Virtual surgical planning, flow simulation and 3D electro-spinning of patient-specific grafts to optimize Fontan hemodynamics
Despite advances in the Fontan procedure, there is an unmet clinical need for patient-specific graft designs that are optimized for variations in patient anatomy. The objective of this study is to design and produce patient-specific Fontan geometries, with the goal of improving hepatic flow distribution (HFD) and reducing power loss (Ploss), and manufacturing these designs by electrospinning.
Cardiac MRI data from patients who previously underwent a Fontan procedure (n=2) was used to create 3D models of their native Fontan geometry using standard image segmentation and geometry reconstruction software. For each patient, alternative designs were explored in silico – including tube-shaped and bifurcated conduits – and their performance in terms of Ploss and HFD probed by computational fluid dynamic (CFD) simulations. Best performing options were then fabricated using electrospinning.
CFD simulations showed that the bifurcated conduit improved HFD between the left and right pulmonary artery, while both types of conduits reduced power loss. In vitro testing with a flow-loop chamber supported the CFD results. The proposed designs were then successfully electrospun into tissue-engineered vascular grafts (TEVG).
Our unique virtual cardiac surgery approach has the potential to improve the quality of surgery by manufacturing patient-specific designs before surgery, that are also optimized with balanced HFD and minimal Ploss , based on refinement of commercially available options for image segmentation, computer aided design, and flow simulations.