Image-Based CFD Analysis of Blood Flow in Non-Porous and Porous Prosthetic Vascular Grafts

A prosthetic vascular graft is an important vascular conduit used for end-to-end anastomosis; however, optimizing pore morphology to improve local hemodynamic performance remains a significant challenge. The purpose of this study was to investigate the influence of regular and reconstructed irregular pore morphologies on local blood flow characteristics in prosthetic vascular grafts. Three graft models, including a non-porous model, a regular porous model with regular square-prism pores, and a reconstructed irregular porous model reconstructed from segmented scanning electron microscopy (SEM) images, were employed to simulate blood flow within virtual end-to-end anastomoses. To enable a direct comparison of pore morphology, the regular and irregular porous models were designed with the same porosity. Steady laminar blood flow through virtual end-to-end anastomoses was simulated using computational fluid dynamics (CFD) assuming Newtonian blood, rigid vessel walls, and a no-slip boundary condition. The non-porous model exhibited a flow pattern representative of a conventional graft and served as the baseline for comparison. Compared with the regular porous model, the reconstructed irregular porous model generated more irregular recirculation patterns, a non-uniform pressure distribution, and significantly greater spatial heterogeneity in wall shear stress (WSS). Although the irregular porous model exhibited the lowest mean and median WSS, it produced the highest localized WSS at sharp pore edges and the largest surface area exposed to low WSS. Quantitative analyses demonstrated that the irregular pore morphology increased the spatial variability in WSS and altered the distribution of low-WSS regions and local recirculation compared with the regular porous model under the same porosity conditions. The results demonstrate that pore morphology, rather than porosity alone, significantly influences local hemodynamic characteristics under identical porosity conditions. Furthermore, the SEM-based reconstruction approach captured realistic spatial variations in flow and WSS that could not be fully reproduced by an idealized regular porous model. These findings provide insights into the hemodynamic effects of porous graft architectures and may contribute to the design and optimization of prosthetic vascular grafts.