Image-based computational hemodynamics of distal aortic arch recoarctation following the Norwood procedure

Currently, few applications of computational hemodynamics predict outcomes after palliative surgery for congenital heart defects such as hypolastic left heart syndrome in infants. Here, we report on three-dimensional imaging methods for modeling recoarctation that commonly occurs in the distal aortic arch following the Norwood procedure. We used computer-aided design to simulate seven stages of increasing stenosis, analyze the resulting hemodynamics, and visualize the impairment of blood flow. A disproportionate drop in pressure occurred when stenosis reached 20% of the cross-sectional area of the descending aorta. The corresponding decrease in blood flow in the descending aorta was relatively small, however. Accordingly our findings suggest a reasonable approach to this phenomenon is watchful waiting rather than immediate surgical intervention. Such patient-specific predictions appear to be valuable for minimizing the risks of corrective surgery. These methods also may be applied to procedures for alleviating other congenital heart defects.