A systematic review and network meta-analysis of preservation techniques of donor kidneys

Kidney transplantation is the preferred treatment for end-stage renal disease, but there is no consensus on the best method for preserving donor kidneys to ensure graft function. This network meta-analysis was conducted to compare the impact of various preservation strategies on the incidence of delayed graft function.

PubMed, Cochrane, EMBASE, and Web of Science were thoroughly searched up to October 2024 for randomized clinical trials comparing different kidney preservation techniques based on predefined criteria. Study quality was appraised via the Cochrane Risk of Bias tool (2.0). Delayed graft function was reported as risk ratios with 95% credible intervals. Surface under the cumulative ranking curve values were leveraged to rank preservation strategies.

Twenty randomized clinical trials involving 6,790 recipients were included. Hypothermia + hypothermic machine perfusion (surface under the cumulative ranking curve, 84.60%), hypothermic machine perfusion (surface under the cumulative ranking curve, 80.85%), and static cold storage + hypothermic machine perfusion (surface under the cumulative ranking curve, 76.46%) were the top 3 preservation strategies for reducing delayed graft function. Subgroup analysis on the basis of donor age, cold ischemia time, and kidney donor sources revealed that hypothermic machine perfusion was the most effective preservation to reduce delayed graft function for donors <55 years, cold ischemia time <15 hours, and donation after cardiac death donors, whereas hypothermia + hypothermic machine perfusion was optimal for donors ≥55 years, cold ischemia time ≥15 hours, and donation after brain death donors.

Hypothermia + hypothermic machine perfusion most effectively reduces delayed graft function, particularly for older donors, longer cold ischemia time, and donation after brain death donors. Donor hypothermia before organ retrieval may offer additional benefits. However, further large-scale, high-quality randomized clinical trials are warranted to substantiate these findings.