The non heart-beating donor

The Benefits of Fibrinolysis Combined with Venous Systemic Oxygen Persufflation (VSOP) in a Rat Model of Donation after Circulatory Death and Orthotopic Liver Transplantation

Organ shortage has led to the increasing utilization of livers retrieved from donors after circulatory death (DCD). These pre-damaged organs are susceptible to further warm ischemia and exhibit minimal tolerance for cold storage. The aim was thus to examine the effects of fibrinolysis combined with Venous Systemic Oxygen Persufflation (VSOP) on the preservation of DCD livers in vivo. Livers of male Lewis rats were explanted after 45 min of warm ischemia, cold-stored for 18 h, and transplanted into a recipient animal. Livers were left untreated or underwent either VSOP or fibrinolysis via Streptokinase (SK) or received combined SK and VSOP. Combined treatment exhibited improved microvascular flow at 168 h (p = 0.0009) and elevated microperfusion velocity at 24 h post-transplantation (p = 0.0007). Combination treatment demonstrated increased portal venous flow (PVF) at 3 and 24 h post-transplantation (p = 0.0004, p < 0.0001), although SK and VSOP analogously achieved increases at 24 h (p = 0.0036, p = 0.0051). Enzyme release was decreased for combination treatment (p = 0.0002, p = 0.0223) and lactate dehydrogenase (LDH) measurements were lower at 24 h post-transplantation (p = 0.0287). Further supporting findings have been obtained in terms of serum cytokine levels and in the alterations of endothelial injury markers. The combination treatment of SK + VSOP might provide improved organ integrity and viability and may therefore warrant further investigation as a potential therapeutic approach in the clinical setting of DCD.

Perfusion of a Kidney Graft from a Donor After Cardiac Death Based on Immediately Started Machine Perfusion: An Experimental Study on a Big Animal

BACKGROUND

Donation after circulatory death donors are becoming a common source of organs for transplant. Despite good long-term outcomes of grafts from donation after circulatory death, this group is affected by a higher occurrence of delayed graft function and primary nonfunction. Our hypothesis is based on the assumption that washing the kidney grafts in the donor's body using a simple mechanical perfusion pump will result in faster and better perfusion of the parenchyma and more efficient cooling compared with hydrostatic perfusion alone.

METHODS

A total of 7 experimental animals (pigs) were used. The animals were divided into 2 groups: group A (n = 3) and group B (n = 4). After a 30-minute ischemic period for the selected kidney (clamped renal vessels), intra-arterial perfusion was performed. In group A perfusion was performed using hydrostatic pressure; in group B mechanical controlled perfusion was performed. After perfusion, declamping of the renal vessels caused restoration of flow. For graft quality evaluation, biopsy specimens were harvested, and the cooling speed was observed. Laboratory markers or renal failure were determined.

RESULTS

We found no significant differences between temperature drop and total diuresis between groups A and B. A significant difference was found between the groups in both flow parameters (flow maximum and mean flow) (P = .007, respectively P = .019). No laboratory parameters were found to be statistically significantly different. Histopathological analysis strongly supports the hypothesis of better flushing of kidney grafts using mechanical perfusion.

CONCLUSIONS

Based on our results, better kidney graft quality can be expected after immediately started mechanical perfusion in situ.

Controversy in the Determination of Death: The Definition and Moment of Death

This essay reviews recent controversy in the determination of death, with particular attention to the definition and moment of death. Definitions of death have evolved from the intuitive to the pathophysiologic and the medicolegal. Many United States jurisdictions have codified the definition of death relying on guidance from the Uniform Determination of Death Act (UDDA). Flaws in the structure of the UDDA have led to misunderstanding of the physiologic nature of death and methods for the determination of death, resulting in a bifurcated concept of death as either circulatory/respiratory or neurologic. The practice of organ donation after circulatory determination of death (DCDD) raises a number of ethical questions, most prominently revolving around the moment of death and manifested as an expedited time to determination of death, a departure from the unitary concept of death, a violation of the dead donor rule, and a challenge to the standard of irreversibility. Attempts to redefine the determination of death from an irreversibility standard to a permanence standard have significant impact on the social contract upon which deceased donor organ transplantation rests, and must entail broad societal examination. The determination of death is best reached by a clear, strict, and uniform irreversibility standard. In deceased donor organ transplantation, the interests of the donor as a person are paramount, and no interest of organ recipients or of the greater society can justify negation of the rights and bodily integrity of the person who is a donor, nor conversion of the altruism of giving into the calculus of taking.

Impact of Cold Ischemia Time on Outcomes of Deceased Donor Kidney Transplantation: An Analysis of a National Registry

Background

Cold ischemia time (CIT) is known to impact kidney graft survival rates. We compare the impact of CIT on graft failure and mortality in circulatory death versus brain death donor kidneys and how it relates to donor age.

Methods

We used the prospective Dutch Organ Transplantation Registry to include 2153 adult recipients of brain death (n = 1266) and circulatory death (n = 887) donor kidneys after static cold storage from transplants performed between 2005 and 2012. CIT was modeled nonlinearly with splines. Associations and interactions between CIT, donor type, donor age, 5-year (death-censored) graft survival, and mortality were evaluated.

Results

The median CIT was 16.2 hours (interquartile range 12.8-20), ranging from 3.4 to 44.7 hours for brain death and 4.7 to 46.6 hours for circulatory death donor kidneys. At >12 hours of CIT, we observed an increased risk of graft failure in kidneys donated after circulatory death versus after brain death. This risk rose significantly at >22 hours of CIT (hazard ratio 1.45; 95% confidence interval, 1.01-2.49; P = 0.043). Kidneys that came from 60-year-old circulatory death donors demonstrated elevated hazard risk at 19 hours of CIT, a shorter timeline than that for kidneys that came from brain death donors of the same age (hazard ratio 1.33; 95% confidence interval, 1.00-1.78; P = 0.045). The additional harmful effects of increased CIT in kidneys from circulatory-death donors were also found for death-censored graft failure but did not affect mortality rates in any significant way.

Conclusions

The findings support the hypothesis that prolonged cold ischemia is more harmful for circulatory death donor kidneys that have already been subjected to a permissible period of warm ischemia. Efforts should be made to reduce CIT, especially for older circulatory death donor kidneys.

Donor liver quality after hypovolemic shock and venous systemic oxygen persufflation in an experimental animal model

BACKGROUND

The ever growing demand for liver transplantation inevitably necessitates an expansion of the donor pool. Utilization of "shock organs" is considered suboptimal to date while the associated outcome has hardly been investigated.

MATERIALS AND METHODS

Male Wistar rats underwent a period of 30 min of hypovolemic shock. After 24 h livers were explanted and prior to reperfusion underwent either 18 h of cold storage (CS; N = 6) or 17 h of CS followed by 60 min venous systemic oxygen persufflation (VSOP; N = 6). The outcome of "shock organs (SHBD)" was compared to heart-beating donor (HBD; N = 12) as positive control and non-heart-beating donor (NHBD; N = 12) as negative control animal groups. Liver function was assessed by measuring enzyme release (AST, ALT, LDH), bile production, portal vein pressure and hepatic oxygen uptake during reperfusion. For reperfusion, the isolated perfused rat liver system was used.

RESULTS

Liver function was severely limited in NHBD group compared to HBD organs after 18 h of CS (e.g., AST; HBD: 32.25 ± 7.25 U/l vs. NHBD: 790 ± 414.56 U/l; p < 0.005). VSOP improved liver function of NHBD organs significantly (AST; NHBD + VSOP: 333.6 ± 149.1 U/l; p < 0.005). SHBD organs showed a comparable outcome to HBD and clearly better results than NHBD organs after 18 h of CS (AST; SHBD: 76.4 ± 21.9 U/l). After 17 h of CS accompanied by 60 min VSOP, no improvement concerning liver function and integrity of SHBD organs was observed while the results were severely deteriorated by VSOP resulting in higher enzyme release (AST; SHBD + VSOP: 213 ± 61 U/l, p < 0.001), higher portal vein pressure (SHBD: 10.8 ± 1.92 mm Hg vs. SHBD + VSOP: 21.6 ± 8.8 mm Hg; p < 0.05) and lower hepatic oxygen uptake (SHBD: 321.75 ± 3.87 ml/glw/min vs. SHBD + VSOP: 395.8 ± 46.64 ml/glw/min, p < 0.05) at 24 h.

CONCLUSIONS

Our data suggest that the potential of "shock organs" within liver transplantation may be underestimated. If our findings are reproducable in humans, SHBD grafts should be considered as a valuable source for expanding the thus far limited donor pool.

DCD donor hemodynamics as predictor of outcome after kidney transplantation

Insufficient hemodynamics during agonal phase-ie, the period between withdrawal of life-sustaining treatment and circulatory arrest-in Maastricht category III circulatory-death donors (DCD) potentially exacerbate ischemia/reperfusion injury. We included 409 Dutch adult recipients of DCD donor kidneys transplanted between 2006 and 2014. Peripheral oxygen saturation (SpO2-with pulse oximetry at the fingertip) and systolic blood pressure (SBP-with arterial catheter) were measured during agonal phase, and were dichotomized into minutes of SpO2 > 60% or SpO2 < 60%, and minutes of SBP > 80 mmHg or SBP < 80 mmHg. Outcome measures were and primary non-function (PNF), delayed graft function (DGF), and three-year graft survival. Primary non-function (PNF) rate was 6.6%, delayed graft function (DGF) rate was 67%, and graft survival at three years was 76%. Longer periods of agonal phase (median 16 min [IQR 11-23]) contributed significantly to an increased risk of DGF (P = .012), but not to PNF (P = .071) and graft failure (P = .528). Multiple logistic regression analysis showed that an increase from 7 to 20 minutes in period of SBP < 80 mmHg was associated with 2.19 times the odds (95% CI 1.08-4.46, P = .030) for DGF. In conclusion, duration of agonal phase is associated with early transplant outcome. SBP < 80 mmHg during agonal phase shows a better discrimination for transplant outcome than SpO2 < 60% does.

Stretching the Limits of Renal Transplantation in Elderly Recipients of Grafts from Elderly Deceased Donors

An increasing number of elderly patients (≥65 years) receive a donor kidney from elderly donors after brain death (DBD) or after circulatory death (DCD). These organs are allocated within the Eurotransplant Senior Program, but outcomes must be evaluated. From the Dutch Organ Transplantation Registry, we selected 3597 recipients (≥18 years) who received a first DBD or DCD kidney during 2002-2012, and categorized them as young or elderly recipients receiving a graft from either a young or elderly donor, stratified by donor type. In multiple logistic regression analysis, elderly recipients of elderly DCD kidneys experienced more delayed graft function and acute rejection than did elderly recipients of young DBD kidneys (odds ratios 10.43 [95% confidence interval (95% CI), 5.75 to 18.91] and 2.78 [95% CI, 1.35 to 5.73], respectively). In Cox regression analysis, elderly recipients of elderly DCD kidneys had a 5-year mortality risk higher than that of elderly recipients of young DBD kidneys (hazard ratio, 1.86; 95% CI, 1.15 to 3.02). Elderly recipients of elderly kidneys had a 5-year mortality rate comparable to that of waitlisted elderly patients remaining on dialysis. Among elderly recipients, 63.8% of those who received elderly DCD kidneys, 45.5% of those who received elderly DBD kidneys, and approximately 26% of those who received young DBD or DCD kidneys had an eGFR<30 ml/min per 1.73 m² (including primary nonfunction) after 1 year. In conclusion, improving donor selection and preservation is warranted if the allocation of elderly DCD grafts to elderly recipients is to be expanded.

Maximizing kidneys for transplantation using machine perfusion: from the past to the future: A comprehensive systematic review and meta-analysis

BACKGROUND

The two main options for renal allograft preservation are static cold storage (CS) and machine perfusion (MP). There has been considerably increased interest in MP preservation of kidneys, however conflicting evidence regarding its efficacy and associated costs have impacted its scale of clinical uptake. Additionally, there is no clear consensus regarding oxygenation, and hypo- or normothermia, in conjunction with MP, and its mechanisms of action are also debated. The primary aims of this article were to elucidate the benefits of MP preservation with and without oxygenation, and/or under normothermic conditions, when compared with CS prior to deceased donor kidney transplantation.

METHODS

Clinical (observational studies and prospective trials) and animal (experimental) articles exploring the use of renal MP were assessed (EMBASE, Medline, and Cochrane databases). Meta-analyses were conducted for the comparisons between hypothermic MP (hypothermic machine perfusion [HMP]) and CS (human studies) and normothermic MP (warm (normothermic) perfusion [WP]) compared with CS or HMP (animal studies). The primary outcome was allograft function. Secondary outcomes included graft and patient survival, acute rejection and parameters of tubular, glomerular and endothelial function. Subgroup analyses were conducted in expanded criteria (ECD) and donation after circulatory (DCD) death donors.

RESULTS

A total of 101 studies (63 human and 38 animal) were included. There was a lower rate of delayed graft function in recipients with HMP donor grafts compared with CS kidneys (RR 0.77; 95% CI 0.69-0.87). Primary nonfunction (PNF) was reduced in ECD kidneys preserved by HMP (RR 0.28; 95% CI 0.09-0.89). Renal function in animal studies was significantly better in WP kidneys compared with both HMP (standardized mean difference [SMD] of peak creatinine 1.66; 95% CI 3.19 to 0.14) and CS (SMD of peak creatinine 1.72; 95% CI 3.09 to 0.34). MP improves renal preservation through the better maintenance of tubular, glomerular, and endothelial function and integrity.

CONCLUSIONS

HMP improves short-term outcomes after renal transplantation, with a less clear effect in the longer-term. There is considerable room for modification of the process to assess whether superior outcomes can be achieved through oxygenation, perfusion fluid manipulation, and alteration of perfusion temperature. In particular, correlative experimental (animal) data provides strong support for more clinical trials investigating normothermic MP.

Controlled Donation After Circulatory Determination of Death

Controlled donation after circulatory determination of death (cDCDD) concerns donation after withdrawal of life-sustaining therapy (W-LST). We examine the ethical issues raised by W-LST in the cDCDD context in the light of a review of cDCDD protocols and the ethical literature. Our analysis confirms that W-LST procedures vary considerably among cDCDD centers and that despite existing recommendations, the conflict of interest in the W-LST decision and process might be difficult to avoid, the process of W-LST might interfere with usual end-of-life care, and there is a risk of hastening death. In order to ensure that the practice of W-LST meets already well-established ethical recommendations, we suggest that W-LST should be managed in the ICU by an ICU physician who has been part of the W-LST decision. Recommending extubation for W-LST, when this is not necessarily the preferred procedure, is inconsistent with the recommendation to follow usual W-LST protocol. As the risk of conflicts of interest in the decision of W-LST and in the process of W-LST exists, this should be acknowledged and disclosed. Finally, when cDCDD programs interfere with W-LST and end-of-life care, this should be transparently disclosed to the family, and specific informed consent is necessary.

Optimal Timing for Venous Systemic Oxygen Persufflation Supplemented with Nitric Oxide Gas in Cold-Stored, Warm Ischemia-Damaged Experimental Liver Grafts

Background/Aim: Worldwide shortage of donor organs has increased the use of donation after cardiac death (DCD). The aim of this study was to analyze the best time point for venous systemic oxygen persufflation (VSOP) supplemented with nitric oxide (NO) gas during the 1st and 24th hour of cold storage (CS) in warm ischemia (WI)-damaged experimental liver grafts. Materials and Methods: Liver grafts (n = 5) were retrieved after 30 min of WI induced by cardiac arrest and CS in histidine-tryptophan-ketoglutarate solution at 4°C. The 1st hour group was immediately persufflated with a VSOP plus NO (VSOP+NO) mixture for 1 h followed by 23 h of static CS (DCD+NO 1st hour). The 24th hour group entailed CS for 23 h followed by 1 h of VSOP+NO persufflation (DCD+NO 24th hour). CS livers without WI but with VSOP served as controls. CS livers with WI represented the fourth group (DCD). Viability of the liver grafts was assessed by normothermic isolated reperfusion for 45 min with oxygenated Krebs-Henseleit buffer. Results: Data are presented as mean ± SEM (control vs. DCD vs. DCD+NO 1st hour vs. DCD+NO 24th hour). After 45 min of reperfusion, the DCD+NO 1st hour group showed significantly lower aspartate aminotransferase (13.4 ± 5.3, 63.2 ± 17.3, 25.6 ± 3.9, and 82.8 ± 27.3 U/l) and lactate dehydrogenase levels (289.4 ± 41.2, 2,139.4 ± 542.7, 577.2 ± 117.2, and 2,429 ± 221.6 U/l). Malondialdehyde levels were significantly abrogated (1.0 ± 0.3, 2.7 ± 1, 1.0 ± 0, and 3.9 ± 1.2 nmol/ml). Significantly higher levels of portal venous pressure were recorded in the DCD+NO 24th hour group (12.0 ± 1, 21.2 ± 3.1, 16.1 ± 1, and 23.2 ± 3.5 mm Hg). NO levels were recorded after 5 min of reperfusion (1.42 ± 0.17, 1.8 ± 0.2, 2.7 ± 0.2, and 2.6 ± 0.1 μmol/l). Bile production levels showed no statistical significance (23.2 ± 3.8, 27.3 ± 1.8, 43.5 ± 18, and 31 ± 2.5 μl/45 min). Conclusion: Our results present the beneficial effects of NO combined with VSOP during the 1st hour of CS of WI-damaged experimental liver grafts.

Influence of delayed graft function and acute rejection on outcomes after kidney transplantation from donors after cardiac death

BACKGROUND

Delayed graft function (DGF) and acute rejection (AR) exert an adverse impact on graft outcomes after kidney transplantation using organs from donation after brain-stem death (DBD) donors. Here, we examine the impact of DGF and AR on graft survival in kidney transplants using organs from donation after cardiac death (DCD) donors.

METHODS

We conducted a single-center retrospective study of DCD and DBD donor kidney transplants. We compared 1- and 4-year graft and patient survival rates, as well as death-censored graft survival (DCGS) rates, between the two groups using univariate analysis, and the impact of DGF and AR on graft function was compared using multivariate analysis.

RESULTS

Eighty DCD and 206 DBD donor transplants were analyzed. Median follow-up was 4.5 years. The incidence of DGF was higher among DCD recipients (73% vs. 27%, P<0.001), and AR was higher among DBD recipients (23% vs. 9%, P<0.001). One-year and 4-year graft survival rates were similar (DCD 94% and 79% vs. DBD 90% and 82%). Among recipients with DGF, the 4-year DCGS rate was better for DCD recipients compared with DBD recipients (100% vs. 92%, P=0.04). Neither DGF nor AR affected the 1-year graft survival rate in DCD recipients, whereas in DBD recipients, the 1-year graft survival rate was worse in the presence of DGF (88% vs. 96%, P=0.04) and the 4-year DCGS rate was worse in the presence of AR (88% vs. 96%, P=0.04).

CONCLUSION

Despite the high incidence of DGF, medium-term outcomes of DCD kidney transplants are comparable to those from DBD transplants. Short-term graft survival from DCD transplants is not adversely influenced by DGF and AR, unlike in DBD transplants.

Kidney donation after cardiac death

There is continuing disparity between demand for and supply of kidneys for transplantation. This review describes the current state of kidney donation after cardiac death (DCD) and provides recommendations for a way forward. The conversion rate for potential DCD donors varies from 40%-80%. Compared to controlled DCD, uncontrolled DCD is more labour intensive, has a lower conversion rate and a higher discard rate. The super-rapid laparotomy technique involving direct aortic cannulation is preferred over in situ perfusion in controlled DCD donation and is associated with lower kidney discard rates, shorter warm ischaemia times and higher graft survival rates. DCD kidneys showed a 5.73-fold increase in the incidence of delayed graft function (DGF) and a higher primary non function rate compared to donation after brain death kidneys, but the long term graft function is equivalent between the two. The cold ischaemia time is a controllable factor that significantly influences the outcome of allografts, for example, limiting it to < 12 h markedly reduces DGF. DCD kidneys from donors < 50 function like standard criteria kidneys and should be viewed as such. As the majority of DCD kidneys are from controlled donation, incorporation of uncontrolled donation will expand the donor pool. Efforts to maximise the supply of kidneys from DCD include: implementing organ recovery from emergency department setting; improving family consent rate; utilising technological developments to optimise organs either prior to recovery from donors or during storage; improving organ allocation to ensure best utility; and improving viability testing to reduce primary non function.

Detection of ATP by "in line" 31P magnetic resonance spectroscopy during oxygenated hypothermic pulsatile perfusion of pigs' kidneys

OBJECT

To demonstrate that adenosine triphosphate (ATP), which provides a valuable biomarker for kidney viability in the context of donation after cardiac death (DCD) transplantation, can be detected by means of (31)P magnetic resonance spectroscopy (MRS) if kidneys are perfused with oxygenated hypothermic pulsatile perfusion (O(2)+HPP).

MATERIALS AND METHODS

Porcine kidney perfusion was carried out using a home made, MR-compatible HPP-machine. Consequently, kidney perfusion could be performed continuously during magnetic resonance imaging and magnetic resonance spectroscopy recording. (31)P MR spectroscopy consisted of 3-dimensional chemical shift imaging (CSI), which allowed for the detection of ATP level in line. (31)P CSI was performed at 3 tesla in 44 min with a nominal voxel size of 6.1 cc.

RESULTS

(31)P CSI enabled the detection of renal ATP when pO(2) was equal to 100 kPa. With pO(2) of 20 kPa, only phosphomonoester, inorganic phosphate and nicotinamide adenine dinucleotide could be found. Semi-quantitative analysis showed that ATP level was 1.3 mM in normal kidney perfused with pO(2) of 100 kPa.

CONCLUSIONS

This combined technology may constitute a new advance in DCD organ diagnostics prior to transplantation, as it allows direct assessment of ATP concentration, which provides a reliable indicator for organ bioenergetics and viability. In this study, kidneys presenting no warm ischemia were tested in order to establish values in normal organs. The test could be easily integrated into the clinical environment and would not generate any additional delay into the transplantation clinical workflow.

Deceased-donor kidney perfusate and urine biomarkers for kidney allograft outcomes: a systematic review

BACKGROUND

Accurate and reliable assessment of kidney quality before transplantation is needed to predict recipient outcomes and to optimize management and allocation of the allograft. The aim of this study was to systematically review the published literature on biomarkers in two mediums (the perfusate from deceased-donor kidneys receiving machine perfusion and deceased-donor urine) that were evaluated for their possible association with outcomes after kidney transplantation.

METHODS

We searched the Ovid Medline and Scopus databases using broad keywords related to deceased-donor biomarkers in kidney transplantation (limited to humans and the English language). Studies were included if they involved deceased-donor kidneys, measured perfusate or urine biomarkers and studied a possible relationship between biomarker concentrations and kidney allograft outcomes. Each included article was assessed for methodological quality.

RESULTS

Of 1430 abstracts screened, 29 studies met the inclusion criteria. Of these, 23 were studies of perfusate (16 biomarkers examined) and 6 were studies of urine (18 biomarkers examined). Only 3 studies (two perfusate) met the criteria of 'good' quality and only 12 were published since 2000. Perfusate lactate dehydrogenase, glutathione-S-transferase (GST) and aspartate transaminase were all found to be significantly associated with delayed graft function in a majority of their respective studies (6/9, 4/6 and 2/2 studies, respectively). Urine neutrophil gelatinase-associated lipocalin, GST, Trolox-equivalent antioxidant capacity and kidney injury molecule-1 were found to be significantly associated with allograft outcomes in single studies that examined diverse end points.

CONCLUSION

Higher quality studies are needed to investigate modern kidney injury biomarkers, to validate novel biomarkers in larger donor populations and to determine the incremental predictive value of biomarkers over traditional clinical variables.

Impact of venous systemic oxygen persufflation supplemented with nitric oxide gas on cold-stored, warm ischemia-damaged experimental liver grafts

The increasing shortage of donor organs has led to the increasing use of organs from non-heart-beating donors. We aimed to assess the impact of venous systemic oxygen persufflation (VSOP) supplemented with nitric oxide (NO) gas during the cold storage (CS) of warm ischemia (WI)-damaged experimental liver grafts. Rat livers (n = 5 per group) were retrieved after 30 minutes of WI induced by cardiac arrest (the WI group) and were thereafter preserved for 24 hours by CS in histidine tryptophan ketoglutarate solution. During CS, gaseous oxygen was insufflated via the caval vein with 40 ppm NO (the VSOP-NO group) or without NO (the VSOP group). Cold-stored livers without WI served as controls. Liver viability was assessed after the preservation period by normothermic isolated reperfusion for 45 minutes with oxygenated Krebs-Henseleit buffer. After 45 minutes of reperfusion, the VSOP-NO-treated livers showed significantly lower alanine aminotransferase values than the WI-damaged livers (10.2 ± 0.2 versus 78.2 ± 14.6 IU/L), whereas the control livers showed no differences from the VSOP-NO-treated livers. The mitochondrial enzyme release was lower in the VSOP-NO group (4.0 ± 0.7 IU/L) versus the WI group (18.2 ± 4.9 IU/L). An increased portal vein pressure was observed throughout reperfusion (45 minutes) in the WI group (21.7 ± 0.2 mm Hg) versus the VSOP-NO group (12.2 ± 0.8 mm Hg) and the control group (19.9 ± 0.4 mm Hg). Furthermore, the NO concentration in the perfusate after 5 minutes of reperfusion was highest in the VSOP-NO group. The release of malondialdehyde into the perfusate was significantly reduced in the VSOP-NO group (0.9 ± 0.1 nmol/mL) versus the WI group (31.3 ± 5.3 nmol/mL). In conclusion, the resuscitation of livers after 30 minutes of WI to a level comparable to that of nonischemically damaged livers is possible with VSOP supplemented with NO gas. Moreover, the application of VSOP with NO minimizes the extent of injuries caused by oxygen free radicals during preservation.

Donation after cardiac death lung transplantation outcomes

PURPOSE OF REVIEW

Lung transplantation is now a well established treatment option for several end-stage respiratory diseases. Survival after lung transplantation has significantly improved over the last decade. The primary limitation to increased utilization of lung transplantation remains donor scarcity. Suitable allografts have been procured from donors after determination of neurologic death and from donors after determination of cardiac death (DDCD or DCD). Historically, the first human lung transplantation performed, utilized an allograft procured after cardiovascular death, also referred to as nonheart-beating donor.The experience at University of Wisconsin in 1993 reintroduced DCD lung transplantation with the first successful clinical case.

RECENT FINDINGS

A potential additional lung allograft source, DCD lung transplantation has been established with very acceptable outcomes observed by several centers. We provide the relevant background for the rationale of donor allograft expansion to include DCD lungs from controlled (Maastricht category III donors).

SUMMARY

This review considers the available evidence for DCD lung transplantation and compares reported primary graft dysfunction rates and current survival data available.

Meloxicam, a COX-2 inhibitor, ameliorates ischemia/reperfusion injury in non-heart-beating donor livers

BACKGROUND/AIMS

Chronic organ donor shortage has led to the consideration to expand the donor pool with livers from non-heart-beating donors (NHBD), although a higher risk of graft dys- or nonfunction is associated with these livers. We examined the effects of selective cyclooxygenase-2 (COX-2) inhibition on hepatic warm ischemia (WI) reperfusion (I/R) injury of NHBD.

METHODS

Male Wistar rats were used as donors and meloxicam (5 mg/kg body weight) was administered into the preservation solution. Livers were excised after 60 min of WI in situ, flushed and preserved for 24 h at 4°C. Reperfusion was carried out in vitro at a constant flow for 45 min. During reperfusion (5, 15, 30 and 45 min), enzyme release of alanine aminotransferase and glutamate lactate dehydrogenase were measured as well as portal venous pressure, bile production and oxygen consumption. The production of malondialdehyde was quantified and TUNEL staining was performed. Quantitative PCR analyzed COX-2 mRNA. COX-2 immunohistochemistry and TxB(2) detection completed the measurements.

RESULTS

Meloxicam treatment led to better functional recovery concerning liver enzyme release, vascular resistance and metabolic activity over time in all animals. Oxidative stress and apoptosis were considerably reduced.

CONCLUSION

Cold storage using meloxicam resulted in significantly better integrity and function of livers retrieved from NHBD. Selective COX-2 inhibition is a new therapeutic approach achieving improved preservation of grafts from NHBD.

Kidney transplantation from donors after cardiac death: uncontrolled versus controlled donation

Kidney donation after cardiac death has been popularized over the last decade. The majority of these kidneys are from controlled donors. The number of organs for transplantation can be further increased by uncontrolled donors after cardiac death. The outcome of uncontrolled compared to controlled donor kidney transplantation is relatively unknown. We compared the long-term outcome of kidney transplantation from uncontrolled (n = 128) and controlled (n = 208) donor kidneys procured in the Maastricht region from January 1, 1981 until January 1, 2008, and transplanted in the Eurotransplant region. The incidence of primary nonfunction and delayed graft function in both uncontrolled and controlled donor kidneys is relatively high (22% vs. 21%, and 61% vs. 56%, p = 0.43, respectively). Ten-year graft and recipient survival are similar in both groups (50% vs. 46%, p = 0.74 and 61% vs. 60%, p = 0.76, respectively). Estimated glomerular filtration rates 1 year after transplantation are 40 ± 16 versus 42 ± 19 mL/min/1.73 m(2) , p = 0.55, with a yearly decline thereafter of 0.67 ± 3 versus 0.70 ± 7 mL/min/1.73 m(2) /year, p = 0.97. The outcome of kidney transplantation from uncontrolled and controlled donors after cardiac death is equivalent. This justifies the expansion of the donor pool with uncontrolled donors to reduce the still growing waiting list for renal transplantation, and may stimulate the implementation of uncontrolled kidney donation programs.

Use of liver grafts from donation after cardiac death donors for recipients with hepatitis C virus

Hepatitis C virus (HCV) infection is the most common indication for orthotopic liver transplantation in the United States. Although studies have addressed the use of expanded criteria donor organs in HCV(+) patients, to date the use of liver grafts from donation after cardiac death (DCD) donors in HCV(+) patients has been addressed by only a limited number of studies. This retrospective analysis was undertaken to study the outcomes of DCD liver grafts used in HCV(+) recipients. Seventy-seven HCV(+) patients who received DCD liver grafts were compared to 77 matched HCV(+) patients who received donation after brain death (DBD) liver grafts and 77 unmatched non-HCV patients who received DCD liver grafts. There were no differences in 1-, 3-, and 5-year patient or graft survival among the groups. Multivariate analysis showed that the Model for End-Stage Liver Disease score [hazard ratio (HR) = 1.037, 95% confidence interval (CI) = 1.006-1.069, P = 0.018] and posttransplant cytomegalovirus infection (HR = 3.367, 95% CI = 1.493-7.593, P = 0.003) were significant factors for graft loss. A comparison of the HCV(+) groups for fibrosis progression based on protocol biopsy samples up to 5 years post-transplant did not show any difference; in multivariate analysis, HCV genotype 1 was the only factor that affected progression to stage 2 fibrosis (genotype 1 versus non-1 genotypes: HR = 2.739, 95% CI = 1.047-7.143, P = 0.040). In conclusion, this match-controlled, retrospective analysis demonstrates that DCD liver graft utilization does not cause untoward effects on disease progression or patient and graft survival in comparison with DBD liver grafts in HCV(+) patients.

Recommendations for the use of extended criteria donors in lung transplantation

Selection criteria for lung donation were based on initial experiences with lung transplantation without further studies to improve them, thereby guaranteeing the best use of donated organs. A definition of an extended criteria donor is therefore required to obtain more lungs to meet the demands of patients awaiting transplantation. Studies have been reviewed for the impact on survival and morbidity of age ranges, oxygen fraction, cause of death, smoking habits, x-ray findings, infection, hepatitis serology and non-heart-beating status, seeking to support physicians to make decisions regarding the use of marginal organs.

Oxygenated hypothermic pulsatile perfusion versus cold static storage for kidneys from non heart-beating donors tested by in-line ATP resynthesis to establish a strategy of preservation

AIM

The scarcity of kidneys for transplantation impels an expansion of the donor source to include the use of organs from Maastricht II and Maastricht I non heart-beating donors. The aim of this study was to establish the best method to preserve kidneys from non heart-beating donors (NHBD): cold static storage (CSS) or perfusion. ATP production during kidney preservation has been retained as a measure of their energetic levels and, consequently, their viability. The presence of warm ischemia with both types of preservation was studied.

METHODS

Porcine kidneys presenting no warm ischemia or 30 minutes of warm ischemia were submitted to immediate oxygenated hypothermic pulsatile perfusion or immediate cold static storage. The study was divided into four groups. ATP resynthesis was measured after 8 h. of perfusion. ATP was assessed by in-line (31)P nuclear magnetic resonance spectroscopy (NMRS) during the preservations.

RESULTS

Only oxygenated perfusion could restore ATP in organs with warm ischemia. Initial cold static storage seems deleterious on organs having suffered from warm ischemia.

DISCUSSION

Only oxygenated perfusion could restore ATP in organs with warm ischemia. Initial cold static storage seems deleterious to organs having suffered from warm ischemia. Oxygenated perfusion must be introduced immediately after kidney removal from non heart-beating donors. In organs without warm ischemia, any kind of preservation is equivalent.

Cold machine perfusion versus static cold storage of kidneys donated after cardiac death: a UK multicenter randomized controlled trial

One third of deceased donor kidneys for transplantation in the UK are donated following cardiac death (DCD). Such kidneys have a high rate of delayed graft function (DGF) following transplantation. We conducted a multicenter, randomized controlled trial to determine whether kidney preservation using cold, pulsatile machine perfusion (MP) was superior to simple cold storage (CS) for DCD kidneys. One kidney from each DCD donor was randomly allocated to CS, the other to MP. A sequential trial design was used with the primary endpoint being DGF, defined as the necessity for dialysis within the first 7 days following transplant. The trial was stopped when data were available for 45 pairs of kidneys. There was no difference in the incidence of DGF between kidneys assigned to MP or CS (58% vs. 56%, respectively), in the context of an asystolic period of 15 min and median cold ischemic times of 13.9 h for MP and 14.3 h for CS kidneys. Renal function at 3 and 12 months was similar between groups, as was graft and patient survival. For kidneys from controlled DCD donors (with mean cold ischemic times around 14 h), MP offers no advantage over CS, which is cheaper and more straightforward.

Liver transplantation using controlled donation after cardiac death donors: an analysis of a large single-center experience

The use of donation after cardiac death (DCD) donors may provide a valuable source of organs for liver transplantation. Concerns regarding primary nonfunction (PNF) and intrahepatic biliary stricture (IHBSs) have limited the enthusiasm for their use. A retrospective analysis of 1436 consecutive deceased donor liver transplants performed between December 1998 and October 2006 was conducted. These included 108 DCD liver transplants, which were compared to 1328 transplants performed with organs from donors meeting the criteria for donation after brain death (DBD). The median follow-up was 48 months. The 1-, 3-, and 5-year patient survival and graft survival for DCD donors were 91.5%, 88.1%, and 88.1% and 79.3%, 74.5%, and 71.0%, respectively. The 1-, 3-, and 5-year patient survival and graft survival for DBD donors were 87.3%, 81.1%, and 77.2% and 81.6%, 74.7%, and 69.1%, respectively. Patient survival and graft survival were not significantly different between DCD donors less than 60 years old, DCD donors greater than 60 years old, and DBD donors. Causes of graft loss included IHBSs (n = 9), PNF (n = 4), recurrent hepatitis C virus (n = 4), hepatic artery thrombosis (n = 1), rejection (n = 2), and patient death (n = 13). Contrary to previously published data, excellent long-term patient survival and graft survival can be obtained with DCD allografts, and in our experience, they are equivalent to those obtained from DBD allografts.

Reduced Liver Apoptosis After Venous Systemic Oxygen Persufflation in Non-Heart-Beating Donors

Graft injury caused by warm ischemia in livers from non-heart-beating donors (NHBDs) strongly affects posttransplantation outcome and is associated with liver apoptosis, which is mediated by death receptors, such as Fas, a surface receptor of the tumor necrosis factor (TNF)-alpha family. The aim of this study was to test the ability of venous systemic oxygen persufflation (VSOP) to reduce apoptotic changes and Fas activation in the liver after warm ischemic insult in vivo. Livers of male Wistar rats were harvested 30 min after cardiac arrest from non-heart-beating donors (NHBD) with (NHBD + O2) or without (NHBD) application of gaseous oxygen during the cold storage period via the suprahepatic caval vein. After 24 h of storage in University of Wisconsin solution at 4 degrees C, viability of the livers was assessed upon isolated reperfusion in vitro. Conventional signs of tissue damage like enzyme release and bile production showed a significantly elevated nonspecific cell injury in the NHBD group. TUNEL staining revealed increased DNA fragmentation of sinusoidal endothelial cells in the NHBD group and more apoptotic hepatocytes than in the control group. All these alterations could be almost abrogated by the use of VSOP in the NHBD + O2 group. The immunohistochemical staining of Fas antigen expression showed a significantly elevated Fas receptor expression in the NHBD and NHBD + O2 groups, in accord with an eightfold increase of Fas receptor mRNA detected by real-time reverse-transcription polymerase chain reaction (RT-PCR). These results demonstrate that the postischemic apoptotic rate of sinusoidal endothelial cells in NHBD livers can be reduced by the use of VSOP. A significant improvement in liver integrity and viability was obtained with this technique, without influencing the expression of Fas expression.

Renal ischemia in rats: mitochondria function and laser autofluorescence

Ischemia-reperfusion injury is the major cause of organ dysfunction or even nonfunction following transplantation. It can attenuate the long-term survival of transplanted organs. To evaluate the severity of renal ischemia injury determined by histology, we applied laser- (442 nm and 532 nm) induced fluorescence (LIF), mitochondria respiration, and membrane swelling to evaluate 28 Wistar rats that underwent left kidney warm ischemia for 20, 40, 60, or 80 minutes. LIF performed before ischemia (control) was repeated at 20, 40, 60, and 80 minutes thereafter. We harvested left kidney tissue samples immediately after LIF determination for histology and mitochondrial analyses: state 3 and 4 respiration, respiration control rate (RCR), and membrane swelling. The association of optic spectroscopy with histological damage showed: LIF, 442 nm (r2 = 0.39, P < .001) and 532 nm, (r2 = 0.18, P = .003); reflecting laser/fluorescence-induced, 442 nm (r2 = 0.20, P = .002) and 532 nm (r2 = 0.004, P = .67). The associations between mitochondria function and tissue damage were: state 3 respiration (r2 = 0.43, P = .0004), state 4 respiration (r2 = 0.03, P = 0.38), RCR (r2 = 0.28, P = .007), and membrane swelling (r2 = 0.02, P = .43). The intensity of fluorescence emitted by tissue excited by laser, especially at a wave length of 442 nm, was determined in real time. Mitochondrial state 3 respiration and respiratory control ratio also exhibited good correlations with the grade of ischemic tissue damage.

[Hystologic and hemodynamic aspects of warm ischemic graft in relation to the preservation method]

OBJECTIVE

The non-heart-beating donor has been proposed as a solution to donor shortage for renal transplantation. Because the nature of such donors, the kidneys so derived have been damaged by primary warm ischemia (WI), and so potentially they may never function. Minimizing graft injury is especially important in case of transplantation form marginal donors because of a high rate of delayed graft function or primary nonfunction. The aim of this experimental study is to assess the structural and hemodynamic consequences of hypothermic perfusion (HP) versus cold storage (CS), in renal allograft after a period of WI.

MATERIAL AND METHODS

We used 20 mini-pigs. WI was achieved by vascular pedicle occlusion during 45 min. We divided organs in 4 groups: A (n=5), kidneys with WI and then transplanted; group B (n=5), grafts with WI and implanted after HP with Belzer solution in our computerized perfusion system. Group C-control, (n=5) transplanted without WI and D (n=5) with WI and 60 min of CS in UW-Viaspan solution. All the procedure was recorded by a computerized data system. Renal vascular resistance (RVR) and renal vascular flow (RVF) were automatically calculated by means of mathematical formulas after renal transplantation. Subsequently histological study was completed in all cases.

RESULTS

We observed two patterns after transplantation: (1). Initial increase of RVR with posterior decrease and increase of vascular flow: in organs with WI and HP prior to transplantation (group B) // organs transplanted without WI (group C-control). Electronic and conventional microscopy showed integrity of endothelial and tubule structure. (2). Initial decrease with posterior increase of RVR. Organs with WI (group A) // organs with WI and CS (group D). Structural study showed endothelial and tubule disruption.

CONCLUSION

In our experimental model machine perfusion preserves endothelial and tubule structure of kidneys with WI. After transplantation the hemodynamic pattern of grafts with WI and HP is similar to the control group (without WI and direct transplantation).

Non heart-beating donors in England

When transplantation started all organs were retrieved from patients immediately after cardio-respiratory arrest, i.e. from non heart-beating donors. After the recognition that death resulted from irreversible damage to the brainstem, organ retrieval rapidly switched to patients certified dead after brainstem testing. These heart-beating-donors have become the principal source of organs for transplantation for the last 30 years. The number of heart-beating-donors are declining and this is likely to continue, therefore cadaveric organs from non-heart-beating donor offers a large potential of resources for organ transplantation. The aim of this study is to examine clinical outcomes of non-heart-beating donors in the past 10 years in the UK as an way of decreasing pressure in the huge waiting list for organs transplantation.

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 6h or 18 h by cold storage (CS). Organ retrieval took place either prior to (ctrl.) or 30 min after cardiac arrest (NHBD). Compared to 6h 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, 6h 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 6h of CS, 1h 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 1h prior to implantation and may help to judge liver viability according to adequate parameters after hypothermic machine perfusion has been established.

Non-heart beating organ donation: overview and future perspectives

New indications for organ transplantation combined with a stagnating number of available donor grafts have severely lengthened the waiting list for almost all types of transplantations. This has led to a renewed interest in non-heart beating (NHB) donation, as a possible solution to bridge the gap between supply and demand. In this review, we present an overview of current NHB donation practice, outcome, existing problems and future perspectives. We focus on possible improvements in donor management, recipient care and new methods of organ preservation that may be better suited for these marginal organs. Successful institution of NHB protocols depends on adapting current transplantation practice at all levels, which is one of the greatest challenges for researchers and professionals in this interesting re-emerging field.

Beyond Operational Tolerance: Effect of Ischemic Injury on Development of Chronic Damage in Renal Grafts

BACKGROUND

The induction of operational tolerance is the holy grail of clinical transplantation. However, in animal models with operational tolerance, long- term grafts still develop chronic damage. The elucidation of the impact of allogenic versus nonallogeneic factors in such a model is important. This study examined the effect of a clinically relevant combination of warm ischemia and cold preservation in the absence of allogeneic response (isografts) and in the context of operational tolerance.

METHODS

Dark Agouti (DA) rat kidneys were transplanted into DA recipients (isografts) or Albino Surgery recipients (allografts) tolerized by two transfusions of DA blood, under cover of cyclosporin A. Grafts were subjected to minimal cold preservation or to 30 mins warm ischemia followed by 24 hrs cold preservation.

RESULTS

After an initial peak of renal dysfunction, serum creatinine concentration returned to normal in isografts and nonischemic allografts, but remained significantly elevated in ischemic allografts (P<0.0002) throughout 6 months follow-up. Both allograft groups developed proteinuria. At 6 months, ischemic isografts and nonischemic allografts demonstrated very mild tubular atrophy and interstitial fibrosis. Tubulointerstitial injury was significantly more severe in ischemic allografts (P<0.01 vs. nonischemic allografts) and was associated with increased infiltrating monocyte/macrophages and NK cells (P<0.05). Moderate glomerulosclerosis was a feature of both allograft groups (P<0.05).

CONCLUSIONS

The modified allogeneic response in operationally tolerant recipients acts in synergy with ischemia/reperfusion injury in the development of chronic damage. Strategies to limit or modify the initial ischemia/reperfusion injury may ameliorate chronic tubulointerstitial damage. Progressive glomerular damage and proteinuria in allografts may require other pharmacological intervention.

Synergistic value of fibrinolysis and hypothermic aerobic preservation with oxygen in the protection of livers from non-heart-beating donors: an experimental model

The chronic organ shortage has led to the reconsideration of marginal donor pools such as non-heart-beating donors (NHBD). The use of these livers is limited due to their minimal tolerance for cold preservation. The aim of this study was to examine the combination of two different therapeutic strategies for the preservation of livers from NHBD. The livers of male Wistar rats were harvested after the induction of cardiac arrest via phrenotomy (30, 90 minutes). Livers were perfused with 10 mL of UW solution (UW), followed by hypothermic preservation with or without insufflation of gaseous oxygen (O2). In one group a fibrinolytic preflush (10 mL of Ringer's containing 7500 IU of streptokinase) was performed with subsequent preservation with O2 (O2+SK). After storage (24 h/4 degrees C/UW) livers were reperfused in vitro. Livers retrieved from heart beating donors served as controls. The results showed that even after only 30 minutes of warm ischemia livers displayed a serious disturbance in vascular perfusion (portal venous pressure, PVP = 7.4 +/- 0.2* versus control: 4.1 +/- 0.5 mmHg), associated with a more than 10-fold increase in enzyme release (ALT: 26819 +/- 513* versus control 683 +/- 152 mU/g/L), which was consistent with a significant depression in bile synthesis (1.21 +/- 0.35* versus 19.36 +/- 2.16 microL/g/45 min). However, these impairments could be prevented with O2. Even after 90 minutes of WI, the function was significant better using aerobic preservation (ALT: 3204 +/- 549 mU/g/L). With a supplementary fibrinolytic preflush, we effectively preserved livers up to 90 minutes of WI with results comparable to livers from heart beating donors with no WI (ALT: 1623 +/- 432 mU/g/L). The combination of these two techniques represents a new therapeutic approach for livers with extended or unclear WI periods in non-heart-beating donors (*P <.05 versus control).

Real-time assessment of in vivo renal ischemia using laser autofluorescence imaging

Potentially transplantable kidneys experience warm ischemia, and this injury is difficult to quantify. We investigate optical spectroscopic methods for evaluating, in real time, warm ischemic kidney injury and reperfusion. Vascular pedicles of rat kidneys are clamped unilaterally for 18 or 85 min, followed by 18 or 35 min of reperfusion, respectively. Contralateral, uninjured kidneys serve as controls. Autofluorescence and cross-polarized light scattering images are acquired every 15 s using 335-nm laser excitation (autofluorescence) and 650+/-20-nm linearly polarized illumination (light scattering). We analyze changes of injured-to-normal kidney autofluorescence intensity ratios during ischemia and reperfusion phases. The effect of excitation with 260 nm is also explored. Average injured-to-normal intensity ratios under 335-nm excitation decrease from 1.0 to 0.78 at 18 min of ischemia, with a return to baseline during 18 min of reperfusion. However, during 85 min of warm ischemia, average intensity ratios level off at 0.65 after 50 min, with no significant change during 35 min of reperfusion. 260-nm excitation results in no autofluorescence changes with ischemia. Cross-polarized light scattering images at 650 nm suggest that changes in hemoglobin absorption are not related to observed temporal behavior of the autofluorescence signal. Real-time detection of kidney tissue changes associated with warm ischemia and reperfusion using laser spectroscopy is feasible. Normalizing autofluorescence changes under 335 nm using the autofluorescence measured under 260-nm excitation may eliminate the need for a control kidney.

Renal transplants from non-heart beating paracetamol overdose donors

INTRODUCTION

Non-heart beating donors (NHBD) are widely encouraged to avert the critical shortage in the kidney donor pool. Ischaemic injury at the time of cardiac arrest in the NHBD is more pronounced and therefore the kidneys resulting are considered marginal. This review describes our experience with four kidneys from two controlled NHBDs who were exposed to paracetamol intoxication and subsequently were treated with mannitol prior to organ donation.

MATERIALS AND METHOD

Two patients with fulminant liver failure following paracetamol overdose were referred as 'withdrawal of treatment' NHBD. As the two patients had developed hepatic encephalopathy they were treated with mannitol to reduce intra-cerebral oedema. The two donors were oligoanuric for at least 24 h prior to cardiac arrest. Following cardiac arrest, in situ perfusion was carried out and the kidneys were removed. One pair of kidneys were machine perfused while the second pair of kidneys were cold stored prior to transplantation.

RESULTS

Pre-transplant assessment of NHBD kidneys resulted in three of four kidneys being transplanted. The NHBD kidneys exhibited a period of delayed graft function (DGF). The early transplant biopsies showed evidence of diffuse cytoplasmic vacuolation. These histological features disappeared with time and the renal function improved until the time of discharge.

DISCUSSION

Non-heart beating donor kidneys are considered marginal and the effect of mannitol and paracetamol drug intoxication will induce reversible sub-lethal injury. A period of dialysis is inevitable in clearing the reactive intermediates of mannitol and paracetamol. The kidneys behaved as traditional controlled NHBD at time of discharge.

Kidney transplantation from non-heart-beating donors after oxygenated low-flow machine perfusion preservation with histidine-tryptophan-ketoglutarate solution

The aim of this study was to determine the potential benefit of aerobic machine preservation (MP) with non-colloidal histidine-tryptophan-ketoglutarate (HTK) solution compared with MP with Belzer machine perfusion solution (MPS) and standard cold storage, after marginal kidneys had been obtained from non-heart-beating donors. Cardiac arrest was electrically induced in anaesthetized German landrace pigs (20-25 kg bw). Their kidneys were harvested 40 min thereafter, flushed with HTK by gravity of 100 cm H2O via the renal artery and then stored in HTK for 18 h at 4 degrees C. Other organs were subjected to oxygenated (pO2>500 mmHg) hypothermic pulsatile low-flow machine perfusion with HTK or MP with Belzer MPS at P(max)=40 mmHg, yielding transrenal flow values of 0.2-0.3 ml/min per g with HTK and approximately twice that amount with Belzer MPS. A well-preserved vascular endothelium and intact tubular epithelium were documented by electron microscopy at the end of perfusion preservation in both solutions as well as after cold storage. Concentrations of ATP (in micromoles per gramme) in tissue homogenates at the end of perfusion preservation with HTK were 1.18+/-0.12 vs 0.16+/-0.02 (P<0.05) after simple cold storage and 2.43+/-0.23 after perfusion with Belzer MPS, thus documenting a relevant effect of low-flow perfusion on tissue oxygenation. Viability of the grafts was followed for 1 week after heterotopic transplantation and bilateral nephrectomy in the recipient pigs. Machine perfusion with HTK significantly improved cortical microcirculation upon early reperfusion in vivo, as well as maximal serum levels of urea and creatinine, compared to recipients receiving cold-stored grafts. No differences could be found between MP with HTK or Belzer MPS. In conclusion, provision of oxygen during storage is possible by low-flow perfusion with HTK as with Belzer MPS and apparently improves graft viability after transplantation.

Assessment of renal ischemia by optical spectroscopy1,2

INTRODUCTION

No reliable method currently exists for quantifying the degree of warm ischemia in kidney grafts before transplantation. We describe a method for evaluating pretransplant warm ischemia time using optical spectroscopic methods.

METHODS

Lewis rat kidney vascular pedicles were clamped unilaterally in vivo for 0, 5, 10, 20, 30, 60, 90, or 120 min; eight animals were studied at each time point. Injured and contralateral control kidneys were then flushed with Euro-Collins solution, resected, and placed on ice. 335 nm excitation autofluorescence as well as cross-polarized light scattering images were then taken of each injured and control kidney using filters of various wavelengths. The intensity ratio of the injured to normal kidneys was compared to ischemia time.

RESULTS

Autofluorescence intensity ratios through a 450-nm filter and light scattering intensity ratios through an 800-nm filter both decreased significantly with increasing ischemia time (P < 0.0001 for each method, one-way analysis of variance). All adjacent and nonadjacent time points between 0 and 90 min were distinguishable using one of these two modalities by Fisher's protected least significant difference.

CONCLUSIONS

Optical spectroscopic methods correlate with warm ischemia time in kidneys that have been subsequently hypothermically preserved. Further studies are needed to correlate results with physiological damage and posttransplant performance.

Retrieving organs from non-heart-beating organ donors: a review of medical and ethical issues

PURPOSE

The increasing gap between numbers of individuals awaiting organ replacement surgery and the supply of organs available for transplant underpins attempts to increase the number of organs available. One practice, used in other countries, is the recovery of organs from non-heart-beating organ donors (NHBD). The purpose of this review is to discuss ethical issues surrounding the use of organs from these donors.

SOURCE

Narrative review from selected Medline references, and other published reports.

PRINCIPAL FINDINGS

NHBD protocols have been established in many countries including the United States. Despite numerous publications, and extensive debate in the literature, significant ethical issues remain unresolved in the retrieval of organs from donors that have died from cessation of cardiac activity. The ethical concerns primarily arise in the determination of death, the tension between the time constraints on recovering organs viable for transplantation, and procedures to enhance organ viability. Despite a concerted effort in the United States, less than half of the organ procurement organizations have NHBD protocols.

CONCLUSION

Canadian centres can learn from the difficulties encountered in other centres that have developed NHBD protocols. A moratorium on Canadian NHBD protocols should be considered until a National consensus reflecting Canadian values has been undertaken.

EMERGENCY DONOR HEART PROTECTION: APPLICATION OF THE PORT ACCESS CATHETER TECHNIQUE USING A PIG HEART TRANSPLANTATION MODEL1

BACKGROUND

Organ shortage limits the number of transplantations, and donor deterioration may precede and often prevent conventional organ preservation. This study evaluates in situ perfusion as a bedside method for cardiac allograft procurement in a large animal model.

METHODS

Thirty Landrace pigs (42 +/- 7 kg) were studied. The hearts in the conventional group underwent cardioplegic arrest with University of Wisconsin solution and sodium-hydrogen exchange inhibitor cariporide as an additive; they were explanted and stored on ice before transplantation. In the in situ group, one catheter was placed in the ascending aorta and another in the right atrium. After disconnection from the ventilator, hypoxia caused circulatory arrest. The aorta was endoclamped, and in situ perfusion of the aortic root was maintained with University of Wisconsin solution and cariporide. After explantation, hearts were stored on ice for 120 min. All hearts were implanted according to the Shumway technique. Ventricular pressure and cardiac output were monitored online, and troponin-I was measured intermittently. Two hours after weaning from extracorporal circulation, the animals were killed and histology was performed.

RESULTS

Catheters were placed through introducers within 5 min. Functional recovery and histology were comparable between the two techniques. Troponin-I increased in both groups during reperfusion but at a faster rate in the in situ technique (P <0.01).

CONCLUSION

In situ perfusion may be suitable for cardiac transplants when donor deterioration requires urgent organ preservation. Catheters can be placed at bedside and modified to achieve multi-organ protection through additional perfusion of the abdominal aorta.