Background: The bidirectional cavopulmonary anastomosis with additional pulmonary blood flow is used as a staged procedure or a definitive palliation of univentricular hearts. In this paper the flow competition occurring between the caval and the pulmonary flows is investigated. The hemodynamics in the superior vena cava and the blood flow distribution into the lungs, as well as the systemic arterial oxygen availability, are correlated with the severity of the right ventricle outflow tract obstruction and the pulmonary arteriolar resistance.
Materials and methods: Computer models of the pre- and postoperative hemodynamics of univentricular hearts were developed. The effects of increasing severity of the right ventricle outflow tract obstruction, with a pulmonary arteriolar resistance ranging from 0.8 to 7.9 nonindexed Woods units, were simulated.
Results: The study indicates that the presence of an additional pulmonary blood flow from the native pulmonary artery may be beneficial. Since an excessive additional blood flow may cause central venous hypertension, its optimal value should be chosen according to the value of pulmonary arteriolar resistance. The model was utilized to simulate four clinical cases.
Conclusions: The simulations show that the model can predict the postoperative hemodynamics and could therefore be usefully applied to predict quantitatively the effect of the native pulmonary blood flow following bidirectional cavopulmonary anastomosis.
Copyright 2000 Academic Press.