Fontan-Associated Liver Disease—Higher Prevalence with Increasing Age

Introduction: Liver fibrosis is increasingly recognized as a potentially serious morbidity associated with Fontan circulation (Fontan-associated liver disease [FALD]). The purpose of this study was to assess the prevalence of liver abnormalities in different age groups.

Methods: Fontan patients were screened for liver abnormalities by abdominal ultrasound and routine laboratory tests. Patients were divided into three groups based on follow-up since Fontan surgery (<5, 5–10, and >10 years). Laboratory tests were interpreted based on age and gender-adjusted reference values.

Results: A total of 273 Fontan patients seen for routine follow-up between March 2013 and August 2018 were included. Abdominal ultrasound was performed in 189 patients, and routine laboratory tests were obtained in all patients. Median age at follow-up was 11 (interquartile range [IQR] 7–16) years, and the follow-up since Fontan surgery was 8 (IQR 4–13) years. Sonographic signs of fibrotic changes included heterogeneous parenchyma, surface nodularity, or hyperechoic lesions in 91 (48%) patients. The prevalence of fibrotic changes increased with longer duration of follow-up (< 5 years: 9/39 [23%]; 5–10 years: 25/55 [45%]; >10 years: 57/95 [60%]; p < 0.001).

Elevated gamma-glutamyltranspeptidase (GGT) levels were common in all groups, but less frequent with more than 10 years of follow-up (< 5 years: 84%; 5–10 years: 96%; >10 years: 67%; p < 0.001). Glutamic–oxaloacetic–transaminase (GOT) levels above normal range were more common with more than 10 years of follow-up (17 vs. 28%, p < 0.033). Thrombocytopenia, a feature of portal hypertension, was observed in 5 and 4% of cases with less than 5 and 5 to 10 years of follow-up, but in 29% with more than 10 years of follow-up (p < 0.001). Hypoalbuminemia was also more common with more than 10 years of follow-up (3 vs. 11%, p = 0.012). Reduced prothrombin activity was found in 28% of cases without oral anticoagulation with no difference between age groups (p = 0.289).

Mean GGT levels were higher in patients with sonographic signs of fibrosis (67 ± 47 vs. 49 ± 30 U/L, p = 0.001), while absolute values of other laboratory data showed no differences. The frequency of hypoalbuminemia was higher in cases with suspected fibrosis (11 vs. 2%, p = 0.027).

Conclusion: The prevalence of ultrasound and laboratory abnormalities suggestive of FALD increases with time since Fontan surgery, but ultrasound abnormalities were not necessarily reflected by laboratory abnormalities and vice versa.

No conflict of interest has been declared by the author(s).