Mazariegos, George

Background. The adoption of technical variant grafts has expanded the donor pool for pediatric liver transplantation, but it also poses a risk of portal vein thrombosis (PVT). This study evaluated risk and prognostic factors of PVT in children undergoing liver transplantation with technical variant grafts. Methods. A total of 3137 pediatric patients from 19 centers were included: 470 received split/reduced deceased donor grafts and 2667 received living donor grafts. Multivariable logistic regression was used to identify risk factors, whereas time-dependent Cox models were used to assess the impact on survival. Results. PVT occurred in 102 patients (3.3%) and was associated with increased mortality (adjusted hazard ratio, 2.86; 95% confidence interval [CI], 1.13-7.25; P = 0.027) and graft loss (adjusted hazard ratio, 9.97; 95% CI, 4.90-20.3; P < 0.001). Risk factors included younger age, lower weight, higher Pediatric End-Stage Liver Disease score, longer cold ischemia and operation times, higher graft-to-recipient weight ratio, increased red blood cell transfusions, and biliary atresia. After adjusting for center, lower weight (odds ratio, 0.84 per kg; 95% CI, 0.71-1.00; P = 0.047) and biliary atresia (odds ratio, 2.34; 95% CI, 1.10-5.00; P = 0.027) remained predictors. Five-year patient (88.4% versus 93.1%) and graft survival (82.7% versus 96.3%) were significantly inferior in patients with PVT. Conclusions. Low-weight children with biliary atresia constituted a high-risk group, highlighting the necessity for early detection and management.

ABSTRACT Background The Society of Pediatric Liver Transplantation (SPLIT) has undergone tremendous growth with > 45 sites contributing data focusing on improving outcomes in pediatric liver transplantation (LT). We report and compare outcomes from the SPLIT Registry. Methods Patients < 18 years with first‐time LT only enrolled into the SPLIT Registry between 2011 and 2023 were included. Data was stratified into eras from the last published registry update (era 1: 2011–2018, era 2: 2018–2023). Results Three thousand five hundred four participants from 47 centers were included (era 1: n = 2159; era 2: n = 1345). Age distribution differed with more children < 1 year. of age at LT in era 2 (era 1: 29% vs. era 2: 33%, p = 0.01). Indications for LT were similar, with biliary atresia (38.8%) and metabolic disease (16.0%) being most common. Exception point use was higher in era 2 (era 1: 45% vs. era 2: 56%, p < 0.001). No difference in graft type (deceased: 81% era 1 vs. 78% era 2, p = 0.78), patient survival at 90 days (era 1: 98.7% vs. era 2: 98.3%), 1 year (era 1: 97.2 vs. era 2: 96.8%), or 3 years (era 1: 95.3% vs. era 2: 95.2%) was noted. Rate of hepatic artery thrombosis was lower in era 2 (era 1: 7% vs. era 2: 5%, p = 0.02). Conclusions Trends in pediatric LT within SPLIT note similar LT indications and graft type, higher utilization of exception points, and lower HAT rates despite transplanting more children < 10 kg. This data underscores the evolution of pediatric LT toward higher survivability and overall patient outcomes.

Background. In December 2018, United Network for Organ Sharing approved an allocation scheme based on recipients’ geographic distance from a deceased donor (acuity circles [ACs]). Previous analyses suggested that ACs would reduce waitlist mortality overall, but their impact on pediatric subgroups was not considered. Methods. We applied Scientific Registry of Transplant Recipients data from 2011 to 2016 toward the Liver Simulated Allocation Model to compare outcomes by age and illness severity for the United Network for Organ Sharing–approved AC and the existing donor service area–/region-based allocation schemes. Means from each allocation scheme were compared using matched-pairs t tests. Results. During a 3-year period, AC allocation is projected to decrease waitlist deaths in infants (39 versus 55; P < 0.001), children (32 versus 50; P < 0.001), and teenagers (15 versus 25; P < 0.001). AC allocation would increase the number of transplants in infants (707 versus 560; P < 0.001), children (677 versus 547; P < 0.001), and teenagers (404 versus 248; P < 0.001). AC allocation led to decreased median pediatric end-stage liver disease/model for end-stage liver disease at transplant for infants (29 versus 30; P = 0.01), children (26 versus 29; P < 0.001), and teenagers (26 versus 31; P < 0.001). Additionally, AC allocation would lead to fewer transplants in status 1B in children (97 versus 103; P = 0.006) but not infants or teenagers. With AC allocation, 77% of pediatric donor organs would be allocated to pediatric candidates, compared to only 46% in donor service area–/region-based allocation (P < 0.001). Conclusions. AC allocation will likely address disparities for pediatric liver transplant candidates and recipients by increasing transplants and decreasing waitlist mortality. It is more consistent with federally mandated requirements for organ allocation.