ABSTRACT
Fontan-associated liver disease (FALD) is a serious complication related to the chronically elevated venous pressure and low cardiac output of this abnormal circulation. However, diagnostic markers for this condition are limited. We hypothesized that specific tests for fibrosis developed for other chronic liver diseases would identify a higher prevalence of FALD than ultrasound and standard laboratory tests and that identified abnormalities would correlate with time post-Fontan. In this cross-sectional study, we assessed 19 children (average age 8.4 ± 4.3 and 5.4 ± 4.1 years post-Fontan) and 8 adults (average age 31.5 ± 8.9 and 21.1 ± 4 years post-Fontan) using standard serum laboratory investigations assessing hepatic integrity and function, the FibroTest, liver ultrasound, and transient elastography (FibroScan). In adult Fontan patients, hemoglobin, C-reactive protein, and gamma-glutamyl transpeptidase were significantly increased, and white blood cell and platelet counts were significantly decreased in comparison to the pediatric cohort. International normalized ratio was mildly elevated in both children and adults. FibroTest results were suggestive of fibrosis regardless of time post-Fontan. FibroScan measurements were significantly correlated with time post-Fontan, but the incidence of ultrasound-detected liver abnormalities was variable. No cases of hepatocellular carcinoma were identified. Abnormalities suggestive of FALD occur in both children and adults post-Fontan. Select laboratory tests, and possibly ultrasound and FibroScan in some patients, appear to have the most promise for the non-invasive detection of FALD.
ABSTRACT
Chronic liver diseases are associated with multiple complications, including cirrhosis, portal hypertension, ascites, synthetic dysfunction and hepatocellular carcinoma, and these processes are increasingly recognized in post-Fontan patients. Fontan-associated liver disease (FALD) can be defined as abnormalities in liver structure and function that result from the Fontan circulation and are not related to another disease process. FALD arises due to chronic congestion of the liver created by the elevated venous pressure and low cardiac output of the Fontan circulation, which may be superimposed on previous liver injury. Pathology studies have generally shown that FALD worsens as time post-Fontan increases, but the prevalence of FALD is not well defined because the majority of Fontan patients, even those with significant hepatic fibrosis, appear to be asymptomatic and biochemical or functional hepatic abnormalities are usually subtle or absent. Alternate non-invasive investigations, derived from the study of other chronic liver diseases, have been tested in small series of pediatric and adult Fontan patients, but they have been confounded by congestion and do not correlate well with liver biopsy findings. Liver disease can complicate Fontan circulatory failure and may even be significant enough to be considered a contraindication to heart transplantation or require combined heart-liver transplantation. The search for the optimal management strategy continues in the setting of increasing numbers of Fontan patients surviving to adulthood and being referred for heart transplantation. Thus, in this review we attempt to define the scope and significance of FALD and address transplant-related assessment and management of this challenging disorder.
