Hemodynamic impact of surgical suturing on pulmonary artery: a fluid-structure interaction analysis across varying bifurcation angles

Right ventricular outflow tract (RVOT) reconstruction has been widely used in the treatment of congenital heart disease. However, surgical interventions for this procedure vary due to inter-patient variations in anatomical structures of the T-shaped pulmonary bifurcation artery between patients. While postoperative hemodynamic conditions, including static pressure, arterial wall stress, and arterial vessel volume changes, play a critical role in determining long-term recovery outcomes and are largely underpinned by bifurcation angles, the impact of the latter variable on the successful outcome of RVOT remains unclear. This paper presents a numerical investigation of a realistic pulmonary artery trunk and its branches following virtual RVOT surgery by using the fluid–structure interaction modeling approach. The impact of bifurcation angles, resulting from surgical suturing, on hemodynamics and pulsatile deformation behavior of the arterial wall is systematically delineated as a function of five bifurcation angles. The results demonstrated that the bifurcation angle significantly affects local wall shear stress (WSS), static pressure distribution, and arterial volume changes throughout the cardiac cycle. Among all configurations, the model with α = 90° exhibited the lowest peak WSS and the most uniform time-averaged WSS distribution, suggesting a more favorable shear environment for endothelial health. Additionally, this model showed moderate arterial volume expansion (∼2.6%), indicating a balanced compliance response under pulsatile flow conditions. This study underscores the importance of considering bifurcation geometry in vascular reconstruction and highlights the value of patient-specific modeling in evaluating postoperative geometries and optimizing vascular reconstruction strategies.