Factors associated with discard of recovered kidneys

We reviewed diseased donor (DD) kidney usage at a single Organ Procurement Organization in Southern California to more closely examine factors associated with discard. From 2001 to 2006, 3863 kidneys from 1959 DDs were recovered, but 454 (11.8%) were subsequently discarded. Among the discarded kidneys, 211 (46.5%) were discarded based upon biopsy findings, 19 (4.2%) due to anatomical abnormalities, 16 (3.5%) based on donor quality, and 14 (3.1%) because they were felt to be too old to be pumped. Multivariate logistic regression analysis was performed using significant prognostic factors upon univariate analyses. According to the magnitude of the adjusted odds ratio (AOR), significant prognostic factors for discard were extreme donor age (AOR = 24.1 of age 70-80 years, P < .001; AOR = 6.34 age 50-69 years, P < .001; AOR = 2.77 age 40-49 years, P < .001; and AOR = 3.09 age <10 years, P < .001 vs age 10-39 years), high final resistance (AOR = 8.86 of >40 vs others, P = .006), glomerulosclerosis (GS) > 20% (AOR = 5.94 vs GS 0%-5%/no biopsy, P < .001), severe atherosclerosis (AOR = 4.66, P = .003), abnormal anatomy (AOR = 2.7, P < .001), and moderate or severe arteriolosclerosis (AOR = 2.2 vs none/mild/no biopsy, P < .001). Among biopsy findings, the presence of GS > 20% was associated with the highest likelihood of discard. A high final resistance increased the likelihood of discard as well. In conclusion, these findings may help to set the groundwork toward a more uniform approach to organ utilization in donor service areas.     

Outcomes and Utilization of Kidneys from Deceased Donors with Acute Kidney Injury

Utilization and long-term outcomes of kidneys from donors with elevated terminal serum creatinine (sCr) levels have not been reported. Using data from the Scientific Registry of Transplant Recipients from 1995 to 2007, recipient outcomes of kidneys from adult donors were evaluated stratified by standard criteria (SCD; n = 82 262) and expanded criteria (ECD; n = 16 978) donor type and by sCr ≤1.5, 1.6–2.0 and >2.0 mg/dL. Discard rates for SCDs were ascertained. The relative risk of graft loss was similar for recipients of SCD kidneys with sCr of 1.6–2.0 and >2.0 mg/dL, compared to ≤1.5 mg/dL. For ECD recipients, the relative risk of graft failure significantly increased with increasing sCr. Of potential SCDs, the adjusted risk of discard was higher with sCr >2.0 mg/dL (adjusted odds ratio [AOR] 7.04, 95% confidence interval [CI] 6.5–7.6) and 1.6–2.0 mg/dL (AOR 2.7; CI 2.5–2.9) relative to sCr ≤1.5 mg/dL. Among potential SCDs, elevated terminal creatinine is a strong independent risk factor for kidney discard; yet, when kidney transplantation is performed elevated donor terminal creatinine is not a risk factor for graft loss. Further research is needed to identify safe practices for the optimal utilization of SCD kidneys from donors with acute kidney injury.     

The improvement in survival of expanded criteria donor kidneys with transplantation era

Abstract: Background: To compensate for the shortage of donor kidneys, use of expanded donor criteria (ECD) has been adopted by many transplant centres. Multiple criteria on which to score such kidneys have been proposed but the evidence base for the definitions is derived from retrospective and registry data only. We aimed to see if analysis of ECD in our population would indicate the need to change our donor selection process. Methods: Data on primary kidney transplants (minimum follow‐up two yr) from 1989 to 2004 were reviewed (n = 635). The primary study endpoint was overall graft survival. Published ECD, including the United Network for Organ Sharing (UNOS) ECD criteria were assessed as potential prognostic variables, in a multivariable Cox proportional hazards model. Results: Patients transplanted after 1996 had improved graft survival compared to those transplanted pre‐1996 HR = 0.51 (0.35–0.76), p = 0.0001. Pre‐1996 UNOS defined ECD kidneys had a markedly increased risk of graft failure compared to live donor kidneys HR = 3.52 (1.9–6.35), p < 0.001. Post‐1996 ECD kidneys had similar prognosis compared to live donor kidneys HR 0.38 (0.1–1.59), p = 0.184. The observed improvement in graft survival was not explained by changes in donor source, cause of end stage renal failure (ESRF), human leukocyte antigen mismatch, recipient age or any histological parameter on implantation biopsy. Conclusions:  The explanation for improved overall graft survival and marked improved survival of ECD kidneys is unclear, but introduction of mycophenolate and subsequent falls in calcineurin inhibitor doses over the study period could be potential factors. These results provide some justification for our current selection and management of ECD kidneys.     

Pulsatile Perfusion Reduces the Incidence of Delayed Graft Function in Expanded Criteria Donor Kidney Transplantation

The use of expanded criteria donors (ECD) has been proposed to help combat the discrepancy between organ availability and need. ECD kidneys are associated with delayed graft function (DGF) and worse long-term survival. The aim of this study is to evaluate the impact of pulsatile perfusion (PP) on DGF and graft survival in transplanted ECD kidneys. From January 2000 to December 2003, 4618 ECD kidney-alone transplants were reported to the United Network for Organ Sharing. PP was performed on 912 renal allografts. The prognostic factors of DGF were analyzed using multivariate logistic regression analysis. Risk factors for reduced allograft viability were greater in donors and recipients of PP kidneys. Three-year graft survival of ECD kidneys preserved with PP was similar to cold storage (CS) kidneys. The incidence of DGF in PP kidneys was significantly lower than CS kidneys (26% vs. 36%, p < 0.001). Despite having a greater number of risk factors for reduced graft viability, the ECD-PP kidneys had similar graft survival compared to ECD-CS kidneys. The use of PP, by decreasing the incidence of DGF, may possibly lead to lower overall costs and increased utilization of donor kidneys.     

Pulsatile Pump Decreases Risk of Delayed Graft Function in Kidneys Donated After Cardiac Death

Organ storage techniques have been under scrutiny to determine the best preservation method, particularly in donation after cardiac death (DCD) kidneys. Conflicting literature on the benefit of pulsatile perfusion (PP) over cold storage (CS) warrants further investigation. We analyzed the risk of developing delayed graft function (DGF) in recipients of DCD and donation after brain death (DBD) kidneys undergoing PP or CS. We stratified on basis of cold ischemic time (CIT) to determine the interaction of preservation techniques, CIT and DCD kidneys on developing DGF. Of 54 136 recipients, 4923 received DCD kidneys of which 3330 (67%) underwent PP. Of 49 213 DBD recipients, 7531 (15%) underwent PP. DCD had a higher risk of DGF versus DBD (adjusted odds ratio, AOR 3.2; 3.0–3.5). PP kidneys had less DGF (AOR 0.59; 0.56–0.63) compared to CS. Interaction models of method by donor type referenced to PP/DBD revealed CS/DBD kidneys had higher DGF (AOR 1.8; 1.7–1.9), whereas CS/DCD kidneys had the highest risk of DGF (AOR 5.01; 4.43–5.67). Even though suggestive for a benefit of PP on DGF, this retrospective analysis cannot address whether this is an intrinsic effect of PP or is associated with the logistics of PP such as discard of DCD kidneys based on pump parameters.     

Association of Lower Costs of Pulsatile Machine Perfusion in Renal Transplantation from Expanded Criteria Donors

Pulsatile machine perfusion (PMP) has been shown to reduce delayed graft function (DGF) in expanded criteria donor (ECD) kidneys. Here, we investigate whether there is a cost benefit associated with PMP utilization in ECD kidney transplants. We analyzed United States Renal Data System (USRDS) data describing Medicare‐insured ECD kidney transplant recipients in 1995–2004 (N = 5840). We examined total Medicare payments for transplant hospitalization and annually for 3 years posttransplant according to PMP utilization. After adjusting for other recipient, donor and transplant factors, PMP utilization was associated with a $2130 reduction (p = 0.007) in hospitalization costs. PMP utilization was also associated with lower DGF risk (p < 0.0001). PMP utilization did not predict differences in rejection, graft survival, patient survival, or costs at 1, 2 and 3 years posttransplant. PMP utilization is correlated with lower costs for the transplant hospitalization, which is likely due to the associated reduction in DGF among recipients of PMP kidneys. However, there is no difference in long‐term Medicare costs for ECD recipients by PMP utilization. A prospective trial is necessary as it will help determine if the associations seen here are due to PMP utilization and not differences in the population studied.     

Impact of cold ischemia time on graft survival among ECD transplant recipients: a paired kidney analysis

Delays in expanded criteria donor (ECD) kidney placement increases cold ischemia times (CIT) potentially leading to discard. The effect of increased CIT on ECD kidney transplant outcomes is unknown. We evaluated paired ECD kidneys (derived from the same donor transplanted to different recipients) from the SRTR registry transplanted between 1995 and 2009 (n = 17,514). To test the effect of CIT, we excluded paired transplants with the same CIT (n = 3286). Of 14,230 recipients (7115 donors) the median difference in CIT was 5 h (Q1 = 3 h, Q3 = 9 h). Delayed graft function (DGF) was significantly more likely between pairs with greater CIT (35% vs. 31%, p < 0.001) including substantially higher rates for CIT differences ≥ 15 h (42%). Overall graft loss was not significantly different between recipients with higher CIT relative to paired donor recipients with lower CIT (p = 0.47) or for pairs with differences of 1-3 h (p = 0.90), 4-9 h (p = 0.41), 10-14 h (p = 0.36) or ≥ 15 h (p = 0.10). Results were consistent in multivariable models adjusted for recipient factors. Although increasing cold ischemia time is a risk factor for DGF among ECD kidney transplants, there is no effect on graft survival which may suggest an important utility for donor kidneys that may not currently be considered viable.     

Associations of Deceased Donor Kidney Injury With Kidney Discard and Function After Transplantation

Deceased donor kidneys with acute kidney injury (AKI) are often discarded due to fear of poor outcomes. We performed a multicenter study to determine associations of AKI (increasing admission‐to‐terminal serum creatinine by AKI Network stages) with kidney discard, delayed graft function (DGF) and 6‐month estimated glomerular filtration rate (eGFR). In 1632 donors, kidney discard risk increased for AKI stages 1, 2 and 3 (compared to no AKI) with adjusted relative risks of 1.28 (1.08–1.52), 1.82 (1.45–2.30) and 2.74 (2.0–3.75), respectively. Adjusted relative risk for DGF also increased by donor AKI stage: 1.27 (1.09–1.49), 1.70 (1.37–2.12) and 2.25 (1.74–2.91), respectively. Six‐month eGFR, however, was similar across AKI categories but was lower for recipients with DGF (48 [interquartile range: 31–61] vs. 58 [45–75] ml/min/1.73m² for no DGF, p < 0.001). There was significant favorable interaction between donor AKI and DGF such that 6‐month eGFR was progressively better for DGF kidneys with increasing donor AKI (46 [29–60], 49 [32–64], 52 [36–59] and 58 [39–71] ml/min/1.73m² for no AKI, stage 1, 2 and 3, respectively; interaction p = 0.05). Donor AKI is associated with kidney discard and DGF, but given acceptable 6‐month allograft function, clinicians should consider cautious expansion into this donor pool.     

Recipient Hemodynamics During Non-Heart-Beating Donor Kidney Transplantation Are Major Predictors of Primary Nonfunction

Non-heart-beating donor (NHBD) kidneys may substantially expand the donor pool, but many transplant centers are reluctant to use these kidneys because of the relatively high incidence of primary nonfunction (PNF). In heart-beating donor kidneys, intravascular fluid depletion during transplant surgery is associated with delayed graft function (DGF). Therefore, we studied the effect of the recipients' hemodynamic status on the outcome of 177 NHBD kidney transplantations. Independent statistically significant predictors of PNF were average central venous pressure (CVP) below 6 cmH(2)O (adjusted odds ratio (AOR) 3.1 (95% CI: 1.4-7.1), p=0.007), average systolic blood pressure below 110 mmHg (AOR 2.6 (95% CI: 1.1-5.9), p=0.03) and pre-operative diastolic blood pressure below 80 mmHg (AOR 2.4 (95% CI: 1.0-5.9), p=0.05). Donor characteristics were not independently associated with PNF (p>0.10). In a subgroup analysis of 56 paired kidneys, 29% of the recipients with the lower CVP of the pair experienced PNF compared with 11% of their counterparts with higher CVP (p=0.09). Our study indicates that recipient hemodynamics during transplant surgery are major predictors of PNF. Therefore, improving recipient hemodynamics by expansion of the intravascular volume is expected to enhance the results of NHBD kidney transplantations and may enlarge the donor pool by increasing the acceptance of NHBD kidneys.     

Outcomes of Kidneys from Donors After Cardiac Death: Implications for Allocation and Preservation

Although donation after cardiac death (DCD) kidneys have a high incidence of delayed graft function (DGF) and have been considered marginal, no tool for stratifying risk of graft loss nor a specific policy governing their allocation exist. We compared outcomes of 2562 DCD, 62,800 standard criteria donor (SCD) and 12,812 expanded criteria donor (ECD) transplants reported between 1993 and 2005, and evaluated factors associated with risk of graft loss and DGF in DCD kidneys. Donor age was the only criterion used in the definition of ECD kidneys that independently predicted graft loss among DCD kidneys. Kidneys from DCD donors <50 had similar long-term graft survival to those from SCD (RR 1.1, p = NS). While DGF was higher among DCD compared to SCD and ECD, limiting cold ischemia (CIT) to <12 h decreased the rate of DGF 15% among DCD <50 kidneys. These findings suggest that DCD <50 kidneys function like SCD kidneys and should not be viewed as marginal or ECD, and further, limiting CIT <12 h markedly reduces DGF.     

Use of perfusion parameters in predicting outcomes of machine-preserved kidneys

Perfusion parameters (PP) and early transplant outcome data from 332 consecutive ECD type kidneys machine preserved on the Waters RM-3 apparatus were reviewed and analyzed to examine the validity of using suboptimal PPs (renal resistance of .41-.60) as a criterion for discarding kidneys. Overall discard rate was 23.5%, with 55% of these having "poor" PP as part of reason for discard. PP analysis after 4 hours on the RM-3 is presented. This encompasses 280 kidneys with renal resistance .40. The PP-related discard rate in the renal resistance .41 to .60 kidneys was 51% versus 17% in the renal resistance 相似文献   

Reconditioning by end‐ischemic hypothermic in‐house machine perfusion: A promising strategy to improve outcome in expanded criteria donors kidney transplantation

This clinical study evaluates end‐ischemic hypothermic machine perfusion (eHMP) in expanded criteria donors (ECD) kidneys. eHMP was initiated upon arrival of the kidney in our center and continued until transplantation. Between 11/2011 and 8/2014 eHMP was performed in 66 ECD kidneys for 369 (98‐912) minutes after 863 (364‐1567) minutes of cold storage (CS). In 49 of 66 cases, the contralateral kidney from the same donor was preserved by static CS only and accepted by another Eurotransplant (ET) center. Five (10.2%) of these kidneys were ultimately judged as “not transplantable” by the accepting center and discarded. After exclusion of early unrelated graft losses, 43 kidney pairs from the same donor were eligible for direct comparison of eHMP vs CS only: primary non‐function and delayed graft function (DGF) were 0% vs 9.3% (P=.04) and 11.6% vs 20.9% (P=.24). There was no statistically significant difference in 1‐year graft survival (eHMP vs CS only: 97.7% vs 88.4%, P=.089). In a multivariate analysis, eHMP was an independent factor for prevention of DGF (OR: 0.28, P=.041). Development of DGF was the strongest risk factor for 1‐year graft failure (Renal resistance: 38.2, P<.001). In summary, eHMP is a promising reconditioning technique to improve the quality and acceptance rate of suboptimal grafts.     

Non-Heart Beating Donor Kidneys with Delayed Graft Function Have Superior Graft Survival Compared with Conventional Heart-Beating Donor Kidneys That Develop Delayed Graft Function

Delayed graft function may have an association with reduced graft survival, and nonheart-beating donor (NHBD) kidneys have higher rates of delayed graft function (DGF) than heart-beating donor (HBD) kidneys. This study compared outcome of renal transplants from HBDs who developed DGF, with NHBDs who developed DGF. All recipients of HBD and NHBD kidneys who developed DGF were identified during a 10-year period. All patients with graft primary nonfunction were excluded from analysis. Four hundred and fifty-six functioning transplants were performed. Delayed graft function occurred in 69 (17%) HBD and 55 (93%) NHBD kidneys. The grafts developing DGF were well matched for donor and recipient age. The rate of acute rejection was similar; [n = 16/69 (23%) HBD vs. n = 13/55 (24%) NHBD]. Cold ischaemia was 21 h in the HBD group and 17 h in NHBD group (p > 0.05). Serum creatinine was similar for both groups at 1.3 and 6 years (p > 0.05 for all time points). Graft survival in the NHBD recipients with DGF was significantly better at 3 years (84%) compared with recipients of a HBD renal transplant that developed DGF (73%) (p < 0.05), and at 6 years (62% survival for HBDs and 84% survival for NHBDs). This study shows that graft survival was better for NHBD kidneys up to 6 years after transplantation.     

Risk factors for delayed kidney function and impact of delayed function on patient and graft survival in adult graft recipients

The influence of delayed kidney graft function on allograft outcome is described controversially in the literature. The aim of the study was to evaluate possible risk factors for delayed graft function (DGF) and investigate the impact of DGF on short- and long-term renal allograft function. Two groups were formed: the first one consisted of patients who gained immediate graft function (IGF) (n = 64) after transplantation and the second group included patients with DGF (n = 31; with at least one dialysis needed in first week after transplantation). The DGF group had a statistically significant longer duration on dialyses prior to transplantation (DGF 54 vs. IGF 33 months; p < 0.05), on average more frequently a re-transplantation (DGF 1.7 vs. IGF 1.3; p < 0.01), a longer re-anastomosis time (DGF 52.9 vs. 44.2 min; p < 0.01), a lower systolic (DGF 136 +/-24 mmHg vs. IGF 158 +/- 25; p < 0.001) and diastolic blood pressure (DGF 78 +/- 14 vs. IGF 89 +/- 16 mmHg; p < 0.01) at admission to the hospital and a higher serum (S)-creatinine at discharge (DGF 2.5 +/- 1.6 vs. IGF 1.6 +/- 0.4 mg/dL; p < 0.01). Prior to transplantation the DGF group had more often advanced vascular diseases (DGF 29.0 vs. IGF 12.5%; p < 0.01) and these patients incurred more frequently new ones during the next 3 yr after transplantation (DGF 22.6 vs. IGF 6.3%; p < 0.001). After 3 yr the graft survival tended to be lower in the DGF group (DGF 74.2 vs. IGF 84.4%; NS), but this difference was not statistically significant.     

Experience in renal and extrarenal transplantation with donation after cardiac death donors with selective use of extracorporeal support

BACKGROUND: Most reports of donation after cardiac death (DCD) donors are exclusive to kidney transplantation and report high rates of delayed graft function (DGF). STUDY DESIGN: From April 1, 2003, to October 3, 2007, we performed 53 kidney transplantations and 4 simultaneous kidney-pancreas transplantations from DCD donors. All DCD donor kidneys were managed with pulsatile perfusion preservation, and all simultaneous kidney-pancreas transplantation donors were managed with extracorporeal support. RESULTS: Of 53 DCD kidney transplantations, 44 (83%) were from standard criteria donors (SCD) and 9 (17%) from expanded criteria donors (ECD). With a mean followup of 12 months, actual patient and kidney graft survival rates were 94% and 87%, respectively. Patient and graft survival rates were 100% in the 4 simultaneous kidney-pancreas transplantations. Incidence of DGF was 57% (60% without versus 20% with extracorporeal support, p = 0.036). Comparison of the 53 DCD donor kidney transplantations with 316 concurrent donation after brain death (DBD) donor adult kidney transplantations (178 SCD, 138 ECD) revealed no differences in demographics or outcomes, except that the DCD donor group had fewer ECDs (17% DCD versus 44% DBD; p = 0.0002), fewer 0-antigen mismatch kidney transplantations (7.5% DCD versus 19% DBD; p = 0.05), and more kidneys preserved with pulsatile perfusion (100% DCD versus 52% DBD; p < 0.0001). Incidences of DGF (57% DCD versus 19% DBD; p < 0.0001) and acute rejection (19% DCD versus 10% DBD; p = 0.10) were higher in the DCD donor group, which resulted in a longer initial length of stay (mean 11 days DCD versus 8.0 days DBD; p = 0.006). CONCLUSIONS: Despite a high incidence of DGF in the absence of extracorporeal support and greater initial resource use, comparable short-term results can be achieved with DCD and DBD donor kidney transplantations.     

Outcome of Nonheart-Beating Donor Kidneys with Prolonged Delayed Graft Function after Transplantation

Nonheart-beating donor (NHBD) kidneys are frequently associated with delayed graft function (DGF), with a deleterious effect on kidney function and allograft survival. The influence and the duration of DGF on the outcome of NHBD kidneys are assessed. All recipients of an NHBD kidney in the period 1993-2003 were reviewed. Excluded from analysis were patients with primary nonfunction (PNF). One hundred and five patients with a functioning NHBD graft were reviewed: 23 (22%) had immediate function (group 1), 40 (38%) had DGF < or = 2 weeks (group 2), 31 (30%) had DGF 15 days to 4 weeks (group 3) and 11 (10%) had DGF for > 4 weeks (group 4). Creatinine clearance at 3 months was higher in groups 1 and 2 versus group 4 (p = 0.015 and p = 0.006, respectively) and was higher in group 2 versus group 4, at 1 year (p = 0.01). Graft survival was 95%, 98%, 97% and 89%, respectively, at 1 year and 95%, 85%, 77% and 89%, respectively, at 5 years, which was not significantly different. The duration of DGF in NHB kidneys has a negative effect on creatinine clearance, but no effect on graft survival.     

Urine NGAL and IL-18 are Predictive Biomarkers for Delayed Graft Function Following Kidney Transplantation

Delayed graft function (DGF) due to tubule cell injury frequently complicates deceased donor kidney transplants. We tested whether urinary neutrophil gelatinase-associated lipocalin (NGAL) and interleukin-18 (IL-18) represent early biomarkers for DGF (defined as dialysis requirement within the first week after transplantation). Urine samples collected on day 0 from recipients of living donor kidneys (n = 23), deceased donor kidneys with prompt graft function (n = 20) and deceased donor kidneys with DGF (n = 10) were analyzed in a double blind fashion by ELISA for NGAL and IL-18. In patients with DGF, peak postoperative serum creatinine requiring dialysis typically occurred 2-4 days after transplant. Urine NGAL and IL-18 values were significantly different in the three groups on day 0, with maximally elevated levels noted in the DGF group (p < 0.0001). The receiver-operating characteristic curve for prediction of DGF based on urine NGAL or IL-18 at day 0 showed an area under the curve of 0.9 for both biomarkers. By multivariate analysis, both urine NGAL and IL-18 on day 0 predicted the trend in serum creatinine in the posttransplant period after adjusting for effects of age, gender, race, urine output and cold ischemia time (p < 0.01). Our results indicate that urine NGAL and IL-18 represent early, predictive biomarkers of DGF.     

Similar Outcomes with Different Rates of Delayed Graft Function May Reflect Center Practice, Not Center Performance

To better understand the implications for considering delayed graft function (DGF) as a performance measure, we compared outcomes associated with a 2- to 3-fold difference in the incidence of DGF at two transplant centers. We analyzed 5072 kidney transplantations between 1984 and 2006 at the University of Minnesota Medical Center (UMMC) and Hennepin County Medical Center (HCMC). In logistic regression the adjusted odds ratio for DGF at HCMC versus UMMC was 3.11 (95% Confidence Interval [CI]= 2.49–3.89) for deceased donors and 2.24 (CI = 1.45–3.47) for living donors. In Cox analysis of 4957 transplantations, slow graft function (SGF; creatinine ≥3.0 mg/dL [230 μmol/L] on day 5 without dialysis) was associated with graft failure at UMMC (Relative Risk [RR]= 1.43, CI = 1.25–1.64), but not HCMC (RR = 0.99, CI = 0.77–1.28). RR's of DGF were similar at both centers. Thus, the lower incidence of DGF at UMMC likely resulted in a higher incidence and higher risk of SGF compared to HCMC. Indeed, graft survival for recipients with DGF at HCMC was similar (p = 0.3741) to that of recipients with SGF at UMMC. We conclude that dialysis per se is likely not a cause of worse graft outcomes. A better definition is needed to measure early graft dysfunction and its effects across transplant programs.     

Prognostic utility of hypothermic machine perfusion in deceased donor renal transplantation

Pulsatile pump perfusion of kidney transplants is known to decrease delayed graft function (DGF) and improve 1 year graft survival when compared to static cold preservation. Kidneys with better flow and resistance parameters on perfusion are likely to have a better post transplant function. These parameters are commonly used to evaluate kidneys being considered for transplantation. This study assesses the time frame for a kidney within which it reaches optimal perfusion parameters. All kidneys pumped between 5/2006 and 9/2009 on a Lifeport? kidney transporter at our local organ procurement agency were studied. 190 kidneys were evaluated and then divided into two groups based on whether terminal flows increased or declined after prolonged perfusion. All kidneys were assessed for changes in flow (F), resistance (R) and temperature at 15 minute intervals. Discards, DGF and one year graft survival were noted. The Student paired t test and Chi-square analysis were used to compare data. A multiple logistic regression analysis was performed to study independent predictors of DGF on pump perfusion. RESULTS: For all kidneys, the mean initial flow was 59 ± 35 mL/min which improved to an average flow of 128 ± 38 mL/min with continued perfusion. The maximal flow and terminal flows were 148 ± 51 and 135 ± 38 mL/min respectively. The flows at 2, 4, and 6 hours was 125 ± 41, 128 ± 42 and 130 ± 39 mL/min respectively. Kidneys that improved on continued perfusion had a significantly lower discard rate (20 vs 34% p < 0.05), but a higher incidence of DGF (64 vs 39%, P < .05). One year graft loss (death censored) was comparable in the two groups. (4/42 vs. 3/33, P = .94). Resistance at 2, 4, and 6 hours was predictive of DGF, as was donor anoxia and cerebrovascular accident (CVA) as the cause of death. CONCLUSIONS: Kidneys on pulsatile pump perfusion tend to show improved flows and decreased resistance over time. The average flow for a kidney is reached by 2 hours. Those kidneys that start with lower flow rates that improve after 2 hours with continued perfusion are less likely to be discarded but are still associated with a greater incidence of delayed graft function. Resistance at 2 hours predicts DGF while initial resistance predicts one year graft survival.     

Calcium ion concentration of machine perfusate predicts early graft function in expanded criteria donor kidneys

Pulsatile preservation offers the advantage of pretransplant assessment of donor kidneys. Selected electrolyte concentrations of machine perfusate were measured over time in order to: (1) describe electrolyte changes in perfusate during the pulsatile preservation of expanded-criteria donor (ECD) kidneys, and (2) to assess the prognostic significance of these characteristics to early graft function. One hundred and fifty ECD kidneys were preserved in our laboratory between 1 January 1995 and 11 January 1997. ECD kidneys were defined as those requiring pretransplant biopsy. Kidneys were grouped by the presence or absence of delayed graft function (DGF), and perfusion parameters were measured every hour during pulsatile perfusion. All kidneys were preserved by continuous hypothermic pulsatile perfusion using Belzer II solution. Renal flow is decreased and renal resistance is increased in the presence of DGF in machine-preserved ECD kidneys. In addition, ionized calcium concentration of the machine perfusate is significantly elevated in the DGF group compared with the No DGF group (0.091 vs 0.054, P = 0.0016). The incidence of DGF is significantly lower in the ECD kidney. Among the pretransplant variables of donor characteristics, perfusion parameters and histology, perfusion parameters are highly predictive of early graft function. In addition, we found that ionized calcium concentration in the perfusate is significantly elevated in kidneys exhibiting DGF, which may have implications for assessing the suitability of donor kidneys for transplantation. Received: 10 August 1998 Received after revision: 9 March 1999 Accepted: 25 June 1999