Simulations of Cervical Lymphatic Vessels to Quantify Optimal Intrinsic Pumping

The lymphatic system maintains extracellular fluid levels in the body while removing metabolic waste products and cellular debris. Reduced flow through cervical lymphatic vessels (CLVs; located in the neck) has recently been implicated in several neurological disorders including traumatic brain injury, stroke, and Alzheimer’s disease. Our research aims to simulate fluid flow through CLVs of rodents, which provides one of the primary routes through which fluid leaves the skull. Recent experimental measurements demonstrate that contractions of vessel segments (i.e. intrinsic pumping), along with the presence of valves, provide the primary driving mechanism for CLVs. To capture the strong nonlinearities of the valves and elastic properties of the lymphangion walls, we adapt a lumped parameter model of the lymphatic system that was introduced by Bertram et al. (Biomech Model Mechanobiol 2014). We investigate how the net flow rate changes as we vary the number of lymphangions, contraction frequency, and contraction phase shift for adjacent lymphangions. We identify the optimal parameter ranges that maximize fluid flow through CLVs. These results provide important insight into brain health and potential mechanisms of neurological disorders.