To investigate the role of preoperative serum FGF19 level in the prognosis of biliary atresia.

Kasai portoenterostomy is currently one of the main treatment methods for biliary atresia, but about 30% of children still require liver transplantation even after receiving the surgery. Accurate prognosis will help select the most suitable treatment method for children, but there is currently a lack of effective preoperative predictive indicators. Serum FGF19 has recently been considered a possible preoperative predictive indicator for biliary atresia, but its predictive value has not been confirmed in a large sample and in Asian population, thus the investigators try to further explore the prognostic value of serum FGF19 in children with biliary atresia based on a large sample.

Inclusion Criteria:

• Samples diagnosed as biliary atresia in Children's Hospital of Fudan University
• Samples with one-year follow-up records after surgery
• Samples with a record of serum total bilirubin levels three months after surgery
• Samples with preoperative serum left（volume > 500ul)

Exclusion Criteria:

• None

The study enrolled patients meeting following conditions.

• Patients diagnosed as biliary atresia in Children's Hospital of Fudan University
• Patients with at least one-year follow-up records after surgery
• Patients with a record of serum total bilirubin levels three months after surgery
• Patients with preoperative serum left（volume > 500ul)