Combined Ex Vivo Hypothermic and Normothermic Perfusion for Assessment of High-Risk Deceased Donor Human Kidneys for Transplantation.

BACKGROUND: Despite careful clinical examination, procurement biopsy and assessment on hypothermic machine perfusion (HMP), a significant number of potentially useable deceased donor kidneys will be discarded because they are deemed unsuitable for transplantation. Ex vivo normothermic perfusion (EVNP) may be useful as a means to further assess high-risk kidneys to determine suitability for transplantation.

METHODS: From June 2014 to October 2015, 7 kidneys (mean donor age 54.3 years and KDPI 79%) that were initially procured with the intention to transplant were discarded based on a combination of clinical findings, suboptimal biopsies, long cold ischemia time and/or poor hypothermic perfusion parameters. They were subsequently placed on EVNP using oxygenated packed red blood cells and supplemental nutrition for a period of 3 hours. Continuous hemodynamic and functional parameters were assessed.

RESULTS: After a mean cold ischemia time (CIT) of 43.7 hours, all 7 kidneys appeared viable on EVNP with progressively increasing renal blood flow over the 3-hour period of perfusion. Five of the 7 kidneys had excellent macroscopic appearance, rapid increase in blood flow to 200-250 ml/min, urine output of 40-260 ml/hr and increasing creatinine clearance.

CONCLUSIONS: Favorable perfusion characteristics and immediate function after a 3 hour course of EVNP suggests that high-risk kidneys subjected to long CIT may have been considered for transplantation. The combined use of ex vivo hypothermic and normothermic perfusion may be a useful strategy to more adequately assess and preserve high-risk kidneys deemed unsuitable for transplantation. A clinical trial will be necessary to validate the usefulness of this approach.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.