Early Kidney Allograft Failure After Simultaneous Liver-kidney Transplantation: Evidence for Utilization of the Safety Net?

Background: With the implementation of the "Safety Net," we aimed to determine the impact of simultaneous liver-kidney transplantation (SLKT), as compared to kidney transplant after liver transplant (KALT), on kidney allograft failure (KF).

Methods: An analysis of the UNOS database for all adult patients who received either an SLKT or KALT from 2002 to 2017. The outcomes were 90-day KF and 1-year KF (as reported to UNOS, at 90- and 365-day postkidney transplant, respectively). We compared the following groups of patients: SLKT <25 (SLKT with final model for end-stage liver disease [MELD] <25), SLKT25/35 (MELD ≥25/<35), and SLKT35 (MELD ≥35) to KALT.

Results: Of the 6276 patients, there were 1481 KALT, 1579 SLKT <25, 1832 SLKT25/35, and 1384 SLKT ≥35. The proportion of patients with 90-day and 1-year KF increased significantly among the KALT, SLKT <25, SLKT25/35, and SLKT ≥35 groups (P < 0.001; test for trend): 90-day KF: 3.3% versus 5.5% versus 7.3% versus 9.3% and 1-year KF: 5.1% versus 9.4% versus 12.3% versus 14.7%. After adjustment and compared with KALT, beginning at an MELD ≥25 those undergoing SLKT had significantly higher risk of 90-day and 1-year KF: 90-day KF: SLKT25/35: hazard ratio, 1.6(1.0-2.3); SLKT ≥35: 2.1(1.3-3.3); 1-year KF: SLKT25/35: hazard ratio, 1.7(1.2-2.4); SLKT ≥35: 2.1(1.5-3.0).

Conclusions: As compared to KALT recipients, SLKT recipients with an MELD ≥25 had significantly higher risk of early KF. Given the now well-established "Safety Net," KALT may serve as an opportunity to improve kidney outcomes in patients with an MELD ≥25.