Doppler ultrasound and 2D shear wave ultrasound elastography for liver fibrosis evaluation in Fontan-associated liver disease

Abstract

Background: The Fontan operation improves survival in patients with single ventricle physiology but is associated with Fontan-associated liver disease (FALD), characterized by progressive fibrosis due to prolonged elevated central venous pressure. While 2D shear wave elastography (2D-SWE) can assess fibrosis, it often overestimates stiffness in congestive conditions. Doppler ultrasound, which evaluates hepatic hemodynamics, may complement 2D-SWE for fibrosis assessment. This study evaluated the diagnostic performance of Doppler ultrasound and 2D-SWE in assessing hepatic fibrosis in Fontan patients and compared the findings with biopsy-proven fibrosis severity.

Method: A retrospective study was conducted on 27 Fontan patients who underwent Doppler ultrasound, 2D-SWE, and liver biopsy between January 2020 and December 2022. ROC curves and AUC values were used to assess diagnostic performance.

Results: AST to Platelet Ratio Index (APRI) and Fibrosis-4 index (FIB-4) scores demonstrated good discriminatory performance, with AUC values of 0.79 and 0.72, respectively. Resistive Index (RI) of hepatic artery showed moderate discriminatory performance (AUC = 0.62), while 2D-SWE demonstrated poor discriminatory ability (AUC = 0.35). When RI was combined with APRI, the AUC improved from 0.79 to 0.82.

Conclusion: APRI and FIB-4 provided the most accurate assessment of significant fibrosis, while RI of hepatic artery may serve as a useful adjunct to serum biomarkers. Incorporating Doppler ultrasound into a multi-parametric model may improve fibrosis evaluation in Fontan patients.

Keywords: 2D shear wave elastography; Doppler ultrasound; Fontan-associated liver disease; Liver fibrosis.

Fig. 1

Schematic representation of Fontan circulation. Systemic venous blood from the superior vena cava (SVC) and inferior vena cava (IVC) is passively directed into the pulmonary arteries without passing through a subpulmonary ventricle (Black arrow). Hepatic venous return drains directly into the systemic venous pathway, exposing the liver to chronically elevated central venous pressure (Red arrow). This hemodynamic profile contributes to hepatic congestion, sinusoidal injury, and fibrosis

Fig. 2

Box-and-whisker plots with overlaid individual data points comparing non-invasive fibrosis markers between Fontan patients with non-significant (F0–F2) and significant (F3–F4) liver fibrosis. APRI: APRI values were significantly higher in the significant fibrosis group (p = 0.009), reflecting its strong discriminatory ability (a). FIB-4: FIB-4 was also elevated in patients with significant fibrosis (p = 0.015), though with slightly lower performance than APRI (b). Liver stiffness: No significant difference in 2D shear wave elastography (SWE) measurements was observed between groups (p = 0.72), likely due to hemodynamic confounding (c). Hepatic artery resistive index (RI): RI trended higher in the significant fibrosis group (p = 0.06), suggesting possible complementary value (d). Boxes represent the interquartile range (IQR), horizontal lines show medians, whiskers indicate 1.5× IQR, and dots represent individual patient values. A colorblind-friendly palette was used

Fig. 3

Receiver operating characteristic (ROC) curve analysis for non-invasive fibrosis assessment in Fontan-associated liver disease (FALD). ROC curves for APRI and FIB-4 demonstrated good discriminatory performance for detecting significant fibrosis, with AUCs of 0.79 and 0.72, respectively (a). The resistive index (RI) showed moderate diagnostic performance with an AUC of 0.62 (b). Liver stiffness measurement by 2D-SWE demonstrated poor discriminatory ability, with an AUC of 0.35 (c). Each curve includes the optimal cut-off point for each parameter