Prevalence, features and predictive factors of liver nodules in Fontan surgery patients: The VALDIG Fonliver prospective cohort.

Background & Aims: Fontan surgery is used to treat a variety of congenital heart malformations, and may lead to advanced chronic liver disease in the long-term. This study examines the prevalence, characteristics and predictors of liver nodules in patients following Fontan surgery.

Methods: This was a prospective, cross-sectional, observational study conducted at 8 European centres. Consecutive patients who had undergone Fontan surgery underwent blood tests, abdominal ultrasonography (US), transient elastography (Fibroscan®), echocardiography, haemodynamic assessments, and abdominal MRI/CT scan. The primary outcome measure was liver nodules detected in the MRI/CT scan. Predictors of liver nodules were identified by multivariate logistic regression.

Results: One hundred and fifty-two patients were enrolled (mean age 27.3 years). The mean time elapsed from surgery to inclusion was 18.3 years. Liver nodule prevalences were 29.6% (95% CI 23-37%) on US and 47.7% (95% CI 39-56%) on MRI/CT. Nodules were usually hyperechoic (76.5%), round-shaped (>80%), hyperenhancing in the arterial phase (92%) and located in the liver periphery (75%). The sensitivity and specificity of US were 50% (95% CI 38-62%) and 85.3% (95% CI 75-92%), respectively. Inter-imaging test agreement was low (adjusted kappa: 0.34). In the multivariate analysis, time since surgery >10 years was the single independent predictor of liver nodules (odds ratio 4.18; p = 0.040). Hepatocellular carcinoma was histologically diagnosed in 2 of the 8 patients with hypervascular liver nodules displaying washout.

Conclusion: While liver nodules are frequent in Fontan patients, they may go unnoticed in US. Liver nodules are usually hyperechoic, hypervascular and predominantly peripheral. This population is at risk of hepatocellular carcinoma, the diagnosis of which requires confirmatory biopsy.

Lay Summary: Fontan surgery is the standard of care for many patients with univentricular congenital cardiopathies. Recent advances have improved the survival of Fontan patients, and nowadays most of them reach adulthood. In this setting, Fontan-associated liver disease (FALD) is increasingly recognised, and has become a significant prognostic factor. Liver nodules are considered a component of FALD yet their prevalence, imaging features and predictors have hardly been evaluated. In this study, we observed that liver nodules are frequent, typically hyperechoic, hypervascular and predominantly peripheral in patients with FALD. This population is at risk of hepatocellular carcinoma, the diagnosis of which must be confirmed by biopsy.