COMPUTATIONAL INVESTIGATION OF PATIENT-SPECIFIC SELF-POWERED FONTAN CIRCULATIONS
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 (TCPC), 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 shunt" (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, patient-specific, computational fluid dynamics model. Two patient-specific models (10 and 24-year-old) were developed using de-identified MRI data provided by Children's Hospital of Philadelphia. 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 while increasing systemic oxygen delivery for these 2 patient-specific models. The IJS in these patient-specific models proved to be less efficient then the IJS results reported in our previous results for a synthetic model of a 2-year-old Fontan. These findings suggest that the cardiac output, and geometry of a specific patient will greatly affect the efficiency of IJS configurations.