Abstract 2032: A Novel Artificial Right Ventricle Improves Hemodynamic Response in the Failing Fontan: Numerical and In vitro Studies
Introduction: The Fontan procedure has been the primary surgical choice for palliating patients with single ventricles. However, the inherent absence of a right ventricle predisposes these patients to poor long-term hemodynamic outcomes. We hypothesize that the use of an artificial right ventricle assist device, specifically designed to conform to post-Fontan hemodynamics, will relieve the two primary hemodynamic problems associated with the failing Fontan: increased central venous pressures, and decreased pulmonary flows.
Methods: A novel low-pressure artificial right ventricle (ARV) axial flow pump was first designed using computational fluid dynamics modeling, and subsequently prototyped for in vitro evaluation. The device measures 9.5 mm in diameter and 25 mm in length. It was placed into a mock total cavopulmonary connection (TCPC) within the extra cardiac conduit for evaluation of hemodynamic response.
Results: Computational results showed that the ARV decreased inferior vena cava (IVC) pressures through proximal suction by up to 14 mm Hg. Further, a low level of shear loading was found, with particle residence times less than 20 ms through the pump. In vitro observations confirmed the pressure drop at the IVC, boost of pulmonary flows by up to 20%, a low power requirement to drive the device, less than 3 mm Hg flow resistance induced by the ARV for cardiac output 1~3 L/min under device failure.
Conclusions: This study indicates the feasibility of using an artificial right ventricle, specifically designed to the hemodynamic constraints of the post-Fontan patient, to the major hemodynamic problems associated with the failing Fontan.