Gunnar Tufveson, et al. (Uppsala University Hospital, S-751 85 Uppsala Sweden)
Machine perfusion of deceased donor kidneys has been shown to improve graft performance. The randomised European multicentre trial published in the New England Journal of Medicine clearly proved the beneficial effect of machine-perfusion on delayed graft function. Furthermore, delayed graft function has also been associated with less favourable long-term outcomes in renal transplantation. In the Uppsala University Hospital, machine perfusion of all deceased donor kidneys started in 2011. As part of the centre’s initial experience with machine perfusion, the team have carried out a comparative study evaluating the rate of delayed graft function of machine-perfused kidneys with non-perfused kidneys.
The catchment area for the four renal transplant centres in Sweden is predetermined. The Uppsala University Hospital catchment area consists of approximately two million inhabitants with a donor rate of between 15 and 20 donors per million population. As a result, the centre could machine perfuse between 60 and 80 kidneys each year. The average age of these donors is between 55 and 60 years, which in some institutions would be termed marginal donors. This is not a classification the Uppsala University Hospital entirely agrees with as they acknowledge only two types of grafts: those that are transplantable and those that are not. However, to judge whether an organ is transplantable or not, there is a need to gather as much information on the quality of the organ as possible. Machine perfusion can help achieve this.
The Nordic decentralised organ allocation system (administered by the local exchange organisation Scandiatransplant) allows the centre to keep 9 out of 10 donor kidneys retrieved, which in turn usually leads to a very good follow-up of the organs used. This retrieval work is shared alongside the Karolinska Hospital in Stockholm, which also has a catchment area of two million inhabitants.
The decision to use machine perfusion routinely in Uppsala University Hospital was based on the proven beneficial effect of reducing delayed graft function, the team’s knowledge of the perfusion system and the “hands on” process for both the retrieval and allocation of donor organs. The team was also aware that whilst the donor kidneys were being perfused, it would allow more time for adequate cross matching, etcetera.
As part of the centre’s initial experience with machine perfusion, the team have carried out a comparative study evaluating the rate of delayed graft function of machine-perfused kidneys with non-perfused kidneys. The non-perfused group comprised of consecutive kidneys transplanted in the centre prior to the introduction of the perfusion machines.
The results of this preliminary study are summarised below:
|Treatment||Cold-Stored (N-77)||Machine Perfused (N=39)|
|Cold ischaemia time (h)||12±4||16±4|
|Delayed graft function (%)||22||13|
|Delayed graft function in
expanded criteria donors (%)
|Hospital stay (days)||17±1||13±1|
|Creatinine at discharge (µmol/L)||166±17||118±17|
|BPAR at any time (%)||42||38|
These results show a substantial decrease in serum creatinine levels at discharge, a reduced percentage of delayed graft function in both standard and expanded criteria donor populations and a shorter hospital stay for the machine-perfused kidney recipients. Although a few handling issues were encountered at the start of the study, mainly related with fittings to the aortic patch, further hands-on experience with the machine led to the transplant team encountering no further technical issues.
Having proven their use within a clinical setting, the centre’s perfusion machines are aiding current research into the identification of surrogate markers of ischemia-reperfusion injuries within porcine renal transplant models.
1. Moers C et al. Machine perfusion or cold storage in deceased-donor kidney transplantation. N Engl J Med 2009;360:7–19.