A multiparameter comparative approach to the three-dimensional numerical analysis of the hemodynamics of total cavopulmonary connection

PURPOSE: Univentricular congenital heart diseases represent a significant challenge in cardiology, requiring a complex staged treatment protocol involving total cavopulmonary connection via the Fontan procedure. The application of advanced numerical methods has proved fundamental to understanding post-surgical behavior, allowing the multidisciplinary team to design more efficient and physiologically realistic anatomies. However, the definition of boundary conditions to represent fluid behavior in anatomical changes following total cavopulmonary connection is still an emerging field, frequently relying on estimates and simplifications. This study aimed to identify an effective set of variables for simplifying the analysis of hemodynamic behavior in total cavopulmonary connection and reducing the requirement for extensive computational resources. METHODS: A multiparameter comparative analysis of simulations was performed by using several variables under rest conditions for specific Fontan configurations, accounting for factors such as turbulent versus laminar flow, Newtonian versus non-Newtonian fluid, and rigid versus flexible vascular walls. results: (i) Newtonian fluid behavior, turbulent flow, steady regime, and rigid walls were found suitable when the distribution of blood flow to the pulmonary arteries is the desired result and (ii) Newtonian fluid behavior, turbulent flow, transient regime, and rigid walls were found suitable when the distribution of blood flow to pulmonary arteries, shear stress, and energy loss are equally important. CONCLUSION: The identified sets of variables provide a solid foundation for future analyses, ensuring reliable results and an efficient use of computational resources.