Preoperative imaging findings to predict 2-year native liver survival after the Kasai procedure in patients with biliary atresia

Abstract

Objectives: To investigate the feasibility of using preoperative imaging indices to predict 2-year native liver survival after the Kasai procedure in patients with biliary atresia (BA).

Materials and methods: The retrospective review included 190 BA patients who underwent the Kasai procedure between 2000 and 2020, with preoperative US and/or MRI, excluding cases with less than 2-year follow-up period. Multivariable logistic regression analysis was performed to identify imaging indices to predict 2-year native liver survival. Kasai failure was defined as the need for liver transplantation or death within 2 years of the Kasai procedure.

Results: Of the 90 patients included, all had preoperative US, and 61 also had MRI. Kasai failure occurred in 52% (47/90). Preoperative US identified gallbladder length (OR 0.40, 95% CI 0.17-0.95, p = 0.039; cutoff 1.6 cm, AUC 67.66) and biliary cysts (OR 24.64, 95% CI 1.97-308.08, p = 0.013) as significant Kasai failure predictors, with a combined accuracy of 73% (60/82). For patients having both preoperative US and MRI, significant predictors were hepatic artery diameter (OR 6.75, 95% CI 1.31-34.88, p = 0.023; cutoff 2 mm, AUC 73.83) and biliary cysts (OR 23.89, 95% CI 1.43-398.82, p = 0.027) on US, and gallbladder length (OR 0.25, 95% CI 0.08-0.76, p = 0.014; cutoff 1.2 cm, AUC 74.72) and spleen size (OR 2.53, 95% CI 1.02-6.29, p = 0.045; cutoff 6.9 cm, AUC 73.72) on MRI, with a combined accuracy of 85% (52/61).

Conclusion: Preoperative US and/or MRI enhance the 2-year native liver survival prediction in BA patients after the Kasai procedure.

Clinical relevance statement: BA patients with hepatic artery diameter > 2 mm (US), gallbladder length < 1.6 cm (US) or < 1.2 cm (MRI), spleen size > 6.9 cm (MRI), and absence of biliary cysts (US/MRI) have a decreased likelihood of 2-year native liver survival.

Key points: • Preoperative US and/or MRI can predict the probability of achieving 2-year native liver survival following the Kasai procedure. • Combining US and MRI improved the accuracy to 85% for predicting 2-year native liver survival in BA patients. • The hepatic artery diameter > 2 mm (US), gallbladder length < 1.6 cm (US) or < 1.2 cm (MRI), spleen size > 6.9 cm (MRI), and no biliary cysts (US/MRI) are significant predictors of Kasai failure in patients with biliary atresia.

Keywords: Biliary atresia; Magnetic resonance imaging; Portoenterostomy, Hepatic; Prognosis; Ultrasonography.