Two-dimensional shear wave elastography in Fontan-associated liver disease: a narrative review

Single ventricle congenital heart defects are rare conditions that require surgical palliation following birth. Often, such defects require multistep surgical procedures in different stages of life. The Fontan operation, considered the final procedure for single ventricle congenital heart disease repair, has been associated with long-term complications to the liver despite its cardiac benefit. Fontan-associated liver disease (FALD) is considered the main hepatological complication post-Fontan surgery. Liver biopsy has been the gold standard for diagnosis. Ultrasound-based shear wave elastography (SWE) has been investigated as a non-invasive adjunct for liver stiffness assessment alongside serological, imaging, and histopathological parameters. This narrative review summarizes the current evidence regarding the use of SWE as a method to assess liver stiffness in FALD, including current applications, technical challenges, and limitations associated with its clinical implementation. Particular emphasis is placed on the confounding influence of hepatic congestion, the lack of validated FALD-specific stiffness thresholds, and the need for standardized acquisition and interpretation protocols.