Extended hypothermic oxygenated machine perfusion enables ex situ preservation of porcine livers for up to 24 hours

Background & Aims

End-ischemic hypothermic oxygenated machine perfusion (HOPE) of the donor liver for 1-2 h mitigates ischemia-reperfusion injury during subsequent liver transplantation. Extended preservation time may be preferred to facilitate difficult recipient hepatectomy or to optimize logistics. We therefore investigated whether end-ischemic dual HOPE (DHOPE) could extend preservation time for up to 24 h using a porcine liver reperfusion model.

Methods

Following 30 min warm ischemia, porcine livers were subjected to 2 h static cold storage (SCS), followed by 2 h, 6 h, or 24 h DHOPE (n = 6 per group). Subsequent normothermic reperfusion was performed for 4 h using autologous blood. Two livers preserved by 24 h SCS served as additional controls. A proof of principle confirmation was carried out in 2 discarded human livers subjected to extended DHOPE. Hepatocellular and cholangiocyte injury and function were assessed. Oxidative stress levels and histology were compared between groups.

Results

Perfusion flows remained stable during DHOPE, regardless of duration. After normothermic reperfusion, livers perfused for 24 h by DHOPE had similar lactate clearance, blood pH, glucose, and alanine aminotransferase levels, and biliary pH, bicarbonate, and LDH levels, as livers perfused for 2 h and 6 h. Levels of malondialdehyde and high-mobility group box 1 in serum and liver parenchyma were similar for all groups. Histological analysis of bile ducts and liver parenchyma revealed no differences between the groups. Extended DHOPE in discarded human livers preserved hepatocellular and cholangiocyte function and histology after reperfusion. In contrast, livers preserved by 24 h SCS were non-functioning.

Conclusion

Extended end-ischemic DHOPE enabled successful preservation of porcine and discarded human donor livers for up to 24 h. Extended DHOPE enables safe extension of preservation time, which may facilitate allocation and transplantation from a logistical perspective, and further expand the donor pool.

Lay summary

It has been suggested that preserving liver grafts with a technique called (dual) hypothermic oxygenated machine perfusion ([D]HOPE) leads to better outcomes after transplantation than if livers are stored on ice, especially if an organ is of lesser quality. In this study, we showed that DHOPE could be used to preserve liver grafts for up to 24 h. This extended procedure could be used globally to facilitate transplantation and expand the donor pool.

Mechanical Postconditioning Promotes Glucose Metabolism and AMPK Activity in Parallel with Improved Post-Ischemic Recovery in an Isolated Rat Heart Model of Donation after Circulatory Death

Donation after circulatory death (DCD) could improve donor heart availability; however, warm ischemia-reperfusion injury raises concerns about graft quality. Mechanical postconditioning (MPC) may limit injury, but mechanisms remain incompletely characterized. Therefore, we investigated the roles of glucose metabolism and key signaling molecules in MPC using an isolated rat heart model of DCD. Hearts underwent 20 min perfusion, 30 min global ischemia, and 60 minu reperfusion with or without MPC (two cycles: 30 s reperfusion—30 s ischemia). Despite identical perfusion conditions, MPC either significantly decreased (low recovery = LoR; 32 ± 5%; p < 0.05), or increased (high recovery = HiR; 59 ± 7%; p < 0.05) the recovery of left ventricular work compared with no MPC (47 ± 9%). Glucose uptake and glycolysis were increased in HiR vs. LoR hearts (p < 0.05), but glucose oxidation was unchanged. Furthermore, in HiR vs. LoR hearts, phosphorylation of raptor, a downstream target of AMPK, increased (p < 0.05), cytochrome c release (p < 0.05) decreased, and TNFα content tended to decrease. Increased glucose uptake and glycolysis, lower mitochondrial damage, and a trend towards decreased pro-inflammatory cytokines occurred specifically in HiR vs. LoR MPC hearts, which may result from greater AMPK activation. Thus, we identify endogenous cellular mechanisms that occur specifically with cardioprotective MPC, which could be elicited in the development of effective reperfusion strategies for DCD cardiac grafts.

Flow-targeted pediatric ex vivo heart perfusion in donation after circulatory death: A porcine model

BACKGROUND

The optimal blood flow and pressure to perfuse pediatric hearts from donation after circulatory death (DCD) on the ex vivo perfusion system has not been elucidated. This study sought to investigate the optimal perfusion strategy for pediatric DCD hearts by using a juvenile porcine model comparing pressure- vs flow-targeted strategy.

METHODS

The hearts of the juvenile DCD pigs were explanted, and the coronary arteries were perfused for 2 hours by the ex vivo heart perfusion system with 2 different perfusion strategies; pressure-targeted perfusion (target coronary perfusion pressure: 40 mm Hg, group A) and flow-targeted perfusion (target coronary perfusion flow: 10 ml/kg/min, group B). The working model heart perfusion was used to assess systolic and diastolic myocardial performance.

RESULTS

The body weight, warm and cold ischemic time, and ex vivo perfusion time were comparable between the groups. In the working model, group B showed significantly preserved cardiac output (A: 70.5 ± 15.3 ml/kg/min vs B: 113.8 ± 15.0 ml/kg/min, p < 0.01), stroke volume (A: 0.4 ± 0.1 ml/kg vs B: 0.7 ± 0.1 ml/kg, p < 0.01), and ejection fraction (A: 18.8% ± 5.9% vs B: 35.0% ± 10.6%, p < 0.01). E/e' and Tei index were also significantly preserved in group B. The percentage gain of heart weight after ex vivo (net increase of the heart weight divided by heart weight at baseline) was significantly smaller in group B (A: 20.0% ± 5.3% vs B: 11.6% ± 5.0%, p < 0.05). Troponin-I, myocardial hemorrhage, oxidative stress markers; myeloperoxidase and 8-hydroxy-2'-deoxyguanosine were also significantly lower after ex vivo perfusion in group B (p < 0.05).

CONCLUSIONS

The tightly controlled flow-targeted myocardial perfusion strategy for DCD donor hearts achieved better myocardial performance by causing less myocardial edema and limiting myocardial reperfusion injury.

First report of a successful pediatric heart transplantation from donation after circulatory death with distant procurement using normothermic regional perfusion and cold storage

Heart transplantation (HT) from donation after circulatory death (DCD) is a promising alternative to expand the heart donor pool. Cold storage can be used in a strategy to successfully retrieve and transplant DCD hearts after reconditioning using normothermic regional perfusion for distant procurement. Herein, we present the first report of a pediatric DCD heart reconditioned with normothermic regional perfusion, preserved using only cold storage while being transported to a neighboring center, and then successfully transplanted after nearly 2 hours of cold static storage. If supported by an appropriate trial, this finding could obviate the need to use expensive perfusion devices for short interhospital distances for DCD heart transportation and stimulate more centers across the world to embrace DCD HT.

Hypothermic oxygenated machine perfusion alleviates liver injury in donation after circulatory death through activating autophagy in mice

Hypothermic oxygenated machine perfusion (HOPE) is a safe and reliable method that could alleviate liver injury in donation after circulatory death (DCD). This study focuses on the role of autophagy in HOPE's protective effect on DCD liver injury. A 30-minute warm ischemic liver model was established in mice. After 4 hours of cold storage (CS), 1 hour of hypothermic machine perfusion (HMP) with 100% O₂ or 100% N₂ was employed. During 2 hours of reperfusion, liver tissue and perfusate were collected to evaluate liver function, oxidative stress level, apoptosis, and necrosis. Western blotting was used to explore the level of autophagy. When the liver experienced warm ischemic injury, LC3B-II expression was significantly enhanced. Compared with the CS, HOPE induced lower release of AST and ALT, as well as lower oxidative stress levels, apoptosis, and necrosis cell numbers, and led to higher tissue ATP content. Meanwhile, expression of autophagy-related proteins, such as ULK1, Atg5, and LC3B-II, increased. When oxygen was completely replaced by nitrogen, the washout effect of HMP did not activate autophagy and did not relieve DCD liver injury. When the autophagy inhibitor 3-methyladenine was used in HOPE, the protective effect of HOPE was attenuated. In conclusion, DCD liver injury activated autophagy compared with healthy liver, while HOPE alleviated DCD liver injury by increasing autophagy levels further in this mouse model. However, HMP with 100% of N₂ had no beneficial effect on DCD liver injury or on autophagy levels compared with CS. The research on autophagy may provide a new strategy for alleviating DCD liver injury in clinical practice.

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.

First report of successful transplantation of a pediatric donor liver graft after hypothermic machine perfusion

One of the main limiting factors in pediatric liver transplantation is donor availability. For adults, DCD liver grafts are increasingly used to expand the donor pool. To improve outcome after DCD liver transplantation, ex situ machine perfusion is used as an alternative organ preservation strategy, with the supplemental value of providing oxygen to the graft during preservation. We here report the first successful transplantation of a pediatric DCD liver graft after hypothermic oxygenated machine perfusion. The full-size liver graft was derived from a 13-year-old, female DCD donor and was end-ischemic pretreated with dual hypothermic oxygenated machine perfusion. Arterial and portal pressures were set at 18 and 4 mm Hg, slightly lower than protocolized settings for adult livers. During 2 hours of machine perfusion, portal and arterial flows increased from 100 to 210 mL/min and 30 to 63 mL/min, respectively. The pretreated liver graft was implanted in a 16-year-old girl with progressive familial intrahepatic cholestasis type 2. Postoperative AST, ALT, and prothrombin time normalized within a week. The recipient quickly recovered and was discharged from the hospital after 18 days. One year after transplantation, she is in excellent condition with a completely normal liver function and histology. This case is the first report of successful transplantation of a pediatric DCD liver graft after hypothermic oxygenated machine perfusion and illustrates the potential role of ex situ machine perfusion in expanding the donor pool and improving outcome after pediatric liver transplantation.

Efficacy of the natural oxygen transporter HEMO2 life® in cold preservation in a preclinical porcine model of donation after cardiac death

The growing use of marginal organs for transplantation pushes current preservation methods toward their limits, and the need for improvement is pressing. We previously demonstrated the benefits of M101, a natural extracellular oxygen carrier compatible with hypothermia, for the preservation of healthy renal grafts in a porcine model of autotransplantation. Herein, we use a variant of this preclinical model to evaluate M101 potential benefits both in static cold storage (CS) and in machine perfusion (MP) preservation in the transplantation outcomes for marginal kidneys. In the CS arm, despite the absence of obvious benefits within the first 2 weeks of follow-up, M101 dose-dependently improved long-term function, normalizing creatininemia after 1 and 3 months. In the MP arm, M101 improved short- and long-term functional outcomes as well as tissue integrity. Importantly, we provide evidence for the additivity of MP and M101 functional effects, showing that the addition of the compound further improves organ preservation, by reducing short-term function loss, with no loss of function or tissue integrity recorded throughout the follow-up. Extending previous observations with healthy kidneys, the present results point at the M101 oxygen carrier as a viable strategy to improve current organ preservation methods in marginal organ transplantation.

Kidney transplantation from donors after uncontrolled circulatory death: the Spanish experience

Donation after uncontrolled circulatory death (uDCD) refers to donation from persons who have died following cardiac arrest and unsuccessful attempt at resuscitation. We report the Spanish experience of uDCD kidney transplantation, and identify factors related to short-term post-transplant outcomes. The Spanish CORE system compiles data on all donation and transplant procedures in the country. Between 2012-2015, 517 kidney transplants from 288 uDCD donors were performed. The incidence of primary non-function was 10%, and the incidence of delayed graft function was 76%. One-year death-censored graft survival was 87%. In a Cox-Model, donor age ≥ 60 years (odds ratio [OR] 2.7; 95% confidence interval [CI] 1.2-6.1), in situ cooling of kidneys versus normothermic regional perfusion (OR 5.6; 95% CI 2.7-11.5) or hypothermic regional perfusion based on the use of extracorporeal membrane oxygenation devices (OR 4.3; 95% CI 2.1-8.6), and a recipient history of prior kidney transplant (OR 3.5; 95% CI 1.5-8.3) all significantly increased the risk of graft loss during the first year after transplantation. Kidney transplantation from uDCD donors provides acceptable 1-year outcomes, although there is room for improvement. Hypothermic and normothermic regional perfusion strategies are preferable to in situ cooling of kidneys from uDCD donors.

Attitudes and self-reported end-of-life care of Australian and New Zealand intensive care doctors in the context of organ donation after circulatory death

The incidence of organ donation after circulatory death (DCD) in Australia and New Zealand (ANZ) has steadily increased in recent years. Intensive care doctors are vital to the implementation of DCD and healthcare professionals' attitudes to DCD can influence their participation. In order to determine ANZ intensive care doctors' attitudes to DCD, to explore if demographic characteristics influence attitude to DCD and to assess if attitude to DCD can predict palliative prescription rationale at the end of life of DCD donors, a cross-sectional online survey was distributed to ANZ intensive care doctors and responses collected between 29 April and 10 June 2016. Exploratory factor analysis was used to define various attributes of attitude to DCD. Results were subjected to comparative statistical analyses to examine the relation between demographic data and attitude to DCD. Multiple regression models were used to examine if attitude to DCD could predict intensive care doctors' palliative prescription rationales at the end of life of DCD donors. One hundred and sixty-one intensive care doctors responded to the survey with 69.4% having worked in intensive care for ten years or more. Respondents responded positively to the support of and perceived importance of DCD in helping those who would benefit from the donations (constructive attributes)(mean composite factor score = 3.84, standard deviation [SD] 0.83), they positively perceived that conducive and facilitative orchestration of DCD helps families cope (mean composite factor score = 3.94, SD 0.72) and that they would manage a DCD donor similar to any patient at the end of their life (mean score = 3.94, SD 0.72). Respondents responded negatively to having concerns that the circulatory death of potential DCD donors does not occur within the specified time frame (mean score = 2.28, SD 1.02). There was an association between organ donation professional education courses, familiarity with national guidelines and positive attitudes to certain attributes of attitude to DCD. Regression models demonstrated the attitude to DCD may predict intensive care doctors' palliative medication prescription rationales at the end of life of the DCD donor. Intensive care doctors in ANZ adopt a morally neutral attitude to DCD where they recognise the importance of organ donation, and support and conduct DCD as a part of good end-of-life care.

Ethics of Liver Transplantation: The Role of the Anesthesiologist

Anesthesiologists have clearly established their place in the history of medical ethics. Our involvement goes back to 1966 when Henri Beecher published his landmark paper on research and informed consent. Participation in the ethics of transplantation is no less important than our previous work. Organ transplant has been life saving for many but also has given rise to many misunderstandings not just from the public but also among our own colleagues. These include methods of allocation and donation, the role that affluence may play in receiving an organ, the definition of death and donation after circulatory death. As perioperative physicians and important members of the transplant team, anesthesiologists are expected to participate in all aspects of care including ethical judgments. This article discusses some of the issues that seem to cause the most confusion and angst for those of us involved in both liver transplantation and in the procurement of organs. It will discuss the definition of death, donation after circulatory death, the anesthesiologists' role on the selection committee, living donor liver transplantation, and transplantation of patients with alcohol-related liver disease.

Perigraft fluid collections after kidney transplantation: Does the type of donor (uncontrolled donation after circulatory death vs. donation after brain death) have a role?

Introduction

Perigraft fluid collection (PFC) is a common complication after kidney transplant. Its etiology is not clear and not all the causes have been identified. The influence of the type of donor has never been evaluated. Our aim was to compare the incidence, severity and management of PFC in recipients of grafts from uncontrolled donors after circulatory death (DCD) with normothermic extracorporeal membrane oxygenation (NECMO) versus recipients of grafts from donors after brain death (DBD).

Material and methods

We conducted a retrospective cohort study of 300 kidney transplants performed in our center between 2007 and 2012. Patients were divided in two groups: 150 recipients of Maastricht II DCD graft and 150 recipients of the DBD graft. Incidence, severity according to Clavien scale and management were analyzed in both groups, and comparison was carried out using Chi-square.

Results

Of the 300 kidney recipients analyzed, 93 (31.4%) suffered PFC, showing no difference between DBD (32.0%) and DCD (30.8%) groups (p = 0.9). Complicated PFC rate (defined as a PFC generating vascular compression, fever or urinary tract obstruction) was 22.9% in the DBD group versus 22.2% in the DCD group (p = 1); most complicated PFC were due to urinary tract obstruction (81%), with no difference between the groups (p = 1). Concerning Clavien scale, 78.5% of the PFC in our series were Clavien I, 19.4% Clavien IIIa and 2.2% Clavien IIIb, with no difference between both groups (p = 1).

Conclusions

PFC is a frequent complication that appears in a third of our patients, showing no difference in the incidence or severity between DBD and uncontrolled DCD graft recipients.

Devices for ex vivo heart and lung perfusion

INTRODUCTION

The number of organs available for heart and lung transplantation is far short of the number that is needed to meet demand. Perfusion and ventilation of donor organs after procurement has led to exciting advances in the field of cardiothoracic transplantation. The clinical implications of this technology allows for techniques to evaluate the quality of an organ, active rehabilitation of organs after procurement and prior to implantation, and increased time between organ procurement and implantation. This ex-vivo perfusion technique has also been referred to in the lay press as the 'heart in a box' or 'lung in a box.'

AREAS COVERED

This review includes information from case reports, case series, and clinical trials on ex vivo heart and lung perfusion. The focus is on the devices, ventilation and perfusion techniques, outcomes, and application of the technology.

EXPERT COMMENTARY

Ex vivo perfusion of donor hearts and lungs prior to transplantation has proven to be a viable alternative to standard cold-preservation strategies. Its use has allowed for ongoing expansion of the donor pool. The biggest barriers to expansion of this technology are access, cost, and lack of evidence which clearly supports superior outcomes.

Hearts transplanted after circulatory death in children: Analysis of the International Society for Heart and Lung Transplantation registry

We aimed to describe worldwide DCD HT experience in children using the International Society for Heart and Lung Transplantation Registry. The Registry was queried for primary HT performed in children (2005-2014). Kaplan-Meier analysis was used to assess survival for recipients grouped by DCD or DBD hearts. Recipient characteristics were compared between DCD and DBD and between survivors and non-survivors of DCD HT. Among 3877 pediatric HT performed, 21 (0.5%) were DCD. DCD 1-year survival was 61% vs 91% DBD, P < .01. DCD recipients were more often supported by ECMO pre-HT (24% vs 6%, P < .001) and more often receiving inhaled nitric oxide (10% vs 0.6%, P < .001) compared to DBD. Older DCD recipients had significantly lower 1-year survival of 57% vs 93% for DBD, P < .01. Survival for infant DCD recipients was not statistically different to DBD recipients (survival 62% at 1 year and 62% at 5 years for DCD vs 85% at 1 year and 77% at 5 years for DBD, P = .15). Recipients of DCD HT who died were more often supported by ECMO pre-HT (56% non-survivors vs 0% survivors, P = .004) and receiving mechanical ventilation (44% vs 0%, P = .012). DCD HT is uncommon in children. DCD-independent factors in recipients may have contributed to worse survival as DCD recipients who died were more often supported by ECMO and mechanical ventilation. More research is needed to identify donor factors and recipient factors that contribute to mortality after DCD HT.

The Rule of Threes: three factors that triple the likelihood of families overriding first person consent for organ donation in the UK

Between 1 April 2012 and 31 March 2015, 263 of the 2244 families in the UK whose loved ones had registered to donate organs for transplantation after their death on the NHS Organ Donor Register chose to override this decision; an override rate of 11.7%. Multivariable logistic regression analysis was applied to data relating to various aspects of the family approach in order to identify factors associated with such overrides. The factors associated with family overrides were failure to involve the Specialist Nurse for Organ Donation in the family approach (odds ratio 3.0), donation after circulatory death (odds ratio 2.7) and Black, Asian or Minority Ethnicity (odds ratio 2.7). This highlights the need to further engage with these groups in exploring donation as an end of life choice, and suggests that there may be, from the perspective of the family, fundamental differences between donation after brainstem death and circulatory death. It further adds to the body of data linking involvement of the Specialist Nurse for Organ Donation in the family approach to improved UK consent rates.

Comparison of outcomes of kidney transplantation from donation after brain death, donation after circulatory death, and donation after brain death followed by circulatory death donors

BACKGROUND

There are three categories of deceased donors of kidney transplantation in China, donation after brain death (DBD), donation after circulatory death (DCD), and donation after brain death followed by circulatory death (DBCD) donors. The aim of this study was to compare the outcomes of kidney transplantation from these three categories of deceased donors.

METHODS

We retrospectively reviewed 469 recipients who received deceased kidney transplantation in our hospital from February 2007 to June 2015. The recipients were divided into three groups according to the source of their donor kidneys: DBD, DCD, or DBCD. The primary endpoints were delayed graft function (DGF), graft loss, and patient death.

RESULTS

The warm ischemia time was much longer in DCD group compared to DBCD group (18.4 minutes vs 12.9 minutes, P < .001). DGF rate was higher in DCD group than in DBD and DBCD groups (22.5% vs 10.2% and 13.8%, respectively, P = .021). Urinary leakage was much higher in DCD group (P = .049). Kaplan-Meier analysis showed that 1-, 2-, and 3-year patient survivals were all comparable among the three groups.

CONCLUSION

DBCD kidney transplantation has lower incidences of DGF and urinary leakage than DCD kidney transplant. However, the overall patient and graft survival were comparable among DBD, DCD, and DBCD kidney transplantation.

Prediction of potential for organ donation after circulatory death in neurocritical patients

BACKGROUND

The success or failure of donation after circulatory death depends largely on the functional warm ischemia time, which is closely related to the duration between withdrawal of life-sustaining treatment and circulatory arrest. However, a reliable predictive model for the duration is absent. We aimed to compare the performance of the Chinese Donation after Circulatory Death Nomogram (C-DCD-Nomogram) and 3 other tools in a cohort of potential donors.

METHODS

In this prospective, multicenter, observational study, data were obtained from 219 consecutive neurocritical patients in China. The patients were followed until circulatory death after withdrawal of life-sustaining treatment.

RESULTS

The C-DCD-Nomogram performed well in predicting patient death within 30, 60, 120 and 240 minutes after withdrawal of life-sustaining treatment with c-statistics of 0.87, 0.88, 0.86 and 0.95, respectively. The DCD-N score was a poor predictor of death within 30, 60 and 240 minutes, with c-statistics of 0.63, 0.69 and 0.59, respectively, although it was able to predict patient death within 120 minutes, with a c-statistic of 0.73. Neither the University of Wisconsin DCD evaluation tool (UWDCD) nor the United Network for Organ Sharing (UNOS) criteria was able to predict patient death within 30, 60, 120 and 240 minutes after withdrawal of life-sustaining treatment (UWDCD tool: 0.48, 0.45, 0.49 and 0.57; UNOS criteria: 0.50, 0.53, 0.51 and 0.63).

CONCLUSION

The C-DCD-Nomogram is superior to the other 3 tools for predicting death within a limited duration after withdrawal of life-sustaining treatment in Chinese neurocritical patients. Thus, it appears to be a reliable tool identifying potential donors after circulatory death.

In-hospital logistics: what are the key aspects for succeeding in each of the steps of the process of controlled donation after circulatory death?

Donation after circulatory death (DCD) donors are becoming an increasingly important population of organ donors in Europe and worldwide. We report the state of the art regarding controlled DCD donation describing the organizational and technical aspects of establishing a controlled DCD programme and provide recommendations regarding the introduction and development of this type of programme.

Steroids can reduce warm ischemic reperfusion injury in a porcine donation after circulatory death model with ex vivo lung perfusion evaluation

Donation after circulatory death (DCD) is being used to increase the number of transplantable organs. The role and timing of steroids in DCD donation and ex vivo lung perfusion (EVLP) has not been thoroughly investigated. In this study, we investigated the effect of steroids on warm ischemic injury in a porcine model (n = 6/group). Following cardiac arrest, grafts were left untouched in the donor (90-min warm ischemia). Graft function was assessed after 6 h of EVLP. In the MP group, 500 mg methylprednisolone was given prior to cardiac arrest and during EVLP. In the CONTR group, no steroids were added. Median lung compliance (13 ml/cmH₂ 0) was significantly better preserved in the CONTR group than in the MP group (30.5 ml/cmH₂ 0). Also, median wet-to-dry weight (6.11 vs. 6.94) and CT density (182.5 vs. 352.9 g/l) were significantly better in the MP group than in the CONTR group, respectively. There was no difference in oxygenation and pulmonary vascular resistance. Perfusate cytokine analysis showed a significant reduction in IL-1β, IL-8, IFN-α, IL-10, TNF-α, and IFN-γ in MP. Cytokines in bronchoalveolar lavage were not decreased except for IFN-gamma. We demonstrated that warm ischemic injury in DCD donation can be attenuated by steroids when given prior to warm ischemia and during EVLP. Ethical context of donor preconditioning should be discussed further.

Lungs donated after circulatory death and prolonged warm ischemia are transplanted successfully after enhanced ex vivo lung perfusion using adenosine A2B receptor antagonism

OBJECTIVE

The current supply of acceptable donor lungs is not sufficient for the number of patients awaiting transplantation. We hypothesized that ex vivo lung perfusion (EVLP) with targeted drug therapy would allow successful rehabilitation and transplantation of donation after circulatory death lungs exposed to 2 hours of warm ischemia.

METHODS

Donor porcine lungs were procured after 2 hours of warm ischemia postcardiac arrest and subjected to 4 hours of cold preservation or EVLP. ATL802, an adenosine A_2B receptor antagonist, was administered to select groups. Four groups (n = 4/group) were randomized: cold preservation (Cold), cold preservation with ATL802 during reperfusion (Cold + ATL802), EVLP (EVLP), and EVLP with ATL802 during ex vivo perfusion (EVLP + ATL802). Lungs subsequently were transplanted, reperfused, and assessed by measuring dynamic lung compliance and oxygenation capacity.

RESULTS

EVLP + ATL802 significantly improved dynamic lung compliance compared with EVLP (25.0 ± 1.8 vs 17.0 ± 2.4 mL/cmH₂O, P = .04), and compared with cold preservation (Cold: 12.2 ± 1.3, P = .004; Cold + ATL802: 10.6 ± 2.0 mL/cmH₂O, P = .002). Oxygenation capacity was highest in EVLP (440.4 ± 37.0 vs Cold: 174.0 ± 61.3 mm Hg, P = .037). No differences in oxygenation or pulmonary edema were observed between EVLP and EVLP + ATL802. A significant decrease in interleukin-12 expression in tissue and bronchoalveolar lavage was identified between groups EVLP and EVLP + ATL802, along with less neutrophil infiltration.

CONCLUSIONS

Severely injured donation after circulatory death lungs subjected to 2 hours of warm ischemia are transplanted successfully after enhanced EVLP with targeted drug therapy. Increased use of lungs after uncontrolled donor cardiac death and prolonged warm ischemia may be possible and may improve transplant wait list times and mortality.

Permanence can be Defended

In donation after the circulatory-respiratory determination of death (DCDD), the dead donor rule requires that the donor be dead before organ procurement can proceed. Under the relevant limb of the Uniform Determination of Death Act 1981 (USA), a person is dead when the cessation of circulatory-respiratory function is 'irreversible'. Critics of current practice in DCDD have argued that the donor is not dead at the time organs are procured, and so the procurement of organs from these donors violates the dead donor rule. We offer a new argument here in defence of current DCDD practice, and, in particular, of the interpretation of the requirement of 'irreversibility' as permanence.

A Single-center Experience of Kidney Transplantation from Donation after Circulatory Death: Challenges and Scope in India

Donation after circulatory death (DCD) has never been attempted in India because of legal constraints and lack of guidelines for the withdrawal of life support in end-of-life situations. The present report describes the initial experience of transplantation of organs from DCD donors in a tertiary care center in India. Between 2011 and 2015, five donors had kidneys retrieved after cardiac arrest. These patients were declared dead after waiting for 5 min with no electrocardiographic signal on monitor following cardiopulmonary resuscitation (CPR), which was restarted in three patients till organ retrieval. All donors received heparin and underwent rapid cannulation of aorta, infusion of preservative cold solution, and immediate surface cooling of organs during retrieval surgery. 9/10 kidneys were utilized. Mean donor age was 29.6 ± 16.3 years, M:F 4:1 and mean age of recipients was 38.7 ± 10.8 years, M:F 7:2. Seven patients required dialysis in postoperative period. Mean postoperative day 0 urine output was 1.9 ± 2.6 L. Baseline creatinine achieved was 1.38 ± 0.35 mg/dl after a mean duration of 26.12 ± 15.4 days. Kidneys from donors where CPR was continued after the declaration of death (n = 3) had better recovery of renal function (time to reach baseline creatinine 21.2 ± 7.2 vs. 34.3 ± 23.7 days, baseline creatinine 1.36 ± 0.25 vs. 1.52 ± 0.45 mg%). In donors without CPR, one kidney never functioned and others had patchy cortical necrosis on protocol biopsy, which was not seen in the kidneys from donors with CPR. Kidneys from DCD donors can serve as a useful adjunct in deceased donor program. Continuing CPR after the declaration of death seems to help in improving outcomes.

Mechanism of Death after Decompressive Craniectomy in Non-Traumatic Brain Injury

Decompressive craniectomy (DC) after devastating brain injury (DBI) may influence the manner in which patients die, having implications for end-of-life care and organ donation. We performed a retrospective review of deaths following a non-traumatic DBI between 2008 and 2012. 160 patients were reviewed; 26 were treated with DC and 134 received standard care. There was no relationship between DC and mechanism of death, (OR 1.18, 95% CI 0.44-3.17). Prospective studies are required to confirm these preliminary finding. DC studies should report the mechanism of death.

Controlled Reperfusion Strategies Improve Cardiac Hemodynamic Recovery after Warm Global Ischemia in an Isolated, Working Rat Heart Model of Donation after Circulatory Death (DCD)

Aims: Donation after circulatory death (DCD) could improve cardiac graft availability, which is currently insufficient to meet transplant demand. However, DCD organs undergo an inevitable period of warm ischemia and most cardioprotective approaches can only be applied at reperfusion (procurement) for ethical reasons. We investigated whether modifying physical conditions at reperfusion, using four different strategies, effectively improves hemodynamic recovery after warm ischemia.

Methods and Results: Isolated hearts of male Wistar rats were perfused in working-mode for 20 min, subjected to 27 min global ischemia (37°C), and 60 min reperfusion (n = 43). Mild hypothermia (30°C, 10 min), mechanical postconditioning (MPC; 2x 30 s reperfusion/30 s ischemia), hypoxia (no O₂, 2 min), or low pH (pH 6.8–7.4, 3 min) was applied at reperfusion and compared with controls (i.e., no strategy). After 60 min reperfusion, recovery of left ventricular work (developed pressure^*heart rate; expressed as percent of pre-ischemic value) was significantly greater for mild hypothermia (62 ± 7%), MPC (65 ± 8%) and hypoxia (61 ± 11%; p < 0.05 for all), but not for low pH (45 ± 13%), vs. controls (44 ± 7%). Increased hemodynamic recovery was associated with greater oxygen consumption (mild hypothermia, MPC) and coronary perfusion (mild hypothermia, MPC, hypoxia), and with reduced markers of necrosis (mild hypothermia, MPC, hypoxia) and mitochondrial damage (mild hypothermia, hypoxia).

Conclusions: Brief modifications in physical conditions at reperfusion, such as hypothermia, mechanical postconditioning, and hypoxia, improve post-ischemic hemodynamic function in our model of DCD. Cardioprotective reperfusion strategies applied at graft procurement could improve DCD graft recovery and limit further injury; however, optimal clinical approaches remain to be characterized.