Correlation of Liver Fibrosis on Ultrasound Elastography and Liver Biopsy After Fontan Operation: Is Non-invasive Always Better?

Fontan-associated liver disease (FALD) is a common complication after the Fontan procedure. A liver biopsy is the gold standard for assessing liver fibrosis. However, ultrasound (US) elastography has increasingly been used as a non-invasive method to diagnose and monitor liver fibrosis. Nonetheless, a clear correlation of severity of fibrosis between US elastography and liver biopsy in this population has not yet been established. In this single-center retrospective study, we included patients with Fontan physiology who had liver fibrosis evaluation between 2008 and 2022 with both US elastography and liver biopsy. Fibrosis was classified by US elastography and liver biopsy based on the METAVIR scoring system and congestive hepatic fibrosis score, respectively. Overall, 29 patients had both US elastography and liver biopsy with a median age of 17 years (IQR 13-27 years). The median time between Fontan operation and liver biopsy was 14 years (IQR 9-23). Nine patients underwent isolated heart transplantation (31%). The median shear wave elastography was 1.97 m/s (IQR 1.66-2.11) with 86% of patient's METAVIR score being > F2. There was no correlation in the severity of fibrosis between US elastography and liver biopsy (polycor = - 0.021). Findings on US elastography had weak correlation with histological fibrosis severity reported in liver biopsy. Further large-scale studies are necessary to assess optimal protocol for using US elastography for surveillance of FALD in Fontan patients.