Abstract 13270: Fontan Fluid Mechanics from 100 Patient-Specific Magnetic Resonance Imaging Scans: A Computational Analysis
Objective Fluid mechanics of the total cavopulmonary connection (TCPC) are hypothesized to mediate functional health in single ventricle (SV) pts. For example, elevated TCPC power losses can impact ventricular function; a balanced hepatic flow distribution (HFD) is important for healthy lung development. This study used computational fluid dynamics to quantify these values in a large cohort of SV pts.
Methods Patient-specific Fontan models were created from magnetic resonance images (MRI) for 100 pts. Phase velocity MRI in the aorta, vena cavae (VC), and pulmonary arteries were used as boundary conditions. Time-averaged simulations were conducted using a validated solver. TCPC energy dissipation (EDI; i.e., indexed power loss), connection resistance (R), and HFD were quantified. Mann-Whitney or Spearman’s correlation were used; significance = p<0.05.
Results The data are summarized in Table 1, and subdivided by connection type. There was a logarithmic correlation (R= -0.40; p<0.001) between cardiac index (CI) and EDI (Figure 1) such that higher power loss corresponded with depressed CI. Compared to extracardiac (EC), intra-atrial (IA) pts were older (p<0.001) and had lower CI (p=0.04). Despite significantly higher total flow percentage to the LPA in EC (p=0.001), there was a trend toward higher HFD (i.e., inferior VC flow) to the RPA (p=0.08) because of caval offsetting. There were no differences in R or EDI between EC and IA.
Conclusion Elevated levels of EDI are correlated with lower CI, supporting the hypothesized importance of TCPC hemodynamics in SV pts. Fontan connection type does not influence hemodynamic efficiency, but does mediate differences in flow distribution.
- © 2012 by American Heart Association, Inc.