Title: Advantages of Normothermic regional perfusion (NRP) to launch a donation after circulatory death (DCD) heart transplantation program
Abstract:
DCD donors represent a valuable resource and have demonstrated its potential to revolutionize the rates of heart transplantation programs in UK. The same trend is starting to be perceived in big transplant centers in USA.
In counterpart, it requires a significant increase in cost and resource utilization, which may limit its utilization to financially strong transplant centres potentially causing disparities in the access for recipients.
Compared with DBD hearts, DCD hearts have been exposed to the additional insult of warm ischemia and distension before and after mechanical cardiac arrest, implicating an important additional challenge in the assessment of these hearts.
There are two methods of retrieval and evaluation of a DCD heart function: a direct procurement and connection to the perfusion machine, or the in-situ reconditioning of the heart in the donor after the circulatory death (NRP) and subsequent arrest, retrieval, and connection to the perfusion device.
To transport and simultaneously maintain an adequate preservation of a procured DCD heart to a distant hospital, it is highly recommended the use of a perfusion machine to keep the organ perfused at normothermia and contracting. The use of ice to preserve hearts after reconditioning with NRP, although it has been utilized by a few centers to decrease costs, is limited to young donors and short transport times, and the results need still to be determined.
There is strong experimental evidence to support DCD heart transplantation.
NRP has been proven effective for the first time by Papworth Hospital team in Cambridge, UK, in 2007. It was demonstrated that the heart of an adult human DCD donor subjected to 23 min of warm ischemia following cardiorespiratory arrest could be reconditioned by placing the donor on extracorporeal perfusion. Following reperfusion, the heart recovered sufficiently to independently support the donor circulation and was weaned off extracorporeal perfusion successfully. However, this heart was not transplanted as the necessary approval and consent for DCD heart donation were not in place at the time.
NRP has substantial advantages over direct procurement: the heart is assessed in situ by transesophageal echo and measurement of filling pressures and cardiac index, and its capacity to support the circulation can be effectively evaluated in an equivalent way as a post-cardiotomy surgical case with cardiopulmonary bypass. If the heart exhibits satisfactory function off bypass, it implies an extra reassurance compared with an organ that is assessed only on the perfusion machine, which is contracting but not pumping under physiological conditions.
Conclusion:
DCD Heart transplantation has been established as an effective tool to significantly increase the donor pool in Heart Transplantation, with a potential of 40% increase or even more if increase in donor age tolerance may be considered in the future.
The advantages of NRP are obviously related to the functional assessment of the organ in situ in the donor. The disadvantage is the increase in costs, resources, and number of team members needed for the procedure.
Biography:
Dr Knop is a Cardiovascular Surgeon at Mayo Clinic, Rochester. He has been a Consultant Cardiothoracic Surgeon in UK and Argentina. He is the main author in publications in reputed journals like the J. of Th and CV Surgery, J. of CTH Surgery, among others. He also served as an Editorial Board member in two journals, Reviewer of Medical Journals, and co-Investigator in the EXCEL and ERICCA study. He was a Lecturer at the University of Cordoba and University of the South in Argentina. His published material served as a reference from other researchers in professional publications in the academic field. He was the speaker in prestigious Symposiums.
He graduated with honours at the University of Buenos Aires.
