Journal articles

Background: 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.

Methods: 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.

Results: 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).

Conclusions: 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.