Combined cold storage-perfusion preservation with a new synthetic perfusate

Survey of Apoptosis After Hypothermic Storage of a Pancreatic β-Cell Line

Insulin-dependent diabetes mellitus is one of the leading causes of death world wide. Donor-derived pancreas and islet of Langerhans transplantation are potential cures, however, postmortem ischemia impacts islet quality. The murine βt3 cell line was used as a model to study apoptosis after hypothermic storage by comparing Unisol™ with Belzer's machine perfusion solution (BMPS) and the University of Wisconsin (UW) solution. The objective was to determine which of these solutions provided the best support for βt3 cells and which solution demonstrated the least amount of apoptotic activity. Several apoptosis markers were measured that included the translocation of phosphatidylserine, caspase activity, and the formation of DNA laddering. In addition, metabolic activity and membrane integrity were also measured. The results demonstrated that the three solutions behaved similarly during overnight cold storage at 4°C. However, Unisol was consistently better than UW solution and BMPS, demonstrating better cell viability and recovery, and lower levels of apoptotic activity when all three parameters were measured. These results demonstrated that apoptosis plays an important role in the survival of cells and tissues during cold storage. Development of solutions to help prevent or decrease the levels of apoptosis after cold storage will likely improve overall cell and tissue recovery and survival in a clinical setting.

Oxygen consumption during oxygenated hypothermic perfusion as a measure of donor organ viability

Hypothermic machine perfusion (HMP) for the preservation of kidneys, recovered from extended criteria organ donors (ECDs), presents the opportunity for assessing ex vivo parameters that may have value in predicting postimplantation organ viability. Organ perfusion and vascular resistance are the parameters most frequently cited as the basis for the decision to use or discard a donor kidney. The limitation of these measures is emphasized by the observation that a significant percentage of ECD kidneys with poor perfusion parameters can provide life-sustaining function after transplantation. It has been suggested that whole organ oxygen consumption (OC) during oxygenated HMP may better reflect the proportion of viable tissue in the organ and more reliably predict posttransplant organ function. Our study correlates renal OC and renal vascular resistance (RVR) during oxygenated HMP with postpreservation glomerular filtration rates (GFRs) in rodent kidneys after 24 hours of oxygenated HMP. Kidneys from adult rodents were preserved for 24 hours using oxygenated HMP and static cold storage (SCS). During oxygenated HMP preservation, organ OC, renal organ flow rates, and RVR were serially measured. After the preservation period, organs were mounted onto a Langendorff device for warming to normal body temperature and measurement of GFR. Oxygen consumption and RVR during HMP were correlated with postpreservation GFR. Oxygen consumption during oxygenated HMP was significantly correlated (r2 = 0.871; p < 0.05) with postpreservation GFR, suggesting that higher OC predicts better postpreservation GFR. In contrast, RVR was poorly correlated with postpreservation GFR (r2 = 0.258; p = 0.199). Glomerular filtration rate in SCS kidneys was 0.002 ± 0.003 ml/min/g. We demonstrate that measurement of organ OC during oxygenated HMP may have significant value in predicting postpreservation organ function.

Development of pancreas storage solutions: Initial screening of cytoprotective supplements for β-cell survival and metabolic status after hypothermic storage

Insulin-dependent diabetes mellitus is one of the leading causes of death world-wide. Donor-derived pancreas and Islet of Langerhans transplantation are potential cures; however, postmortem ischemia impacts islet quality. The murine βt3 cell line was employed as a model to study cell viability and proliferation after hypothermic storage by comparing Belzer's Machine Perfusion Solution with Unisol™ Solution. The objective was to determine which of these solutions provided the best base line support for βt3 cells and to screen potential cytoprotective additives to the solutions. Initial βt3 cell viability was similar in the two storage solutions; however, better proliferation was observed after storage in Unisol Solution. The caspase inhibitor, Q-VD-OPH, and α-tocopherol improved viability in both storage solutions, suggesting that apoptotic pathways may be responsible for cell death during hypothermic storage of βt3 cells. Analysis of apoptosis markers, caspase activity, and DNA laddering showed a reduction in apoptosis when these additives were included. The effects of Q-VD-OPH and α-tocopherol were also synergistic when employed together during either hypothermic exposure, post-hypothermic physiologic incubation, or combinations of hypothermic exposure and physiologic incubation. These results suggest that both supplements should be included in pancreas hypothermic storage solutions and in islet culture media during post-isolation culture prior to transplantation.

Mouse IPK: A Powerful Tool to Partially Characterize Renal Reperfusion and Preservation Injury

Main Problem

The molecular basis of renal preservation injury is not well understood. Since mouse kidney transplantation models are not useful in this setting, a mouse Isolated Perfused Kidney (IPK) model was developed to take advantage of mouse genetic design capabilities for testing complex biological hypothesis regarding mechanisms of preservation injury in transplanted kidneys.

Methods

Mouse kidneys were recovered, preserved, and reperfused in-vitro with an acellular physiological crystalloid buffer containing hypo-physiological oncotic pressure. Outcome variables were measured to predict preservation injury. These included perfusate flow, vascular resistance, VO₂, urine output, GFR, proteinuria, LDH release, and edema. The model was tested by subjecting mouse kidneys to cold storage in University of Wisconsin (UW) solution for 24, 48, or 72 hours (time-dependent preservation injury), cold storage in Euro-Collins Solution (solution dependent preservation injury), and exposure to prior warm ischemia (DCD dependent preservation injury).

Results

The model accurately predicted the qualitative and quantitative changes in the readouts based on known responses to preservation injury in kidney transplants in large animals and humans.

Conclusion

The mouse IPK accurately predicts many of the variables associated with renal organ preservation injury in the very early phases of reperfusion and may provide an attractive model for studying the molecular basis of renal preservation injury.

In situ preservation of kidneys from donors after cardiac death: results and complications

OBJECTIVES

To describe the results and complications of in situ preservation (ISP) of kidneys from donors after cardiac death (DCD).

BACKGROUND

DCD donors are increasingly being used to expand the pool of donor kidneys. ISP reduces warm ischemic injury which is associated with DCD donation.

METHODS

Insertion of a double-balloon triple-lumen catheter allows selective perfusion of the abdominal aorta to preserve the kidneys in situ. From January 2001 until August 2005, 133 ISP procedures were initiated in our procurement area.

RESULTS

Fifty-six (42%) ISP procedures led to transplantation; in the remaining 77 cases (58%), the donation procedure was abandoned or both kidneys were discarded because of ISP complications (n = 31), poor graft quality (n = 23), no consent for donation (n = 13), medical contraindications (n = 8), or unknown cause (n = 2). Increasing donor age (odds ratio (OR) 1.06 per year, P < 0.001) and uncontrolled DCD donation (OR 5.4, P < 0.001) were independently correlated with ISP complications. After transplantation, prolonged double-balloon triple-lumen catheter insertion time was an independent predictor of graft failure (OR 2.0, P = 0.05). Selected controlled DCD donors were managed by rapid laparotomy and direct aortic cannulation; graft survival of these kidneys was superior to kidneys from controlled DCD donors managed by ISP.

CONCLUSIONS

A minority of initiated ISP procedures led to transplantation, resulting in a high workload compared with donation after brain death. The association between increasing catheter insertion time and inferior graft outcome emphasizes the need for fast and effective surgery. Therefore, rapid laparotomy with direct aortic cannulation is preferred over ISP in controlled DCD donation. Despite these limitations, we have expanded our donor pool 3- to 4-fold by procuring DCD kidneys that were preserved in situ.

Influence of Pulsatile Perfusion Preservation on Outcomes in Kidney Transplantation from Expanded Criteria Donors

BACKGROUND

Expanded criteria donors (ECDs) increase the donor organ pool, but the value of transplanting these kidneys has been questioned because of concerns about diminished survival, poorer renal function, and higher rates of delayed graft function.

STUDY DESIGN

Retrospective analysis of intermediate-term outcomes in ECD kidney transplantations according to method of preservation at a single center using a standardized approach.

RESULTS

Over a 5-year period, we performed 141 donations-after-brain-death ECD kidney transplantations into adult recipients. A total of 114 kidneys (81%) were managed with combined cold-storage and pulsatile perfusion preservation (PPP), and the remaining 27 (19%) were preserved with cold storage (CS). The PPP group had a higher proportion of kidneys preserved for longer than 30 hours (28% versus 0, p < 0.001) and a longer mean cold ischemia time (24.5 hours PPP versus 19 hours CS, p < 0.01). Other donor and recipient characteristics were similar between groups. Incidence of delayed graft function was 11% in PPP-stored kidneys versus 37% in CS kidneys (p = 0.002). With a mean followup of 27 months, patient (91% PPP versus 96% CS) and kidney graft survival (81% PPP versus 81.5% CS) rates were comparable. Mean 12-month serum creatinine (1.9 mg/dL) and calculated Modification of Diet in Renal Disease glomerular filtration rate (41 mL/min) values were similar between groups.

CONCLUSIONS

Despite longer cold ischemia times, recipients of ECD kidneys managed with PPP had similar survival and functional outcomes, but experienced a marked reduction in the rate of delayed graft function.

Donation after cardiac death kidneys with low severity pre-arrest acute renal failure

The widening gap between supply and demand for renal transplantation has prompted many centers to use donors after cardiac death. Some of these donors exhibit signs of acute renal failure (ARF) prior to cardiac arrest. Concern has been expressed about poor quality of graft function from such donors. In response to this perception, we reviewed 49 single renal transplant recipients from category III donors after cardiac death between 1998 and 2005, at our center. All kidneys but one had hypothermic machine perfusion and viability testing prior to transplantation. According to the RIFLE criteria, nine recipients had kidneys from donors with "low severity pre-arrest ARF". The remainder of the recipients were used as control group. There was no statistical significant difference in delayed graft function and rejection rates between these two groups. Recipients GFR at 12 months was 44.4 +/- 17.1 and 45.2 +/- 14.7 (mL/min/1.73m(2)) from donors with ARF and without ARF, respectively (p = 0.96). In conclusion, low severity ARF in kidneys from controlled after cardiac death donors can be a reversible condition after transplantation. Short-term results are comparable to the kidneys from same category donors without renal failure, providing that some form of viability assessment is implemented prior to transplantation.

Redox-active iron released during machine perfusion predicts viability of ischemically injured deceased donor kidneys

Redox-active iron, catalyzing the generation of reactive oxygen species, has been implicated in experimental renal ischemia-reperfusion injury. However, in clinical transplantation, it is unknown whether redox-active iron is involved in the pathophysiology of ischemic injury of non-heart-beating (NHB) donor kidneys. We measured redox-active iron concentrations in perfusate samples of 231 deceased donor kidneys that were preserved by machine pulsatile perfusion at our institution between May 1998 and November 2002 using the bleomycin detectable iron assay. During machine pulsatile perfusion, redox-active iron was released into the preservation solution. Ischemically injured NHB donor kidneys had significantly higher perfusate redox-active iron concentrations than heart-beating (HB) donor kidneys that were not subjected to warm ischemia (3.9 +/- 1.1 vs. 2.8 +/- 1.0 micromol/L, p = 0.001). Moreover, redox-active iron concentration was an independent predictor of post-transplant graft viability (odds ratio 1.68, p = 0.01) and added predictive value to currently available donor and graft characteristics. This was particularly evident in uncontrolled NHB donor kidneys for which there is the greatest uncertainty about transplant outcomes. Therefore, perfusate redox-active iron concentration shows promise as a novel viability marker of NHB donor kidneys.

[Recent advances in the comprehension of the effects of cold ischemia in kidney graft]

Cold ischemia is the best known method to preserve kidneys for transplant. However, it produces several detrimental effects. First, cellular necrosis. Secondarily, during the hypothermic period a mitochondrial injury process develops which makes the cell entering a pre-apoptotic state. This apoptosis occurs definitively in the reperfusion. Preservation solutions currently available are not perfect and are not able to avoid cold-related cell injuries. The addition of certain substances to UW solution (desferrioxamine) has shown experimentally a reduction in mitochondrial cold-related lesions. Isolated hypothermic kidney perfusion reduces initial graft dysfunction about 20% in comparison to hypothermic storage. This fact relates to important either economical as functional consequences.

The potential benefits of 1.5% hetastarch as a cardioplegia additive

INTRODUCTION

Myocardial edema is a clinically relevant problem found in post-ischemic reperfused hearts. The objective of this study was to understand the effects of hetastarch-supplemented cardioplegia on post-ischemic edema and cardiac function.

MATERIALS AND METHODS

Swine hearts were arrested with either St. Thomas Hospital cardioplegia with (n=6) or without (n=7) 1.5% hetastarch. Following hypothermic global ischemia, hearts were crystalloid reperfused in a four-chamber isolated working mode.

RESULTS

Hetastarch decreased myocardial water content gains after three hours of reperfusion (control versus hetastarch, hour 0: 67+/-5% versus 67+/-3%, NS; hour 3: 82+/-2% versus 78+/-1%, p=0.1). Post-ischemic control group left ventricular end-diastolic pressures were elevated after 1h (in mm Hg, hour 0: 13+/-2, hour 1: 19+/-3, hour 2: 19+/-3, hour 3: 20+/-2) but remained stable (<16 mm Hg) in the hetastarch group. Post-reperfusion creatine phosphokinase perfusate levels in the hetastarch treated hearts were decreased (control: 1.6 IU/l/g versus hetastarch: 0.6 IU/l/g, p=0.15).

DISCUSSION/CONCLUSIONS

Hetastarch treatment delayed myocardial edema development and attenuated myocardial creatine kinase efflux, thereby preserving diastolic function.

Applicability of histidine-tryptophan-ketoglutarate solution in right lobe adult-to-adult live donor liver transplantation

In a consecutive series of 60 right lobe adult-to-adult live donor liver transplantations (ALDLTs), safety and efficacy of the University of Wisconsin (UW) and histidine-tryptophan-ketoglutarate (HTK) solution were evaluated. The first 30 liver grafts were perfused with UW solution and the subsequent 30 by HTK solution. Donor and recipient characteristics of both groups were comparable. All liver graft implantations were performed with cross-clamping of the inferior vena cava (IVC) and without veno-venous bypass. Main outcome measures were posttransplantation liver biochemistry, prothrombin time, and recipient morbidity, as well as graft and recipient survival. There were no significant differences of the outcome measures between the 2 groups. The low potassium content of the HTK solution nonetheless offered logistic advantages. In 25 of the 30 recipients of the HTK group, portal vein anastomosis was performed with a clamp on the donor portal vein while the clamps on the IVC were already released. This shortened the period during which the IVC was being cross-clamped. HTK solution was as safe and effective as a cold storage solution as UW solution in ALDLT. Its low potassium content has advantage of earlier restoration of patency of the IVC and thus hemodynamic stability. The cost of using HTK solution was also lower.

Nonheart-beating kidney donation: current practice and future developments

BACKGROUND

Nonheart-beating kidney donation (NHBD) is gaining acceptance as a method of donor pool expansion. However, a number of practitioners have concerns over rates of delayed graft function, acute rejection, and long-term graft survival. The ethical issues associated with NHBD are complex and may be a further disincentive. Tailored strategies for preservation, viability prediction, and immunosuppression for kidneys from this source have the potential to maximize the number of available organs. This review article presents the current practice of NHBD kidney transplantation, examines the results and draws comparisons with cadaveric kidneys, and explores some areas of potential development.

METHODS

A review of the current literature on NHBD kidney donation was performed.

RESULTS

The renewed interest in NHBD kidneys is driven by a continuing shortfall in available organs. Those centers involved in NHBD report an increase in kidney transplants of the order of 16% to 40% and there is no evidence that the financial costs are higher with NHBDs. The majority of experience comes from Maastricht category 2 NHBDs, where an estimation of warm time is possible. This is generally limited to 40 minutes. There are variations in the technique for kidney preservation prior to retrieval, but most centers use an aortic balloon catheter. Much work has looked at the ideal technique for kidney preservation prior to implantation. Evidence suggests that machine perfusion produces the best initial function rates, decreased use of adjuvant immunotherapy and fewer haemodialysis sessions than static cold storage.

CONCLUSION

Despite being associated with poorer initial graft function, the long-term allograft survival of NHBD kidneys does not differ from the results of transplantation from cadaveric kidneys. Further, serum creatinine levels are generally equivalent. Constant reassessment of the ethical issues is required for donation to be increased while respecting public concerns. Use of viability assessment and tailoring of immune suppression for NHBD kidneys may allow a further increase in donation from this source.

Simultaneous pancreas-kidney (SPK) transplantation from controlled non-heart-beating donors (NHBDs)

From January 1993 through June 1999, 18 simultaneous pancreas-kidney transplants (SPKs) were performed from controlled non-heart-beating donors (NHBDs) and 339 SPKs were performed from heart-beating donors (HBDs). No difference in donor characteristics was noted except for warm ischemic time, which was 14.8 min (range 4-46 min) for NHBDs. Following transplantation, no difference in pancreatic function was noted; however, a higher rate of enteric conversions was seen in pancreas transplants from NHBDs (32% vs. 13%; p < 0.01). Hemodialysis for acute tubular necrosis (ATN) was higher in kidney transplants from NHBDs (22.2% vs. 4.1%; p = 0.009) as was discharge serum creatinine (1.7 mg/dl vs. 1.5 mg/dl; p < 0.05). Also, the number of patients remaining rejection free was lower for NHBDs and approached significance (33.3% vs. 50.1%; p = 0.07). However, no difference in patient survival (100% vs. 95.4%) or pancreatic (87.4% vs. 86.5%) and renal (86.3% vs. 86.3%) allograft survival was noted during the study period. Our results indicate that SPK transplantation from controlled NHBDs is a viable method for increasing the number of pancreas and kidney transplants available for transplantation.

Perfusate lactate dehydrogenase level and intrarenal resistance could not be adequate markers of perfusion quality during isolated kidney perfusion

The main goal of this work was to study the influence of perfusion pressure and flow waveform during kidney perfusion, and the relationship between renal vascular resistance (RVR) and lactate dehydrogenase (LDH) concentration in the perfusate. Simultaneous constant pressure kidney perfusions were performed with either pulsatile or continuous flow at either 30 or 80 mm Hg of constant perfusion pressure. Mean flow, pressure, and RVR were displayed online during perfusion. Perfusate samples for LDH, creatine phosphatase kinase (CPK), and alkaline phosphatase (AP) determinations were taken. At the end of the perfusion, 2 ml of Evans blue was injected into the circuit to obtain images of perfusate distribution, and the kidneys were weighed. Also, hematoxylin/eosine studies were performed, showing more Bowman's space and tubular dilation in kidneys perfused with high pressure. We did not find differences in RVR between kidneys perfused at 30 and 80 mm Hg; nevertheless, perfusate distribution was better in the 80 mm Hg perfusions. We did not find any correlation between enzyme release and RVR in kidneys perfused with different mean pressures. These findings suggest that vascular resistance and LDH concentration cannot be independently considered as adequate markers of perfusate distribution.

The influence of pulsatile preservation on renal transplantation in the 1990s

BACKGROUND

Unlike simple cold storage (CS), pulsatile machine preservation (MP) of kidneys for transplantation permits pharmacologic manipulation of the perfusate and aids in the pretransplant assessment of the kidney graft. These characteristics of MP may have importance in the era of increasing use of extended criteria donor kidneys. The overall aim of this article is to critically assess practices at our preservation unit with respect to graft function. Specific aims are to (1) compare the influence of MP versus CS on graft function, (2) determine which pretransplant variables have significance in pretransplant assessment, and (3) determine whether pharmacologic manipulation during MP is advantageous.

METHODS

There were 650 consecutive kidneys preserved in our laboratory between January 1, 1993 and March 1, 999, by either MP or CS. All MP kidneys were preserved by continuous hypothermic pulsatile perfusion using Belzer-MPS or Belzer II solution. Perfusion parameters and electrolytes were measured serially during pulsatile perfusion. All CS kidneys were stored in University of Wisconsin solution. All kidneys obtained from donors exhibiting extended criteria features underwent pretransplant frozen section biopsies. Transmission electron microscopy (EM) was performed on a subset of kidneys undergoing pharmacologic manipulation. Four agents were assessed prospectively for their ability to influence MP characteristics when added to perfusate: PGE1, trifluoperazine, verapamil, and papaverine.

RESULTS

MP was associated with improved immediate, 1-, and 2-year graft function and reduced length of initial hospital stay when compared with CS grafts. Changes in the machine perfusion variables flow and resistance, and the [Ca++] in perfusate, were significantly associated with delayed graft function (DGF) after the transplant. Biopsy information was not predictive of DGF. The addition of PGE1 to perfusate improved MP characteristics, reduced the release of [Ca++] into perfusate, and ameliorated mitochondrial ischemic injury in transmission EM images. Early graft function was improved in the presence of PGE1+MP, compared with function in the presence of other pharmacologic agents or CS alone.

CONCLUSIONS

MP is associated with improved early and long term renal function. Moreover, PGE1 augments MP in improving graft function. The combination of MP+PGE1 may be important in optimizing the ability to use extended donor criteria kidneys and, thereby, improve the overall efficiency of cadaveric renal transplantation.

Risk factors for delayed graft function in cadaveric kidney transplantation: a prospective study of renal function and graft survival after preservation with University of Wisconsin solution in multi-organ donors. European Multicenter Study Group

BACKGROUND

Delayed graft function (DGF) remains an important complication in renal transplantation. In this multicenter study, we investigated the influence of donor and recipient factors on the occurrence of DGF and DGF's effect on long-term graft survival.

METHODS

A total of 547 transplanted kidney allografts, retrieved from multi-organ donors, were analyzed, and results were compared with literature on kidney-only donors.

RESULTS

Median follow-up of patients without graft failure was 3.4 years. Twenty-four percent of the recipients developed DGF. In univariate analysis, the following factors significantly increased the incidence of DGF: (a) among the donor factors, mean creatinine level >120 micromol/L and prolonged cold ischemia time (CIT); and (b) among the recipient factors, previous transplant(s), no intraoperative use of mannitol, poor quality of reperfusion, absence of intraoperative diuresis, and pretransplant anuria or oliguria. After stepwise logistic regression, donor age, CIT, recipient's number of previous transplants, and intraoperative diuresis proved to be of independent prognostic value for the occurrence of DGF. Overall graft survival was 91%, 87%, and 72% at 3 months, 1 year, and 4 years after transplantation, respectively. In case of DGF, graft survival was approximately 10% lower when compared with cases with immediate graft function (P<0.001). No difference in incidence of DGF was found between grafts of multi-organ donors and kidney-only donors.

CONCLUSIONS

DGF results in an approximately 10% higher rate of graft failure. DGF incidence can be reduced by the administration of mannitol during transplantation, which minimizes CIT and optimizes donor management. Grafts from multi-organ donors and kidney-only donors appear to be of equal quality.

Short-term outcome of kidney transplants from non-heart-beating donors after preservation by machine perfusion

In this study, the short-term outcome of renal transplants from non-heart-beating donors (NHBD) preserved by machine perfusion (MP) is evaluated and compared to preservation by cold storage (CS). Twenty-two NHBD kidneys were procured during 1993 and 1994 after in situ perfusion with histidine-tryptophan ketoglutarate and preserved by continuous perfusion using University of Wisconsin organ preservation solution for MP as a perfusate. Between 1980 and 1992, 57 NHBD kidneys were procured and preserved by CS. Donors in the MP group sustained increased first warm ischemia times (WIT1) (P < 0.1) and recipients in the MP group suffered longer anastomosis time, worse HLA-DR mismatch, and more initial use of cyclosporin as immunosuppressant; all these factors are known to be deleterious to short-term outcome. Despite these unfavorable conditions, delayed function (DF) rate was decreased in the MP group, although not significantly. However, when considering only kidneys with WIT1 > or = 45 min, short-term outcome was significantly better in the MP group (P < 0.05). We conclude that MP is superior for the preservation of NHBD kidneys, especially after prolonged warm ischemia.

The use of a novel monitoring apparatus and modified Belzer hydroxyethyl starch perfusate for analysis of glomerular filtration during hypothermic perfusion preservation

The present study describes an experimental model for measurement of glomerular filtration during hypothermic perfusion preservation (HPP). To facilitate glomerular filtration during HPP, perfusate oncotic pressure was reduced by lowering the concentration of hydroxyethyl starch. Lewis rats underwent HPP at a mean perfusion pressure of 40-46 mmHg. An isograft model was used to demonstrate that retrieval and preparation for HPP did not impact adversely on renal function. Total cold ischemic time (CIT) consisted of the time from retrieval and preparation for perfusion (2 hr) added to the time of HPP. Tubular function studies demonstrated identical concentrations of Na+ and iohexol in ureteral effluent (UE) compared with circulating perfusate and, as such, established that UE flow represented a direct measure of glomerular filtration. Glomerular filtration rate (GFR) was then monitored during HPP by collecting UE in a beaker housed within a computerized Mettler balance system. GFR evolved in a characteristic, biphasic pattern during HPP, increasing from baseline values to reach a peak level at 4.8+/-0.3 hr of CIT and declining progressively thereafter. At 2.5 hr, time of peak values, 10 hr, 19.5 hr, and 24 hr of CIT, GFR values were 29+/-6 microl/min, 39+/-7 microl/min, 20+/-4 microl/min (n=15; P<0.01), 7+/-2 microl/min (n=14; P<0.001), and 14+/-6 microl/min (n=5), respectively. Intrarenal perfusate flows at the same time intervals were 4180+/-292 microl/min, 4083+/-290 microl/min, 3577+/-294 microl/min (P=NS), 1948+/-393 microl/min (P<0.001), and 2175+/-743 microl/min, respectively. Filtration fraction (FF) initially changed in parallel to glomerular filtration. Thereafter, FF either declined at a disproportionately slow rate compared with GFR (n=8) or increased rapidly (n=7). The data suggest that (1) primary change(s) in glomerular dynamics occur during HPP and (2) declining perfusate flow during the later stages of HPP reflects increasing renal vascular resistance localized at a postglomerular level. The data provide an experimental basis for investigating the clinical utility of monitoring glomerular filtration during HPP.

Effect of hydroxyethylstarch in brain-dead kidney donors on renal function in kidney-transplant recipients

BACKGROUND

Hydroxyethylstarch used as a plasma-volume expander in brain-dead kidney donors has been suggested to induce osmotic-nephrosis-like lesions. We have studied its effect on kidney-transplant function.

METHODS

52 patients who had received hydroxyethylstarch of iodinated contrast-media before brain death were excluded. 69 other brain-dead patients were prospectively included over 18 months and randomised into two groups. In the hydroxyethylstarch-gelatin group, patients received hydroxyethylstarch up to 33 mL/kg for colloid plasma-volume expansion, and afterwards received modified fluid gelatin. In the gelatin-only group, patients received only modified fluid gelatin as colloid plasma-volume expander. Multiple organs were procured in 29 cases, which included the kidneys in 27 cases (hydroxyethylstarch-gelatin 15, gelatin-only 12).

FINDINGS

There were no significant differences in the characteristics of patients between the two groups of kidney donors or of recipients (except for a small imbalance in sex in the recipients). During the first 8 days after transplantation, nine of 27 (33%) patients required extrarenal haemodialysis or haemodiafiltration in the hydroxyethylstarch-gelatin group compared with one of 20 (5%) in the gelatin-only group (p = 0.029). Serum creatinine concentrations were significantly lower in the gelatin-only group than in the other group (p = 0.009). 10 days after transplantation, mean (SD) serum creatinine was, respectively, 145 (70) and 312 (259) mumol/L.

INTERPRETATION

These data suggest that hydroxyethylstarch used as a plasma-volume expander in brain-dead donors impairs immediate renal function in kidney-transplant recipients.

Determinants of graft survival after renal transplantation

We studied multiple determinants of graft survival at a single center and the effects of nonimmunologic graft loss on transplant survival. This retrospective study examined the results of 589 cadaver donor transplants performed between 1986 and 1992. Graft survival rates were calculated using Kaplan-Meier estimates for both overall graft survival (all causes of graft loss) and immunologic graft survival (function lost due to acute or chronic rejection and noncompliance). Cadaver graft survival was significantly poorer with an increasing degree of DR mismatch (P=0.02). An analysis of pretransplant variables showed graft loss risk was highest with greater DR mismatches, two B-antigen mismatch, higher donor serum creatinine, and younger recipient age. After transplantation, acute rejection was the most significant factor associated with long-term graft survival. Our data demonstrate a significant advantage for zero DR and one DR mismatch cadaver donor transplants, with excellent immunologic graft survival. This study suggests that a combination of immediate graft function, prevention of acute rejection by appropriate early immunosuppressive therapy, and acceptable DR match enhances cadaveric graft survival.

Outcome of transplantation of non-heart-beating donor kidneys

To reduce the shortage of kidneys for transplantation, we started a non-heart-beating (NHB) donor programme, and compared the short-term and long-term outcomes of kidneys from NHB donors with those of a matched group of kidneys from heart-beating (HB) donors. 57 NHB kidneys were procured at the University Hospital in Maastricht and at three regional hospitals in the Netherlands, and were transplanted in 21 transplant centres within the Eurotransplant exchange organisation. 114 matched controls from HB donors were selected from Eurotransplant files. Mean follow-up was 85 months. At 5 years, graft survival was 54% for NHB kidneys and 55% for HB kidneys; patient survival was 75% and 77%. Kidneys from NHB donors had a significantly higher rate of delayed graft function (60% vs 35%), resulting in a longer hospital stay. Primary non-function of the graft was seen as frequently in the NHB donor-kidney group as in the HB group (14% vs 8%, p = 0.3). We conclude that NHB donors are a valuable source of kidneys for transplantation.

[Can hydroxyethylamidon be used during intensive care of brain-dead organ donors?]

In France, most of the kidney grafts are obtained from brain dead organ donors. Brain death induces numerous changes, especially in haemodynamic status, requiring the infusion of large volumes of fluid. The aim of this study was to evaluate the effect of hydroxyethyl starch (HES) on the organ donors and the kidney graft function in recipients. We compared two groups of brain dead organ donors and the kidney grafts, differing by the infused solutions: either a combination of HES (Elohes, Biosedra) and 4% human albumin solutions (HES group), or albumin alone in the control group (Albumin group). In the two groups, sex-ratio, age, cause of brain death and duration of therapy were similar. Fluid requirements were identical in the two groups: respectively 2,211 +/- 1,512 mL in the Albumin group vs 2,452 +/- 1,094 mL in the HES group (p = 0.17). However, the volume of albumin was significantly decreased in the HES group: 711 +/- 822 mL (p = 0.0001). Therefore the cost was lower in the latter: 638 +/- 633 vs 1766 +/- 788 FF. The coagulation status was not significantly different between the two groups. Amylasemia was higher in the HES group, but the difference was not significant. In the Albumin group, urinary output increased, but not significantly and creatinemia was decreased: 113.9 +/- 62 vs 131.5 +/- 44 mumol.L-1 (p < 0.05). The two groups of recipients were also similar for sex-ratio, age, kind of graft, cause of the chronic renal failure and ischaemia times.(ABSTRACT TRUNCATED AT 250 WORDS)

Failure of perfusion with oxygenated Krebs-Ringer solution to preserve the eccrine function of the vascular endothelium in bone

An ex vivo canine tibia preparation was perfused at a constant rate with aerated (95% O2-5% CO2) Krebs-Ringer solution for 24 h. Bolus injections of norepinephrine (0.125-0.5 micrograms) were given and then acetylcholine (5 x 10(-5) M) was used to stimulate endothelial production of smooth muscle relaxing factors. Following 1 h of perfusion the addition of acetylcholine resulted in significant attenuation of the response to norepinephrine (p < 0.001). After 4 h perfusion acetylcholine did not attenuate the norepinephrine response, but addition of L-arginine (the precursor of endothelial-derived relaxing factor) resulted in significant attenuation in the presence of acetylcholine (p < 0.005). At 6, 12, and 24 h the acetylcholine did not attenuate the norepinephrine response. It is concluded that normothermic, continuous perfusion with oxygenated Krebs-Ringer solution results in normal endothelial eccrine activity up to 1 h. Following this period there is substrate depletion but endothelial eccrine function can be demonstrated for up to 4 h. At 6 h this function cannot be demonstrated, suggesting degradation of the functional integrity of the endothelium.

The use of UW solution in clinical transplantation. A 4-year experience

The development of the University of Wisconsin (UW) cold storage solution has extended safe preservation of the liver and pancreas from 6 to 24 hours or more. From May 1987 until November 1991, 288 livers and 163 simultaneous pancreas/kidney transplants were performed using UW solution. The mean preservation times were: liver, 12.7 +/- 4.4 hours, pancreas 17.2 +/- 4.4 hours, and kidney, 19.2 +/- 4.3 hours. Included in this series were 35 reduced-sized liver transplants, 7 cluster transplants, and 132 combined liver/pancreas retrievals. No differences in allograft function or graft-related complications were seen in organs preserved for less than or longer than 12 hours or in grafts from combined liver/pancreas retrievals. All pancreas/kidney transplants and most liver transplants were performed semi-electively. Actuarial 1-month patient and graft survival after liver transplantation was 91.4% and 80.2%, and at 4 years was 74.0% and 62.0%, respectively. After pancreas/kidney transplantation, the actuarial patient survival at 1 month and 4 years was 99.4% and 90.5%, respectively, whereas pancreatic and renal allograft survival at 1 month was 97.5% and 96.8%, and at 4 years was 83.0% and 83.4%, respectively. The ability to extend preservation times with UW solution has many advantages; however, the most important contribution of UW solution to clinical transplantation has been the increased utilization of scarce donor organs for more recipients because the previously imposed constraints on preservation time have been removed.

Ethical decisions in the history of organ transplantation

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A new liver perfusion and preservation system for transplantation research in large animals

A kidney perfusion machine, model MOX-100 (Waters Instruments, Ltd, Rochester, MN) was modified to allow continuous perfusion of the portal vein and pulsatile perfusion of the hepatic artery of the liver. Additional apparatus consists of a cooling system, a membrane oxygenator, a filter for foreign bodies, and bubble traps. This system not only allows hypothermic perfusion preservation of the liver graft, but furthermore enables investigation of ex vivo simulation of various circulatory circumstances in which physiological perfusion of the liver is studied. We have used this system to evaluate the viability of liver allografts preserved by cold storage. The liver was placed on the perfusion system and perfused with blood with a hematocrit of approximately 20%, and maintained at 37 degrees C for 3 h. The flows of the hepatic artery and portal vein were adjusted to 0.33 mL and 0.67 mL/g of liver tissue, respectively. Parameters of viability consisted of hourly bile output, oxygen consumption, liver enzymes, electrolytes, vascular resistance, and liver histology. This method of liver assessment in large animals will allow the objective evaluation of organ viability for transplantation and thereby improve the outcome of organ transplantation. Furthermore, this pump enables investigation into the pathophysiology of liver ischemia and preservation.