Noninvasive assessment of liver status in adult patients after the Fontan procedure

A hemodynamic derangement in Fontan circulation causes liver pathology known as Fontan‑associated liver disease. Although liver biopsy is a standard for diagnosis of liver fibrosis, noninvasive methods are being developed, including shear wave elastography (SWE). We aimed to evaluate the degree of liver stiffness (LS) using SWE in patients with Fontan circulation in a long‑term follow‑up and to investigate a relationship between patient characteristics and LS. The study included 59 patients after the Fontan procedure. Clinical examinations and laboratory tests were performed. According to the stage of LS, patients were divided into 2 subgroups: group 1 (METAVIR stages F1 and F2) and group 2 (METAVIR stages F3 and F4). The ratio of aspartate transaminase to alanine transaminase, aspartate transaminase‑to‑platelet ratio index (APRI), fibrosis‑4 (FIB‑4) score, and Forns index were assessed. The median LS was 9.1 kPa (interquartile range, 3.9–18.5 kPa). Five patients (9%) demonstrated LS in stage F1; 14 (26%), F2; 28 (52%), F3; and 7 (13%), F4. Group 2 had significantly higher aspartate transaminase and γ‑glutamyltranspeptidase levels, APRI, FIB‑4, and Forns index, and lower platelet count than group 1. A canonical correlation analysis indicated that LS and thrombocytopenia were related to time from the Fontan procedure, age at procedure, and single ventricular ejection fraction. We showed that adult patients after the Fontan procedure develop liver dysfunction. Time from surgery, age at procedure, and single ventricular ejection fraction are related to the degree of LS assessed by SWE. Finally, SWE, APRI, Forns index, and FIB‑4 score may help assess the degree of liver fibrosis.