Time of Cold Storage Prior to Start of Hypothermic Machine Perfusion and Its Influence on Graft Survival

Hypothermic machine perfusion (HMP) has become a standard method of preservation for kidneys procured from expanded-criteria donors and donors after cardiac death. There are different systems and approaches to the HMP preservation period, with cold storage prior to HMP sometimes taking several hours. This study evaluated whether the time at which kidneys receive HMP had any influence on the outcomes of kidney transplantation.

In this analysis, patient and graft survival were evaluated over a 1-year post-transplantation period. Patients who received HMP kidneys (n = 379) were divided into 2 groups: those who received kidneys with a cold ischemia time (CIT) prior to HMP <295 minutes (group G1; n = 254) and those who received kidneys with CIT prior to HMP >295 minutes (group G2; n = 125).

Delayed graft function was observed in 31.8% (81/254) of patients in group G1 vs 46.4% (58/125) of patients in group G2 (P = .007). One-year graft survival was statistically higher in the group G1 (93.2%; 233/254) vs group G2 (86.5%; 105/125, P = .029). Mean 1-year estimated glomerular filtration rate was significantly better in the group G1.

In conclusion, introduction of HMP up to 295 minutes from procurement led to better early and 1-year graft results. Kidneys should receive HMP as soon as possible after retrieval, preferably during procurement.