Does Normothermic Machine Perfusion Still Provide an Advantage for Deceased Donor Kidney Transplantation? A Systematic Review and Preliminary Meta-Analysis.

Background: Patients with end-stage renal disease often face prolonged waiting times for kidney transplants. Historically, the use of marginal kidneys was limited due to suboptimal preservation methods. Normothermic machine perfusion (NMP) preserves physiological activity during the preservation process, potentially improving graft function and viability, expanding the use of marginal kidneys. While preliminary results are promising, NMP has not yet undergone sufficient clinical trials to determine whether it offers advantages over more widely used techniques. The aim of this systematic review is to assess several outcomes between kidneys that underwent NMP compared to traditional preservation methods after kidney transplant.

Methods: A systematic review was conducted following PRISMA guidelines. Randomized controlled trials, case series, and studies comparing NMP with hypothermic machine perfusion (HMP) or static cold storage (SCS) were included. The primary outcome assessed was delayed graft function (DGF). Secondary outcomes included primary non-function (PNF), acute rejection, and 1-year graft survival.

Results: Eight NMP studies met the inclusion criteria. Meta-analysis showed significant differences in DGF between NMP and control (HMP or SCS) groups (OR: 0.47 [0.22, 0.99], p < 0.05). There were no significant differences between NMP and controls for PNF, acute rejection, or 1-year graft survival.

Conclusions: These findings suggest that NMP yields similar adverse outcome rates compared to traditional methods. Notably, NMP could be associated with reduced rates of DGF. While NMP is a promising technique for renal allograft preservation, further randomized controlled trials are necessary to definitively establish its benefits over conventional preservation methods.