Patient-Specific 3-Dimensional-Bioprinted Model for In Vitro Analysis and Treatment Planning of Pulmonary Artery Atresia in Tetralogy of Fallot and Major Aortopulmonary Collateral Arteries.

Background Tetralogy of Fallot with major aortopulmonary collateral arteries is a heterogeneous form of pulmonary artery (PA) stenosis that requires multiple forms of intervention. We present a patient-specific in vitro platform capable of sustained flow that can be used to train proceduralists and surgical teams in current interventions, as well as in developing novel therapeutic approaches to treat various vascular anomalies. Our objective is to develop an in vitro model of PA stenosis based on patient data that can be used as an in vitro phantom to model cardiovascular disease and explore potential interventions. Methods and Results From patient-specific scans obtained via computer tomography or 3-dimensional (3D) rotational angiography, we generated digital 3D models of the arteries. Subsequently, in vitro models of tetralogy of Fallot with major aortopulmonary collateral arteries were first 3D printed using biocompatible resins and next bioprinted using gelatin methacrylate hydrogel to simulate neonatal vasculature or second-order branches of an older patient with tetralogy of Fallot with major aortopulmonary collateral arteries. Printed models were used to study creation of extraluminal connection between an atretic PA and a major aortopulmonary collateral artery using a catheter-based interventional method. Following the recanalization, engineered PA constructs were perfused and flow was visualized using contrast agents and x-ray angiography. Further, computational fluid dynamics modeling was used to analyze flow in the recanalized model. Conclusions New 3D-printed and computational fluid dynamics models for vascular atresia were successfully created. We demonstrated the unique capability of a printed model to develop a novel technique for establishing blood flow in atretic vessels using clinical imaging, together with 3D bioprinting-based tissue engineering techniques. Additive biomanufacturing technologies can enable fabrication of functional vascular phantoms to model PA stenosis conditions that can help develop novel clinical applications.