Effect of Valve Spacing on Pumping Performance of Lymphatic Vessels

The lymphatic system is crucial for maintaining body’s homeostasis by transporting interstitial fluid (lymph), fatty acid, and immune cells. The lymph and various macromolecules are transported through networks of valves and contracting vessels, which allows unidirectional pumping without any centralized pump against adverse pressure gradient. For this work, we employ a fully coupled 3D fluid-structure interaction model to focus on the effect of lymphatic valve spacing and vessel contraction on pumping performance in terms of factors such as flowrate and pumping efficiency. Our results indicate that flowrate can be optimized by having valve spacing smaller than the vessel contraction wavelength, as such valve placement decreases the backflow caused during lymphatic pumping. On the other hand, smaller valve spacing increases viscous losses in the vessel. Thus, our results provide a greater understanding of the role that lymphatic valves play, specifically on how different valve positions alter lymphatic pumping performance.