Pulsatile machine perfusion vs. cold storage of kidneys for transplantation: a rapid and systematic review

: Objective: To identify and prioritize key areas for further research in kidney preservation systems. Materials and methods: We conducted a systematic review and meta‐analysis of the effectiveness of machine perfusion and cold storage techniques in reducing delayed graft function (DGF) and improving graft survival in recipients of kidneys from beating and non‐heart‐beating donors. Literature quantifying the link between DGF and graft survival was used to evaluate the potential long‐term impact of machine perfusion and cold storage systems. Cox proportional hazards modelling was used to predict graft survival and graft years gained over 10 yr. Monte Carlo sensitivity analysis was conducted to evaluate stochastic uncertainties within the model. Results: Machine perfusion leads to a relative risk of DGF of approximately 80% (67%, 96%) compared with cold storage, although the evidence base is limited in quality and study size. Direct evidence on graft survival at 1 yr demonstrates no statistically significant difference between machine perfusion and cold storage. Predictions based upon quantifying the link between DGF and graft survival suggest potential improvements of between 0 and 6% at 10 yr. Discussion: Studies of high methodological quality and sufficient size are required to determine whether machine preservation leads to reduce rates of DGF. Predicted impact on graft survival implies that direct evidence would require a large population followed up over a long period of time. Registry database analysis supported by validation of the link between DGF and graft survival may be preferable and more feasible than randomized controlled trials.