Cisterna Chyli Dilation Is a Risk Factor for Liver Nodules and Hepatocellular Carcinoma in Fontan‐Associated Liver Disease: Pathophysiological Role of Lymphatic Dysfunction

AIM: In Fontan-associated liver disease (FALD), chronic congestion often confounds conventional fibrosis markers, complicating surveillance for hepatocellular carcinoma (HCC). Although lymphatic dysfunction is fundamental to Fontan physiology, its contribution to hepatocarcinogenesis remains unclear. We aimed to investigate how lymphatic congestion, quantified by cisterna chyli (CC) dilation, is associated with liver nodules and HCC. METHODS: We retrospectively analyzed 77 patients with FALD who underwent cardiac catheterization and contrast-enhanced computed tomography or magnetic resonance imaging. Clinical, hemodynamic, and lymphatic parameters were evaluated to identify factors independently associated with liver nodules. HCC-related analyses were carried out exploratorily because of the limited number of HCC cases. RESULTS: Liver nodules were identified in 43 patients (55.8%), including six patients with HCC. CC diameter was 3.2 mm, 4.1 mm, and 6.6 mm in the non-nodule, nodule without HCC, and HCC groups, respectively (p < 0.0001). In multivariable analysis, larger CC diameter and higher total bile acid (TBA) levels were independently associated with liver nodules, whereas anticoagulant therapy showed an inverse trend. Exploratory analyses suggested an association between larger CC diameter and HCC. CC diameter showed positive correlations with central venous pressure indices and TBA, suggesting a relationship between CC enlargement and the hemodynamic and hepatic abnormalities of FALD. CONCLUSION: CC dilation was associated with liver nodules in FALD and may reflect lymphatic and hemodynamic burden related to chronic venous congestion. Its potential association with HCC requires validation in larger prospective cohorts.