Abstract
Background: The study objective was to test underlying physical
laws behind a proposed novel device for failing Fontan and investigate
whether the device could be implemented theoretically to improve
hemodynamics in failing Fontan circulation.
Methods : A 4-arm setup was designed and fabricated to simulate
an actual Fontan circuit in the form of a junction of the superior and
inferior vena cavae (SVC, IVC) with the right and left pulmonary
arteries (RPA, LPA). A provision for placement of an oscillating ball
along the RPA-LPA path to push fluid away from SVC and IVC was created.
The rate of ball oscillations and initial pressure of fluid on SVC and
IVC limbs were varied. The pressure-drop times in the vena cavae limbs
were measured at varying ball oscillations and resistances in the
RPA-LPA pathway. The test was considered positive if increasing
oscillations of the ball allowed for quicker pressure drop in the SVC
and IVC limbs indicating quicker discharge of fluid through the RPA and
LPA. 48 different experiments were conducted to simulate different
physical conditions and the results were plotted and analyzed to draw a
conclusion.
Results : The time required for pressure drop in the experiment
without ball was the least across all set of readings. This meant that
placing an oscillating ball along the RPA -LPA path created obstruction
to flow rather than enhance it. Increasing rate of ball oscillations
increased degree of obstruction to flow.
Conclusion : The proposed interventional method is unsuitable
for improving hemodynamics in failing Fontan circulation.