Multiphysics Simulations of a Bioprinted Pulsatile Fontan Conduit.

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.