Hypothermic Ex Vivo Perfusion: Protecting the Donor Heart and the Recipient.

We congratulate McLeod et al1 on their study demonstrating successful preservation of hearts for 72 hours utilizing normothermic ex vivo perfusion (NEVP) and plasma cross-circulation, using a live para-corporeal donor sheep. This is a great achievement, because heart preservation was well beyond current clinical storage time limits. However, although the authors note future plans to simplify, the preservation method could be considered methodologically challenging. Additionally, the clinical relevance is somewhat difficult to determine, because of the absence of donor brain death (BD) and related sequelae, well reported to impair organ function.