Non-heart-beating Donors Research Articles

Fibrinolytic Treatment Improves the Quality of Lungs Retrieved From Non-Heart-Beating Donors

The use of non-heart-beating donors (NHBDs) is an alternative strategy to increase the limited number of donors. The ex vivo evaluation has been proposed to assess the function of the lungs from NHBDs as an interim evaluation of the graft before transplantation. We evaluated the effect of a fibrinolytic agent, urokinase, in a pig ex vivo evaluation model. Domestic pigs (30-38 kg) were divided in 3 groups of 5 pigs each. In the Control Heart-Beating Donor (HBD) Group, the lungs were flushed, explanted, and stored in cold solution (4 degrees C) of low potassium dextran for 4 hours. The pigs in the other 2 study groups were non-heart-beating donors (NHBD), and their lungs were topically cooled for 1 hour in the closed chest after 3 hours of warm ischemia. Urokinase (100,000 IU) was added into the perfusate during reperfusion 1n 1 of the NHBD groups (NHBD-UROK). Hemodynamic and aerodynamic parameters were measured. The wet-to-dry weight ratio was calculated. There was a significant difference between NHBD-UROK and NHBD Groups in pulmonary vascular resistance (22.5 +/- 3.06 vs 39.02 +/- 6.6 Wood Units, p = 0.032), partial pressure of arterial oxygen/fraction of inspired oxygen (250.8 +/- 23.3 vs 148.9 +/- 14.6 mm Hg, p = 0.032), oxygenation index (6.9 +/- 0.7 vs 15.9 +/- 3.2, p = 0.016), and wet-to-dry weight ratio (5.99 +/- 0.2 vs 7.74 +/- 0.3, p = 0.016). Pulmonary vascular resistance did not differ between the HBD and NHBD-UROK Groups but was significantly higher in the NHBD Group than in the HBD Group (p = 0.032). Adding urokinase into the perfusate during ex vivo evaluation resulted in improved graft function by reducing pulmonary vascular resistance and increasing oxygenation after 3 hours of warm ischemia. This ex vivo evaluation model is feasible and may be used to recondition grafts from NHBDs.

Impact of Female Sex Hormones on Liver Tissue Lactic Acidosis During Ischemia

Lower liver transplant success is observed when the donor is female. Intracellular acidosis during ischemia is proposed to contribute to the injury sustained by the transplanted organ and its role in livers obtained from nonheartbeating donors is unclear. Research has shown that livers of female rats develop a greater degree of intracellular acidosis during ischemia than males. This work explores the role of sex hormones in mediating this sex difference. Subgroups of neutered female rats were given 17 beta-estradiol (E), progesterone (P), or combination (E+P). To compare the effects of female sex hormones in males, subgroups of intact and castrated males received 17 beta-estradiol. In vivo and ischemic liver biopsies were taken and analyzed for lactate and H. Although there was no effect of hormone therapy on baseline metabolic parameters, during ischemia compared to neutered females, livers from E females significantly (P<0.01) increased lactate by 56% and H+ by 71%, while E+P significantly increased only lactate (39%; P<0.05). Livers from neutered males given 17 beta-estradiol showed significantly greater (P<0.001) accumulation of lactate (80%) and H+ (79%). This was even shown in intact males, where despite a blunted response, 17 beta-estradiol, significantly (P<0.05) increased lactate by 39% and H+ by 25%. This study illustrates the mechanisms for the sex difference in the liver's metabolic response to ischemia are estrogen mediated, which is seen even in the presence of male hormones, thus offering one explanation for the lower liver transplant success when the donor is female.

A total ischemia time of &gt;24 h does not preclude transplantation of kidneys from non-heartbeating donors

A total ischemia time of >24 h does not preclude transplantation of kidneys from non-heartbeating donors

Liver integrity after warm ischemia in situ and brief preservation ex vivo: The value of aerobic post-conditioning

We evaluated the respective effects of warm ischemic injury in non-heart-beating donor (NHBD) grafts and/or cold ischemia time on liver viability. Eventually, the restorative potential of oxygenated hypothermic perfusion after cold storage should be investigated. Livers were retrieved from male Wistar rats and preserved with HTK-solution for 6 h or 18 h by cold storage (CS). Organ retrieval took place either prior to (ctrl.) or 30 min after cardiac arrest (NHBD). Compared to 6 h CS of ctrl. livers, enzyme leakage and functional recovery (oxygen consumption, ammonia clearance, bile production) upon warm reperfusion were massively deteriorated after 18 h CS in NHBD-livers. By contrast, 6 h CS of NHBD resulted in an only limited impairment of all parameters, which was found quite similar to the results in ctrl. after 18 h CS. Induction of cellular apoptosis (cleavage PARP) was found equally influenced by preceding warm ischemia (NHBD) or extended times of CS, but significantly triggered only by the combination of both events. After 6 h of CS, 1 h of oxygenated hypothermic machine perfusion (‘post-conditioning’) was able to bring the performance of NHBD-liver into line with the controls. Based on this work, we concluded that a limited time of warm ischemia in the donor only multiplied graft injury after long-term CS, but does not need to preclude acceptable results if reperfusion is initiated after short periods of CS. Moreover, conditioning of those grafts is effective even 1 h prior to implantation and may help to judge liver viability according to adequate parameters after hypothermic machine perfusion has been established.

Sequential Quadruple Immunosuppression Including Sirolimus in Extended Criteria and Nonheartbeating Donor Kidney Transplantation

The aim was to evaluate feasibility and safety of calcineurin inhibitor-free immunosuppression in high-risk donor kidney transplantation with sequential sirolimus introduction. Kidney transplant patients (n=76) with a donor aged >60 years, donor with acute renal failure, or a nonheartbeating donor were included. Immunosuppression consisted of antithymocyte globulin or basiliximab, mycophenolate mofetil, prednisone, and sequential introduction of sirolimus. One-year patient survival was 96.2% and 95.8%; graft survival was 94.2% and 91.7%; acute rejection rates were 21.2% and 12.4%; delayed graft function was 21.2% and 66.7%; and creatinine clearance was 58+/-20 mL/min and 56+/-21 mL/min for the brain-dead donor group and the nonheartbeating donor group, respectively. Most adverse events were infections, but also three lymphoceles, three urinary fistulas, three wound seromas. Sequential sirolimus introduction in high-risk donor kidney transplantation was found to lead to good patient and graft survival and incidence of acute rejection and delayed graft function.

Measures of care in adult renal transplant recipients in the United Kingdom (Chapter 11)

The total number of patients active on the transplant waiting list (adult and paediatric) on 31 December 2005 was 5736, an 8% increase from the previous year. On 31 December 2005, 45.7% of prevalent adult RRT patients in the UK, had a functioning renal transplant which equated to 19,074 patients. During 2005, the death rate in prevalent transplant patients was 2.7 per 100 patient years. An additional 3.1% of all prevalent transplants failed with patients returning to dialysis. During 2005, deceased heart beating donor numbers decreased by 18% compared to 2004. In comparison, non-heart beating donors and living kidney donors increased by 35% and 17%, respectively, in 2005. The proportion of renal transplants performed from deceased heart beating donors fell from 68% in 2004 to 60% in 2005. There is wide variation in prevalence per million population (pmp) of transplanted patients resident in each local authority area across the United Kingdom. Total 11.4% of incident transplants in 2005 were due to patients with diabetes. The median eGFR was 46.1 ml/min/1.73 m(2), with 18% of prevalent transplant recipients having an eGFR <30 ml/min/1.73 m(2). The median Hb in prevalent transplant recipients was 12.9 g/dl, with 10% of patients having an Hb <10 g/dl. The median systolic and diastolic BP was 136 and 79 mmHg, respectively, with only 25% of patients within guidelines. Transplant function analysed by CKD stages 1-2 (eGFR < 60), 3 (eGFR 30-59), 4 (eGFR 15-29) and 5 (eGFR < 15), shows that these categories account for 24%, 59%, 15% and 2.5% of patients, respectively. Haemoglobin values fall with decreasing eGFR such that of the 2.5% of transplant patients with eGFR <15 ml/min, 27% had an Hb <10 g/dl and 51% <11 g/dl. Control of iPTH was poor in transplant recipients in CKD stages 4 and 5, with 22% and 50% of patients, respectively, having a PTH > 32 pmol/l (=300 ng/l). Patients with failing transplants are less likely to achieve RA targets of key biochemical variables when compared to patients on dialysis. There is still wide variability in the completeness of data returns from individual units.

Reduction of Ischemia–Reperfusion Injury in the Rat Kidney by FTY720, a Synthetic Derivative of Sphingosine

The current shortage of organ donors has led many centers to use marginal and nonheart-beating donors (NHBDs). Recent research has implicated the infiltration of lymphocytes as an important mediator of ischemia-reperfusion injury (IRI). FTY720 is an immunosuppressant that promotes lymphocyte sequestration into lymph nodes. The purpose of this study was to examine the potential for FTY720 to abrogate IRI when subjected to increasing ischemic times. Male Sprague-Dawley rats underwent bilateral flank incision with removal of the right kidney and clamping of the left hilum. Groups were divided into ischemia times of 45, 55, and 65min; each group was further divided into a control group (IRI only), IRI+FTY720 (1 mg/kg/d), and IRI+cyclosporine (15 mg/kg/d), n=4 per group. Thre days after 45 min of ischemia, serum creatinine in the ischemia only (477+/-37 micromol/L) and cyclosporine groups (698+/-32 micromol/L) was significantly increased compared with the FTY720-treated animals (194+/-66 micromol/L). The beneficial effect of FTY720 was also observed at 55 and 65 min; indeed, FTY720-treated animals demonstrated signs of recovery from 65 min of ischemia whereas control and cyclosporine-treated animals required sacrifice between days 3 and 5. Treatment with FTY720 reduced renal damage assessed histologically and also reduced apoptosis and increased cell proliferation. Treatment with FTY720 reduced IRI and prevented unrecoverable acute renal failure after significant ischemic injury. This study suggests that FTY720 may help improve the quality of grafts from NHBD and marginal donors by abrogating the IRI insult.

Two cases of primary non‐functioning kidney from the same donor

Abstract: We report two cases of primary non‐functioning kidney from the same non‐heart beating donor (NHBD). A 42‐yr‐old man received a renal transplant from a NHBD. The donor was a 38‐yr‐old male who died of neck spinal injury. The warm ischemic time was 61 min. One h after reperfusion, the graft became edematous and congested in the presence of normal and adequate vascular anastomosis and lack of renal vein thrombosis. The one‐h biopsy specimen showed acute tubular necrosis and severe congestion with occasional platelet aggregates in glomerular capillaries. The graft was resected on post‐transplantation day 6. Graftectomy specimen revealed renal cortical necrosis. The contralateral kidney of the same donor was transplanted into a 54‐yr‐old male. The one‐h biopsy specimen showed tubular degeneration and neutrophil infiltration in peritubular capillaries, but no glomerular congestion or thrombus. The recipient died on post‐transplantation day 4. Although the cause of death was unknown, necropsy of the renal graft showed renal cortical necrosis, similar to case 1. Ischemia/reperfusion injury was considered the cause of non‐functioning kidney in both cases, because of long warm ischemic time. The biopsy specimens at zero‐h from both grafts showed focal tubular degeneration only without distinct necrosis, indicating it is difficult to predict viability based on the pathological findings at zero‐h or one‐h biopsies. There is a need for further understanding of clinical and histological patterns in order to define the criteria of viability of kidney transplant.

The Influence of Pulsatile Preservation in Kidney Transplantation From Non–Heart-Beating Donors

Continuous hypothermic pulsatile perfusion (CHPP) may offer improved early function compared with cold static perfusion (CSP) for heart-beating cadaveric donors. With an expanding pool of donors, ie, non–heart-beating donors (NHBD), we present our preliminary results with the use of CHPP compared with CSP to preserve kidney grafts retrieved from NHBD. Eighteen consecutive locally procured cadaveric kidneys from NHBD were preserved using CHPP using UW machine perfusion solution in the Life Port kidney transporter. Perfusion parameters were measured serially during pulsatile perfusion. This group was compared with 18 NHBD cadaveric kidneys preserved with CSP. No organs were lost due to faulty technique of preparation or preparation of pulsatile perfusion. Immediate renal function was observed in 13 cases (72.2%). In CSP in NHBD, we had 16 cases with delayed graft function (88.8%). These early results show that the use of pulsatile perfusion to preserve kidneys from NHBD may be associated with improved early outcomes. Longer follow-up is required to answer the more important question as to whether it offers long-term improvements that justify the extra cost and complexity.

Liver Transplantation Using Non-Heart-Beating Donors: Belgian Experience

Mortality on liver transplantation (OLT) waiting lists has increased dramatically. Until recently, non-heart-beating donors (NHBD) were not considered suitable for OLT, because of a higher risk of primary graft nonfunction (PNF) and biliary strictures. However, recent experimental/clinical evidence has indicated that NHBD-OLT is feasible when the period of warm ischemia is short. Purpose To characterize the results of NHBD-OLT in Belgium, a survey was sent to all Belgian OLT centers. Results Between January 2003 and November 2005, 16 livers originating from NHBD were procured and transplanted. The mean donor age was 48.8 years, including 9 males and 7 females with mean time of stop-therapy to cardiac arrest being 18 minutes and from cardiac arrest to liver cold perfusion, 10.5 minutes. Mean recipient age was 52.2 years including 12 males and 4 females. Mean cold ischemia time was 7 hours 15 minutes. No PNF requiring re-OLT was observed. Mean post-OLT peak transaminase was 2209 IU/L, which was higher among imported versus locally procured grafts. Biliary complications occurred in 6 patients requiring re-OLT (n = 2), endoscopic treatment (n = 2), surgical treatment (n = 1), or left untreated (n = 1). These tended to be more frequent after prolonged warm ischemia. Graft and patient survivals were 62.5% and 81.3%, respectively, with a follow-up of 3 to 36 months. Conclusion This survey showed acceptable graft/patient survivals after NHBD-LT. The NHBD-liver grafts suffered a high rate of ischemic injury and biliary complications and therefore should be used carefully, namely with no additional donor risk factors, lower risk recipients, and short cold/warm ischemia.

Canine Bilateral Lung Transplantation After 18-hour Preservation Using Non–heart-beating Donors

We previously reported that lung inflation with oxygen, EPC-K1 (a diester alpha-tocopherol and ascorbic acid), urokinase and low-potassium dextran glucose (LPDG) solution can be beneficial in lung preservation. In the present study, a canine bilateral lung transplantation (BLT) model was used to evaluate long-term lung preservation of non-heart-beating donors (NHBDs). Animals were euthanized without heparinization and left at room temperature for 2 hours until lung extraction. After cardiac arrest, the lungs were kept inflated with 100% oxygen. After extraction, the donor lungs were flushed with LPDG solution containing EPC-K1 (1.0 mg/liter), followed by injection of urokinase (120,000 IU) into the pulmonary artery. Eighteen BLTs were performed after preservation at 4 degrees C. Total ischemic time was scheduled for 12 hours in Group 1 (n = 6), 18 hours in Group 2 (n = 6) and 24 hours in Group 3 (n = 6). After BLT, recipients were followed up for 6 hours. An additional 6 BLTs were performed as a chronic study in the same setting as for Group 2. All animals in Groups 1 and 2 showed excellent pulmonary function during the 6-hour post-transplant assessment time, in contrast to only 2 dogs from Group 3. In the chronic study, all 6 animals showed excellent pulmonary function for 24 hours (PaO2 = 528 +/- 8 mm Hg with 100% oxygen) and 2 of them survived for >1 week. Successful chronic lung preservation (18 hours) using NHBDs is achievable in a canine BLT model.

Outcome of Kidney Transplantation From Nonheart-Beating Versus Heart-Beating Cadaveric Donors

This study aimed to assess outcomes of kidney transplants from nonheart-beating (NHB) compared with heart-beating (HB) cadaveric donors with meta-analytical techniques. A literature search was performed for studies comparing kidney transplants from NHB vs. HB cadaveric donors between 1992 and 2005. The following outcomes were evaluated: warm and cold ischemia times, primary nonfunction, delayed graft function, length of hospital stay, acute graft rejection, patient and graft survival, and post-transplant serum creatinine. Eighteen comparative studies of 114,081 patients matched the selection criteria; 1,858 received kidney from NHB and 112,223 from HB donor. Warm ischemia time was significantly longer for the NHB group by 24 min (P<0.001). Cold ischemia time was similar for the two groups (P=0.97). The incidence of primary nonfunction and delayed graft function was 2.4 times (P<0.001) and 3.6 times (P<0.001) greater, respectively, in the NHB group. Length of hospital stay was longer for the NHB group by 4.6 days (P<0.001). The 6-month, 2-year, and 5-year patient survival were similar between the two groups. The incidence of acute rejection was similar between the two groups whereas the initial graft survival advantage in favor of the HB group diminished gradually over the course of time. There was no statistically significant difference between the two groups for the recipient serum creatinine levels at 3 and 12 months after transplantation. NHB donors carry the potential of expanding the cadaveric kidney pool. Although, transplants from NHB donors are associated with a greater incidence of early adverse events, long-term outcomes appear comparable with those of transplants from HB donors.

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.

Results of Clinical Lung Transplant From Uncontrolled Non-Heart-Beating Donors

The scarcity of grafts for lung transplant and the growing number of candidates expecting an organ has led to an increase of deaths in patients waiting for lung transplantation. Non-heart-beating donors (NHBD) represent a promising source of grafts for those who are involved in clinical lung transplantation. We present the results of our series of 17 out-of-hospital NHBD lung transplantations performed since 2002. We have collected data from 17 donors and recipients involved in NHBD lung transplants since 2002, as well as data referring to the type of procedure and peri-operative events. We describe the incidence of post-operative complications with special attention to primary graft disfunction (PGD), bronchial healing, bronchiolitis obliterans syndrome (BOS), and survival. We used Kaplan-Meier method to obtain the survival curve. G2-G3 PGD was reported in 9 patients (53%), with a complete restoration of the partial pressure of arterial oxygen/fraction of inspired oxygen ratio in 170 hours for G2 and 168 hours for G3. There were no deaths directly related to PGD. Acute rejection was detected in 7 patients (41%), 4 of which exceeded grade 1. The incidence of BOS after transplantation was 1 (7%) of 14 patients during the first year, 2 (11%) of 9 in the second year, and 2 (50%) of 4 in the third year. Hospital mortality rate was 17%. The survival rates were 82% at 3 months, 69%, at 1 year, and 58% at 3 years. Mid-term results confirm the adequacy of uncontrolled NHBD as a promising complementary source of lung donors for clinical transplant.

A new disposable perfusion machine, nuclear magnetic resonance compatible, to test the marginal organs and the kidneys from non-heart-beating donors before transplantation

This article is the first report about our new hypothermic pulsatile perfusion machine (HUG's HPP-machine) for kidney perfusion. This machine will be used for (31)P NMR spectroscopy. The aim is to obtain scores of viability of marginal kidneys and those from non-heart-beating donors (NHBD) before transplantation using HPP as it has been demonstrated necessary in these situations. The most predictable test is the ratio of phosphomonoester on inorganic phosphorus (PME/Pi) that can be obtained from (31)P spectroscopy. The machine has been built to allow perfusion of kidneys in the range of that performed with the traditional Belzer, Mox-Waters machines and others, but compatible with the magnetic fields of the MRI apparatus used for (31)P NMR spectroscopy. In this publication, the technical aspects of this new aerobic HPP-machine compatible with MRI is presented.

Transplantation From Non–Heart-Beating Donors

Non–heart-beating donor (NHBD) transplants have been reintroduced into clinical practice because of the progressively rising number of patients on the transplant waiting list and relatively static numbers of cadaver organ donors. Several units have undertaken NHBD programs utilizing category 3 of Maastricht criteria. The current data show encouraging outcomes, which give rise to further interest in this donor pool. This manuscript briefly summarizes the most recent reports in this field.

Retrograde flush following topical cooling is superior to preserve the non-heart-beating donor lung☆☆☆

The use of non-heart-beating donors (NHBD) has been propagated as an alternative to overcome the scarcity of pulmonary grafts. Formation of microthrombi after circulatory arrest, however, is a major concern for the development of reperfusion injury. We looked at the effect and the best route of pulmonary flush following topical cooling in NHBD. Non-heparinized pigs were sacrificed by ventricular fibrillation and divided into three groups (n=6 per group). After 1h of in situ warm ischaemia and 2.5h of topical cooling, lungs in group I were retrieved unflushed (NF). In group II, lungs were explanted following an anterograde flush (AF) through the pulmonary artery with 50 ml/kg Perfadex (6 degrees C). Finally, in group III, lungs were retrieved after an identical but retrograde flush (RF) via the left atrium. Flush effluent was sampled at intervals to measure haemoglobin concentration. Performance of the left lung was assessed during 60 min in our ex vivo reperfusion model. Wet-to-dry weight ratio (W/D) of both lungs was calculated as an index of pulmonary oedema. IL-1beta and TNF-alpha protein levels in bronchial lavage fluid from both lungs were compared between groups. Haemoglobin concentration (g/dl) was higher in the first effluent in RF versus AF (3.4+/-1.1 vs 0.6+/-0.1; p<0.05). Pulmonary vascular resistance (dynes x s x cm(-5)) was 975+/-85 RF versus 1567+/-98 AF and 1576+/-88 NF at 60 min of reperfusion (p<0.001). Oxygenation (mmHg) and compliance (ml/cmH(2)O) were higher (491+/-44 vs 472+/-61 and 430+/-33 NS, 22+/-3 vs 19+/-3 and 14+/-1 NS, respectively) and plateau airway pressure (cmH(2)O) was lower (11+/-1 vs 13+/-1 and 13+/-1 NS) after RF versus AF and NF, respectively. No differences in cytokine levels or in W/D ratios were observed between groups after reperfusion. Histology demonstrated microthrombi more often present after AF and NF compared to RF. Retrograde flush of the lung following topical cooling in the NHBD results in a better washout of residual blood and microthrombi and subsequent reduced pulmonary vascular resistance upon reperfusion.

Comparison of HTK and Hypertonic Citrate to Intraarterial Cooling in Human Non–Heart-Beating Kidney Donors

Intraarterial cooling (IAC) of non–heart-beating donors (NHBD) for renal donation requires a cheap, low-viscosity solution. HTK contains a high hydrogen ion buffer level that theoretically should reduce the observable acidosis associated with ongoing anaerobic metabolism. A retrospective comparison of all retrieved NHBD kidneys as well as of viability on the Organ Recovery Systems Lifeporter machine perfusion circuit was performed with respect to the preservation solution HTK or Marshall’s HOC. Forty-two NHBD kidneys (19 HTK and 23 HOC) were machine perfused between February 2004 and May 2005. Most of the HTK kidneys were obtained from uncontrolled donors (12 vs 5; Fisher exact test, P = .01). As a consequence, the glutathione- s-transferase viability assay (411 vs 292 IU/L, P = .12) and the lactate concentrations (2.33 vs 1.94 mmol/L, P = .13) were higher among the HTK cohort. There was evidence of greater buffering capacity in HTK, since the lactate:hydrogen ion ratios were consistently lower during the first 2 perfusion hours (1 hour P = .03, 2 hour P = .02). A linear regression analysis confirmed that this was related to the IAC solution (ANCOVA, P < .001). All controlled donor kidneys passed viability testing and were transplanted. In contrast, 83% (10/12) of the uncontrolled donor kidneys preserved with HTK passed the viability test and were transplanted, compared with only 20% (1/5) of the HOC-treated comparators (Fisher exact test, P = .03). It may be concluded that the postulated advantages of improved pH buffering with HTK appear to have clinical relevance.

Non-heartbeating donation of kidneys for transplantation

There is a persistent shortage of kidneys available for transplantation. In the early 1980s, therefore, we published the concept of non-heartbeating (NHB) donation; that is, procurement of kidneys from donors whose death has been accompanied by irreversible circulatory arrest. NHB donors are generally categorized using four definitions; category III (awaiting cardiac arrest) and category IV (cardiac arrest while braindead)--or 'controlled'--donors are the most suitable for initiating NHB donation programs. Delayed graft function is associated with use of kidneys from such donors, but has no effect on graft survival in the short or long term. Use of kidneys from category I (dead upon arrival at hospital) and category II (unsuccessfully resuscitated), or 'uncontrolled', donors is likewise associated with delayed graft function, but also with an increased risk of primary nonfunction. Viability testing of donated organs from these sources is a prerequisite for transplantation. Machine preservation parameters and enzyme release measurements help to distinguish viable from nonviable kidneys. The proportion of NHB donor kidneys in the total pool of postmortem kidneys differs considerably between countries. In The Netherlands, the proportion is nearly 50%. This figure is markedly higher than that in the US and Canada, where national programs have now been initiated to increase rates of NHB donation. In the future, warm preservation techniques might facilitate better viability testing, thereby increasing NHB donation from category I and II donors and further reducing the shortage of kidneys available for transplantation.

Redox-active iron level predicts viability of renal grafts from non-heart beating donors

Redox-active iron level predicts viability of renal grafts from non-heart beating donors