Abstract: Objective To investigate risk factors for portal vein stenosis (PVS) after liver transplantation in children with biliary atresia (BA) and summarize prevention and treatment strategies.Methods Clinical data of BA children who underwent liver transplantation from May 2018 to August 2025 were retrospectively analyzed.According to whether PVS occurred after the operation,the patients were divided into the PVS group (5 cases) and the control group (23 cases).Univariate and multivariate Logistic regression were used to analyze the risk factors of PVS in children with BA after liver transplantation.Results Univariate analysis showed that postoperative recipient portal vein diameter ≤5mm,body weight ≤7kg,GRWR between 2%-4%,preoperative Kasai procedure,and donor liver cold ischemia time were associated with PVS (P<0.05).Multivariate analysis identified postoperative recipient portal vein diameter ≤5mm ,body weight ≤7kg ,GRWR between 2%-4% ,preoperative Kasai procedure ,and donor liver cold ischemia time  as independent risk factors for PVS.Conclusion Recipient portal vein diameter ≤5mm,body weight ≤7kg,GRWR outside the 2%-4% range,preoperative Kasai procedure,and donor liver cold ischemia time are independent risk factors for PVS after liver transplantation in small infants with BA.

Key words: biliary atresia, liver transplantation, portal vein stenosis, risk factors, prevention and treatment strategies