Abstract 405: A Personalized, 3D Printed in vitro Model of Vascular Anastomosis in Single Ventricle Heart Defects

Abstract

Single ventricle physiology is a complex disease state requiring multiple open-heart surgeries to achieve stable hemodynamics. For patients with abnormalities in the pulmonary arteries (PAs), these must be remedied before the patient can be a candidate for such palliations. Transcatheter techniques could rescue this subset of single ventricle patients through intervascular PA connections, allowing a high-risk population to ultimately achieve stable pulmonary blood flow. However, there is currently no in vitro platform to model transcatheter processes for anastomosis, particularly to palliate single ventricle defects. This project utilizes 3D bioprinting and perfusion bioreactor technologies to develop a functional in vitro biological device to model severely stenotic PAs of single ventricle patients. Human endothelial (ECs) & smooth muscle (SMCs) cells embedded in extracellular matrix bioink are used in a multi-material bioprinting approach to create 3D bilayer vascular structures with controlled geometry and flow. In collaboration with CHOA Cardiac Catheterization Laboratory , stent devices are deployed in the printed model to re-establish intervascular connection. Healthy, stenotic, and stented tissues are cultured via a bioreactor and analyzed for flow hemodynamics by echo PIV and 4D MR imaging. Cell viability, proliferation, and endothelialization of printed vessels, plus EC-SMC interplay were closely monitored pre- and post- anastomosis, to identify the effect of geometry and flow on cellular overgrowth. This advanced planning enables a subset of single ventricle patients, otherwise not eligible, to ultimately accept further palliative strategies.