Related Experiment Video
Updated: May 16, 2025
In Silico Clinical Trials for Cardiovascular Disease
Published on: May 27, 2022
Multiphysics Simulations of a Bioprinted Pulsatile Fontan Conduit
Zinan Hu1, Jessica E Herrmann2,3, Erica L Schwarz4,5
1Department of Mechanical Engineering, Stanford University, Stanford, CA 94305.
Insights
A novel bioprinted pulsatile conduit offers a potential solution for single ventricle heart patients, significantly improving Fontan circulation hemodynamics by reducing venous pressure and boosting cardiac output.
Area of Science:
- Biomedical Engineering
- Cardiovascular Physiology
- Regenerative Medicine
Background:
- Single ventricle congenital heart disease necessitates palliative Fontan surgery.
- Fontan circulation results in elevated central venous pressure, reduced cardiac output, and poor outcomes.
- Existing Fontan physiology presents significant clinical challenges.
Purpose of the Study:
- To propose and evaluate a bioprinted pulsatile conduit as a secondary power source for Fontan circulation.
- To optimize conduit design using a multiphysics computational framework.
- To investigate the potential of the conduit to improve Fontan physiology and reduce adverse sequelae.
Main Methods:
- Development of a multiphysics computational framework integrating electrophysiology, cardiomyocyte contractility, and fluid-structure interaction.
- Coupling the conduit model to a lumped parameter network representing Fontan physiology.
- Simulation of various myocardial contractility levels, contraction durations, fiber directions, and valve placements.
Main Results:
- An initial conduit design reduced liver (inferior vena cava) pressure from 16.4 to 9.3 mmHg and increased cardiac output by 29%.
- An optimized design with valves reduced liver pressure to 7.3 mmHg and increased cardiac output by 38%, nearing normal hemodynamics.
- Conduit valves are critical for performance; their absence compromises results.
- A potential drawback is the linear increase in superior vena cava pressure with reduced liver pressure.
Conclusions:
- A bioprinted pulsatile conduit can significantly improve Fontan circulation hemodynamics.
- Computational modeling is effective for guiding the design of such biomedical devices.
- Further research is needed to address potential drawbacks like superior vena cava pressure elevation.
Abstract:
For single ventricle congenital heart patients, Fontan surgery is the final stage in a series of palliative procedures, bypassing the heart to enable passive flow of de-oxygenated blood from the inferior vena cava (IVC) to the pulmonary arteries. This circulation leads to severely elevated central venous pressure, diminished cardiac output, and thus numerous sequelae and premature mortality. To address these issues, we propose a bioprinted pulsatile conduit to provide a secondary power source for the Fontan circulation. A multiphysics computational framework was developed to predict conduit performance and to guide design prior to printing. Physics components included electrophysiology, cardiomyocyte contractility, and fluid-structure interaction coupled to a closed-loop lumped parameter network representing Fontan physiology. A range of myocardial contractility was considered and simulated. The initial conduit design with adult ventricular cardiomyocyte contractility values coupled to a Purkinje network demonstrated potential to reduce liver (IVC) pressure from 16.4 to 9.3 mmHg and increase cardiac output by 29%. After systematically assessing the impacts of contraction duration, fiber direction, and valve placement on conduit performance, we identified a favorable design that successfully reduces liver pressure to 7.3 mmHg and increases cardiac output by 38%, almost normalizing adverse hemodynamics in the lower venous circulation. Valves at the input and output of the conduit are essential to achieve these satisfactory results; without valves, performance is compromised. However, a potential drawback of the design is the elevation of superior vena cava (SVC) pressure, which varies linearly with liver pressure reduction.
