A convenient nomogram for predicting early death or liver transplantation after the Kasai procedure in patients with biliary atresia

Abstract

Purpose: Many patients with biliary atresia (BA) after the Kasai procedure (KP) progress to death or require liver transplantation to achieve long-term survival; however, most cases of death/liver transplantation (D/LT) occur in the early period after KP (usually within 1 year). This study was designed to construct a convenient nomogram for predicting early D/LT in patients with BA after KP.

Methods: A BA cohort was established in May 2017, and up to May 2023, 112 patients with 1-5 years of follow-up were enrolled in the study and randomly (ratio, 3:1) divided into a training cohort for constructing a nomogram (n = 84) and a validation cohort (n = 28) for externally validating the discrimination and calibration. The training cohort was divided into two groups: the early D/LT group (patients who died or had undergone LT within 1 year after KP [n = 35]) and the control group (patients who survived through the native liver more than 1 year after KP [n = 49]). Multivariate logistic regression and stepwise regression were applied to detect variables with the best predictive ability for the construction of the nomogram. The discrimination and calibration of the nomogram were internally and externally validated.

Results: The Kaplan-Meier (K-M) curve showed an actual 1-year native liver transplantation (NLS) rate of 57.1% and an estimated 2-year NLS rate of 55.2%. By multivariate regression and stepwise regression, age at KP, jaundice clearance (JC) speed 1 month after KP, early-onset PC (initial time < 36.5 days) after KP, sex, aspartate aminotransferase-to-platelet ratio index (APRI), and weight at KP were identified as the independent variables with the best ability to predict early D/LT and were used to construct a nomogram. The developed nomogram based on these independent variables showed relatively good discrimination and calibration according to internal and external validation.

Conclusion: Most D/LTs were early D/LTs that occurred within 1 year after KP. The established nomogram based on predictors, including sex, weight at the KP, the APRI, age at the KP, JC speed 1 month after the KP, and early PC, may be useful for predicting early D/LT and may be helpful for counseling BA patients about patient prognosis after KP. This study was retrospectively registered at ClinicalTrials.gov (NCT05909033) in June 2023.

Keywords: Biliary atresia; Early death/liver transplantation; Kasai procedure; Native liver survival; Nomogram.