Hemodynamic Forces Effective in Reshaping Vascular Geometry

Besides the medical education, simulations became an attractive diagnostic method in some clinical cases. Recent advances in computerized image processing bring new practices entitled as “patient specific simulation” to the agenda. One of the successful applications which examines hemodynamic forces as a result of the interaction between blood flow and vessel wall constitutes the topic of this study. In this study, the terms and laws which provided a theoretical basis for the hemodynamic forces in circulatory system were evaluated from the biophysical point of view. With this perspective, the concepts of fluid viscosity and blood flow in elastic vessel were emphasized. The impacts of height and vessel diameter differences on flow conditions were discussed in terms of Bernoulli and continuity laws. Viscosity effect and the other factors that may impede the fluid flow were discussed in accordance with Poiseuille’s law. The relation between transmural pressure and dilatation in elastic vessel was evaluated considering Laplace law. Then, the dynamic forces in radial and axial directions occurring during fluid flow were defined. Clinically, it is important to know the interactions between blood and vessel wall endothelia. Current in-vivo methods are not suitable for the measurements of spatial and temporal patterns of these interactions. However, classical engineering method of computational fluid dynamics, recently, took place in medical simulations that made it possible to calculate the hemodynamic parameters for every volume element defined in three-dimensional anatomically realistic vessel model. Patient specific simulations that are believed to be the core of the future project of “clinical diagnostic expert systems” will be an important tool in prescribing patient specific treatment and in the assessment of complication risks. With this perspective in this paper, we discussed the theoretical background and elucidated the role of hemodynamic forces in vascular pathologies.