Computational Investigation of a Self-Powered Fontan Circulation

Abstract

Children born with anatomic or functional "single ventricle" must progress through two or more major operations to sustain life. This management sequence culminates in the total cavopulmonary connection, or "Fontan" operation. A consequence of the "Fontan circulation", however, is elevated central venous pressure and inadequate ventricular preload, which contribute to continued morbidity. We propose a solution to these problems by increasing pulmonary blood flow using an "injection jet" (IJS) in which the source of blood flow and energy is the ventricle itself. The IJS has the unique property of lowering venous pressure while enhancing pulmonary blood flow and ventricular preload. We report preliminary results of an analysis of this circulation using a tightly-coupled, multi-scale computational fluid dynamics model. Our calculations show that, constraining the excess volume load to the ventricle at 50% (pulmonary to systemic flow ratio of 1.5), an optimally configured IJS can lower venous pressure by 3 mmHg while increasing systemic oxygen delivery. Even this small decrease in venous pressure may have substantial clinical impact on the Fontan patient. These findings support the potential for a straightforward surgical modification to decrease venous pressure, and perhaps improve clinical outcome in selected patients.

Hemodynamic Effects of A Simplified Venturi Conduit for Fontan Circulation: A Pilot, In Silico Analysis

“…Lack of pulsatile flow will result in elevation of pulmonary artery pressure, pulmonary vascular resistance 26,27 , and decreased endothelial-dependent vasorelaxation response of the pulmonary arteries 25 , which has a pernicious effect on Fontan circulation. Although the mass flow rate of RPA was significantly increased in this study, pressure of the venae cavae would not reach the criterion of pulmonary hypertension even if pulmonary vascular resistance was relatively high 16,17 .…”

Numerical Investigation of the Effects of Prosthetic Aortic Valve Design on Aortic Hemodynamic Characteristics

“…In the coupling scheme, the 0D LPMs with resistance elements were coupled with the 3D model at the outlet boundaries, including the outlets of descending aorta (DAo), BA, LCCA and LSA. A "tight coupling" algorithm [29][30][31] was used to transfer the data at the coupling interfaces. At the beginning of the coupling, an initial pressure is applied as the initial condition.…”

Energetics of blood flow in Fontan circulation under VAD support

“…TCPC allows to support an acceptable level of pulmonary circulation with reduction of the patients’ morbidity and mortality . At the same time, there is a high risk of the cardiovascular system to fail due to various reasons such as ventricular dysfunction, elevated pulmonary vascular impedance, inadequate preload to the ventricle, increased neurohumoral activation, and elevated systemic venous pressure . In order to increase the patients’ survival rate and the quality of their life, along with different TCPC connections oriented to improve blood hemodynamics, mechanical circulatory support (MCS) is applied as another auspicious treatment option …”

“…It was shown that 3D and 4D blood flow data received from computational fluid dynamics (CFD) and magnetic resonance imaging can be used for measuring the adverse energetics . Whereas multi‐scale modeling can be used for the simulation of the hemodynamic effects of the Fontan circulation . In theory, an optimal TCPC connection should decrease the loading level of a single ventricle and extend the life of the Fontan patients.…”

“…3 Whereas multi-scale modeling can be used for the simulation of the hemodynamic effects of the Fontan circulation. 6 In theory, an optimal TCPC connection should decrease the loading level of a single ventricle and extend the life of the Fontan patients.…”