Survival outcomes in adult recipients using pediatric deceased donor liver grafts. A PSM analysis from the OPTN/UNOS liver transplant registry

The use of pediatric donor grafts in adult recipients is a viable option to help address persistent organ shortages. Existing data is inconclusive regarding outcomes of pediatric-to-adult liver transplantation. Using the UNOS-STAR database, adults receiving a whole liver graft in the US between 2010 and 2019 were retrospectively identified. Patients were divided into two groups depending on whether they received a graft from a pediatric-donor (≤12y) or an adult-donor (≥18y). The groups were further matched using propensity-score matching (PSM) in a 1:1 ratio. Liver grafts disposition trends from pediatric donors ≤12y, as well as usage patterns of these grafts for adult recipients across UNOS regions were analyzed. The primary outcomes of this study were graft and patient survival. Secondary outcomes included LOS and need for re-transplantation. There were 4,798 deceased donors ≤12 years during the study period. Of those, 3476 liver grafts were recovered for transplant, 203/3,476 were discarded and 3,273/3,476 transplanted. Twenty percent of those recipients were adults ≥18y. PSM created a cohort of 642 patients, (pediatric-donor group n = 321, adult-donor group n = 321). Survival analyses revealed no difference in graft survival (p = 0.64) or overall patient survival (p = 0.74) between pediatric-donor and adult-donor groups. Likewise, secondary outcomes were comparable between groups. Although not statistically significant, adults in the pediatric-donor group showed a trend toward higher rates of re-transplantation (4.4%) vs those in the adult-donor group (1.9%) (p = 0.07). A subgroup PSM analysis including only recipients with MELD score >18 further demonstrated comparable results including similar LOS, re-transplantation rates, graft failure (log-rank p-value = 0.57) and patient mortality (log rank p-value = 0.38). Pediatric-to-adult liver transplantation could represent a safe and effective option in the event that a pediatric graft is available and declined by all potential pediatric recipients, particularly if performed under careful patient selection, and in centers with pediatric liver transplant and/or LDLT. Our results are in favor of utilizing pediatric-donor livers in adult patients since there is no significant difference in mortality or graft survival and could potentially increase organ utilization by avoiding discard of these grafts.