Effect of organ donation after circulatory determination of death on number of organ transplants from donors with neurologic determination of death

Using extracorporeal membrane oxygenation in donations after cardiac death or brain death: A single-center experience and long-term outcome

Aims

The use of extended criteria donors is a routine practice that sometimes involves extracorporeal membrane oxygenation (ECMO) in donations after cardiac death or brain death.

Methods

We performed a retrospective study in a single center from January 2006 to December 2019. The study included 90 deceased donor liver transplants. The patients were divided into three groups: the donation after brain death (DBD) group (n = 58, 64.4%), the DBD with ECMO group (n = 11, 12.2%) and the donation after cardiac death (DCD) with ECMO group (n = 21, 23.3%).

Results

There were no significant differences between the DBD with ECMO group and the DBD group. When comparing the DCD with ECMO group and the DBD group, there were statistically significant differences for total warm ischemia time (p < 0.001), total cold ischemia time (p = 0.023), and split liver transplantation (p < 0.001), and there was significantly poor recovery in regard to total bilirubin level (p = 0.027) for the DCD with ECMO group by repeated measures ANOVA. The 5-year survival rates of the DBD, DBD with ECMO, and DCD with ECMO groups were 78.1%, 90.9%, and 75.6%, respectively. The survival rate was not significantly different when comparing the DBD group to either the DBD with ECMO group (p = 0.435) or the DCD with ECMO group (p = 0.310).

Conclusions

Using ECMO in donations after cardiac death or brain death is a good technology, and it contributed to 35.6% of the liver graft pool.

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.

Anesthetic Considerations During Heart Transplantation Using Donation After Circulatory Death

Worldwide, the majority of heart transplant organs are from donation after brain death. However, the shortage of suitable donors places severe limitations on this route. One option to increase the donor pool is to use organs from donation after circulatory death (DCD). Transplant centers for solid organs have been using DCD organs for years. At this time, 40% of solid organ transplantation in the United Kingdom uses organs from DCD. Use of DCD for solid organ transplants in Canada is also rising. Recently, there has been interest in using DCD organs for heart transplantation. The authors will discuss their experience of 4 heart transplants with organs from DCD donors after normothermic regional perfusion (NRP). The authors' first heart transplant using a DCD organ was in January 2020, and the fourth was in March 2020, just before the coronavirus disease 2019 (COVID-19) pandemic. The authors' protocol using NRP allows adequate evaluation of the donor heart to confidently determine organ acceptance. The co-location of the donor and the recipient in neighboring operating rooms limits ischemic times. Avoidance of an expensive ex vivo organ perfusion machine is an additional benefit for programs that may not have the resources required to purchase and maintain the machine. Some hospitals may not have the resources and space to be able to co-locate both the donor and recipient. Use of cold storage may be an option to transport the procured organ, similar to donation after brain death organs. The authors hope that this technique of NRP in DCD donors can help further increase the donor pool for heart transplantation in the United States.

Portable Normothermic Cardiac Perfusion System in Donation After Cardiocirculatory Death: A Health Technology Assessment

BACKGROUND

Heart transplantation is the most effective treatment for people experiencing end-stage heart failure whose quality of life and life expectancy are unacceptable. However, there is a chronic shortage of donor hearts to meet the demand, so it is essential to expand the donor pool and increase supply. Heart donation mainly occurs after brain death (neurological determination of death [NDD]), but it may also be feasible after cardiocirculatory death (when the heart has stopped beating and there is no longer blood flow or a pulse), provided specialized preservation techniques are used. An investigational device, a portable normothermic cardiac perfusion system, could make it possible to procure, preserve, and transport hearts donated after cardiocirculatory death (DCD). We conducted a health technology assessment of a portable normothermic cardiac perfusion system for the preservation and transportation of DCD hearts for adult transplantation. This included an evaluation of the effectiveness, safety, value for money, and budget impact of publicly funding this system, as well as an evaluation of patient preferences and values.

METHODS

We performed a systematic review of the clinical literature published since 1998 that examined the clinical safety and effectiveness of a portable normothermic cardiac perfusion system for DCD heart transplantation. We assessed the risk of bias of each included study and the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We also reviewed the economic evidence published during the same time period for the cost-effectiveness of a portable normothermic cardiac perfusion system for DCD hearts compared with cold storage for NDD hearts. We further estimated the 5-year net budget impact of publicly funding a normothermic cardiac perfusion system for DCD heart transplantation for adults on Ontario's waitlist. To contextualize the potential value of a portable normothermic cardiac perfusion system, we spoke with people waiting for a heart transplant, people who had received a heart transplant, and family members of organ donors.

RESULTS

We screened 2,386 clinical citations. One study and two case reports met the inclusion criteria. The survival of recipients of DCD hearts procured with a portable normothermic cardiac perfusion system did not differ significantly from the survival of recipients of hearts donated after NDD at 30 days or 90 days, nor was there a significant difference in cumulative survival at 1 year post-transplant (GRADE: Very Low). The occurrence of rejection and graft failure also did not significantly differ between the groups (GRADE: Very Low). Cardiac function in the early post-operative period was better in DCD hearts than NDD hearts (GRADE: Very Low). There were no differences in outcomes between DCD procurement techniques.The economic literature search yielded 62 citations. One report met the inclusion criteria but was not directly applicable to the Ontario context. Given the lack of clinical and economic evidence on long-term outcomes, we did not conduct a primary economic evaluation. In the budget impact analysis, based on the number of DCD donors under 40 years of age in the last 5 years, we estimated that the increased availability of donor hearts made possible by the technology would result in an additional seven transplants in year 1, increasing to 12 in year 5. The annual net budget impact of publicly funding a normothermic cardiac perfusion system for the transplantation of DCD hearts in Ontario over the next 5 years is about $2.0 million in the first year and about $0.9 million in each of years 2 through 5, yielding a total net budget impact of about $5.6 million. This number increases to about $10.3 million if the transplant volume increases to 18 hearts in year 1 (meaning a subsequent increase of up to 21 hearts in year 5). If transplantation were limited to people who do not qualify for a ventricular assistive device or who qualify but do not wish to receive one, the total 5-year net budget impact would be about $7.9 million.People waiting for a heart transplant or who had received a heart transplant and family members of organ donors expressed no substantial concerns about the potential use of a portable normothermic cardiac perfusion system. They hope that it may increase the number of donor hearts available for transplant. For family members of organ donors, a perfusion system may provide comfort and value if it can increase the successful procurement of donor hearts.

CONCLUSIONS

Based on very low quality of evidence, the outcomes for recipients of DCD hearts preserved using a portable normothermic cardiac perfusion system appear to be similar to outcomes for recipients of NDD hearts. Owing to a lack of evidence relevant to the Ontario context, we were unable to determine whether a portable normothermic perfusion system may be cost-effective. We estimate that publicly funding a portable normothermic cardiac perfusion system for DCD heart transplantation over the next 5 years will cost about $5.6 million. The people we spoke with believe that the system may increase the number of hearts available for transplant and therefore increase the number of heart transplants that can be done.

Acceptability of cardiac donation after circulatory determination of death: a survey of the Canadian public

PURPOSE

Cardiac transplantation is a definitive therapy for end-stage heart failure, but demand exceeds supply. Cardiac donation after circulatory determination of death (cardiac DCDD) can be performed using direct procurement and perfusion (DPP), where cardiac activity is restored after heart recovery, or (NRP), where brain blood supply is surgically interrupted, circulation to the thoraco-abdominal organs is restored within the donor's body, followed by heart recovery. While cardiac DCDD would increase the number of heart donors, uptake of programs has been slowed in part because of ethical concerns within the medical community. These debates have been largely devoid of discussion regarding public perceptions. We conducted a national survey of public perceptions regarding cardiac DCDD.

METHODS

We surveyed 1,001 Canadians about their attitudes towards cardiac DCDD using a rigorously designed and pre-tested survey.

RESULTS

We found that 843 of 1,001 respondents (84.2%; 95% confidence interval [CI], 81.8 to 86.3) accepted the DPP approach, 642 (64.1%; 95% CI, 61.1 to 67.0) would agree to donate their heart using DPP, and 696 (69.5%; 95% CI, 66.6 to 72.3) would consent to the same for a family member. We found that 779 respondents of 1,001 respondents (77.8%; 95% CI, 75.1 to 80.3) accepted the NRP approach, 587 (58.6%; 95% CI, 55.5 to 61.6) would agree to donate their heart using NRP, and 636 (63.5%; 95% CI, 60.5 to 66.4) would consent to the same for a family member. Most respondents supported the implementation of DPP (738 respondents or 73.7%; 95% CI, 70.9 to 76.3) and NRP (655 respondents or 65.4%; 95% CI, 62.4 to 68.3) in Canada.

CONCLUSION

The results of this national survey of public attitudes towards cardiac DCDD will inform the implementation of cardiac DCDD programs in a manner that is consistent with public values.

Missed opportunities for DCD kidney donors: Evaluation of warm ischemic time and associated functional warm ischemic time

INTRODUCTION

Many transplant centers utilize a hard cutoff of 2 hours of warm ischemic time (WIT), defined as the time from withdrawal of life-sustaining measures to cold organ flush, to exclude donation after circulatory determination of death (DCD) kidney donation. As a result, almost a quarter of withdrawals to retrieve DCD organs fail to produce kidney transplants in Ontario. In order to assess our ability to increase organ yield, we wanted to characterize WIT and functional WIT (fWIT, time from systolic blood pressure <50 mm Hg to cold organ flush), as well as determine the time at which potential donors eventually die in those that did not become organ donors.

METHODS

A retrospective review of all DCD kidney donors in Ontario was performed utilizing the Trillium Gift of Life Database from April 2013 to February 2018.

RESULTS

Of 350 DCD kidney donors analyzed, 46.9% had < 0.5 hours, 51.7% between 0.5 and 2 hours, and 1.4% >2 hours of WIT. In each of these categories (WIT <0.5 hours, 0.5-2 hours and >2 hours), the percentage of patients with fWIT <30 minutes was 100%, 94.4%, and 100%, respectively (P = NS). There were 106 potential donors who did not end up donating due to WIT >2 hours. Of these, 20.8% died between 2 and 4 hours, 10.4% between 4 and 6 hours, and 68.8% beyond 6 hours.

DISCUSSION

The percentage of donors with fWIT >30 minutes did not increase with increasing WIT in DCD donors that went on to donate organs. These data support assessment of waiting up to 4 hours for DCD kidney donation as long as fWIT remains low.

Deceased organ donation potential in Canada: a review of consecutive deaths in Alberta

BACKGROUND

Transplantation is the most effective treatment for many patients with end-stage organ failure. There is a gap between the number of patients who would benefit from transplantation and availability of organs. We assessed maximum potential for deceased donation in Alberta and barriers to increasing the donation rate.

METHODS

All deaths that occurred in Alberta in 2015 in areas where mechanical ventilation could be provided were retrospectively identified using administrative data. Medical records were reviewed by donation coordinators and critical care physicians with expertise in donation, using a standardized tool to determine whether deceased patients could potentially have been organ donors.

RESULTS

There were 2,706 deaths occurring in either an intensive care unit or emergency department, of which 1,252 were attributable to a non-neurologic cause: 946 involved cardiac arrests with unsuccessful resuscitation, and 57 were not mechanically ventilated. Of the remaining 451 deaths, 117 (28 donors per million population [dpmp]) either were, or could potentially have been, organ donors after neurologic determination of death (NDD). Of these, 19 (4.5 dpmp) were not appropriately identified or referred, and 45 approached families (10.8 dpmp) did not provide consent. Non-identified NDD cases accounted for a larger proportion of deaths due to neurologic causes in emergency departments (18%) than in intensive care units (2%) (P < 0.0001) and in rural (9%) compared with urban centres (3%) (P = 0.05). If routinely available, donation after circulatory death (DCD) could potentially have been possible in as many as 113 (27 dpmp) cases.

CONCLUSIONS

Maximum deceased organ donation potential in Alberta is approximately 55 dpmp. The current donation rate has potential to increase with more widespread availability of DCD and a higher consent rate.

Development of a multinational registry of pediatric deceased organ donation activity

BACKGROUND

There are no currently agreed upon international standards for reporting of pediatric deceased organ donation activity. This leads to difficulty in comparisons between jurisdictions for both researchers and policy stakeholders. The goal of this project was to develop and test a standardized registry for pediatric deceased donation activity.

METHODS

Four countries (Canada, Spain, USA, and the UK) with geographical and practice diversity were approached to participate. Iterative exchanges were used to create data fields and definitions that were acceptable to all participants. Data from 2011 to 2015 (inclusive) were requested from national health databases and analyzed on a secure, web-based survey platform.

RESULTS

Data were obtained from three of the four countries (Canada unable to provide). Total pediatric donation rates were stable over the 5-year period, but with variation between countries. pDCD rates were the most variable, representing 32.2% of total pediatric donation in the UK, 14.4% in the United States, and 2.6% in Spain during the studied period. Most organs from pediatric donors were allocated to adult recipients, though the rates of allocation of pediatric kidneys to pediatric recipients ranged from 7% in the United States to 40% in Spain.

DISCUSSION

In this limited cohort of three countries, we demonstrated substantial variation in pediatric donation rates and practice. These data highlight opportunities for practice improvement such as the development of rigorous clinical practice guidelines. Future development of this registry will seek to engage more countries, and address barriers that prevented full participation of approached jurisdictions.

Evolution of Deceased Organ Donation Activity Versus Efficiency Over a 15-year Period: An International Comparison

BACKGROUND

The donation rate (DR) per million population is not ideal for an efficiency comparison of national deceased organ donation programs. The DR does not account for variabilities in the potential for deceased donation which mainly depends on fatalities from causes leading to brain death. In this study, the donation activity was put into relation to the mortality from selected causes. Based on that metric, this study assesses the efficiency of different donation programs.

METHODS

This is a retrospective analysis of 2001 to 2015 deceased organ donation and mortality registry data. Included are 27 Council of Europe countries, as well as the United States. A donor conversion index (DCI) was calculated for assessing donation program efficiency over time and in international comparisons.

RESULTS

According to the DCI and of the countries included in the study, Spain, France, and the United States had the most efficient donation programs in 2015. Even though mortality from the selected causes decreased in most countries during the study period, differences in international comparisons persist. This indicates that the potential for deceased organ donation and its conversion into actual donation is far from being similar internationally.

CONCLUSIONS

Compared with the DR, the DCI takes into account the potential for deceased organ donation, and therefore is a more accurate metric of performance. National donation programs could optimize performance by identifying the areas where most potential is lost, and by implementing measures to tackle these issues.

Organ donation in trauma victims: A systematic review and meta-analysis

BACKGROUND

Although trauma patients represent a large pool of potential organ donors (PODs), the donor conversion rates (DCRs) in this population are unclear. Our primary objective was to synthesize published evidence on DCRs in trauma patients. As a secondary objective, we investigated factors that affect organ donation (OD) in the trauma population.

METHODS

We searched four electronic databases (PubMed, Embase, Web of Science, and Cochrane Library) and gray literature for articles on OD in trauma patients (PROSPERO 2017: CRD42017070388). Articles were excluded if it was not possible to calculate the DCR (actual organ donors divided by PODs). We pooled DCRs and performed subgroups analysis by trauma subpopulation, patients' age, and study publication date.

RESULTS

We identified 27 articles with a total of 123,142 participants. Cohorts ranged in size from 28 to 120,512 patients (median, 132), with most studies performed in the United States. Conversion rates among individual studies ranged from 14.0% to 75.2% (median, 49.3%). All 27 studies were included in the meta-analysis. We found a pooled DCR of 48.1% using the random effects model. There was a high level of heterogeneity between studies (I = 97.4%). Upon subgroup analysis, we found DCRs were higher in head trauma patients compared with traumatic cardiac arrest patients (45.3% vs 20.9%, p < 0.001), in pediatric patients compared with adults (61.0% vs 38.0%, p = 0.018), and in studies published after 2007 compared with those published before (50.8% vs 43.9%, p < 0.001). Few studies assessed for factors associated with OD in trauma patients.

CONCLUSIONS

We found variation in DCRs among trauma patients (range, 14.0-75.2%) and estimated a pooled DCR of 48.1%. Our results are limited by heterogeneity across studies, which may be attributable to differences in study design and population, definitions of a POD, and in the institutional criteria and processes regarding OD.

LEVEL OF EVIDENCE

Systematic reviews and meta-analyses level III.

Ten years of Israel's organ transplant law: is it on the right track?

The Israeli organ donor law was established in 2008. In the ensuing 10 years there have been some improvements in deceased donation and living donor rates and a reduction in the unethical practice of transplant tourism. There is, however, controversy regarding increased access to transplant for those who have been living donors, who are family members of deceased donors, or who have registered their intent to donate. The issue of routine retrieval versus obtaining consent for organ donation has also been raised. This commentary will address these issue, and propose some steps for improvement of the current Israeli organ donation system.