Background and hypotheses: High venous pressures and associated hepatic congestion are important drivers for Fontan-associated liver disease. The prognostic significance of hepatomegaly as a marker of congestion however is not well defined and is further explored in this research study.
Methods: Fontan patients who have had liver ultrasound scans were identified from the Prince Sultan Cardiac Centre Fontan Database and had their anatomic, surgical, clinical histories abstracted from the electronic medical records following institutional ethics approval. Liver volumes were determined retrospectively from reviewing individual US images, and these, divided into tertiles, were analysed in the context of the predefined endpoints of (i) Primary - death or heart or liver transplantation, or (ii) Secondary - combined endpoint of death, transplantation, arrhythmia, or protein-losing enteropathy.
Results: Mean indexed liver volumes for the entire cohort (n = 199) were 1065.1 ± 312.1 ml/m2, range 387 to 2071 ml/m2. Patients with the largest liver volumes (highest tertile) were less likely to have a functioning fenestration compared to those in the lowest tertile 44% versus 56% p = 0.016 and experienced the highest burden of mortality and heart or heart-liver transplantation, p = 0.016, and were more likely to reach the composite endpoint of death, protein-losing enteropathy, arrhythmia, or transplantation, p = 0.010. Liver volumes had an overall predictive accuracy for the combined outcome of 61% (CI 53%, 67%, p = 0.009).
Conclusions: Liver volumetry may serve as a potentially important congestion biomarker for adverse outcomes after the Fontan operation.
Keywords: Fontan operation; Fontan-associated liver disease; cirrhosis; congestion; heart failure; liver CT; liver ultrasound; single ventricle physiology; tricuspid atresia.