Abstract 15000: Quantification of Vessel Growth and Flow Changes in Fontan Patients: Impact on Hemodynamics
Background: The total cavopulmonary connection (TCPC) vessels are theorized to experience geometrical and flow changes over time. These variations can affect the connection hemodynamics and can have an impact on long-term patient outcome. This study aimed to quantify these variations in 29 single ventricle patients with a completed Fontan.
Methods: Cardiac magnetic resonance and phase contrast CMR images were acquired at two time points (T2-T1=4.6±1.6 years) for all patients. TCPC anatomy and flows were reconstructed from CMR using custom MATLAB programs. The vascular modeling toolkit (VMTK) was used for the geometrical analysis. Mean vessel diameters and flow rates were normalized by body surface area (BSA).
Computational flow simulations were conducted using a validated solver prescribing time-averaged boundary conditions to quantify the indexed TCPC power loss (iPL) (with respect to BSA and systemic flow). Wilcoxon matched-pair signed rank test was used to assess the differences between time points.
Results: Table 1 reports the variables evaluated for T1 and T2. Normalized diameters decreased significantly; flow increases were proportional to BSA changes for all vessels except for the superior vena cava (SVC); systemic (Fontan pathway (FP)/SVC) and pulmonary (left pulmonary artery -LPA/ right pulmonary artery -RPA) flow ratios were not significantly different. For the hemodynamics, iPL showed a significant increase between time points.
Conclusions: Although absolute diameters increased significantly, diameters normalized to BSA decreased. The increase of iPL from T1 to T2 suggests decreasing hemodynamic efficiency over time, may negatively influence Fontan patient clinical outcomes.
- © 2013 by American Heart Association, Inc.