Elastography-The New Standard in the Assessment of Fibrosis After Pediatric Liver Transplantation?

The development of graft fibrosis after pediatric liver transplantation (PLT) remains a major concern as it can lead to graft failure and ultimately graft loss. Elastography is a non-invasive method to assess liver fibrosis, but its role in the posttransplant setting is unclear. The aim of our study was to evaluate shear wave elastography (SWE) in the assessment of liver fibrosis after PLT, including split-liver recipients.

We retrospectively analyzed data from PLT recipients who underwent surveillance liver biopsy and concurrent 2D-SWE during the study period from April 2018 to July 2021. Spearman's correlation was used to compare histologic fibrosis stages with liver stiffness measurements (LSM) by 2D-SWE. AUROC analysis was performed to evaluate the performance. One sample t-test was used to compare results with reference values of healthy children.

62 cases were included. 29% showed histologic fibrosis. LSM by 2D-SWE were feasible in all children regardless of age or graft type. There was a significant correlation between LSM and fibrosis stage for all three scoring systems used (Ishak, p = 0.003; METAVIR, p = 0.005; LAF Score, p = 0.003). Patients with a history of biliary complications had increased liver stiffness (p = 0.015). The AUROC of 2D-SWE for predicting significant liver graft fibrosis was 0.81. Liver stiffness after PLT without graft fibrosis was higher than in healthy subjects, but comparable to that in children with chronic liver disease without fibrosis.

2D-SWE can reliably detect children with significant liver graft fibrosis, even in split-liver recipients. This study demonstrates the value of a non-invasive tool for fibrosis staging after PLT. 2D-SWE has the potential to improve long-term outcomes after PLT and to reduce the number of surveillance liver biopsies. But elastography is not a substitute for liver biopsy.