Abstract
Children with biliary atresia (BA) who survive with their native liver after Kasai portoenterostomy (KPE) remain at high risk of progressive portal hypertension (PHT). Reliable, non-invasive tools for longitudinal risk stratification are therefore essential in pediatric follow-up. To evaluate the diagnostic performance of liver stiffness value (LSV) and spleen stiffness value (SSV), individually and in combination, for predicting a surrogate endpoint of portal hypertension (PHT) in children with BA after KPE, and to characterize their temporal evolution following surgery. In this prospective cross-sectional study, 40 post-KPE BA children and 45 age-matched healthy controls underwent conventional ultrasound, Doppler evaluation, and shear wave elastography (SWE) of the liver and spleen. Surrogate PHT was defined by splenomegaly and thrombocytopenia. Group comparisons, Spearman correlations, generalized linear models, logistic regression, and receiver operating characteristic analysis were performed. Forty BA patients (20 female; median age 72 months [IQR 48-84]) and 45 controls (24 female; median age 84 months [IQR 48-120]) were analyzed. Both LSV and SSV were higher in the BA group (p < 0.001). SSV correlated strongly with spleen size, splenic vein diameter, and platelet count (all p < 0.01). In multivariate analysis, SSV was independently predicted by splenic vein velocity, while LSV was influenced by total bilirubin (p < 0.05). For predicting surrogate PHT, SSV (AUC, 0.78; 95% CI 0.63, 0.93) outperformed LSV (AUC, 0.76; 95% CI 0.61, 0.90). The combined model achieved an AUC of 0.80 (95% CI 0.67, 0.94). SSV is a robust, non-invasive biomarker for PHT in children with BA, reflecting portal hemodynamic adaptation and being less affected by cholestatic confounding than LSV. Incorporating spleen stiffness into routine ultrasound follow-up may improve non-invasive risk stratification and optimize surveillance strategies in post-KPE pediatric patients.