Hypothermic Machine Perfusion of Kidneys Compensates for Extended Storage Time: A Single Intervention With a Significant Impact.

Introduction: Delayed graft function (DGF) adversely affects graft survival and function. Machine perfusion (MP) improves DGF rate and may compensate for extended storage time.

Material And Methods: In this single-center cohort study, we included 193 consecutive kidney transplantations. MP was used in 78 kidneys (36%) and static cold storage (CS) in 115 kidneys (64%). CS kidneys were transplanted first followed by MP kidneys if stored differently. Pairs of kidneys from the same donor were subjected for subgroup analysis and included 58 pairs. The primary endpoints were the rate of DGF and 1- and 5-year graft survival. The secondary endpoints were the rate of the primary nonfunction, mortality, acute rejection, duration of DGF, and 5-year estimated glomerular filtration rate.

Results: Median cold ischemia time (CIT) was significantly different between the MP and CS groups (24 vs 20 hours, P < .05). MP significantly reduced the rate of DGF (MP vs CS: 21.8% vs 42.6%, P < .05, odds ratio 0.34, 95% confidence interval 0.17-0.67) with no impact on overall 1- and 5-year survival rates. Storage method did not affect the duration of DGF, mortality rate, acute rejection, or the 5-year estimated glomerular filtration rate.

Conclusions: Hypothermic pulsatile MP significantly reduced the rate of DGF in kidneys transplanted with CIT equal to or longer than 12 hours. It is safe and may compensate for longer storage time.