|Year : 2009 | Volume
| Issue : 4 | Page : 562-563
Deceased donor kidney transplantation: Machine perfusion versus cold storage
TJ Nirmal, Samiran Adhikary
Department of Urology, Christian Medical College, Vellore, India
|Date of Web Publication||30-Nov-2009|
T J Nirmal
Department of Urology, Christian Medical College, Vellore
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Nirmal T J, Adhikary S. Deceased donor kidney transplantation: Machine perfusion versus cold storage. Indian J Urol 2009;25:562-3
Moers C, Smits JM, Maathuis MH, Treckmann J, van Gelder F, Napieralski BP, van Kasterop-Kutz M, van der Heide JJ, Squifflet JP, van Heurn E, Kirste GR, Rahmel A, Leuvenink HG, Paul A, Pirenne J, Ploeg RJ. Machine perfusion or cold storage in deceased-donor kidney transplantation. N Engl J Med. 2009 Jan 1;360(1):7-19.
| Summary|| |
The aim of this multicentric, prospective, controlled trial was to assess whether machine perfusion or static cold storage was better for preserving kidney allografts from deceased donors.  The authors randomly assigned one kidney from 336 consecutive deceased donors to either machine perfusion or static cold storage preservation. In 25 donors (4.6%), preservation methods were switched because of aberrant vascular anatomy of the kidney assigned to machine perfusion.
Organ donors were 16 years of age or older and consisted of either donation after brain death (DBD, 87.5%) or Maastricht category III donation after cardiac death (DCD, 12.5%) donors. The LifePort Kidney Transporter device was used for machine perfusion. Kidney pairs were included only if both kidneys were actually transplanted as kidney-only transplants into two different recipients, and both recipients survived at least one week after transplantation. All 672 recipients were followed up for one year.
Mean cold ischemia times were 15.0 hours in each group. The incidence of delayed graft function (DGF) was 20.8% with machine perfusion compared to 26.5% with cold storage preservation (adjusted odds ratio = 0.57, P = 0.01). The incidence of functional DGF was 22.9% with machine perfusion compared to 30.1% with cold storage preservation (P = 0.03). The comparative incidence of primary nonfunction (2.1% machine perfusion vs. 4.8% cold storage, P = 0.08) did not reach statistical significance. The duration of DGF was three days shorter with machine perfusion (10 vs. 13 days with cold storage, P = 0.04). The magnitude of the above effects was similar for DBD, DCD, and expanded criteria donors (ECD). Daily serum creatinine levels in the first two weeks post transplant were significantly lower in the machine perfusion group, but two-week creatinine clearance values were no different according to method of preservation.
The one-year kidney graft survival rate was significantly greater in the machine perfusion group (94 vs. 90%, P = 0.04). In the first year after transplantation, machine perfusion significantly reduced the risk for graft failure (hazard ratio 0.52, P = 0.03), whereas the presence of DGF increased the risk for graft failure (hazard ratio 1.69, P < 0.001). No differences were noted in patient survival, length of hospital stay, acute rejection, or calcineurin inhibitor toxicity between the two groups.
The authors concluded that machine perfusion appears to be a superior method of preservation regardless of deceased donor category, based on a lower incidence and shorter duration of DGF and improved one-year graft survival when compared to static cold storage.
| Comments|| |
Methods of clinically preserving kidneys were developed during the late 1960s by Belzer, who used continuous hypothermic machine perfusion,  and by Collins, who introduced a cold solution for flushing and storage (cold storage) of the kidney 
There have been numerous previous studies directly comparing static cold storage to machine perfusion preservation, particularly with standard criteria DBD donor kidneys with cold ischemia times of 24 hours or less, which suggest that neither preservation technique was associated with a clinical advantage. However, recent reports have suggested that machine perfusion may lower the risk for DGF in ECD kidneys. ,
The above report by Moers et al. is the largest prospective randomized study till date that addresses this issue. The strength of this study lies in the 'paired donor kidney study design' which eliminates donor factors as an explanation for the subsequent differences in clinical outcomes.
However, approximately half the numbers of kidneys considered for entry into the study were excluded for one reason or another, suggesting a bias toward 'better' donors. Kidneys with multiple vessels which were considered too difficult to store using machine perfusion were switched to the cold storage group, therefore making 'randomization' questionable. Kidneys with multiple vessels are known to have a higher incidence of DGF; therefore, this is likely to have skewed the results against cold storage.
Preliminary results from another ongoing prospective trial "The PPART study" reported no statistically significant differences between machine perfusion and cold storage at three-month follow up.  However, this study demonstrates a significant decline in graft loss at one year for kidneys preserved by machine perfusion. Whether this improvement in short-term graft survival will translate into a long-term benefit is unknown.
Another important lacuna in the study was the unavailability of an economic analysis in terms of cost per quality adjusted life year or cost per DGF avoided. Whether benefits of machine perfusion translate into cost-effectiveness remain unanswered. The National Institute for Health and Clinical Excellence recommends that the choice of storage method should be based on the expertise and equipment available to the teams collecting the kidney, how the teams are organized, and the distances involved. If more than one of the storage methods is equally suitable the least costly should be used. 
Ultimately, understanding the factors that mitigate ischemia-reperfusion injury and longer follow-up are necessary to fully delineate the benefits of, and risks for, various preservation techniques in deceased donor kidney transplantation.
| References|| |
|1.||Moers C, Smits JM, Maathuis MH, Treckmann J, van Gelder F, Napieralski BP, et al. Machine perfusion or cold storage in deceased-donor kidney transplantation. N Engl J Med 2009;360:7-19. |
|2.||Belzer FO, Ashby BS, Dunphy JE. 24-hour and 72-hour preservation of canine kidneys. Lancet 1967;2:536. |
|3.||Collins GM, Bravo-Shugarman M, Terasaki PI. Kidney preservation for transplantation. Initial perfusion and 30 hours' ice storage. Lancet 1969;2:1219. |
|4.||Schold JD, Kaplan B, Howard RJ, Reed AI, Foley DP, Meier-Kriesche HU. Are we frozen in time? Analysis of the utilization and efficacy of pulsatile perfusion in renal transplantation. Am J Transplant 2005;5:1681-8. |
|5.||Wight JP, Chilcott JB, Holmes MW, Brewer N. Pulsatile machine perfusion vs. cold storage of kidneys for transplantation: a rapid and systematic review. Clin Transplant 2003;17:293-307. |
|6.||Machine perfusion systems and cold static storage of kidneys from deceased donors. NICE technology appraisal guidance 165. Jan 2009. |