Blood test assessment of liver ultrasound findings in patients with Fontan surgery.

Hepatic complications are common in patients with Fontan surgery. The objective of this observational study is to compare demographic, clinical and blood test data in patients older than 14 years old with a Fontan procedure (cases) and asymptomatic patients with single non-operated restrictive ventricular septal defect (VSD) (controls) and to determine whether there are differences in blood collection and liver disease scores according to the liver ultrasound findings in the group of Fontan patients. The liver findings were classified as mild (normal or heterogeneous echogenicity) and significant (nodular surface, small hyperechoic nodules or hepatocarcinoma). 74 patients (14 patients with a Fontan procedure and 60 patients with a restrictive VSD) were included in the study. Median age was 18 (14-45) years old and 41 patients were males. Fontan patients had significantly lower platelet count, lower mean platelet volume (MPV) and lower glucose levels than patients with single non-operated restrictive VSD. On the contrary, Fontan patients showed higher liver enzymes [aspartate aminotransferase (AST) and alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT)], N-terminal pro-brain natriuretic peptide (NT-pro-BNP) and thyroid-stimulating hormone (TSH) concentrations than patients with restrictive VSD. 4 out of 14 (29%) patients with Fontan operation and significant liver ultrasound findings showed greater number of cardiac surgeries, lower MPV values and higher GGT and TSH levels than Fontan patients with mild findings. In conclusion, Fontan patients showed higher liver enzymes (AST, ALT and GGT) than controls and Fontan patients with significant liver ultrasound findings had higher GGT and TSH concentrations than Fontan patients with mild findings.