Design and Simulation of Patient-Specific Tissue-Engineered Bifurcated Right Ventricle-Pulmonary Artery Grafts using Computational Fluid Dynamics

Patient-specific biodegradable grafts target to enhance surgical repairs of complex congenital heart defects (CHD). This study reports the design, simulation, and creation of bifurcated right ventricle-pulmonary artery (RVPA) conduit grafts for patients with CHD. The original right ventricle outflow tract and RVPA conduit-anatomies of two patients (n=2) who previously underwent Rastelli type surgical repair for their CHD were created using medical image segmentation software based on magnetic resonance imaging data. The pulsatile RVPA flow was simulated utilizing computational fluid dynamics (CFD) to calculate important hemodynamic parameters. The re-designed RVPA geometries for the patients were created by varying the radius and angle of the pulmonary artery bifurcation. The wall shear stress and power loss results of the re-designed RVPA models were compared to identify the best performing graft. The hemodynamic results demonstrated that the designed optimized grafts outperformed the original grafts. To test the feasibility of designed grafts in vivo, the bifurcated RVPA conduit of a pig was manufactured using a 3D printed mandrel and electrospinning technique before the implantation. The implanted graft allowed new tissue formation within weeks. The results of our study and simulations provide an insight into the creation of optimal performing tissue-engineered bifurcated grafts for the patients with CHD in the surgical planning process. Integration of flow simulations to support design and electrospinning technique to manufacture patient-specific biodegradable grafts has the potential to improve surgical outcomes in CHD.