Impact of a National Controlled Donation After Circulatory Death (DCD) Program on Organ Donation in the United Kingdom: A 10-Year Study

A ten-year retrospective analysis of decompressive craniectomy or craniotomy after severe brain injury and its implications for donation after brain death

Craniotomy or decompressive craniectomy are among the therapeutic options to prevent or treat secondary damage after severe brain injury. The choice of procedure depends, among other things, on the type and severity of the initial injury. It remains controversial whether both procedures influence the neurological outcome differently. Thus, estimating the risk of brain herniation and death and consequently potential organ donation remains difficult. All patients at the University Hospital Münster for whom an isolated craniotomy or decompressive craniectomy was performed as a treatment after severe brain injury between 2013 and 2022 were retrospectively included. Proportion of survivors and deceased were evaluated. Deceased were further analyzed regarding anticoagulants, comorbidities, type of brain injury, potential and utilized donation after brain death. 595 patients were identified, 296 patients survived, and 299 deceased. Proportion of decompressive craniectomy was higher than craniotomy in survivors (89% vs. 11%, p < 0.001). Brain death was diagnosed in 12 deceased and 10 donations were utilized. Utilized donations were comparable after both procedures (5% vs. 2%, p = 0.194). Preserved brain stem reflexes as a reason against donation did not differ between decompressive craniectomy or craniotomy (32% vs. 29%, p = 0.470). Patients with severe brain injury were more likely to survive after decompressive craniectomy than craniotomy. Among the deceased, potential and utilized donations did not differ between both procedures. This suggests that brain death can occur independent of the previous neurosurgical procedure and that organ donation should always be considered in end-of-life decisions for patients with a fatal prognosis.

Post-COVID-19 pandemic organ donation activities in Germany: a multicenter retrospective analysis

Introduction

The COVID-19 pandemic had a negative impact on the number of solid organ transplantations. After a global decline of 16% in 2020, their numbers subsequently returned to pre-pandemic levels. In contrast, numbers in Germany remained almost constant in 2020 and 2021 but fell by 6.9% in 2022. The reasons for this divergent development are unknown.

Methods

The number of deceased with a severe brain damage, potential and utilized donors after braindeath and the intensive care unit treatment capacity were retrospectively compared for the years 2022 and 2021 at five university hospitals in North Rhine-Westphalia, Germany. Reasons for a donation not utilized were reviewed. To enable a comparison of the results with the whole of Germany and the pre-pandemic period, numbers of potential and utilized donors were extracted from official organ donation activity reports of all harvesting hospitals in Germany for the years 2019-2022.

Results

The numbers of deceased with a severe brain damage (-10%), potential (-9%), and utilized donors after braindeath (-44%), and intensive care unit treatment capacities (-7.2%) were significantly lower in 2022 than 2021. A COVID-19 infection was a rarer (-79%), but donor instability (+44%) a more frequent reason against donation in 2022, whereas preserved brain stem reflexes remained the most frequent reason in both years (54%). Overall numbers of potential and utilized donations in Germany were lower in 2022 than in the pre-pandemic period, but this was mainly due to lower numbers in hospitals of lower care. The number of potential donors in all university hospitals were higher in 2022 but utilized donations still lower than in 2019.

Conclusion

The decrease in potential and utilized donations was a result of reduced intensive care unit treatment capacities and a lower conversion rate at the five university hospitals. A COVID-19 infection did not play a role in 2022. These results indicate that ICU treatment capacities must be restored to increase donations. The lower number of potential donors and the even lower conversion rate in 2022 throughout Germany show that restructuring the organ procurement process in Germany needs to be discussed to increase the number of donations.

Trajectories of systolic blood pressure decline in kidney transplant donors prior to circulatory death and delayed graft function

BACKGROUND

Kidneys donated after circulatory death suffer a period of functional warm ischaemia before death, which may lead to early ischaemic injury. Effects of haemodynamic trajectories during the agonal phase on delayed graft function (DGF) is unknown. We aimed to predict the risk of DGF using patterns of trajectories of systolic blood pressure (SBP) declines in Maastricht category 3 kidney donors.

METHODS

We conducted a cohort study of all kidney transplant recipients in Australia who received kidneys from donation after circulatory death donors, divided into a derivation cohort (transplants between 9 April 2014 and 2 January 2018 [462 donors]) and a validation cohort (transplants between 6 January 2018 and 24 December 2019 [324 donors]). Patterns of SBP decline using latent class models were evaluated against the odds of DGF using a two-stage linear mixed effects model.

RESULTS

In the derivation cohort, 462 donors were included in the latent class analyses and 379 donors in the mixed effects model. Of the 696 eligible transplant recipients, 380 (54.6%) experienced DGF. Ten different trajectories, with distinct patterns of SBP decline were identified. Compared with recipients from donors with the slowest decline in SBP after withdrawal of cardiorespiratory support, the adjusted odds ratio (aOR) for DGF was 5.5 [95% confidence interval (CI) 1.38-28.0] for recipients from donors with a steeper decline and lowest SBP [mean 49.5 mmHg (standard deviation 12.5)] at the time of withdrawal. For every 1 mmHg/min reduction in the rate of decline of SBP, the respective aORs for DGF were 0.95 (95% CI 0.91-0.99) and 0.98 (95% CI 0.93-1.0) in the random forest and least absolute shrinkage and selection operator models. In the validation cohort, the respective aORs were 0.95 (95% CI 0.91-1.0) and 0.99 (95% CI 0.94-1.0).

CONCLUSION

Trajectories of SBP decline and their determinants are predictive of DGF. These results support a trajectory-based assessment of haemodynamic changes in donors after circulatory death during the agonal phase for donor suitability and post-transplant outcomes.

How Large is the Potential of Brain Dead Donors and what Prevents Utilization? A Multicenter Retrospective Analysis at Seven University Hospitals in North Rhine-Westphalia

Organ donation after brain death is constantly lower in Germany compared to other countries. Instead, representative surveys show a positive attitude towards donation. Why this does not translate into more donations remains questionable. We retrospectively analyzed all potential brain dead donors treated in the university hospitals of Aachen, Bielefeld, Bonn, Essen, Düsseldorf, Cologne and Münster between June 2020 and July 2021. 300 potential brain dead donors were identified. Donation was utilized in 69 cases (23%). Refused consent (n = 190), and failed utilization despite consent (n = 41) were reasons for a donation not realized. Consent was significantly higher in potential donors with a known attitude towards donation (n = 94) compared to a decision by family members (n = 195) (49% vs. 33%, p = 0.012). The potential donor´s age, status of interviewer, and the timing of the interview with decision-makers had no influence on consent rates, and it was comparable between hospitals. Refused consent was the predominant reason for a donation not utilized. Consent rate was lower than in surveys, only a known attitude towards donation had a significant positive influence. This indicates that survey results do not translate well into everyday clinical practice and promoting a previously documented decision on organ donation is important.

Variability in criteria for death determination in the intensive care unit

PURPOSE

Variability in practice exists in death determination by circulatory criteria in the context of organ donation. We sought to describe the practices of intensive care health care professionals for death determination by circulatory criteria with and without organ donation.

METHODS

This study is a retrospective analysis of prospectively collected data. We included patients with death determination by circulatory criteria in intensive care units at 16 hospitals in Canada, three in the Czech Republic, and one in the Netherlands. Results were recorded using a checklist for the determination of death questionnaire.

RESULTS

A total of 583 patients had their death determination checklist reviewed for statistical analysis. The mean (standard deviation) age in years was 64 (15). Three hundred and fourteen (54.0%) patients were from Canada, 230 (39.5%) were from the Czech Republic, and 38 (6.5%) were from the Netherlands. Fifty-two (8.9%) patients proceeded with donation after death determination by circulatory criteria (DCD). The most common diagnostic tests reported for the whole group were absent heart sounds by auscultation (81.8%), flat continuous arterial blood pressure (ABP) tracing (77.0%), and flat electrocardiogram tracing (73.2%). In patients who successfully underwent DCD (N = 52), death was determined most frequently using a flat continuous ABP tracing (94%), absent pulse oximetry (85%), and absent palpable pulse (77%).

CONCLUSION

In this study, we have described practices for death determination by circulatory criteria both within and between countries. Though some variability exists, we are reassured that appropriate criteria are almost always used in the context of organ donation. In particular, the use of continuous ABP monitoring in DCD was consistent. It highlights the need for standardization of practice and up to date guidelines, especially within the context of DCD where there is both an ethical and a legal requirement to adhere to the dead donor rule, while minimizing time between death determination and organ procurement.

Donation after circulatory death and lung transplantation

Lung transplantation is the most effective modality for the treatment of patients with end-stage lung diseases. Unfortunately, many people cannot benefit from this therapy due to insufficient donor availability. In this review and update article, we discuss donation after circulatory death (DCD), which is undoubtedly essential among the strategies developed to increase the donor pool. However, there are ethical and legislative considerations in the DCD process that are different from those of donation after brain death (DBD). Among others, the critical aspects of DCD are the concept of the end of life, cessation of futile treatments, and withdrawal of life-sustaining therapy. In addition, this review describes a rationale for using lungs from DCD donors and provides some important definitions, highlighting the key differences between DCD and DBD, including physiological aspects pertinent to each category. The unique ability of lungs to maintain cell viability without circulation, assuming that oxygen is supplied to the alveoli-an essential aspect of DCD-is also discussed. Furthermore, an updated review of the clinical experience with DCD for lung transplantation across international centers, recent advances in DCD, and some ethical dilemmas that deserve attention are also reported.

Critical pathways for controlled donation after circulatory death in France

INTRODUCTION

In 2015, France authorised controlled donation after circulatory death (cDCD) according to a nationally approved protocol. The aim of this study is to provide an overview from the perspective of critical care specialists of cDCD. The primary objective is to assess how the organ donation procedure affects the withdrawal of life-sustaining therapies (WLST) process. The secondary objective is to assess the impact of cDCD donors' diagnoses on the whole process.

MATERIAL AND METHODS

This 2015-2019 prospective observational multicentre study evaluated the WLST process in all potential cDCD donors identified nationwide, comparing 2 different sets of subgroups: 1- those whose WLST began after organ donation was ruled out vs. while it was still under consideration; 2- those with a main diagnosis of post-anoxic brain injury (PABI) vs. primary brain injury (PBI) at the time of the WLST decision.

RESULTS

The study analysed 908 potential cDCD donors. Organ donation remained under consideration at WLST initiation for 54.5% of them with longer intervals between their WLST decision and its initiation (2 [1-4] vs. 1 [1-2] days, P < 0.01). Overall, 60% had post-anoxic brain injury. Time from ICU admission to WLST decision was longer for primary brain injury donors (10 [4-21] vs. 6 [4-9] days, P < 0.01). Median time to death (agonal phase) was 15 [15-20] minutes.

CONCLUSIONS

French cDCD donors are mostly related to post-anoxic brain injury. The organ donation process does not accelerate WLST decision but increases the interval between the WLST decision and its initiation.

Human liver stem cell-derived extracellular vesicles reduce injury in a model of normothermic machine perfusion of rat livers previously exposed to a prolonged warm ischemia

Livers from donors after circulatory death (DCD) are a promising option to increase the donor pool, but their use is associated with higher complication rate and inferior graft survival. Normothermic machine perfusion (NMP) keeps the graft at 37°C, providing nutrients and oxygen supply. Human liver stem cell‐derived extracellular vesicles (HLSC‐EVs) are able to reduce liver injury and promote regeneration. We investigated the efficacy of a reconditioning strategy with HLSC‐EVs in an experimental model of NMP. Following total hepatectomy, rat livers were divided into 4 groups: (i) healthy livers, (ii) warm ischemic livers (60 min of warm ischemia), (iii) warm ischemic livers treated with 5 × 10⁸ HLSC‐EVs/g‐liver, and (iv) warm ischemic livers treated with a 25 × 10⁸ HLSC‐EVs/g‐liver. NMP lasted 6 h and HLSC‐EVs (Unicyte AG, Germany) were administered within the first 15 min. Compared to controls, HLSC‐EV treatment significantly reduced transaminases release. Moreover, HLSC‐EVs enhanced liver metabolism by promoting phosphate utilization and pH self‐regulation. As compared to controls, the higher dose of HLSC‐EV was associated with significantly higher bile production and lower intrahepatic resistance. Histologically, this group showed reduced necrosis and enhanced proliferation. In conclusion, HLSC‐EV treatment during NMP was feasible and effective in reducing injury in a DCD model with prolonged warm ischemia.

Outcomes for circulatory death and brainstem death pancreas transplantation with or without use of normothermic regional perfusion

Simultaneous pancreas and kidney transplantation is the optimum treatment for patients with type 1 diabetes and renal failure, providing survival benefit over deceased donor kidney transplant alone. Here the authors demonstrate that utilization of donation after circulatory death pancreases is a safe approach to expanding the donor pool with equivalent results to donation after brainstem death transplantation. They also demonstrate that pancreas transplantation after normothermic regional perfusion is feasible, but it will require ongoing prospective study to ensure that the benefits seen for liver transplantation do not come at the expense of pancreas transplant outcomes.

Wide Variation in the Percentage of Donation After Circulatory Death Donors Across Donor Service Areas: A Potential Target for Improvement

BACKGROUND

Substantial differences exist in the clinical characteristics of donors across the 58 donor service areas (DSAs). Organ procurement organization (OPO) performance metrics incorporate organs donated after circulatory determination of death (DCDD) donors but do not measure potential DCDD donors.

METHODS

Using 2011-2016 United Network for Organ Sharing data, we examined the variability in DCDD donors/all deceased donors (%DCDD) across DSAs. We supplemented United Network for Organ Sharing data with CDC death records and OPO statistics to characterize underlying process and system factors that may correlate with donors and utilization.

RESULTS

Among 52 184 deceased donors, the %DCDD varied widely across DSAs, with a median of 15.1% (interquartile range [9.3%, 20.9%]; range 0.0%-32.0%). The %DCDD had a modest positive correlation with 4 DSA factors: median match model for end-stage liver disease, proportion of white deaths out of total deaths, kidney center competition, and %DCDD livers by a local transplant center (all Spearman coefficients 0.289-0.464), and negative correlation with 1 factor: mean kidney waiting time (Spearman coefficient -0.388). Adjusting for correlated variables in linear regression explained 46.3% of the variability in %DCDD.

CONCLUSIONS

Donor pool demographics, waitlist metrics, center competition, and DCDD utilization explain only a portion of the variability of DCDD donors. This requires further studies and policy changes to encourage consideration of all possible organ donors.

Allocation of liver grafts worldwide - Is there a best system?

BACKGROUND & AIMS

An optimal allocation system for scarce resources should simultaneously ensure maximal utility, but also equity. The most frequent principles for allocation policies in liver transplantation are therefore criteria that rely on pre-transplant survival (sickest first policy), post-transplant survival (utility), or on their combination (benefit). However, large differences exist between centers and countries for ethical and legislative reasons. The aim of this study was to report the current worldwide practice of liver graft allocation and discuss respective advantages and disadvantages.

METHODS

Countries around the world that perform 95 or more deceased donor liver transplantations per year were analyzed for donation and allocation policies, as well as recipient characteristics.

RESULTS

Most countries use the model for end-stage liver disease (MELD) score, or variations of it, for organ allocation, while some countries opt for center-based allocation systems based on their specific requirements, and some countries combine both a MELD and center-based approach. Both the MELD and center-specific allocation systems have inherent limitations. For example, most countries or allocation systems address the limitations of the MELD system by adding extra points to recipient's laboratory scores based on clinical information. It is also clear from this study that cancer, as an indication for liver transplantation, requires special attention.

CONCLUSION

The sickest first policy is the most reasonable basis for the allocation of liver grafts. While MELD is currently the standard for this model, many adjustments were implemented in most countries. A future globally applicable strategy should combine donor and recipient factors, predicting probability of death on the waiting list, post-transplant survival and morbidity, and perhaps costs.

LAY SUMMARY

An optimal allocation system for scarce resources should simultaneously ensure maximal utility, but also equity. While the model for end-stage liver disease is currently the standard for this model, many adjustments were implemented in most countries. A future globally applicable strategy should combine donor and recipient factors predicting probability of death on the waiting list, post-transplant survival and morbidity, and perhaps costs.

The UK-DCD-Risk-Score - practical and new guidance for allocation of a specific organ to a recipient?

Introduction: Multiple factors contribute to the overall outcome in donation after circulatory death liver transplantation. The majority is however inconsistently reported with various acceptance criteria and thresholds, when to decline a specific graft. Recent improvement in outcome was based on an increased awareness of the cumulative risk, combining donor and recipient parameters, which encouraged the community to accept livers with an overall higher risk. Areas covered: This review pictures the large number of risk factors in this field with a special focus on parameters, which contribute to available prediction models. Next, features of the recently developed UK-DCD-Risk-Score, which led to a significantly impaired graft survival, above a suggested threshold of >10 score points, are discussed. The clinical impact of this new model on the background of other prediction tools with their subsequent limitations is highlighted in a next chapter. Finally, we provide suggestions, how to further improve outcomes in this challenging field of transplantation. Expert opinion: Despite the recent development of new prediction models, including the UK-DCD-Risk-Score, which provides a sufficient prediction of graft loss after DCD liver transplantation, the consideration of other confounders is essential to better understand the overall risk and metabolic liver status to improve the comparability of clinical studies. More uniform definitions and thresholds of individual risk factors are required.

First Scandinavian Protocol for Controlled Donation After Circulatory Death Using Normothermic Regional Perfusion

Background

Donation after circulatory death (DCD) can increase the pool of available organs for transplantation. This pilot study evaluates the implementation of a controlled DCD (cDCD) protocol using normothermic regional perfusion in Norway.

Methods

Patients aged 16 to 60 years that are in coma with documented devastating brain injury in need of mechanical ventilation, who would most likely attain cardiac arrest within 60 minutes after extubation, were eligible. With the acceptance from the next of kin and their wish for organ donation, life support was withdrawn and cardiac arrest observed. After a 5-minute no-touch period, extracorporeal membrane oxygenation for post mortem regional normothermic regional perfusion was established. Cerebral and cardiac reperfusion was prevented by an aortic occlusion catheter. Measured glomerular filtration rates 1 year postengraftment were compared between cDCD grafts and age-matched grafts donated after brain death (DBD).

Results

Eight cDCD were performed from 2014 to 2015. Circulation ceased median 12 (range, 6-24) minutes after withdrawal of life-sustaining treatment. Fourteen kidneys and 2 livers were retrieved and subsequently transplanted. Functional warm ischemic time was 26 (20-51) minutes. Regional perfusion was applied for 97 minutes (54-106 minutes). Measured glomerular filtration rate 1 year postengraftment was not significantly different between cDCD and donation after brain death organs, 75 (65-76) vs 60 (37-112) mL/min per 1.73 m² (P = 0.23). No complications have been observed in the 2 cDCD livers.

Conclusion

A protocol for cDCD is successfully established in Norway. Excellent transplant outcomes have encouraged us to continue this work addressing the shortage of organs for transplantation.