WSS）与平均血流速度之间存在很强的线性相关性，这表明尽管存在局部几何变化，但此处检查的压缩水平下深静脉中的血流可以用泊肃叶定律来近似。希望对深静脉系统中的 WSS 的定量分析将有助于未来压缩袜的设计和优化。
