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This Article Full Text Full Text (PDF) All Versions of this Article: 294/5/H2112    most recent 01302.2007v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Downie, S. P. Articles by Xu, X. Y. PubMed PubMed Citation Articles by Downie, S. P. Articles by Xu, X. Y.

Effects of elastic compression stockings on wall shear stress in deep and superficial veins of the calf

¹Department of Chemical Engineering, ²Cardiovascular Magnetic Resonance Unit, Royal Brompton and Harefield NHS Trust, ³International Centre for Circulatory Health and ⁶Vascular Surgery, St. Mary's NHS Trust, and ⁴Faculty of Medicine, National Heart and Lung Institute, Cardiovascular Science St. Marys National Health Service Trust; and ⁵Department of Bioengineering, Imperial College London, London, United Kingdom

Submitted 6 November 2007 ; accepted in final form 5 March 2008

The purpose of this study was to estimate wall shear stress (WSS) in individual vessels of the venous circulation of the calf and quantify the effects of elastic compression based on change of vessel geometry and velocity waveform. The great saphenous vein and either a peroneal or posterior tibial vein have been imaged in four healthy subjects using magnetic resonance imaging, with and without the presence of a grade 1 medical stocking. Flow through image-based reconstructed geometries was numerically simulated for both a range of steady flow rates and ultrasound-derived transient velocity waveforms, scaled to give a standardized time averaged flow rate. For steady flow, the stocking produced an average percentage increase in mean WSS of 100% in the great saphenous vein across a range of 0.125–1.25 ml/s. The percentage increase in the peroneal/posterior tibial veins varied from 490 to 650% across a range of 0.5–5 ml/s. In addition, application of the stocking eliminated periods of very low or zero flow from the transient waveforms. The average minimum value of WSS in all vessels without the stocking was <0.1 Pa. With the stocking, this was increased to 0.7 Pa in the great saphenous and 0.9 Pa in the peroneal/posterior tibial veins. The pathophysiological effects of these changes are discussed. In conclusion, the flight stocking was effective in raising venous WSS levels in prone subjects, and this effect was much more pronounced in the deep vessels. The stocking also tended to prevent cessation of flow during periods of increased downstream pressure produced by respiration.

calf veins; deep vein thrombosis; hemodynamics; numerical simulation