Review of Randomized Clinical Trials of Donor Management and Organ Preservation in Deceased Donors: Opportunities and Issues

Developing Guidance for Donor Intervention Randomized Controlled Trials: Initial Discussions From the Canada-United Kingdom 2022 Workshop

BACKGROUND

Donor interventions, including medications, protocols, and medical devices administered to donors, can enhance transplantable organ quality and quantity and maximize transplantation success. However, there is paucity of high-quality evidence about their effectiveness, in part because of ethical, practical, and regulatory challenges, and lack of guidance about conduct of donor intervention randomized controlled trials (RCTs).

METHODS

With the vision to develop authoritative guidance for conduct of donor intervention RCTs, we convened a workshop of Canadian-United Kingdom experts in organ donation and transplantation ethics, research, and policy to identify stakeholders, explore unique challenges, and develop research agenda to inform future work in this promising field.

RESULTS

Donor intervention trials should consider perspectives of broad group of stakeholders including donors, transplant recipients, and their families; researchers in donation and transplantation; research ethics boards; and healthcare providers and administrators involved in donation and transplantation. Unique challenges include (1) research ethics (living versus deceased status of the donor at the time of intervention, intervention versus outcomes assessment in different individuals, harm-benefit analysis in donors versus recipients, consent, and impact on research bystanders); (2) outcome data standardization and linkage; and (3) regulatory and governance considerations.

CONCLUSIONS

Donor intervention RCTs hold potential to benefit organ transplantation outcomes but face unique research ethics, outcome data, and regulatory challenges. By developing research agenda to address these challenges, our workshop was an important first step toward developing Canada-United Kingdom guidance for donor intervention RCTs that are poised to improve the quality and availability of transplantable organs.

Complications in Post-Liver Transplant Patients

Liver transplantation (LT) is the treatment of choice for liver failure and selected cases of malignancies. Transplantation activity has increased over the years, and indications for LT have been widened, leading to organ shortage. To face this condition, a high selection of recipients with prioritizing systems and an enlargement of the donor pool were necessary. Several authors published their case series reporting the results obtained with the use of marginal donors, which seem to have progressively improved over the years. The introduction of in situ and ex situ machine perfusion, although still strongly debated, and better knowledge and treatment of the complications may have a role in achieving better results. With longer survival rates, a significant number of patients will suffer from long-term complications. An extensive review of the literature concerning short- and long-term outcomes is reported trying to highlight the most recent findings. The heterogeneity of the behaviors within the different centers is evident, leading to a difficult comparison of the results and making explicit the need to obtain more consent from experts.

Research and Innovation in Organ Donation: Recommendations From an International Consensus Forum

This report provides recommendations from the Research and Innovation domain as part of the International Donation and Transplantation Legislative and Policy Forum (hereafter the Forum) to provide expert guidance on the structure of an ideal organ and tissue donation and transplantation system. The recommendations focus on deceased donation research and are intended for clinicians, investigators, decision-makers, and patient, family, and donor (PFD) partners involved in the field.

Methods

We identified topics impacting donation research through consensus using nominal group technique. Members performed narrative reviews and synthesized current knowledge on each topic, which included academic articles, policy documents, and gray literature. Using the nominal group technique, committee members discussed significant findings, which provided evidence for our recommendations. The Forum's scientific committee then vetted recommendations.

Results

We developed 16 recommendations in 3 key areas to provide stakeholders guidance in developing a robust deceased donor research framework. These include PFD and public involvement in research; donor, surrogate, and recipient consent within a research ethics framework; and data management. We highlight the importance of PFD and public partner involvement in research, we define the minimum ethical requirements for the protection of donors and recipients of both target and nontarget organ recipients, and we recommend the creation of a centrally administered donor research oversight committee, a single specialist institutional review board, and a research oversight body to facilitate coordination and ethical oversight of organ donor intervention research.

Conclusions

Our recommendations provide a roadmap for developing and implementing an ethical deceased donation research framework that continually builds public trust. Although these recommendations can be applied to jurisdictions developing or reforming their organ and tissue donation and transplantation system, stakeholders are encouraged to collaborate and respond to their specific jurisdictional needs related to organ and tissue shortages.

Family experiences with non-therapeutic research on dying patients in the intensive care unit

Experiences of substitute decision-makers with requests for consent to non-therapeutic research participation during the dying process, including to what degree such requests are perceived as burdensome, have not been well described. In this study, we explored the lived experiences of family members who consented to non-therapeutic research participation on behalf of an imminently dying patient.We interviewed 33 family members involved in surrogate research consent decisions for dying patients in intensive care. Non-therapeutic research involved continuous physiological monitoring of dying patients prior to and for 30 min following cessation of circulation. At some study centres participation involved installation of bedside computers. At one centre electroencephalogram monitoring was used with a subset of participants. Aside from additional monitoring, the research protocol did not involve deviations from usual end-of-life care.Thematic analysis of interviews suggests most family members did not perceive this minimal-risk, non-therapeutic study to affect their time with patients during the dying process, nor did they perceive research consent as an additional burden. In our analysis, consenting for participation in perimortem research offered families of the dying an opportunity to affirm the intrinsic value of patients' lives and contributions. This opportunity may be particularly important for families of patients who consented to organ donation but did not proceed to organ retrieval.Our work supports concerns that traditional models of informed consent fail to account for possible benefits and harms of perimortem research to surviving families. Further research into consent models which integrate patient and family perspectives is needed.

Hemodynamic Effects of High-dose Levothyroxine and Methylprednisolone in Brain-dead Potential Organ Donors

BACKGROUND

Hormonal replacement therapy is administered to many brain-dead organ donors to improve hemodynamic stability. Previous clinical studies present conflicting results with several randomized studies reporting no benefit.

METHODS

Consecutive adult donors (N = 199) were randomized to receive high-dose levothyroxine, high-dose methylprednisolone, both (Combo), or no hormonal therapy (Control). Vasopressor requirements using the vasoactive-inotropic score (VIS) were assessed at baseline, 4 h, and at procurement. Crossover to the Combo group was sufficient to require separate intention-to-treat and per-protocol analyses.

RESULTS

In the intention-to-treat analysis, the mean (±SD) reduction in VIS from baseline to procurement was 1.6 ± 2.6, 14.9 ± 2.6, 10.9 ± 2.6, and 7.1 ± 2.6 for the levothyroxine, methylprednisolone, Combo, and Control groups, respectively. While controlling for the baseline score, the reduction in VIS was significantly greater in the methylprednisolone and Combo groups and significantly less in the levothyroxine group compared with controls. Results were similar in the per-protocol analysis.

CONCLUSION

High-dose methylprednisolone alone or in combination with levothyroxine allowed for significant reduction in vasopressor support in organ donors. Levothyroxine alone offered no advantage in reducing vasopressor support. Organ yield, transplantation rates, and recipient outcomes were not adversely affected.

Variability in deceased donor care in Canada: a report of the Canada-DONATE cohort study

PURPOSE

Canadian donor management practices have not been reported. Our aim was to inform clinicians and other stakeholders about the range of current practices.

METHODS

This prospective observational cohort study enrolled consecutive, newly consented organ donors from August 1 2015 to July 31 2018 at 27 academic and five community adult intensive care units in British Columbia, Alberta, Ontario, and Quebec. Research staff prospectively recorded donor management data. Provincial organ donation organizations verified the organs donated. We formally compared practices across provinces.

RESULTS

Over a median collection period of eight months, 622 potential donors were classified at baseline as having neurologic determination of death (NDD donors; n = 403) or circulatory death (DCD donors; n = 219). Among NDD donors, 85.6% underwent apnea testing (rarely with carbon dioxide insufflation), 33.2% underwent ancillary testing, and subsequent therapeutic hypothermia (34-35°C) was rare. Neurologic determination of death donors were more hemodynamically unstable with most having received vasopressin and norepinephrine infusions, with a large majority having received high-dose corticosteroids and intravenous thyroxine. Among DCD donors, 61.6% received corticosteroids, and 8.9% received thyroxine. Most donors did not receive lung-protective ventilation strategies. Invasive procedures after donation consent included bronchoscopy (71.7%), cardiac catheterization (NDD donors only; 21.3%), and blood transfusions (19.3%). Physicians ordered intravenous antemortem heparin for 94.8% of DCD donors. The cohort donated 1,629 organs resulting in 1,532 transplants. Case selection, death determinations, and hormone, nutrition and heparin practices all varied across provinces.

CONCLUSION

These study findings highlight areas for knowledge translation and further clinical research. Interprovincial discrepancies will likely pose unique challenges to national randomized trials.

TRIAL REGISTRATION

www.clinicaltrials.gov (NCT03114436); registered 10 April, 2017.

Renal Procurement: Techniques for Optimizing the Quality of the Graft in the Cadaveric Setting

PURPOSE OF REVIEW

Kidney transplantation is the best treatment for end-stage renal disease. However, due to organ shortage, suboptimal grafts are increasingly being used.

RECENT FINDINGS

We carried out a review on the methods and techniques of organ optimization in the cadaveric setting. Donor care is the first link in a chain of care. Right after brain death, there is a set of changes, of which hormonal and hemodynamic changes are the most relevant. Several studies have been conducted to determine which drugs to administer, although in most cases, the results are not definitive. The main goal seems rather achieve a set of biochemical and hemodynamic objectives. The ischemia-reperfusion injury is a critical factor for kidney damage in transplantation. One of the ways found to deal with this type of injury is preconditioning. Local and remote ischemic preconditioning has been studied for various organs, but studies on the kidney are scarce. A new promising area is pharmacological preconditioning, which is taking its first steps. Main surgical techniques were established in the late twentieth century. Some minor new features have been introduced to deal with anatomical variations or the emergence of donation after circulatory death. Finally, after harvesting, it is necessary to ensure the best conditions for the kidneys until the time of transplantation. Much has evolved since static cold preservation, but the best preservation conditions are yet to be determined. Conservation in the cold has come to be questioned, and great results have appeared at temperatures closer to physiological.

Heterogeneity of Bile Duct Management in the Development of Ischemic Cholangiopathy After Liver Transplantation: Results of a European Liver and Intestine Transplant Association Survey

BACKGROUND

Surgical factors and direct cytotoxicity of bile salts on cholangiocytes may play a role in the development of ischemic cholangiopathy (IC) after liver transplantation (LTx). There is no validated consensus on how to protect the bile ducts during procurement, static preservation, and LTx. Meanwhile, IC remains the most troublesome complication after LTx.

AIM

To characterize bile duct management techniques during the LTx process among European transplant centers in cases of donation after brain death (DBD) and circulatory death (DCD).

METHOD

An European Liver and Intestine Transplant Association-European Liver Transplant Registry web survey designed to conceal respondents' personal information was sent to surgeons procuring and/or transplanting livers in Europe.

RESULTS

Sixty-five percent of responses came from large transplant centers (>50 procurements/y). In 8% of DBDs and 14% of DCDs the bile duct is not rinsed. In 46% of DBDs and 52% of DCDs surgeons prefer to remove the gallbladder after graft reperfusion. Protocols concerning preservation solutions (nature, pressure, volume) are extremely heterogeneous. In 54% of DBDs and 61% of DCDs an arterial back table pressure perfusion is performed. Steroids (20%-10%), heparin (72%-60%), prostacyclin (3%-7%), and fibrinolytics (4%-11%) are used as donor-protective interventions in DBD and DCD cases, respectively. In 2% of DBD and 6% of DCD cases a hepatic artery reperfusion is performed first. In 4% of DBD and 6% of DCD cases, fibrinolytics are administered through the hepatic artery during the bench and/or implantation.

CONCLUSION

This European web survey shows for the first time the heterogeneity in the management of bile ducts during procurement, preservation, and transplantation in Europe. In the context of sharing more marginal liver grafts, an expert meeting must be organized to formulate guidelines to be applied to protect liver grafts against IC.

Evaluation of outcomes in renal transplantation with hypothermic machine perfusion for the preservation of kidneys from expanded criteria donors

In 2012, an expert working group from the French Transplant Health Authority recommended the use of hypothermic machine perfusion (HMP) to improve kidney preservation and transplant outcomes from expanded criteria donors, deceased after brain death. This study compares HMP and cold storage (CS) effects on delayed graft function (DGF) and transplant outcomes. We identified 4,316 kidney transplants from expanded criteria donors (2011-2014) in France through the French Transplant Registry. DGF occurrence was analyzed with a logistic regression, excluding preemptive transplants. One-year graft failure was analyzed with a Cox regression. A subpopulation of 66 paired kidneys was identified: one preserved by HMP and the other by CS from the same donor. Kidneys preserved by HMP (801) vs CS (3515) were associated with more frequent recipient comorbidities and older donors and recipients. HMP had a protective effect against DGF (24% in HMP group and 38% in CS group, OR = 0.49 [0.40-0.60]). Results were similar in the paired kidneys (OR = 0.23 [0.04-0.57]). HMP use decreased risk for 1-year graft failure (HR = 0.77 [0.60-0.99]). Initial hospital stays were shorter in the HMP group (P < 0.001). Our results confirm the reduction in DGF occurrence among expanded criteria donors kidneys preserved by HMP.

Adherence to guidelines for the management of donors after brain death

PURPOSE

Guideline adherence for the management of a donor after brain death (DBD) is largely unknown. This study aimed to perform an importance-performance analysis of prioritized key interventions (KIs) by linking guideline adherence rates to expert consensus ratings for the management of a DBD.

MATERIALS AND METHODS

This observational, cross-sectional multicenter study was performed in 21 Belgian ICUs. A retrospective review of patient records of adult utilized DBDs between 2013 and 2016 used 67 KIs to describe adherence to guidelines.

RESULTS

A total of 296 patients were included. Thirty-five of 67 KIs had a high level of adherence congruent to a high expert panel rating of importance. Nineteen of 67 KIs had a low level of adherence in spite of a high level of importance according to expert consensus. However, inadequate documentation proved an important issue, hampering true guideline adherence assessment. Adherence ranged between 3 and 100% for single KI items and on average, patients received 72% of the integrated expert panel recommended care set.

CONCLUSIONS

Guideline adherence to an expert panel predefined care set in DBD donor management proved moderate leaving substantial room for improvement. An importance-performance analysis can be used to improve implementation and documentation of guidelines.

Perspectives toward brain death diagnosis and management of the potential organ donor

BACKGROUND

Organ donation and transplantation represent one of the most important scientific advances over the last decades. Due to the complexity of these procedures and related ethical-legal aspects, however, there are a lot of doubts and uncertainty about the brain death diagnosis and the maintenance of potential organ donor.

AIM

To identify and discuss the different meanings and experiences of registered nurses and physicians from an adult intensive care unit in relation to the diagnosis of brain death and the maintenance of potential organ donors for transplantation purposes.

STUDY DESIGN

Participants were registered nurses and physicians from an adult intensive care unit at a University Hospital from Brazil. Data were collected through semi-structured interviews and analyzed using content analysis.

ETHICAL CONSIDERATIONS

This study was approved by the University of São Paulo at Ribeirão Preto College of Nursing Research Ethics Committee.

RESULTS

Two main categories emerged from the analysis: (1) brain death diagnosis and its implications and (2) maintenance of the potential organ donor and its repercussion in the donation-transplantation process. Six subcategories were also identified: (1.1) understanding the brain death diagnosis as a tool to aid decision-making; (1.2) diagnosis as guarantee of rights; (1.3) difficulties encountered to establish the diagnosis; (1.4) clinical criteria adopted in Brazil and related ethical-legal aspects; (2.1) specificities of care to the brain dead person and outcomes; and (2.2) nurse's duties toward the brain dead person.

CONCLUSION

Although the brain death diagnosis is scientifically and legally defined in Brazil and the maintenance of the potential organ donor for transplantation purposes has been addressed during the last years, there are still some doubts about the subject, as its understanding varies according to the personal beliefs, culture, and educational background of individuals, including those who work in this scenario.

Development of key interventions and quality indicators for the management of an adult potential donor after brain death: a RAND modified Delphi approach

Background

A substantial degree of variability in practices exists amongst donor hospitals regarding the donor detection, determination of brain death, application of donor management techniques or achievement of donor management goals. A possible strategy to standardize the donation process and to optimize outcomes could lie in the implementation of a care pathway. The aim of the study was to identify and select a set of relevant key interventions and quality indicators in order to develop a specific care pathway for donation after brain death and to rigorously evaluate its impact.

Methods

A RAND modified three-round Delphi approach was used to build consensus within a single country about potential key interventions and quality indicators identified in existing guidelines, review articles, process flow diagrams and the results of the Organ Donation European Quality System (ODEQUS) project. Comments and additional key interventions and quality indicators, identified in the first round, were evaluated in the following rounds and a subsequent physical meeting. The study was conducted over a 4-month time period in 2016.

Results

A multidisciplinary panel of 18 Belgian experts with different relevant backgrounds completed the three Delphi rounds. Out of a total of 80 key interventions assessed throughout the Delphi process, 65 were considered to contribute to the quality of care for the management of a potential donor after brain death; 11 out of 12 quality indicators were validated for relevance and feasibility. Detection of all potential donors after brain death in the intensive care unit and documentation of cause of no donation were rated as the most important quality indicators.

Conclusions

Using a RAND modified Delphi approach, consensus was reached for a set of 65 key interventions and 11 quality indicators for the management of a potential donor after brain death. This set is considered to be applicable in quality improvement programs for the care of potential donors after brain death, while taking into account each country’s legislation and regulations regarding organ donation and transplantation.

Electronic supplementary material

The online version of this article (10.1186/s12913-018-3386-1) contains supplementary material, which is available to authorized users.

Hamilton-DONATE: a city-wide pilot observational study of the ICU management of deceased organ donors

PURPOSE

Improving the medical care of deceased organ donors to increase transplant rates and improve allograft function requires an understanding of the current epidemiology and clinical practices of deceased donation within intensive care units (ICUs). Herein, we report the results of our investigation into the feasibility of a multicentre prospective cohort study addressing the afformentioned issues.

METHODS

We conducted a 12-month prospective observational cohort study in six ICUs and one coronary care unit in Hamilton, Canada. We included consecutive children and adults following consent for deceased organ donation (including neurologic determination of death [NDD] or donation after circulatory death [DCD]). Intensive care unit research staff recorded donor management data from hospital records, extending from one day prior to the consent for organ donation up to the time of organ retrieval. The provincial Organ Donation Organization (ODO) supplemented these data and, additionally, provided data on corresponding organ recipients. We identified, evaluated, and measured three potential obstacles to the feasibility of a national cohort study: obtaining authorization to implement the study with a waiver of research consent, accessibility of transplant recipient data, and the time required to complete very detailed case report forms (CRFs), with valuable lessons learned for implementation in future projects.

RESULTS

The local Research Ethics Board and the ODO Privacy Office both authorized the recording of donor and recipient study data with a waiver of research consent. Sixty-seven consecutive consented donors were included (31 NDD and 36 DCD donors); 50 of them provided 144 organs for transplantation to 141 recipients. We identified the age and sex of the recipients as well as the location and date of transplant for all organ recipients in Ontario; however, we obtained no recipient data for six organs transported outside of Ontario. Intensive care unit research staff estimated that future CRF completion will require five to seven hours per patient.

CONCLUSION

The Hamilton-DONATE pilot study supports the feasibility of a larger cohort study to describe the epidemiology and clinical practices related to deceased donor care in Canada.

TRIAL REGISTRATION

wwwclinicaltrials.gov (NCT02902783). Registered 16 September 2016.

Systematic review on the treatment of deceased organ donors

BACKGROUND

Currently, there is no consensus on which treatments should be a part of standard deceased-donor management to improve graft quality and transplantation outcomes. The objective of this systematic review was to evaluate the effects of treatments of the deceased, solid-organ donor on graft function and survival after transplantation.

METHODS

Pubmed, Embase, Cochrane, and Clinicaltrials.gov were systematically searched for randomized controlled trials that compared deceased-donor treatment versus placebo or no treatment.

RESULTS

A total of 33 studies were selected for this systematic review. Eleven studies were included for meta-analyses on three different treatment strategies. The meta-analysis on methylprednisolone treatment in liver donors (two studies, 183 participants) showed no effect of the treatment on rates of acute rejection. The meta-analysis on antidiuretic hormone treatment in kidney donors (two studies, 222 participants) indicates no benefit in the prevention of delayed graft function. The remaining meta-analyses (seven studies, 334 participants) compared the effects of 10 min of ischaemic preconditioning on outcomes after liver transplantation and showed that ischaemic preconditioning improved short-term liver function, but not long-term transplant outcomes.

CONCLUSIONS

There is currently insufficient evidence to conclude that any particular drug treatment or any intervention in the deceased donor improves long-term graft or patient survival after transplantation.

Organ-specific responses during brain death: increased aerobic metabolism in the liver and anaerobic metabolism with decreased perfusion in the kidneys

Hepatic and renal energy status prior to transplantation correlates with graft survival. However, effects of brain death (BD) on organ-specific energy status are largely unknown. We studied metabolism, perfusion, oxygen consumption, and mitochondrial function in the liver and kidneys following BD. BD was induced in mechanically-ventilated rats, inflating an epidurally-placed Fogarty-catheter, with sham-operated rats as controls. A 9.4T-preclinical MRI system measured hourly oxygen availability (BOLD-related R2*) and perfusion (T1-weighted). After 4 hrs, tissue was collected, mitochondria isolated and assessed with high-resolution respirometry. Quantitative proteomics, qPCR, and biochemistry was performed on stored tissue/plasma. Following BD, the liver increased glycolytic gene expression (Pfk-1) with decreased glycogen stores, while the kidneys increased anaerobic- (Ldha) and decreased gluconeogenic-related gene expression (Pck-1). Hepatic oxygen consumption increased, while renal perfusion decreased. ATP levels dropped in both organs while mitochondrial respiration and complex I/ATP synthase activity were unaffected. In conclusion, the liver responds to increased metabolic demands during BD, enhancing aerobic metabolism with functional mitochondria. The kidneys shift towards anaerobic energy production while renal perfusion decreases. Our findings highlight the need for an organ-specific approach to assess and optimise graft quality prior to transplantation, to optimise hepatic metabolic conditions and improve renal perfusion while supporting cellular detoxification.

Organ-Protective Intensive Care in Organ Donors

BACKGROUND

The ascertainment of brain death (the irreversible, total loss of brain function) gives the physician the opportunity to limit or stop further treatment. Alternatively, if the brain-dead individual is an organ donor, the mode of treatment can be changed from patient-centered to donationcentered. Consensus-derived recommendations for the organ-protective treatment of brain-dead organ donors are not yet available in Germany.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed, and on the authors' clinical experience.

RESULTS

Brain death causes major pathophysiological changes, including an increase in catecholamine levels and a sudden drop in the concentration of multiple hormones, among them antidiuretic hormone, cortisol, insulin, and triand tetraiodothyronine. These changes affect the function of all organ systems, as well as the hemodynamic state and the regulation of body temperature. The use of standardized donor management protocols might well increase the rate of transplanted organs per donor and improve the quality of the transplanted organs. In addition, the administration of methylprednisolone, desmopressin, and vasopressin could be a useful supplement to treatment in some cases. Randomized controlled trials have not yet demonstrated either improved organ function or prolonged survival of the transplant recipients.

CONCLUSION

The evidence base for organ-protective intensive care is weak; most of the available evidence is on the level of expert opinion. There is good reason to believe, however, that the continuation of intensive care, in the sense of early donor management, can make organ transplantation more successful both by increasing the number of transplantable organs and by improving organ quality.

Strategies to Restore Adenosine Triphosphate (ATP) Level After More than 20 Hours of Cold Ischemia Time in Human Marginal Kidney Grafts

Background

The persisting organ shortage in the field of transplantation recommends the use of marginal kidneys which poorly tolerate ischemic damage. Adenosine triphosphate (ATP) depletion during cold ischemia time (CIT) is considered crucial for graft function. We tested different strategies of kidney perfusion before transplantation in the attempt to improve the technique.

Material/Methods

Twenty human discarded kidneys from donors after brain death and with at least 20 hours of CIT were randomized to the following experimental groups (treatment time three-hours at 4°C): a) static cold storage (CS); b) static cold hyperbaric oxygenation (Hyp); c) hypothermic perfusion (PE); d) hypothermic perfusion in hyperbaric oxygenation (PE-Hyp); and e) hypothermic oxygenated perfusion (PE-O₂).

Results

Histological results showed that perfusion with or without oxygen did not produce any endothelial damage. A depletion of ATP content following the preservation procedure was observed in CS, PE, and Hyp, while PE-Hyp and PE-O₂ were associated with a net increase of ATP content with respect to baseline level. In addition, PE-Hyp was associated with a significant downregulation of endothelial isoform of nitric oxide synthase (eNOS) gene expression and of hypoxia inducible factor-1α (HIF-1α).

Conclusions

Hyperbaric or normobaric oxygenation with perfusion improves organ metabolic preservation compared to other methods. This approach may prevent the onset of delayed graft function, but clinical trials are needed to confirm this.

Hepatitis C virus genotyping of organ donor samples to aid in transplantation of HCV-positive organs

Given the availability of new highly efficacious anti-HCV therapies, some clinicians have advocated for wider use of kidneys from hepatitis C virus-positive (HCV+) donors, including transplanting them into HCV-negative recipients. As treatment regimens for HCV are commonly guided by genotype, pretransplant HCV genotyping of tissue donors would be beneficial. To our knowledge, donor HCV genotyping has never been reported. We retrieved archived frozen plasma samples for 17 previous organ donors through a local organ procurement organization. We performed HCV genotyping using the eSensor HCVg Direct Test (GenMark Diagnostics) and also by Sanger sequencing, for confirmation (Retrogen). In addition, viral loads were measured using the COBAS AmpliPrep/TaqMan system (Roche Diagnostics). We found that most of the samples (n = 14) were HCV Genotype 1a with the remainder being Genotype 2b (n = 1) or Genotype 3 (n = 2). All genotyping results were concordant with Sanger sequencing. The average HCV viral load in the sample group was ~ 1.6 million IU/mL (range: ~16 000 IU/mL to 7 million IU/mL). We demonstrate that viral RNA from organ donor plasma can be successfully genotyped for HCV. This ability suggests that transplantation of HCV+ kidneys into HCV-negative recipients, followed by genotype-guided antiviral therapy, could be feasible.

Canada-DONATE study protocol: a prospective national observational study of the medical management of deceased organ donors

INTRODUCTION

Research on the management of deceased organ donors aims to improve the number and quality of transplants and recipient outcomes. In Canada, this research is challenged by regionalisation of donation services within provinces and the geographical, clinical and administrative separation of donation from transplantation services. This study aims to build a national platform for future clinical trials in donor management. Objectives are to engage collaborators at donation hospitals and organ donation organisations (ODOs) across Canada, describe current practices, evaluate the effectiveness of donation-specific interventions and assess the feasibility of future clinical trials.

METHODS AND ANALYSIS

This ongoing prospective observational study of the medical management of deceased organ donors will enrol more than 650 consented potential donors from adult intensive care units at 33 hospital sites across Canada, each participating for 12 months. ODOs ensure enrolment of consecutive eligible participants. Research staff record detailed data about participants, therapies, organ assessments, death declaration procedures and adverse clinical exposures from the time of donation consent to organ recovery. ODOs provide reasons that organs are declined, dates and places of transplantation, and recipient age and sex.Descriptive analyses will summarise current practices. Effectiveness analyses will examine donation-specific interventions with respect to the number of transplants, using multilevel regression models to account for clustering by donor, hospitals and ODOs. Feasibility analyses will focus on acceptance of the research consent model; participation of academic and community hospitals as well as ODOs; and accessibility of recipient data.

ETHICS AND DISSEMINATION

This study uses a waiver of research consent. Hospitals will receive reports on local practices benchmarked to (1) national practices and (2) national donor management guidelines. We will report findings to donation and transplant collaborators (ie, clinicians, researchers, ODOs) and publish in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT03114436.

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.

Keys to successful organ procurement: An experience-based review of clinical practices at a high-performing health-care organization

Organ procurement (OP) from donors after brain death and circulatory death represents the primary source of transplanted organs. Despite favorable laws and regulations, OP continues to face challenges for a number of reasons, including institutional, personal, and societal barriers. This focused review presents some of the key components of a successful OP program at a large, high-performing regional health network. This review focuses on effective team approaches, aggressive resuscitative strategies, optimal communication, family support, and community outreach efforts.

Organ donor management: Eight common recommendations and actions that deserve reflection

Despite major advances in our understanding of the physiopathology of brain death (BD), there are important controversies as to which protocol is the most appropriate for organ donor management. Many recent reviews on this subject offer recommendations that are sometimes contradictory and in some cases are not applied to other critically ill patients. This article offers a review of the publications (many of them recent) with an impact upon these controversial measures and which can help to confirm, refute or open new areas of research into the most appropriate measures for the management of organ donors in BD, and which should contribute to discard certain established recommendations based on preconceived ideas, that lead to actions lacking a physiopathological basis. Aspects such as catecholamine storm management, use of vasoactive drugs, hemodynamic objectives and monitoring, assessment of the heart for donation, and general care of the donor in BD are reviewed.

Living donor kidney allograft survival ≥ 50 years

The first successful kidney transplant occurred in 1954. Since then, long-term graft survival has been an elusive idealistic goal of transplantation. Yet 62 years later, we know of only 6 kidney transplant recipients who have achieved ≥  50-year graft survival while being on no immunosuppression or a substantially reduced regimen. Herein, we report graft survival  ≥ 50 years in 2 living donor recipients who have been maintained on standard-of-care immunosuppression the entire time. For our 2 recipients, their living donor's altruism altered the course, length, and quality of their life, which by all accounts can be deemed normal: They attended college, held jobs, had successful pregnancies, raised families, and were productive members of society. Both donors are still alive and well, more than 50 years post-donation; both have an acceptable GFR and normal blood pressure, with hyperlipidemia as their only medical problem. These 2 intertwined stories illustrate the tremendous potential of a successful kidney transplant: long-term survival with a normal lifestyle and excellent quality of life, even after more than 5 decades on full-dose immunosuppression.

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.

Progress in Transplantation: Will It Be Achieved in Big Steps or by Marginal Gains?

A wish for progress in transplantation assumes that there are needs not met by the currently available therapy and that the barriers to resolving the problems can be surmounted. There are 5 major unmet needs: the potential to avoid transplantation either by prevention of disease or provision of an alternative to natural biological organ replacement; geographic heterogeneity of access to, and quality of, transplantation; availability of transplantation to those in need of it; survival of the patient and the transplant; and the avoidance of adverse effects of immunosuppression. During the past 50 years, there have been advances on at least 4 of these 5 fronts that illustrate the interplay of "big steps" and "marginal gains" in the following areas: surgical technique, testing the immunologic barriers, introduction of chemical and biological immunosuppression, and prophylaxis for microbial infections. The potential for further improvement comes in 5 major areas: blood biomarkers for monitoring of rejection, drug-free transplantation through the development of stable tolerance, eliminating the impact of ischemia-reperfusion injury, xenotransplantation of porcine kidneys, and finally, the possibility of autologous regeneration of functioning kidney tissue to treat advanced kidney disease.

Euthyroid Sick Syndrome

In this review, we discuss the characteristics, pathophysiology, and therapeutic implications of the euthyroid sick syndrome. Multiple mechanisms have been identified to contribute to the development of euthyroid sick syndrome, including alterations in the iodothyronine deiodinases, thyroid-stimulating hormone secretion, thyroid hormone binding to plasma protein, transport of thyroid hormone in peripheral tissues, and thyroid hormone receptor activity. The euthyroid sick syndrome appears to be a complex mix of physiologic adaptation and pathologic response to acute illness. The underlying cause for these alterations has not yet been elucidated. Treatment of the euthyroid sick syndrome with thyroid hormone to restore normal serum thyroid hormone levels in an effort to improve disease prognosis and outcomes continues to be a focus of many clinical studies, although currently available data do not provide evidence of a clear benefit of treatment.

Necessities for a Clinical Islet Program

For more than two decades we have been refining advances in islet cell transplantation as a clinical therapy for patients suffering from type 1 diabetes. A great deal of effort has gone to making this a viable therapy for a broader range of patients with type 1 diabetes. Clinical results have progressively improved, demonstrating clinical outcomes on par with other organ transplants, specifically in terms of insulin independence, graft and patient survival. We are now at the point where islet cell transplantation, in the form of allotransplantation, has become accepted as a clinical therapy in adult patients affected by type 1 diabetes, in particular those suffering from severe hypoglycaemic unawareness. This chapter provides an overview on how this has been undertaken over the years to provide outcomes on par with other organ transplantation results. In particular this chapter focuses on the processes and facilities that are required to establish a clinical islet isolation and transplantation program. It also outlines the very important underpinning processes of selection of the organ donor for islet isolation, the processes of organ donor operation and preservation of the pancreas by various means and the ideal ways to best improve outcomes for human islet cell isolation. Providing these more optimal conditions we can underpin the isolation processes to provide islets for transplantation and as such a safe, effective and feasible therapeutic option for an increasing number of patients suffering from type 1 diabetes with severe hypoglycaemic unawareness.

Deceased Donor Intervention Research: A Survey of Transplant Surgeons, Organ Procurement Professionals, and Institutional Review Board Members

Innovative deceased donor intervention strategies have the potential to increase the number and quality of transplantable organs. Yet there is confusion over regulatory and legal requirements, as well as ethical considerations. We surveyed transplant surgeons (n = 294), organ procurement organization (OPO) professionals (n = 83), and institutional review board (IRB) members (n = 317) and found wide variations in their perceptions about research classification, risk assessment for donors and organ transplant recipients, regulatory oversight requirements, and informed consent in the context of deceased donor intervention research. For instance, when presented with different research scenarios, IRB members were more likely than transplant surgeons and OPO professionals to feel that study review and oversight were necessary by the IRBs at the investigator, donor, and transplant center hospitals. Survey findings underscore the need to clarify ethical, legal, and regulatory requirements and their application to deceased donor intervention research to accelerate the pace of scientific discovery and facilitate more transplants.

Anti-Apoptotic Effects of 3,3',5-Triiodo-L-Thyronine in the Liver of Brain-Dead Rats

Background

Thyroid hormone treatment in brain-dead organ donors has been extensively studied and applied in the clinical setting. However, its clinical applicability remains controversial due to a varying degree of success and a lack of mechanistic understanding about the therapeutic effects of 3,3’,5-Triiodo-L-thyronine (T₃). T₃ pre-conditioning leads to anti-apoptotic and pro-mitotic effects in liver tissue following ischemia/reperfusion injury. Therefore, we aimed to study the effects of T₃ pre-conditioning in the liver of brain-dead rats.

Methods

Brain death (BD) was induced in mechanically ventilated rats by inflation of a Fogarty catheter in the epidural space. T₃ (0.1 mg/kg) or vehicle was administered intraperitoneally 2 h prior to BD induction. After 4 h of BD, serum and liver tissue were collected. RT-qPCR, routine biochemistry, and immunohistochemistry were performed.

Results

Brain-dead animals treated with T₃ had lower plasma levels of AST and ALT, reduced Bax gene expression, and less hepatic cleaved Caspase-3 activation compared to brain-dead animals treated with vehicle. Interestingly, no differences in the expression of inflammatory genes (IL-6, MCP-1, IL-1β) or the presence of pro-mitotic markers (Cyclin-D and Ki-67) were found in brain-dead animals treated with T₃ compared to vehicle-treated animals.

Conclusion

T₃ pre-conditioning leads to beneficial effects in the liver of brain-dead rats as seen by lower cellular injury and reduced apoptosis, and supports the suggested role of T₃ hormone therapy in the management of brain-dead donors.

Thyroid hormone in the frontier of cell protection, survival and functional recovery

Thyroid hormone (TH) exerts important actions on cellular energy metabolism, accelerating O2consumption with consequent reactive oxygen species (ROS) generation and redox signalling affording cell protection, a response that is contributed by redox-independent mechanisms. These processes underlie genomic and non-genomic pathways, which are integrated and exhibit hierarchical organisation. ROS production led to the activation of the redox-sensitive transcription factors nuclear factor-κB, signal transducer and activator of transcription 3, activating protein 1 and nuclear factor erythroid 2-related factor 2, promoting cell protection and survival by TH. These features involve enhancement in the homeostatic potential including antioxidant, antiapoptotic, antiinflammatory and cell proliferation responses, besides higher detoxification capabilities and energy supply through AMP-activated protein kinase upregulation. The above aspects constitute the molecular basis for TH-induced preconditioning of the liver that exerts protection against ischemia-reperfusion injury, a strategy also observed in extrahepatic organs of experimental animals and with other types of injury, which awaits application in the clinical setting. Noteworthy, re-adjusting TH to normal levels results in several beneficial effects; for example, it lengthens the cold storage time of organs for transplantation from brain-dead donors; allows a superior neurological outcome in infants of <28 weeks of gestation; reduces the cognitive side-effects of lithium and improves electroconvulsive therapy in patients with bipolar disorders.

Protocolized fluid therapy in brain-dead donors: the multicenter randomized MOnIToR trial

BACKGROUND

Critical shortages of organs for transplantation jeopardize many lives. Observational data suggest that better fluid management for deceased organ donors could increase organ recovery. We conducted the first large multicenter randomized trial in brain-dead donors to determine whether protocolized fluid therapy increases the number of organs transplanted.

METHODS

We randomly assigned donors to either protocolized or usual care in eight organ procurement organizations. A "protocol-guided fluid therapy" algorithm targeting the cardiac index, mean arterial pressure and pulse pressure variation was used. Our primary outcome was the number of organs transplanted per donor, and our primary analysis was intention to treat. Secondary analyses included: (1) modified intention to treat where only subjects able to receive the intervention were included and (2) 12-month survival in transplant recipients. The study was stopped early.

RESULTS

We enrolled 556 donors: 279 protocolized care and 277 usual care. Groups had similar characteristics at baseline. The study protocol could be implemented in 76 % of subjects randomized to the intervention. There was no significant difference in mean number of organs transplanted per donor: 3.39 organs per donor (95 % CI 3.14-3.63) with protocolized care compared to 3.29 usual care (95 % CI 3.04-3.54; mean difference, 0.1, 95 % CI -0.25 to 0.45; p = 0.56). In modified intention-to-treat analysis the mean number of organs increased (3.52 organs per donor, 95 % CI 3.23-3.8), but not statistically significantly (mean difference, 0.23, 95 % CI -0.15 to 0.61; p = 0.23). Among the 1,430 recipients of organs from study subjects with data available, 56 deaths (7.8 %) occurred in the protocolized care arm and 56 (7.9 %) in the usual care arm in the first year (hazard ratio: 0.97, p = 0.86).

CONCLUSIONS

In brain-dead organ donors, protocol-guided fluid therapy compared to usual care may not increase the number of organs transplanted per donor.

Ischemic preconditioning affects long-term cell fate through DNA damage-related molecular signaling and altered proliferation

Despite the potential of ischemic preconditioning for organ protection, long-term effects in terms of molecular processes and cell fates are ill defined. We determined consequences of hepatic ischemic preconditioning in rats, including cell transplantation assays. Ischemic preconditioning induced persistent alterations; for example, after 5 days liver histology was normal, but γ-glutamyl transpeptidase expression was observed, with altered antioxidant enzyme content, lipid peroxidation, and oxidative DNA adducts. Nonetheless, ischemic preconditioning partially protected from toxic liver injury. Similarly, primary hepatocytes from donor livers preconditioned with ischemia exhibited undesirably altered antioxidant enzyme content and lipid peroxidation, but better withstood insults. However, donor hepatocytes from livers preconditioned with ischemia did not engraft better than hepatocytes from control livers. Moreover, proliferation of hepatocytes from donor livers preconditioned with ischemia decreased under liver repopulation conditions. Hepatocytes from donor livers preconditioned with ischemia showed oxidative DNA damage with expression of genes involved in MAPK signaling that impose G1/S and G2/M checkpoint restrictions, including p38 MAPK-regulated or ERK-1/2-regulated cell-cycle genes such as FOS, MAPK8, MYC, various cyclins, CDKN2A, CDKN2B, TP53, and RB1. Thus, although ischemic preconditioning allowed hepatocytes to better withstand secondary insults, accompanying DNA damage and molecular events simultaneously impaired their proliferation capacity over the long term. Mitigation of ischemic preconditioning-induced DNA damage and deleterious molecular perturbations holds promise for advancing clinical applications.

Treating the donor

PURPOSE OF REVIEW

Current pressures of organ supply and demand require maximization of potential for organ donation. The donor population is older and has more significant comorbidity than in the past.Optimal management of the donor after brain death (DBD) is essential to ensure that the greatest number of organs can be transplanted per donor. Defining evidence-based drugs and techniques to assist this has never been more important.

RECENT FINDINGS

Care of patients with catastrophic brain injury incorporating supportive therapy targeted at specific goals and delivered by experienced specialists provides the best donation outcomes. Such pathways represent best practice critical care applied to this population. In this context, the value of some previously recommended therapies appears questionable and warrants reassessment. Prolonged (>24 h) incorporeal organ conditioning may have significant benefits.Extracorporeal support in the resuscitation arena is emerging and, in patients who fail to respond, may yield a new source of donors.

SUMMARY

Early identification of potential DBD, best practice critical care, and achieving defined treatment goals are associated with more transplantable organs. Study of a complex intervention like donor management presents significant problems of organization, ethics and consent. This situation is recognized internationally and progress is being made.

Donation after circulatory death: current practices, ongoing challenges, and potential improvements

Organ donation after circulatory death (DCD) has been endorsed by the World Health Organization and is practiced worldwide. This overview examines current DCD practices, identifies problems and challenges, and suggests clinical strategies for possible improvement. Although there is uniform agreement on DCD donor candidacy (ventilator-dependent individuals with nonrecoverable or irreversible neurologic injury not meeting brain death criteria), there are variations in all aspects of DCD practice. Utilization of DCD organs is limited by hypoxia, hypotension, reduced--then absent--organ perfusion, and ischemia/reperfusion syndrome. Nevertheless, DCD kidneys exhibit comparable function and survival to donors with brain death kidneys, although they have higher rates of primary graft nonfunction, delayed graft function, discard, and retrieval associated injury. Concern over ischemic organ injury underscores the reluctance to recover extrarenal DCD organs since lack of medical therapy to support inadequate allograft function limits their acceptability. Nevertheless, limited results with DCD pancreas, liver, and lung allografts (but not heart) are now approaching that of donors with brain death organs. Pretransplant machine perfusion of DCD kidneys (vs. static storage) may reduce delayed graft function but has no effect on long-term organ function and survival. Normothermic regional perfusion used during DCD abdominal organ retrieval may reduce ischemic organ injury and increase the number of usable organs, although critical confirmative studies have yet to be done. Minor increases in usable DCD kidneys could accrue from increased use of pediatric DCD kidneys and from selective use of DCD/ECD kidneys, whereas a modest increase could result through utilization of donors declared dead beyond 1 hr from withdrawal of life support therapy. A significant increase in transplantable kidneys could be achieved by extension of the concept of living kidney donation in relation to imminent death of potential DCD donors. Progress in research to identify, prevent, and repair DCD-associated organ retrieval injury should improve utilization of DCD organs. Recent results using ex situ pretransplant organ perfusion of DCD organs has been encouraging in this regard.

Efficacy and safety of phenylephrine in the management of low systolic blood pressure after renal transplantation

BACKGROUND

Phenylephrine can be used to treat postoperative hypotension after renal transplantation. However, its effect on the renal allograft is unknown. We evaluated the safety and efficacy of this approach.

STUDY DESIGN

A retrospective cohort study of 307 renal transplant recipients between November 2005 and October 2011 was conducted, including 75 who required phenylephrine, 46 of whom were deceased donors renal transplant (DDRT) recipients and 29 who were living donor transplant (LDRT) recipients. These were compared with 75 controls matched by sex, age, type of transplant, and etiology of renal failure. The primary outcome was rate of delayed graft function (DGF). The following statistical tools were used: paired t-test for continuous data, McNemar's test for categorical data, and a nonlinear mixed decay model for change in serum creatinine (Cr).

RESULTS

Of 46 DDRT recipients who required phenylephrine, 17 developed DGF compared with 10 matched controls (relative risk [RR] 2.9, CI 1.4 to 6.0, p = 0.0040). Only one LDRT recipient required hemodialysis (DGF). No differences were noted in the number of hemodialysis treatments required (mean 2.7 in treatment group vs 3.4 in control). No significant differences were observed between phenylephrine and control groups in renal function on postoperative days 30, 90, and 365 Cr or graft survival. The immediate postoperative normalization of Cr was slower in the DDRT phenylephrine group compared with DDRT controls (p < 0.0001), but no difference in Cr was noted before discharge (p = 0.49).

CONCLUSIONS

Although there is a brief association between phenylephrine administration and a slower rate of transplanted kidney recovery, there is no clinically or statistically significant impaired outcome in the phenylephrine group at time of discharge. Administration of phenylephrine to support low blood pressure after renal transplant appears safe.

Nonthyroidal illness syndrome

PURPOSE OF REVIEW

The current state of the pathophysiology, diagnosis, and therapeutic implications of the nonthyroidal illness syndrome is reviewed.

RECENT FINDINGS

Previous studies attributed the development of the nonthyroidal illness syndrome to alterations in three main areas of thyroid hormone metabolism: deiodinase activity, thyroid-stimulating hormone secretion, and hormone binding to serum proteins. New studies suggest that alterations in thyroid hormone transport into tissues and alterations of the nuclear thyroid hormone receptors may also play a role. Therapy of the nonthyroidal illness syndrome remains a controversial topic.

SUMMARY

Multiple factors lead to the development of the nonthyroidal illness syndrome, including alterations in type 1 and 3 deiodinase activity, thyrotropin-releasing hormone and thyroid-stimulating hormone secretion, hormone binding to plasma proteins, thyroid hormone transporter expression and activity, and the thyroid hormone nuclear receptor complex. These data show that acute and chronic illness affect all aspects of thyroid hormone metabolism and action. Some of these changes are physiologic and some are pharmacologic. The mediators of these alterations are still largely unclear. There continues to be no indication for thyroid hormone therapy in the vast majority of patients with the nonthyroidal illness syndrome, although interesting data suggest a possible role for treating a small subset of patients.

Challenges to research and innovation to optimize deceased donor organ quality and quantity

Solid organ transplantation is encumbered by an increasing number of waitlisted patients unrequited by the current organ supply. Preclinical models suggest that advances in deceased donor management and treatment can increase the quantity and quality of organs available for transplantation. However, the science of donor intervention and the execution of high quality, prospective, multi-center, randomized-controlled trials are restricted by a myriad of logistical challenges mired in regulatory and ethical ambiguity. By highlighting the obstacles to conducting research in deceased donors, this report endeavors to stimulate the creation of a multi-disciplinary framework to facilitate the design, implementation and supervision of innovative trials that increase the quantity and/or quality of deceased donor organs.

The impact of vascular anastomosis time on early kidney transplant outcomes

Background

Most studies have found cold ischemic time to be an important predictor of delayed graft function in kidney transplantation. Relatively less is known about the warm time associated with vascular anastomosis and early outcomes.

Methods

A retrospective cohort of 298 consecutive solitary deceased donor kidney recipients from January 2006 to August 2012 was analyzed to examine the association between anastomosis time and delayed graft function (need for dialysis) and length of hospital stay.

Results

Delayed graft function (DGF) was observed in 56 patients (18.8%). The median anastomosis time was 30 minutes (interquartile range 24, 45 minutes). Anastomosis time was independently associated with DGF in a multivariable, binary logistic regression analysis (odds Ratio (OR) 1.037 per minute, 95% CI 1.016, 1.057, P = 0.001). An anastomosis time >29 minutes was also associated with a 3.5 fold higher (OR 3.5, 95% CI 1.6, 7.3, P = 0.001) risk of DGF. Median days in hospital was 9 (interquartile range 7, 14 days). Every 5 minutes of longer anastomosis time (0.20 days per minute, 95% CI 0.13, 0.27, P <0.001) was associated with 1 extra day in hospital in a multivariable linear regression model. An anastomosis time >29 minutes was associated with 3.8 (95% CI 1.6, 6.0, P <0.001) more days in hospital.

Conclusion

Anastomosis time may be an underappreciated but modifiable variable in dictating use of hospital resources. The impact of anastomosis time on longer term outcomes deserves further study.

Machine perfusion viability testing

PURPOSE OF REVIEW

Pretransplant assessment of kidney graft viability may help clinicians to decide whether to accept or discard a kidney for transplantation. With the increasing demand for donor kidneys and the increased use of marginal kidneys, the need of viability markers has increased to pursue superior transplant outcomes. Hypothermic machine perfusion (HMP) provides the theoretical opportunity to assess the viability of donor kidneys. We discuss the novel developments in viability testing during HMP and address the future prospects.

RECENT FINDINGS

HMP viability testing has focused on the analysis of machine perfusion parameters and perfusate biomarkers. Renal resistance and the biomarkers lactate dehydrogenase, aspartate transaminase, glutathione-S-transferase, N-acetyl-β-D-glucosaminidase, heart-type fatty acid binding protein, lipid peroxidation products, redox-active iron and IL-18 are correlated with transplant outcome in terms of development of delayed graft function or graft survival. However, they all lack adequate predictive value for transplant outcome. New techniques including contrast-enhanced ultrasound, three-dimensional ultrasound and magnetic resonance spectrometry are promising methods to test kidney viability during HMP, but their value has to be established. The introduction of normothermic machine perfusion offers other promising opportunities for viability testing.

SUMMARY

Machine perfusion characteristics and perfusate biomarkers have been extensively studied. They often correlate with the transplant outcome, but the present viability tests are not reliable predictors of transplant outcome. New developments in kidney graft viability assessment are necessary to have a chance of being clinically useful in the future.

Prediction of three-year outcome of renal transplantation from optimal donors versus expanded criteria donors

BACKGROUND/AIMS

The shortage in organ supply has required the use of expanded criteria donors (ECD) for kidney transplantation. Current pre-transplant evaluations of ECD organs are based on histological, clinical or mixed criteria. This monocentric study investigates the predictivity of Karpinski's histological score on 3-year graft function in renal transplant. Ex-post classification using Nyberg's score was carried out to assess the reliability of a purely clinical score and its applicability for organ allocation.

METHODS

We evaluated 407 deceased donors (251 optimal and 156 ECD) for renal transplants performed between 2001 and 2006. The differences in creatinine levels and MDRD-GFR at transplant and 1, 2 and 3 years post-transplant between optimal donors and ECD were recorded. Amongst ECD organs, the effect of different Karpinski score classes (0-1, 2, 3, 4, double transplants) on 3-year graft outcomes was analyzed. We then compared renal function over time across the Nyberg grades (A, B, C, and D).

RESULTS

Karpinski scores 0-1 and 2 and double transplants were associated with improved graft function compared to scores 3 and 4. Nyberg's clinical score shows a good fit with medium-term outcome and Karpinski's score, but among the donors with a high Nyberg grade (C and D), it fails to differentiate between allocable or non-allocable organs (due to Karpinski's score ≥7).

CONCLUSIONS

Our data demonstrate a correlation of histological damage at the time of transplant with 3-year graft function, but at present we are unable to provide any supposition on the possible outcome of the discarded kidneys.