Outcomes and survival analysis of old-to-old simultaneous pancreas and kidney transplantation

Outcomes of old-donor simultaneous pancreas-kidney transplantation (SPKT) have not been thoroughly studied. Scientific Registry of Transplant Recipients data reported for SPKT candidates receiving dialysis wait-listed between 1993 and 2008 (n = 7937) were analyzed for outcomes among those who remained listed (n = 3301) and of SPKT recipients (n = 4636) using multivariable time-dependent regression models. Recipients were stratified by donor/recipient age (cutoff 40 years) into: young-to-young (n = 2099), young-to-old (n = 1873), old-to-young (n = 293), and old-to-old (n = 371). The overall mortality was 12%, 14%, 20%, and 24%, respectively, for those transplanted, and 50% for those remaining on the waiting list. On multivariable analysis, old-donor SPKT was associated with significantly higher overall risks of patient death, death-censored pancreas, and kidney graft failure in both young (73%, 53%, and 63% increased risk, respectively) and old (91%, 124%, and 85% increased risk, respectively) recipients. The adjusted relative mortality risk was similar for recipients of old-donor SPKT compared with wait-listed patients including those who subsequently received young-donor transplants (aHR 0.95; 95% CI 0.78, 1.12) except for candidates in OPOs with waiting times ≥604 days (aHR 0.65, 95% CI 0.45-0.94). Old-donor SPKT results in significantly worse graft survival and patient mortality without any waiting-time benefit as compared to young-donor SPKT, except for candidates with expected long waiting times.