A One-Dimensional (1D) Computational Fluid Dynamics Study of Fontan-Associated Liver Disease (FALD)

Area of Science:

• Cardiovascular Physiology
• Hepatology
• Biomedical Engineering

Background:

• Fontan-associated liver disease (FALD) is a significant complication in patients with univentricular physiology, particularly those with hypoplastic left heart syndrome (HLHS).
• Patients with HLHS often experience reduced cardiac output and hepatic blood flow due to the Fontan circuit, increasing FALD risk.
• Double outlet right ventricle (DORV) patients with similar univentricular physiology show a lower incidence of FALD, suggesting distinct hemodynamic profiles.

Purpose of the Study:

• To investigate the hemodynamic differences in the liver between patients with HLHS and single-ventricle Fontan physiology (DORV).
• To simulate and predict hemodynamic changes associated with FALD progression in an HLHS patient.
• To elucidate the specific hemodynamic mechanisms underlying FALD development in Fontan circulation.

Main Methods:

• Utilized a patient-specific, one-dimensional computational fluid dynamics (1D-CFD) model.
• Compared liver hemodynamics between an HLHS patient and an age/size-matched DORV control patient.
• Simulated various stages of FALD progression in the HLHS patient model.

Main Results:

• The HLHS patient exhibited higher hepatic arterial pressure than the DORV patient, with this difference increasing as FALD progressed.
• Elevated average portal pressures were observed in HLHS patients compared to DORV patients.
• Simulated FALD conditions showed increased wall shear stress in the hepatic network and decreased wall shear stress in the portal network, indicative of portal hypertension and altered liver perfusion.

Conclusions:

• HLHS patients demonstrate distinct hepatic hemodynamics compared to DORV patients, characterized by higher pressures and altered flow patterns.
• Computational modeling effectively predicts hemodynamic changes associated with FALD progression, highlighting regions at risk for fibrosis.
• These findings provide crucial insights into the hemodynamic drivers of FALD in Fontan circulation, aiding in risk stratification and management.