Hemodynamic analysis and comparison of different arterial bypass models considering microcirculation

Coronary artery bypass grafting (CABG) is the first-line therapy for 90% coronary artery stenosis, yet conventional hemodynamic simulations of CABG ignore the microcirculation system, leading to a lack of physiological condition. In this work, we construct numerical models of one-way/two-way arterial bypass with 20°, 30° and 45° anastomotic angles for 90% stenosis, integrate microcirculation as a seepage outlet via porous media, and adopt two-way fluid-structure interaction (FSI) to assess key hemodynamic and structural parameters across representative cross-sections. The results show that the 30° anastomotic angle outperforms 20° and 45° in both configurations, and two-way bypass exhibits superior hemodynamic performance to one-way bypass, with the 30° two-way bypass model achieving the most stable structural response and optimal local hemodynamic microenvironment. This study reveals the optimal CABG design parameters under microcirculatory regulation, offering a hemodynamic theoretical basis for individualized CABG surgical planning and preoperative decision-making in cardiovascular clinical practice.