Impact of the Model for End-Stage Liver Disease Score On the Outcomes of Small-for-Size Grafts in the Setting of Pediatric Living Donor Liver Transplantation.

Abstract

(Background) In the field of adult living donor liver transplantation (LDLT), it has generally reported that recipients receiving small-for-size grafts (SFSGs) exhibit poor outcomes and prognoses, whereas the outcomes and prognoses of pediatric recipients receiving SFSGs are unknown. The purpose of this study was to identify risk factors for graft failure in order to establish a preoperative strategy for SFSGs. (Patients & Methods) Among 225 LDLT procedures performed between May 2001 and December 2012, 13 LDLT (5.8%) were undertaken using SFSGs. A SFSG was defined as that having a graft volume (GV) of less than 40% of the standard liver volume (SLV). The original disease was biliary atresia in 9 patients (69.2%), graft failure in 1, Wilson disease in 1, ornithine transcarbamylase deficiency in 1, and a congenital extrahepatic portosystemic shunt in 1. The mean patient age and body weight were 12.9±2.0 years and 41.7±9.2 kg, respectively. We performed univariate analyses to identify factors associated with graft failure in patients receiving SFSGs. (Results) The graft survival of the patients without SFSGs (n=212) and those receiving SFSGs (n=13) was 93.4% and 76.9%, respectively (p<0.005). The univariate analysis showed that the model for end-stage liver disease (MELD) score to be an independent risk factor for graft failure among the patients receiving SFSGs (p=0.014). The preoperative MELD scores were significantly higher in the graft failure group than in the survival group (22.3±11.0 vs 10.6±2.3). According to the receiver operative characteristic analysis of the recipient survival and preoperative MELD scores, the area under the curve was 0.767 and the cut-off value for the MELD score was 15. The cause of graft failure was bacterial infections in all three recipients, and the timing of graft failure occurred at a median of 70 days postoperatively (14-88 days). (Conclusions) Pediatric LDLT using SFSGs is associated with poor outcomes and prognoses, especially in patients with a preoperative MELD score of more than 15.