An ex vivo system to study hemodynamic initiated vascular remodeling in arterial bifurcations

Vascular disease is the leading cause of mortality worldwide, and accounts for over 860,000 deaths annually in the United States. Hemodynamics has been implicated as one of the primary factors influencing vessel remodeling in vascular disease. Vasculature is highly responsive to specific blood flow parameters such as wall shear stress, wall shear stress gradient and systemic pressure. Understanding how these properties affect vessel health is critical to future vascular disease treatment.;Previous in vivo studies have demonstrated a relationship between hemodynamic parameters at bifurcations, atherosclerotic lesion formation and aneurysm development. Though in vivo experiments can test general hypotheses and yield invaluable results, obtaining definitive information is difficult due to the myriad of complex biological pathways that exist in animal models. In vitro cell culture experiments can isolate and test specific variables; however, their utility is limited due to their two-dimensional nature and oversimplification of biological systems.;We have developed an ex vivo system in which explanted arteries can be subjected to precisely controlled hemodynamic conditions and vascular responses can be studied. In this system, tissue can be sustained in an in vivo-like environment with specifically defined variables. Using 3D angiography and computational fluid dynamics we can correlate bifurcation hemodynamics with vessel morphology changes. Arterial bifurcations were subjected to modified flow in an ex vivo environment up to 48 hours. Histological analysis indicated that the vessels were still healthy and did not exhibit signs of degeneration following the experiment. This preliminary result indicates that our ex vivo flow system is a viable candidate for analyzing the effects of modified flow on arterial bifurcation morphology.