PatientSpecific Subvalvular Apparatuses Consisting of Chordae Tendineae and Papillary Muscles to Complete Mitral Valve Replicas Mitral valve regurgitation is one of the most common heart valve diseases and mitral valve repair is the favored but challenging therapy. To improve preoperative understanding of mitral valve anatomy and enable preoperative simulation of mitral valve repair, patientspecific mitral valve replicas have been developed. However, most of these replicas are missing the subvalvular apparatus consisting of cords, the chordae tendineae, and papillary muscles. Hence, as they only represent incomplete anatomy, it is impossible to simulate the repair technique implantation of artificial chordae tendineae on them. To solve this problem, we developed patientspecific subvalvular apparatus replicas completing the mitral valve replicas. From 3D ultrasound images of hearts, the chordae tendineae were segmented and used to realize the subvalvular apparatus replicas which were 3D printed from soft material and integrated into the existing mitral valve replicas. The mitral valve replicas with subvalvular apparatus were assessed by an expert heart surgeon who rated them as realistic and successfully simulated mitral valve repair by implanting artificial chordae tendineae into them.

Design and Simulation of PatientSpecific TissueEngineered Bifurcated Right VentriclePulmonary Artery Grafts using Computational Fluid Dynamics Patientspecific biodegradable grafts target to enhance surgical repairs of complex congenital heart defects (CHD). This study reports the design, simulation, and creation of bifurcated right ventriclepulmonary artery (RVPA) conduit grafts for patients with CHD. The original right ventricle outflow tract and RVPA conduitanatomies of two patients (n2) 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 redesigned 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 redesigned 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 tissueengineered bifurcated grafts for the patients with CHD in the surgical planning process. Integration of flow simulations to support design and electrospinning technique to manufacture patientspecific biodegradable grafts has the potential to improve surgical outcomes in CHD.