Early predictors of success of Kasai operation in children with biliary atresia

Aim: Aim of the study was the evaluation of early predictive parameters of event-free survival (not listed for liver transplantation, not transplanted, no death) in children suffering from biliary atresia after hepatoportoenterostomy (Kasai procedure) in order to optimize pretransplant management. Patients and Methods: Sixty-seven infants were treated with the Kasai operation at our institution over a 20-year period from 1978 until 1998. Median age at time of operation was 51 days after birth (range 19-180 days). Of these 67 infants, 24 children with complete datasets and an observation time of at least one year were evaluated retrospectively using a Cox regression model. The response variable was event-free survival after a median observation time of 4.9 years (1.11- 10.37 years). Six variables were entered as covariates: alanine aminotransferase (ALAT), cholinesterase activity, bilirubin, age at the time of Kasai operation and tracer excretion and uptake during hepatobiliary scintigraphy (HBSS). All variables were evaluated six weeks after operation. For subsequent cut-off determination, a receiver operating analysis (ROC analysis) was carried out. Results: Tracer excretion shown by HBSS showed the highest prognostic power to predict event-free survival after Kasai operation (log rank 18.68, p < 0.0001) followed by bilirubin and ALAT as further significant parameters in the first univariate step of the Cox regression model. In the subsequent multivariate step, the prognostic power of HBSS was improved only by bilirubin (log rank 24.6, p < 0.0001). The ROC analysis determined a cut-off for bilirubin concentrations of 57 mu mol/l for event-free survival with a sensitivity of 80% and a specificity of 78.6%. The five-year event-free survival-rate was 100% in the group with good tracer excretion and a bilirubin concentration of 57 mu mol/l and 27% for the other group (log rank test, p < 0.0001). Conclusion: Early predictors of success of the Kasai operation in children with biliary atresia are free tracer excretion as shown by HBSS and a serum bilirubin concentration < 57 mu mol/l six weeks after the operation. Thus, children with bilirubin concentrations above this level should be carefully and frequently monitored with regard to a transplantation requirement in order to optimize pretransplant management.