Experimental Evaluation of the Physiologic Response of the Venous Valve

There is inadequate understanding of the mechanisms that cause veins and venous valves to fail. Problems related to vein and valve failure include deep venous thrombosis (DVT), chronic venous insufficiency (CVI), leg ulcers, and pulmonary embolism (PE). The primary objective of this research is to develop a fundamental understanding of the hemodynamics of venous blood flow. To achieve this objective, a fluid flow circuit is used with an artificial vein and valve system to simulate the basic features of biological venous fluid flow. It is widely known that biochemical reactions regulated by blood borne enzymes affect parameters such as vascular geometry, viscosity of blood and elasticity of blood vessels. One of the main benefits of the artificial system is that the experiments give results that are based solely on the mechanical effects of the venous valve geometry and avoids the effects of blood borne enzymes. This work is a collaboration with the Texas Tech Health Sciences Center. This col-laboration has assisted in the design of an artificial system that closely approximates the actual biological system. This collaboration also allows for the validation of the artificial system by comparison with harvested in vitro human specimens of venous valves that are tested in the experimental fluid flow circuit. Current medical imaging technology such as ultrasonic duplex scanning, allows doctors to non-invasively define and characterize the dimensions of deep vein valves in vivo [1]. However, there is a gap in knowledge that allows for relating how these dimensions affect the competency of the valves. Competency is a measure of valvular performance and indicates how well a valve prevents retrograde flow, thus regulating venous pressure and assisting the venous system to return blood to the heart from the extremities of the human body. ∗Author to whom all correspondence should be sent