Impact of CRRT on graft outcomes in kidney transplantation from deceased donors with severe acute kidney injury

Kidney transplantation (KT) is the preferred treatment for end-stage renal disease. However, challenges arise when using kidneys from deceased donors (DDs) with severe acute kidney injury (AKI). This study investigated the impact of continuous renal replacement therapy (CRRT) on graft outcomes in recipients of kidneys from DDs classified as acute kidney injury network (AKIN) stage 2 or 3. A retrospective analysis was conducted on patients who received kidneys from DDs managed at Korea University Anam and Guro Hospital between 2010 and 2020. Recipients were included if the donor had AKIN stage ≥ 2 AKI. They were categorized into three groups: AKIN 2, AKIN 3 without CRRT, and AKIN 3 with CRRT. Clinical characteristics and transplant outcomes, including delayed graft function (DGF), DGF duration, number of hemodialysis (HD) sessions, biopsy-proven acute rejection (BPAR), and graft survival, were compared among groups. During the study period, a total of 219 DDs were managed at our centers. Among them, 81 donors met the criteria for AKIN stage ≥ 2. From these donors, 81 recipients underwent KT, including 29 recipients who received kidneys from CRRT-treated donors. The incidence of DGF was the highest in the CRRT group (51.7%, P = 0.001). The CRRT group also required more HD sessions during the DGF period (2.6 ± 3.6 sessions vs. 1.6 ± 3.9 sessions, P = 0.001), although the CRRT group had a numerically shorter DGF duration than the non-CRRT AKIN 3 group (11.5 ± 6.9 days vs. 14.2 ± 8.7 days). The number of HD sessions was greater in the CRRT group, suggesting a more proactive perioperative support approach. BPAR rates were not significantly different across groups. One-year graft failure occurred in 5.0%, 3.1%, and 6.9% of recipients in AKIN 2, AKIN 3 non-CRRT, and AKIN 3 CRRT groups, respectively. Death-censored graft loss did not occur in any groups. Although CRRT was associated with a higher incidence of DGF, it might facilitate earlier recovery of graft function in recipients of kidneys from DDs with severe AKI. These findings support the use of kidneys from CRRT-treated donors, highlighting their potential to expand the donor pool without compromising one-year graft outcomes.