***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: In a r and omized trial conducted in 9 Ontario transplant centers , 107 cadaver kidney donors were r and omized so that both kidneys were preserved either by simple cold storage ( CS ) or by pulsatile perfusion ( PP ) . After exclusions and losses to follow-up , there were 90 patients in the CS group and 91 in the PP group . Total preservation times were similar in the two groups ( 27.7 + /- 12 and 30.5 + /- 10 hr ) , as was the proportion of kidneys with long ( greater than 36 hr ) storage times ( 21 % and 26 % ) . Twelve-month graft survival was 70 % for CS and 75 % for PP ( not significant , NS ) ; patient survival was 89 % for CS and 95 % for PP ( NS ) . The incidence of kidneys that never functioned was also similar in the two groups ( 14 % vs. 15 % , respectively ) . However , the risk of early , reversible graft dysfunction was significantly higher for CS ( 44 % ) than for PP ( 31 % ) . The same effect was observed with two independent methods of assessment of graft function . The chief effect of PP on renal function was in reduction of the mean serum creatinine at 1 week ( 632 mumol/L for CS vs. 403 mumol/L for PP , P less than .001 ) . There was no significant influence of storage mode on the rapidity of urine output or number of dialyses required . No apparent effect of cyclosporine on the results with either preservation method was seen . We conclude that the case for retention of PP for kidney preservation now rests on its ability to achieve slightly better initial function than CS . However , the mild dysfunction observed with CS did not appear to translate into long-term detriment . When these considerations are weighed against the increased cost of PP , the advantage may lie with cold storage Background . Retrospective evidence suggests that lactate dehydrogenase , aspartate aminotransferase , total glutathione-S-transferase ( GST ) , alanine-aminopeptidase , N-acetyl-&bgr;-d-glucosaminidase ( NAG ) , and heart-type fatty acid binding protein ( H-FABP ) measured during kidney machine perfusion ( MP ) could have predictive value for posttransplant outcome . However , these data may be biased due to organ discard based on biomarker measurements , and previous analyses were not adjusted for likely confounding factors . No reliable prospect i ve evidence has been available so far . Nevertheless , some centers already use these biomarkers to aid decisions on accepting or discarding a donor kidney . Methods . From 306 deceased-donor kidneys donated after brain death or controlled cardiac death and included in an international r and omized controlled trial , these six biomarkers were measured in the MP perfusate . In this unselected prospect i ve data set , we tested whether concentrations were associated with delayed graft function , primary nonfunction , and graft survival . Multivariate regression models investigated whether the biomarkers remained independent predictors when adjusted for relevant confounding factors . Results . GST , NAG , and H-FABP were independent predictors of delayed graft function but not of primary nonfunction and graft survival . Lactate dehydrogenase , aspartate aminotransferase , and alanine-aminopeptidase had no independent prognostic potential for any of the endpoints . Perfusate biomarker concentrations had no relevant correlation with cold ischemic time or renal vascular resistance on the pump . Conclusions . Increased GST , NAG , or H-FABP concentrations during MP are an indication to adjust posttransplant recipient management . However , this study shows for the first time that perfusate biomarker measurements should not lead to kidney discard Background Hypothermic machine perfusion ( HMP ) of deceased donor kidneys is associated with better outcome when compared to static cold storage ( CS ) . Nevertheless , there is little evidence whether kidneys with short cold ischemia time ( CIT ) also benefit from HMP and whether HMP can safely extend CIT . Methods We analyzed prospect ively collected data from the Machine Preservation Trial , an international r and omized controlled trial . Seven hundred fifty-two consecutive renal transplants were included : 1 kidney of each of the 376 donors was preserved by HMP , the contralateral organ was preserved by CS . Results The mean CIT was 3:05 PM ( SD , 4:58 AM ) . A subgroup analysis was performed , groups were based on CIT duration : 0 to 10 hours , 10 to 15 hours , 15 to 20 hours , or 20 hours or longer . Delayed graft function ( DGF ) incidence in the subgroup with up to 10 hours CIT was 6.0 % ( N = 3/50 ) in the HMP arm and 28.1 % ( N = 18/64 ) in the CS arm ( univariable P = 0.002 ; multivariable odds ratio [ OR ] , 0.02 ; P = 0.007 ) . Cold ischemia time remained an independent risk factor for DGF for machine perfused kidneys recovered from donation after brain death donors ( OR , 1.06 ; 95 % confidence interval [ CI ] , 1.017 - 1.117 ; P = 0.008 ) , donation after circulatory death donors ( OR , 1.13 ; 95 % CI , 1.035 - 1.233 ; P = 0.006 ) and exp and ed criteria donors ( OR , 1.14 ; 95 % CI , 1.057 - 1.236 ; P = 0.001 ) . Conclusions In conclusion , HMP result ed in remarkably lower rates of DGF in renal grafts that were transplanted after a short CIT . Also , CIT remained an independent risk factor for DGF in HMP-preserved kidneys The purpose of this study was to analyze the possible effects of machine perfusion ( MP ) versus cold storage ( CS ) on delayed graft function ( DGF ) and early graft survival in exp and ed criteria donor kidneys ( ECD ) . As part of the previously reported international r and omized controlled trial 91 consecutive heart-beating deceased ECDs -- defined according to the United Network of Organ Sharing definition -- were included in the study . From each donor one kidney was r and omized to MP and the contralateral kidney to CS . All recipients were followed for 1 year . The primary endpoint was DGF . Secondary endpoints included primary nonfunction and graft survival . DGF occurred in 27 patients in the CS group ( 29.7 % ) and in 20 patients in the MP group ( 22 % ) . Using the logistic regression model MP significantly reduced the risk of DGF compared with CS ( OR 0.460 , P=0.047 ) . The incidence of nonfunction in the CS group ( 12 % ) was four times higher than in the MP group ( 3 % ) ( P=0.04 ) . One-year graft survival was significantly higher in machine perfused kidneys compared with cold stored kidneys ( 92.3 % vs. 80.2 % , P=0.02 ) . In the present study , MP preservation clearly reduced the risk of DGF and improved 1-year graft survival and function in ECD kidneys . ( Current Controlled Trials number : IS RCT N83876362 ) BACKGROUND Owing to the shortage of donors , organs with an increased risk potential such as grafts recovered from exp and ed criteria donors are increasingly being used in transplants . Machine perfusion ( MP ) technology offers the possibility of determining the biomarkers in the perfusion solution so that conclusions might be drawn regarding the effectiveness of organ preservation and organ viability . METHODS All kidneys from the MP arm of our multicenter , r and omized , controlled trial of MP whose donors were aged 55 years or older were included in the present study . The biomarkers , total glutathione-S-transferase ( GST ) , α-GST , and π-GST and markers for lipid peroxidation and cell decay were determined in the MP perfusate and correlated with the outcomes after kidney transplantation . RESULTS A total of 111 machine perfused kidneys were included in the present study . The mean donor age was 64.1 ± 6.6 y.  The average cold ischemic time  was 13.8 ± 5.3 h. Total GST , α-GST , and lipid peroxidation markers were significantly elevated at the end of MP . However , according to the multivariate analysis , only the lipid peroxidation markers were independent predictors of delayed graft function after transplantation . CONCLUSIONS Our data suggest that routine determination of lipid peroxidation markers in the perfusate of exp and ed criteria donor kidneys can provide the opportunity to identify the kidneys that have sustained severe oxidative damage and should be excluded from transplantation . Additional analysis of a larger cohort with more primary nonfunction cases is needed to confirm these findings Organ shortage has led to an increased use of kidneys from cardiac death donors ( DCDs ) , but controversies about the methods of organ preservation still exist . This study aims to compare the effect of machine perfusion ( MP ) and cold storage ( CS ) in protecting kidneys harvested from DCDs . 141 kidney pairs from DCDs between July 2010 and July 2015 were included in this r and omized controlled study . One kidney from each donor was r and omly assigned to MP and the contralateral kidney was assigned to CS . Delayed graft function ( DGF ) rate , resistance index of renal arteries , early renal function , and survival rates were used to estimate the effect of preservation . The results showed that MP decreased the rate of DGF from 33.3 to 22.0 % ( P = 0.033 ) . Ultrasound of the kidneys within 48 h after transplantation showed that the resistance index of renal main artery ( 0.673 ± 0.063 vs. 0.793 ± 0.124 , P < 0.001 ) , sub segmental artery ( 0.66 ± 0.062 vs. 0.764 ± 0.077 , P < 0.001 ) and interlobular artery ( 0.648 ± 0.056 vs. 0.745 ± 0.111 , P = 0.023 ) were all significantly lower in the MP group than those in the CS group . Furthermore , compared to the CS group , in the first 7 days following transplantation , the median urine volume was significantly higher ( 4080 mL vs. 3000 mL , P = 0.047 ) in kidneys sustained using MP and the median serum creatinine was remarkably lower ( 180 µmol/L vs. 390 µmol/L , P = 0.024 ) . More importantly , MP group had higher 1- and 3-year graft survival rates ( 98 % vs. 93 % , P = 0.026 ; 93 % vs. 82 % , P = 0.036 , respectively  ) . Hypothermic MP improved the outcomes of DCD kidney transplantation To assess the application of a hypothermic machine perfusion device ( LifePort ) in kidney transplantation from donation after cardiac death ( DCD ) donors , 24 pairs of DCD kidneys were r and omly divided into two groups : one of the paired kidneys from the same donor was perfused with the LifePort machine ( hypothermic machine perfusion [ HMP ] ) , and the contralateral kidney was prepared using common static cold preservation ( CCP ) . The two groups were compared with respect to the incidence of delayed graft function ( DGF ) , level of graft function , and pathological changes in time-zero biopsy specimens . The incidence of DGF was 16.7 and 37.5 % in the HMP and CCP groups , respectively ; the difference between the two groups was statistically significant ( P < 0.05 ) . The incidence of acute rejection was 4.1 ( 1/24 ) and 8.3 % ( 2/24 ) in the HMP and CCP groups , respectively ; this difference was not statistically significant ( P > 0.05 ) . Forty-eight kidney patients were followed up for 6 months , and the two groups of recipients all survived , yielding a survival rate of 100 % . The mean 6-month serum creatinine levels were 98.7 ± 23.6 µmol/L in the HMP group and 105.3 ± 35.1 µmol/L in the CCP group ; there was no significant difference between the two groups . HMP can reduce the incidence of DGF in DCD kidneys , and this effect is greater for exp and ed criteria donors kidneys . HMP can also improve early renal function BACKGROUND Static cold storage is generally used to preserve kidney allografts from deceased donors .  Hypothermic machine perfusion may improve outcomes after transplantation , but few sufficiently powered prospect i ve studies have addressed this possibility . METHODS In this international r and omized , controlled trial , we r and omly assigned one kidney from 336 consecutive deceased donors to machine perfusion and the other to cold storage .  All 672 recipients were followed for 1 year . The primary end point was delayed graft function ( requiring dialysis in the first week after transplantation ) . Secondary end points were the duration of delayed graft function , delayed graft function defined by the rate of the decrease in the serum creatinine level , primary nonfunction , the serum creatinine level and clearance , acute rejection , toxicity of the calcineurin inhibitor , the length of hospital stay , 
    Output:
    
HMP is superior to SCS in deceased donor kidney transplantation .
This is true for both DBD and DCD kidneys , and remains true in the modern era ( studies performed in the last decade ) .