Long-Term Care in Fontan Circulation: Surveillance and Management of Fontan-Associated Liver Disease and Protein-Losing Enteropathy

Abstract Purpose of Review This manuscript reviews the clinical spectrum and management of Fontan-associated liver disease (FALD) and protein-losing enteropathy (PLE), examining how chronic venous hypertension leads to multisystem injury. Recent Findings Liver fibrosis is now recognized as an early and nearly universal complication after the Fontan procedure, with cirrhosis affecting approximately 43% of patients by 30 years post-operation. Although post-2001 survival exceeds 90%, standard biomarkers and imaging frequently underestimate disease severity, as liver stiffness measurements are confounded by hepatic congestion. Liver biopsy remains the gold standard for staging. Summary FALD is an inevitable consequence of Fontan physiology, characterized by sinusoidal congestion and progressive fibrosis, while PLE results from multifactorial gastrointestinal protein loss. The key clinical implication is the importance of a multidisciplinary approach, particularly when considering transition from isolated heart transplantation to combined heart–liver transplantation in advanced disease. Future research should prioritize standardized staging systems and targeted therapies to reduce lymphatic dysfunction and fibrosis progression.