Kidney donation after cardiac death

Predicting outcomes after kidney transplantation: Can Pareto's rules help us to do so?

Kidney transplantation is the best option for kidney replacement therapy, even considering that most of the times the grafts do not survive as long as their recipients. In the Khalil et al's experience, published in this issue of the Journal, they analyze their second kidney graft survival and describe those significant predictors of early loss. This editorial comments on the results and put in perspec tive that most of the times, long-term graft survival could be inadvertently jeopardized if the immunosuppressive therapy is reduced or withdrawn for any reason, and that it could happen frequently if the transplant physician intends to innovate with the clinical care without proper evidence-based data.

Evaluation of Oxidative Stress and Metabolic Profile in a Preclinical Kidney Transplantation Model According to Different Preservation Modalities

This study addresses a joint nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) spectroscopy approach to provide a platform for dynamic assessment of kidney viability and metabolism. On porcine kidney models, ROS production, oxidative damage kinetics, and metabolic changes occurring both during the period between organ retrieval and implantation and after kidney graft were examined. The 1H-NMR metabolic profile—valine, alanine, acetate, trimetylamine-N-oxide, glutathione, lactate, and the EPR oxidative stress—resulting from ischemia/reperfusion injury after preservation (8 h) by static cold storage (SCS) and ex vivo machine perfusion (HMP) methods were monitored. The functional recovery after transplantation (14 days) was evaluated by serum creatinine (SCr), oxidative stress (ROS), and damage (thiobarbituric-acid-reactive substances and protein carbonyl enzymatic) assessments. At 8 h of preservation storage, a significantly (p < 0.0001) higher ROS production was measured in the SCS vs. HMP group. Significantly higher concentration data (p < 0.05−0.0001) in HMP vs. SCS for all the monitored metabolites were found as well. The HMP group showed a better function recovery. The comparison of the areas under the SCr curves (AUC) returned a significantly smaller (−12.5 %) AUC in the HMP vs. SCS. EPR-ROS concentration (μmol·g−1) from bioptic kidney tissue samples were significantly lower in HMP vs. SCS. The same result was found for the NMR monitored metabolites: lactate: −59.76%, alanine: −43.17%; valine: −58.56%; and TMAO: −77.96%. No changes were observed in either group under light microscopy. In conclusion, a better and more rapid normalization of oxidative stress and functional recovery after transplantation were observed by HMP utilization.

The Optimization of Renal Graft Preservation Temperature to Mitigate Cold Ischemia-Reperfusion Injury in Kidney Transplantation

Renal transplantation is the preferred treatment for patients with end-stage renal disease. The current gold standard of kidney preservation for transplantation is static cold storage (SCS) at 4 °C. However, SCS contributes to renal ischemia-reperfusion injury (IRI), a pathological process that negatively impacts graft survival and function. Recent efforts to mitigate cold renal IRI involve preserving renal grafts at higher or subnormothermic temperatures. These temperatures may be beneficial in reducing the risk of cold renal IRI, while also maintaining active biological processes such as increasing the expression of mitochondrial protective metabolites. In this review, we discuss different preservation temperatures for renal transplantation and pharmacological supplementation of kidney preservation solutions with hydrogen sulfide to determine an optimal preservation temperature to mitigate cold renal IRI and enhance renal graft function and recipient survival.

The Impact of Nutritional Supplementation on Donor Kidneys During Oxygenated Ex Vivo Subnormothermic Preservation

Evidence suggests that nutritional supplementation during normothermic ex vivo perfusion improves organ preservation. However, it is unclear whether the same benefit is observed during room temperature (subnormothermic) oxygenated perfusion. In this study, we tested the impact of providing complete nutrition during subnormothermic perfusion on kidney outcomes.

Does prolonged cold ischemia affect outcomes in donation after cardiac death donor kidney transplants?

    : The purpose of this study was to analyze the combined effect of cold ischemia time (CIT) and donation after cardiac death (DCD, with requisite warm ischemia time, WIT) on kidney transplant (KT) outcomes.

METHODS

Single center retrospective review of DCD KT recipients stratified by CIT.

RESULTS

From 6/08 to 10/20, we performed 446 DCD KTs (115 CIT ≤20, 205 CIT 20-30, 88 CIT 30-40, 38 CIT ≥40 hours). Mean WITs (26/25/27/23 minutes) and KDPI values (59%/55%/55%/59%) were similar while mean CITs (16.4/23.6/33.4/42.5 hours) and pump times (10.3/13.6/16.1/20.4 hours) differed across groups (p < 0.05). With a mean 6-year follow-up, patient survival (84%/84%/74%/84%) was similar. Kidney graft survival (GS) (72%/72%/56%/58%) and death censored GS (DCGS) (82%/80%/63%/67%) rates decreased whereas rates of primary nonfunction (PNF, 0.9%/2.4%/9.1%/7.9%) and delayed graft function (DGF) (36%/48%/50%/69%) increased with longer CIT (≥30 hours, p<0.05). Meaningful years free of dialysis, which we refer to as Allograft Life Years, were achieved in all cohorts (4.5/4.3/3.9/4.3 years per patient transplanted).

CONCLUSION

DCD donor kidneys with prolonged CIT (≥30 hours) are associated with increased rates of DGF and PNF, along with decreased GS and DCGS. Despite this, Allograft Life Years were gained even with longer CITs, demonstrating the utility of using these allografts. This article is protected by copyright. All rights reserved.

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.

Subnormothermic Perfusion with H2S Donor AP39 Improves DCD Porcine Renal Graft Outcomes in an Ex Vivo Model of Kidney Preservation and Reperfusion

Cold preservation is the standard of care for renal grafts. However, research on alternatives like perfusion at higher temperatures and supplementing preservation solutions with hydrogen sulfide (H₂S) has gained momentum. In this study, we investigated whether adding H₂S donor AP39 to porcine blood during subnormothermic perfusion at 21 °C improves renal graft outcomes. Porcine kidneys were nephrectomized after 30 min of clamping the renal pedicles and treated to 4 h of static cold storage (SCS) on ice or ex vivo subnormothermic perfusion at 21 °C with autologous blood alone (SNT) or with AP39 (SNTAP). All kidneys were reperfused ex vivo with autologous blood at 37 °C for 4 h. Urine output, histopathology and RNAseq were used to evaluate the renal graft function, injury and gene expression profiles, respectively. The SNTAP group exhibited significantly higher urine output than other groups during preservation and reperfusion, along with significantly lower apoptotic injury compared to the SCS group. The SNTAP group also exhibited differential pro-survival gene expression patterns compared to the SCS (downregulation of pro-apoptotic genes) and SNT (downregulation of hypoxia response genes) groups. Subnormothermic perfusion at 21 °C with H₂S-supplemented blood improves renal graft outcomes. Further research is needed to facilitate the clinical translation of this approach.

Kidney transplantation from donation after circulatory death using abdominal normothermic oxygenated circulation: are the outcomes equivalent?

PURPOSE

To increase the pool of kidneys available for transplantation, a renewed interest in donation after circulatory death (DCD) has emerged. This study aims to determine the outcomes of kidney transplantation from DCD after abdominal normothermic oxygenated circulation (ANOR) support.

METHODS

From January 2016 to December 2018, 58 kidneys were implanted from uncontrolled DCD after ANOR support. We performed an observational prospective study, assessing graft function and cumulative incidence of surgical complications. A descriptive analysis was conducted. Potential determinants of the outcomes were evaluated, including donor and receptor gender and age, and warm and cold ischemia times. Regression coefficients (β) and odds ratio (OR) were calculated with 95% confidence intervals. A p-value < 0.05 was considered statistically significant. Statistical analysis was accomplished using Stata 11.0 software.

RESULTS

The median follow-up time was 31.2 months. Delayed graft function (DGF) was evident in 80%, with a mean Cr one month after transplantation of 1.81 mg/dL and 1.33 mg/dL after one year. Primary non-function (PNF) occurred in 5.2% of cases. Male donors were associated with a lower DGF (OR = 0.21, p < 0.05), and a higher donor age was a predictor of poorer graft function at one year (β = - 0.88, p < 0.05). Surgical complications occurred in 31% patients, predominantly vascular. Warm ischemia time superior to 60 min correlated with a higher risk of surgical complications (OR = 11.33, p < 0.05).

CONCLUSION

Kidney transplantation from DCD is a valuable option, allowing an improvement in the balance between patients waiting for a transplant and the available kidneys.

Comparison of Centrifugal and Pulsatile Perfusion to Preserve Donor Kidneys Using Ex Vivo Subnormothermic Perfusion

OBJECTIVE

We have previously demonstrated benefits of kidney preservation utilizing an oxygenated subnormothermic ex vivo perfusion platform. Herein, we aim to compare pulsatile versus centrifugal (steady and uniform flow) perfusion with the goal of optimizing renal preservation with these devices. Materials and methods: Pig kidneys were procured following 30 min of warm ischemia by cross-clamping both renal arteries. Paired kidneys were cannulated and underwent either: oxygenated pulsatile or centrifugal perfusion using a hemoglobin oxygen carrier at room temperature with our ex vivo machine perfusion platform for 4 hr. Kidneys were reperfused with whole blood for 4 hr at 37° C. Renal function, pathology and evidence of inflammation were assessed post-perfusion. Results: Both pump systems performed equally well with organs exhibiting similar renal blood flow, and function post-reperfusion. Histologic evidence of renal damage using apoptosis staining and acute tubular necrosis scores was similar between groups. This was corroborated with urinary assessment of renal damage (NGAL 1) and inflammation (IL-6), as levels were similar between groups. Conclusion: In our porcine model with added warm ischemia simulating the effects of reperfusion after transplantation, pulsatile perfusion yielded similar renal protection compared with centrifugal perfusion kidney preservation. Both methods of perfusion can be used in ex vivo kidney perfusion systems.

Nationwide Outcomes after Renal Transplantation from Kidney-Only versus Multiple-Organ Deceased Donors

To assess renal transplant outcomes after donation by kidney-only (KO) versus multiple-organ (MO) donors on a national scale. The United Network for Organ Sharing database was examined for patients undergoing isolated kidney transplant from a deceased donor from 2000 through 2016. Comparison was made between recipients of grafts from KO versus MO donors at baseline and in a cohort of KO and MO recipients matched via propensity scoring. Outcomes of interest included delayed graft function (DGF), patient survival, and the cumulative incidence of graft loss. There were 33,326 recipients in the KO cohort versus 144,690 in the MO cohort. Donation after cardiac death donors were more prevalent in the KO group (43.8% vs 5.3%; P < 0.001). DGF occurred in 36.1 per cent of the KO versus 22.7 per cent of the MO recipients ( P < 0.001). Five-year survival was 79.5 per cent versus 83.4 per cent ( P < 0.001) in the KO versus MO group. After propensity matching, DGF was still more common in the KO group (33.1% vs 30.1%; P < 0.001). Patient survival was similar (79.5% KO vs 80.1% MO; P = 0.117). Cumulative incidence of graft loss was higher in the KO group (17.8% vs 16.8%). Survival outcomes from KO donors are actually quite good and should not be considered as inferior to MO donors.

Reconstitution of T-Cell Subsets Following Thymoglobulin-Induced Depletion in High Immunologic Risk and Donation After Cardiac Death Renal Transplant Recipients

INTRODUCTION

Depletion therapy in high immunologic risk (HR) patients by antithymocyte globulin (rATG) induces lymphopenia and subsequent compartmental repopulation of T-cell subsets. rATG is also given to patients receiving kidneys from donations after cardiac death (DCDs) to mitigate innate immune activation associated with the DCD process.

METHODS

We compared the T-cell response with rATG in both HR and DCD kidney recipients. We examined the reconstitution of T-cell subsets after rATG treatment in HR and DCD recipients (n = 19 per group) by multicolor flow cytometry.

RESULTS

Following treatment, there was a rapid drop in the frequency of T cells in both groups, which persisted over 28 days. HR patients had an early surge in the frequency of CD4⁺ naïve, effector-memory, and regulatory T cells. Although we found a significant proliferation of the T cells in both groups, the DCD cohort had a blunted response as well as reduced CD4⁺ T-cell immune-reactivity compare with the HR group.

CONCLUSIONS

Our data suggest that there is a lack of significant homeostatic proliferative response in DCD recipients following rATG, and CD4⁺ T cells may be less reactive in the DCD group than previously thought, indicating that rATG treatment may not have to be considered a first-line induction therapy in DCD recipients.

Outcomes of DCD kidneys recovered for transplantation with versus without pre-mortem heparin administration

BACKGROUND

Pre-mortem heparin administration during donation after circulatory death (DCD) organ recovery may be particularly important to improve perfusion and prevent graft thrombosis. However, pre-mortem heparin administration is not universally practiced in the US and scarce data exist regarding its efficacy.

METHODS

Using a national transplant registry data, we identified DCD kidneys recovered for transplantation from January 1, 2003, to March 10, 2017, and examined discard and outcomes after transplantation using bivariate and multivariable analyses. Organs with unknown or missing donor heparin status (n = 193), seropositive HIV (n = 10), HTLV (n = 33), hepatitis B (n = 26), or hepatitis C (n = 648) were excluded.

RESULTS

Of 24 861 DCD kidneys recovered with (n = 22 557) or without pre-mortem heparin administration (n = 2304), discard occurred in 19.1% and 20.8%, respectively (P = 0.05). On multivariate analysis, heparin use was not associated with discard (aOR 1.02, 95% CI 0.89-1.17, P = 0.820). Overall graft survival of no-heparin (n = 1791) vs heparin groups (n = 17 968) was similar on univariate and multivariate analysis (aHR 0.98, 95% CI 0.87-1.09, P = 0.640).

CONCLUSION

DCD kidneys from donors that have not received pre-mortem heparin administration have acceptable transplant outcomes and are not associated with discard.

Subnormothermic Oxygenated Perfusion Optimally Preserves Donor Kidneys Ex Vivo

Introduction

The current methods of preserving donor kidneys in nonoxygenated cold conditions minimally protect the kidney against ischemia-reperfusion injury (IRI), a major source of complications in clinical transplantation. However, preserving kidneys with oxygenated perfusion is not currently feasible due to the lack of an ideal perfusion mechanism that facilitates perfusion with blood at warm temperature. Here, we have designed an innovative renal pump circuit system that can perfuse blood or acellular oxygen carrier under flexible temperatures, pressures, and oxygenation. We have tested this apparatus to study optimal conditions of storage of our porcine model of donation after cardiac death (DCD) kidneys.

Methods

Porcine kidneys were retrieved after 30 minutes of cross-clamping renal pedicles in situ. Cessation of blood mimics postcardiac death in humans and simulates DCD warm ischemic injury. Procured kidneys were flushed and subjected to static cold storage (SCS) for 4 hours. For warm perfusion, kidneys were cannulated for pulsatile oxygenated perfusion with blood:PlasmaLyte for 4 hours at 15 °C, 22 °C, and 37 °C. To mimic posttransplant scenario, all kidneys were reperfused with blood for an additional 4 hours at 37 °C.

Results

Compared with all other groups, 22 °C perfusion resulted in significant reduction of acute tubular necrosis (ATN), apoptosis, kidney damage markers, Toll-like receptor signaling, and cytokine production. It was associated with maximal renal blood flow and urine output. Kidneys stored at 15 °C thrombosed within 2 hours under this condition. Martius Scarlet Blue staining confirmed that 22 °C was the optimal temperature to minimize hemorrhage and blood clots.

Conclusion

Our novel study shows that oxygenated perfusion at near-room-temperature provides optimal donor kidney storage conditions.

Nonimmunologic Factors Affecting Long-Term Outcomes of Deceased-Donor Kidney Transplant

OBJECTIVES

We investigated the impact of nonimmuno-logic factors on patient and graft survival after deceased-donor kidney transplant.

MATERIALS AND METHODS

All deceased-donor kidney transplants performed between January 2004 and December 2015 were included in our analyses. We used the independent t test to calculate significant differences between means above and below medians of various parameters.

RESULTS

All study patients (N = 205; 58.7% males) received antithymocyte globulin as induction therapy and standard maintenance therapy. Patients were free from infection, malignancy, and cardiac, liver, and pulmonary system abnormalities. Most patients (89.2%) were recipients of a first graft. Median patient age, weight, and cold ischemia time were 38 years, 65 kg, and 15 hours, respectively. Delayed graft function, diabetes mellitus, and hypertension occurred in 19.1%, 43.4%, and 77.9% of patients, respectively. The 1- and 5-year graft survival rates were 95% and 73.8%. Graft survival was not affected by donor or recipient sex or recipient diabetes or hypertension. However, graft survival was longer in patients who received no graft biopsy (8.2 vs 6.9 y; P = .027) and in those who had diagnosis of calcineurin inhibitor nephrotoxicity versus antibody-mediated rejection after biopsy (8.19 vs 3.66 y; P = .0047). Longer survival was shown with donors who had traumatic death versus cerebro-vascular accident (5.9 vs 5.3 y; P = .029) and donors below the 50th percentile in age (8.23 and 7.14 y; P = .0026) but less with donors who had terminal acute kidney injury (6.97 vs 8.16 y; P = .0062). We found a negative correlation between graft survival and donor age (P = .01) and 1-year serum creatinine (P = .01).

CONCLUSIONS

Donor age, cause of brain death, and acute kidney injury affected graft survival in our study cohort but not donor or recipient sex or posttransplant or donor blood pressure.

CORM-401 Reduces Ischemia Reperfusion Injury in an Ex Vivo Renal Porcine Model of the Donation After Circulatory Death

BACKGROUND

Carbon monoxide (CO) inhalation protects organ by reducing inflammation and cell death during transplantation processes in animal model. However, using CO in clinical transplantation is difficult due to its delivery in a controlled manner. A manganese-containing CO releasing molecules (CORM)-401 has recently been synthesized which can efficiently deliver 3 molar equivalents of CO. We report the ability of this anti-inflammatory CORM-401 to reduce ischemia reperfusion injury associated with prolonged cold storage of renal allografts obtained from donation after circulatory death in a porcine model of transplantation.

METHODS

To stimulate donation after circulatory death condition, kidneys from large male Landrace pig were retrieved after 1 hour warm ischemia in situ by cross-clamping the renal pedicle. Procured kidneys, after a brief flushing with histidine-tryptophan-ketoglutarate solution were subjected to pulsatile perfusion at 4°C with University of Wisconsin solution for 4 hours and both kidneys were treated with either 200 μM CORM-401 or inactive CORM-401, respectively. Kidneys were then reperfused with normothermic isogeneic porcine blood through oxygenated pulsatile perfusion for 10 hours. Urine was collected, vascular flow was assessed during reperfusion and histopathology was assessed after 10 hours of reperfusion.

RESULTS

We have found that CORM-401 administration reduced urinary protein excretion, attenuated kidney damage markers (kidney damage marker-1 and neutrophil gelatinase-associated lipocalin), and reduced ATN and dUTP nick end labeling staining in histopathologic sections. CORM-401 also prevented intrarenal hemorrhage and vascular clotting during reperfusion. Mechanistically, CORM-401 appeared to exert anti-inflammatory actions by suppressing Toll-like receptors 2, 4, and 6.

CONCLUSIONS

Carbon monoxide releasing molecules-401 provides renal protection after cold storage of kidneys and provides a novel clinically relevant ex vivo organ preservation strategy.

Hypothermia and kidney: a focus on ischaemia-reperfusion injury

Cellular damage after reperfusion of ischaemic tissue is defined as ischaemia–reperfusion injury (IRI). Hypothermia is able to decrease oxygen consumption, preventing a rapid loss of mitochondrial activity. However, even though cooling can help to decrease the deleterious effects of ischaemia, the consequences are not exclusively beneficial, such that hypothermic storage is a compromise between benefits and harm. The present review details the relationship between renal IRI and hypothermia, describing the pathophysiology of IRI and hypothermic protection through experimental evidence. Although experimental models of renal IRI are a valuable tool for understanding the pathophysiology of renal ischaemia–reperfusion, the clinical transfer of experimental results has several limitations, particularly because of anatomical and physiological differences. In this review limitations of animal models but also hypothermia as a strategy to protect the kidney from IRI are discussed. We also attempt to describe three clinical scenarios where hypothermia is used in clinical settings of IRI: transplantation, deceased donors and post-cardiac arrest.

The role of extracorporeal membrane oxygenation in patients after irreversible cardiac arrest as potential organ donors

The number of people waiting for a kidney or liver transplant is growing systematically. Due to the latest advances in transplantation, persons after irreversible cardiac arrest and confirmation of death have become potential organ donors. It is estimated that they may increase the number of donations by more than 40%. However, without good organization and communication between pre-hospital care providers, emergency departments, intensive care units and transplantation units, it is almost impossible to save the organs of potential donors in good condition. Various systems, including extracorporeal membrane oxygenation (ECMO), supporting perfusion of organs for transplantation play a key role. In 2016 the "ECMO for Greater Poland" program was established. Although its main goal is to improve the survival rate of patients suffering from life-threatening cardiopulmonary conditions, one of its branches aims to increase the donation rate in patients with irreversible cardiac arrest. In this review, the role of ECMO in the latter group as the potential organ donors is presented.

Histopathologic Findings of Potential Kidney Donors With Asymptomatic Microscopic Hematuria: Impact on Donation

INTRODUCTION

Isolated microscopic hematuria (IMH) is not uncommon in potential kidney donors.

AIM

The aim was to study the kidney biopsy findings of potential kidney donors with IMH and the impact of the histopathologic diagnoses on the decision to accept or decline such donors from kidney donation.

METHODS

In this retrospective study, all the potential kidney donors with IMH were identified from the medical records of patients who underwent kidney biopsies between January 2010 and December 2016.

RESULTS

Forty-five such individuals were identified. The mean age of these potential donors was 32.6 years and 76% were male. All of them had normal blood pressure and no significant proteinuria. Seventeen (38%) biopsies showed histopathologic abnormalities; thin basement membrane disease (n = 13; 28%) was the most common cause followed by immunoglobulin (Ig)A nephropathy (n = 4; 9%). Donors with abnormal biopsy findings were excluded from donation. However, 62% of the potential donors had normal kidney biopsy findings and were accepted for kidney donation.

CONCLUSION

IMH justifies extensive work-up including kidney biopsy to identify donors who may have underlying significant glomerular pathology excluding them from kidney donation. On the other hand, kidney biopsy also helps in accepting the donors if it does not show significant abnormality.

ICU Management of the Potential Organ Donor: State of the Art

End-organ failure is associated with high mortality and morbidity, in addition to increased health care costs. Organ transplantation is the only definitive treatment that can improve survival and quality of life in such patients; however, due to the persistent mismatch between organ supply and demand, waiting lists continue to grow across the world. Careful intensive care management of the potential organ donor with goal-directed therapy has the potential to optimize organ function and improve donation yield.

Is There a Particular Ethical Practice and Policy Space in North America for Uncontrolled Kidney Donation after Circulatory Death?

Despite successful transplantation outcomes in Europe, uncontrolled organ donation after circulatory determination of death (uDCDD) has essentially been a non-starter in North America. In this paper, I identify and explore a set of interesting, ethics-related considerations that are of relevance to this organ donation-transplantation practice. The analysis provides a theoretical platform for my development of a proposal for the creation of a particular ethical practice and policy space for kidney uDCDD in the U.S. and Canada that recognizes and aims to effectively address the various, identified challenges and constraints.

Organ donation protocols

Organ transplantation improves survival and quality of life in patients with end-organ failure. Waiting lists continue to grow across the world despite remarkable advances in the transplantation process, from the creation of public engagement campaigns to the development of critical pathways for the timely identification, referral, approach, and treatment of the potential organ donor. The pathophysiology of dying triggers systemic changes that are intimately related to organ viability. The intensive care management of the potential organ donor optimizes organ function and improves the donation yield, representing a significant step in reducing the mismatch between organ supply and demand. Different beliefs and cultures reflect diverse legislations and donation practices amongst different countries, creating a challenge to standardized practices. Maintaining public trust is necessary for continued progress in organ donation and transplantation, hence the urge for a joint effort in creating uniform protocols that ensure transparent practices within the medical community.

Kidney donation after circulatory death: current evidence and opportunities for pediatric recipients

Organ donation after circulatory death (DCD) has experienced a revival worldwide over the past 20 years, and is now widely practiced for kidney transplantation. Some previous concerns about these organs such as the high incidence of delayed graft function have been alleviated through evidence from adult studies. There are now a number of large adult cohorts reporting favorable 5-year outcomes for DCD kidney transplants, comparable to kidneys donated after brain death (DBD). This has resulted in a marked increase in the use of DCD kidneys for adult recipients in some countries and an increase in the overall number of kidney transplants. In contrast, the uptake of DCD kidneys for pediatric recipients is still low and concerns still exist over the longer-term outcomes of DCD organs. In view of the data from adult practice and the poor outcomes for children who stay on dialysis, DCD kidney transplantation should be offered as an option for children on the kidney transplant waiting list.

Changing Patterns of Organ Donation: Brain Dead Donors Are Not Being Lost by Donation After Circulatory Death

The clinical characteristics of all New England Organ Bank (NEOB) donors after circulatory death (DCD) donors were analyzed between July 1, 2009, and June 30, 2014. During that 5-year period, there were 494 authorized medically suitable potential DCDs that the NEOB evaluated, constituting more than 30% of deceased donors coordinated annually by the NEOB. From the cohort of 494 authorized potential DCDs, 331 (67%) became actual DCD, 82 (17%) were attempted as a DCD but did not progress to donation, and 81 (16%) transitioned to an actual donor after brain death (DBD). Two hundred seventy-six organs were transplanted from the 81 donors that transitioned from DCD to actual DBD, including 24 heart, 70 liver, 12 single and 14 bilateral lung, and 12 pancreas transplants. When patients with devastating brain injury admitted to the intensive care units are registered donors, the Organ Procurement Organization staff should share the patient's donation decision with the health care team and the patient's family, as early as possible after the comfort measures only discussion has been initiated. The experience of the NEOB becomes an important reference of the successful implementation of DCD that enables an expansion of deceased donation (inclusive of DBD).

Influence of a modified preservation solution in kidney transplantation: A comparative experimental study in a porcine model

BACKGROUND/OBJECTIVE

Currently, due to lack of optimal donors, more marginal organs are transplanted. Therefore, there is a high interest to ameliorate preischemic organ preservation, especially for critical donor organs. In this regard, a new histidine-tryptophane ketoglutarate (HTK-N) solution has been designed and its protective efficacy was compared with the standard preservation solutions-University of Wisconsin solution and standard HTK or Custodiol (Bretschneider's solution).

METHODS

Seventy-two landrace pigs were included into the study, as donors and recipients. The donor kidneys were perfused during explantation with cold University of Wisconsin solution (n = 12), standard HTK (n = 12), or HTK-N solutions (n = 12), kept in the respective preservation solution at 4°C for 30 hours, implanted in the recipient pigs, and reperfused. The pigs survived in daily control for 7 days. The serum creatinine and blood urea nitrogen were assessed in pre- and postreperfusion phase on the 3^rd day and 7^th day posttransplantation. Additionally, tissue samples were taken to analyze the histopathological degree of tubular injury and regeneration before and after reperfusion.

RESULTS

The three preservation groups were comparable in age, body weight, and hemodynamic parameters. According to statistical proof, they differed in none of the control parameters.

CONCLUSION

Although the new preservation HTK solution is in several points a well-thought-out modification of the standard HTK solution, its preservation efficacy, at least for kidney preservation in a pig model for 30 hours, seems to be comparable to the current used solutions. A real advantage, however, could be confirmed in clinical settings, where marginal organs may influence the clinical outcome.

Pathological characteristics of liver allografts from donation after brain death followed by cardiac death in pigs

Donation after brain death followed by circulatory death (DBCD) is a unique practice in China. The aim of this study was to define the pathologic characteristics of DBCD liver allografts in a porcine model. Fifteen male pigs (25-30 kg) were allocated randomly into donation after brain death (DBD), donation after circulatory death (DCD) and DBCD groups. Brain death was induced by augmenting intracranial pressure. Circulatory death was induced by withdrawal of life support in DBCD group and by venous injection of 40 mL 10% potassium chloride in DCD group. The donor livers were perfused in situ and kept in cold storage for 4 h. Liver tissue and common bile duct samples were collected for hematoxylin and eosin staining, TUNEL testing and electron microscopic examination. Spot necrosis was found in hepatic parenchyma of DBD and DBCD groups, while a large area of necrosis was shown in DCD group. The apoptosis rate of hepatocytes in DBD [(0.56±0.30)%] and DBCD [(0.50 ± 0.11)%] groups was much lower than that in DCD group [(3.78±0.33)%] (P<0.05). And there was no significant difference between DBD group and DBCD group (P>0.05)). The structures of bile duct were intact in both DBD and DBCD groups, while the biliary epithelium was totally damaged in DCD group. Under electron microscope, the DBD hepatocytes were characterized by intact cell membrane, well-organized endoplasmic reticulum, mild mitochondria edema and abundant glycogens. Broken cell membrane, mild inflammatory cell infiltration and sinusoidal epithelium edema, as well as reduced glycogen volume, were found in the DBCD hepatocytes. The DCD hepatocytes had more profound cell organelle injury and much less glycogen storage. In conclusion, the preservation injury of DBCD liver allografts is much less severe than that of un-controlled DCD, but more severe than that of DBD liver allografts under electron microscope, which might reflect post-transplant liver function to some extent.

Outcome and cost analysis of induction immunosuppression with IL2Mab or ATG in DCD kidney transplants

BACKGROUND

Kidney transplantation from DCD now represents a significant part of the overall transplant activity in the UK. Outcome of different induction immunosuppression regimes and related cost benefit analysis has been reported by very few studies.This is a single centre study on frequency-matched patients who received a DCD kidney transplant between August 2007 and August 2009.

METHODS

Data on 45 patients divided in 2 groups were collected prospectively and analyzed retrospectively. Group A (24 patients) received IL2Mab and Group B (21 patients) ATG as induction immunosuppression. Patient and graft survival were similar in both groups.

RESULTS

In the ATG-induced group, there was a significant lower rate of DGF, BPAR, and infections requiring readmission.A cost analysis was performed including all immunosuppression-related costs, and it has shown remarkable savings in the ATG-induced group.

CONCLUSION

Considering that the number of DCD kidney transplants is destined to rise in the UK, we believe that ATG is a valid option to continue optimizing outcomes of DCD kidney transplant. In our experience, ATG proved to be safe, effective, and contributed to significant cost savings.

Central nervous system syndromes in solid organ transplant recipients

Solid organ transplant recipients have a high incidence of central nervous system (CNS) complications, including both focal and diffuse neurologic deficits. In the immunocompromised host, the initial clinical evaluation must focus on both life-threatening CNS infections and vascular or anatomic lesions. The clinical signs and symptoms of CNS processes are modified by the immunosuppression required to prevent graft rejection. In this population, these etiologies often coexist with drug toxicities and metabolic abnormalities that complicate the development of a specific approach to clinical management. This review assesses the multiple risk factors for CNS processes in solid organ transplant recipients and establishes a timeline to assist in the evaluation and management of these complex patients.