Therapeutic hypothermia not as good as machine perfusion for Kidney Transplant: NEJM

Researchers have found in a new study that therapeutic hypothermia was less effective than device perfusion of the kidney in minimizing delayed graft function in brain-dead organ donors.In other words therapeutic hypothermia of donors didn't preserve kidney function as well as machine perfusion of the organ during cold storage.

The research was  published in The New England Journal of Medicine.

The delayed graft function in kidney recipients following transplantation has been found to be decreased by therapeutic hypothermia in brain-dead organ donors. Data are required to compare hypothermia and machine perfusion's effects on outcomes following kidney transplantation. In order to test their idea, Darren Malinoski and his team undertook this investigation.

Researchers randomly assigned brain-dead kidney donors at six American organ procurement institutions to receive therapeutic hypothermia (hypothermia group), ex situ renal hypothermic machine perfusion (which is considered as machine-perfusion group), or both (combination-therapy group). Delay in graft function in kidney transplant patients was the main result (defined as the initiation of dialysis during the first 7 days after transplantation). Additionally, they assessed whether combining the two techniques was more effective than either of the separate treatments and if hypothermia alone was noninferior to machine perfusion alone. One year after the transplant, graft survival was one of the secondary outcomes.

The key findings of this study were:

1349 kidneys were donated from the 725 enrolled donors: 359 kidneys underwent hypothermia, 511 had machine perfusion, and 479 underwent combination treatment. 

In the hypothermia group, 109 patients (30%), the machine-perfusion group, 99 patients (19%), and the combination treatment group, 103 patients (22%) all experienced delayed graft function. 

In comparison to machine perfusion, hypothermia had an adjusted risk ratio for delayed graft function of 1.72, combination treatment had an adjusted risk ratio of 1.09, and hypothermia had an adjusted risk ratio of 1.57. 

The incidence of graft survival at one year was comparable across the three groups. 

10 negative events in total were noted, including cardiovascular instability in 9 donors and organ loss in 1 donor as a result of a perfusion issue.

In conclusion, hypothermia and mechanical perfusion did not offer any further protection.

Reference: 

 Malinoski, D., Saunders, C., Swain, S., Groat, T., Wood, P. R., Reese, J., Nelson, R., Prinz, J., Kishish, K., Van De Walker, C., Geraghty, P. J., Broglio, K., & Niemann, C. U. (2023). Hypothermia or Machine Perfusion in Kidney Donors. In New England Journal of Medicine (Vol. 388, Issue 5, pp. 418–426). Massachusetts Medical Society. https://doi.org/10.1056/nejmoa2118265