[Clinical study of causes and outcomes in pediatric liver retransplantation]

Objective: To investigate the etiology,clinical features and prognosis of pediatric liver retransplantation. Methods: The data of 1 024 cases of pediatric liver transplantation (<18 years old) from January 2014 to December 2019 operated at Tianjin First Central Hospital were collected,retrospectively. Retransplantation was performed in 26 cases,among which 25 cases received secondary liver transplantation and 1 case received a third liver transplantation. There were 13 male and 12 female patients among the 25 patients. The median age was 12.9(20.5) months(range: 5.8 to 134.8 months), the body weight was 8.0(5.6) kg(range: 5.0 to 30.0 kg) at the time of retransplantation. The pediatric end-stage liver disease(PELD) score was 17.0(21.3) (range: 0 to 45) before retransplantation. The etiology of retransplantation was biliary complications in 7 cases,primary nonfunction of liver graft in 5 cases,antibody-mediated rejection in 4 cases,hepatic artery thrombosis in 3 cases,portal vein thrombosis in 3 cases,concomitant hepatic artery and portal vein thrombosis in 2 cases,thrombogenesis of inferior Vena Cava in 1 case and sinusoidal obstruction syndrome in 1 case. The patients were divided into two groups according to the time interval(30 days) between two liver transplantations,8 patients were classified into early-retransplantation(≤30 days) group and 18 patients were classified into late-retransplantation (>30 days) group. The etiology of liver retransplantation,pre-transplant score,time interval between two transplantations,surgical aspects,major complications and survival rates were compared between the two groups. Continuous variables with normal distribution were compared with t test,while Mann-Whitney U test was applied to compare variables without normal distribution. Categorical variables were compared with chi-square test. The survival curves were created by Kaplan-Meier method and compared by Log Rank test. Results: The median follow-up time was 26.8(30.2) months(range: 1 day to 85.7 months), and the incidence of retransplantation was 1.9%. In the early-retransplantation group,the duration of surgery was (439.8±151.0)minutes,the graft-to-recipient weight ratio was 5.0(1.8)%(range:3.6% to 6.1%),the main cause for retransplantation were primary nonfunction and vascular complications. In the late-retransplantation group,the duration of surgery was (604.4±158.0)minutes,the graft-to-recipient weight ratio was 3.4(2.1)%(range:1.4% to 5.3%),the main cause for retransplantation were biliary complications,antibody mediated rejection and vascular complications.The 3-month,1-year and 2-year recipient survival rates in the early-retransplantation group were all 62.3%,while the recipient survival rates in the late-retransplantation group were 100%,93.8% and 93.8%,respectively. The difference of recipient survival rates was significant between the early-retransplantation group and the late-retransplantation group(P=0.019). The overall 3-month,1-year and 3-year recipient survival rates after the primary liver transplantation were 97.1%,95.4%,94.1%,respectively. Conclusions: The vascular complications,biliary complications,primary nonfunction and antibody-mediated rejection are the main causes of liver retransplantation.The PELD score is higher in patients receiving early retransplantation,while the surgery is relatively more complex in patients receiving late retransplantation,which is reflected by longer duration of surgeries. Patients in the late-retransplantation group showed similar recipient survival rates with primary liver transplantation recipients,and the survival rates are superior to those of patients in the early-retransplantation group. Infection and multiple organ failure are the most common fatal causes after retransplantation.