Association of balanced abdominal organ transplant center volumes with patient outcomes.

Abstract

The volume-outcome relationship for organ-specific transplantation is well-described; it is unknown if the relative balance of kidney compared with liver volumes within an institution relates to organ-specific outcomes. We assessed the association between relative balance within a transplant center and outcomes. National retrospective analysis of isolated kidney and liver transplants in United States 2005-2014 followed through 2019. Latent class analysis defined transplant center phenotypes. Multivariate Cox models estimated death-censored graft loss and mortality. Latent class analysis identified four phenotypes: kidney only (n=117), kidney dominant (n=36), mixed/balanced (n=90), and liver dominant (n=13). Compared to mixed centers, the risk of kidney graft loss was higher at kidney-dominant (HR 1.07, p<.001) and liver-dominant (HR 1.10, p<.001) centers, while kidney-only (HR 1.06, p=.01) centers had higher mortality. Liver graft loss was not associated with phenotype, but risk of patient death was lower (HR 0.93, p=.02) at liver dominant and higher (HR 1.06, p=.02) at kidney-dominant centers. A mixed phenotype was associated with improved kidney transplant outcomes, whereas liver transplant outcomes were best at liver-dominant centers. While these findings need to be verified with center-level resources, optimization of shared resources could improve patient and organ outcomes.