  Fontan operation as the current standard of care for the palliation of single
ventricle defects results in significant late complications. Using a mechanical
circulatory device for the right circulation to serve the function of the
missing subpulmonary ventricle could potentially stabilize the failing Fontan
circulation. This study aims to elucidate the hydraulic operating regions that
should be targeted for designing cavopulmonary blood pumps. By integrating
numerical analysis and available clinical information, the interaction of the
cavopulmonary support via the IVC and full assist configurations with a wide
range of simulated adult failing scenarios was investigated; with IVC and full
assist corresponding to the inferior venous return or the entire venous return,
respectively, being routed through the device. We identified the desired
hydraulic operating regions for a cavopulmonary assist device by clustering all
head pressures and corresponding pump flows that result in hemodynamic
improvement for each simulated failing Fontan physiology. Results show that IVC
support can produce beneficial hemodynamics in only a small fraction of failing
Fontan scenarios. Cavopulmonary assist device could increase cardiac index by
35% and decrease the inferior vena cava pressure by 45% depending on the
patient's pre-support hemodynamic state and surgical configuration of the
cavopulmonary assist device (IVC or full support). The desired flow-pressure
operating regions we identified can serve as the performance criteria for
designing cavopulmonary assist devices as well as evaluating off-label use of
commercially available left-side blood pumps for failing Fontan cavopulmonary
support.
