Introduction
Approximately 50 years ago, Francis Fontan pioneered an operation for
tricuspid atresia that bears his name today.1 The
Fontan procedure refers to any operation that shunts the systemic venous
return to the pulmonary bed by bypassing the right ventricle (RV) or the
subpulmonary ventricle. It can be applied to a wide array of congenital
heart diseases such as tricuspid atresia, hypoplastic left heart
syndrome and unbalanced atrioventricular canal where there is a single
functional ventricle. Despite restoring normal oxygen levels in the
body, the operation creates a neoportal system where adequate cardiac
output can be generated only at the expense of increased systemic venous
congestion.2 Additionally, the loss of pulsatility and
chronic low-flow state of Fontan circulation induces pulmonary
vasoconstriction and raises the pulmonary vascular resistance. This
results in slow but relentless damage to the end organ systems,
especially the liver. Numerous designs of assist devices that have been
previously described provide a push to the venous blood entering the
lungs to mimic a normal RV.3-5 A novel interventional
approach in the form of an oscillating ball along the pulmonary artery
pathway to improve the hemodynamics in failing Fontan circuit is studied
herewith. The objective of the experimental study was to test the
hypothesis that placement of an oscillating ball along the pulmonary
artery pathway in an experimental Fontan model would increase the
forward flow of blood into the lungs and reduce the pressure in the
systemic veins.