Donation after cardiac death in pediatric organ transplantation:

Lung transplantation in children

Lung transplantation is a well-established treatment for children facing advanced lung disease and pulmonary vascular disorders. However, organ shortage remains highest in children. For fitting the small chest of children, transplantation of downsized adult lungs, lobes, or even segments were successfully established. The worldwide median survival after pediatric lung transplantation is currently 5.7 years, while under consideration of age, underlying disease, and peri- and posttransplant center experience, median survival of more than 10 years is reported. Timing of referral for transplantation, ischemia-reperfusion injury, primary graft dysfunction, and acute and chronic rejection after transplantation remain the main challenges.

Organ donation by children in Australia, 2000-2019: impact of the 2009 National Reform Program. A population-based registry data study

OBJECTIVES

To assess the impact of the 2009 National Reform Program for organ donation in Australia on the number and characteristics of organ donors under 16 years of age.

DESIGN, SETTING, PARTICIPANTS

Retrospective observational time series study; analysis of Australia and New Zealand Organ Donation (ANZOD) registry data for all consented potential deceased organ donors under 16 years of age during 2000-2019, and of numbers of donors aged 16 years or more reported in ANZOD annual reports.

MAIN OUTCOME MEASURES

Difference between 2000-2008 (pre-reform) and 2009-2019 (reform period) in annual organ donor rates (donors per million population), by age group (under 16 years, 16 years or more), reported as incidence rate ratio (IRR).

SECONDARY OUTCOMES

Differences in child donor characteristics during 2000-2008 and 2009-2019.

RESULTS

During 2000-2019, 400 children under 16 years of age were consented potential deceased organ donors, of whom 374 were actual deceased donors (94%): 146 during 2000-2008, 228 during 2009-2019. The median annual rate was 3.3 (interquartile range [IQR], 3.0-4.3) actual donors per million population during 2000-2008 and 4.2 (IQR, 3.6-5.2) donors per million population during 2009-2019 (IRR, 1.15; 95% confidence interval [CI], 0.93-1.42). In contrast, the difference between the two periods was statistically significant for donors aged 16 years or more, rising from 11.7 (IQR, 11.2-11.8) to 19.9 (IQR, 18.3-24.4) actual donors per million population (IRR, 1.75; 95% CI, 1.66-1.85). The median age of actual organ donors under 16 was similar during 2000-2008 (11 years; IQR, 7-14 years) and 2009-2019 (10 years; IQR, 4-14 years), as was the proportion of donors in this age group under 10 kg (2000-2008: four of 146, 3%; 2009-2019: 14 of 228, 6%).

CONCLUSIONS

Despite its overall effect on organ donation rates, the National Reform Program was not effective in increasing the numbers of donors under 16 years of age. Relying on broad initiatives for adult donors may not be appropriate for achieving this aim.

Use of DCD organs: Expanding the donor pool to increase pediatric transplantation

The number of children being listed for transplant continues to be greater than the number of available organs. In fact, over the past decade, rates of liver and kidney transplants in pediatric transplantation are essentially unchanged (Am J Transplant. 2020;20:193 and Am J Transplant. 2020;20:20). The use of DCD donors offers a potential solution to organ scarcity; however, the use of DCD organs in pediatric transplantation remains a rare event. Pediatric transplants done using carefully chosen DCD donor organs have shown to have outcomes similar to those seen with the use of donation after brain death (DBD) donors. Herein, we review the literature to examine the utilization of DCD livers and kidneys, outcomes of these allografts, and assess if DCD organs are a viable method to increase organ availability in pediatric transplantation.

Overview of pediatric kidney transplantation

Kidney transplantation is the treatment of choice for pediatric patients with end-stage kidney disease. Unlike adult recipients undergoing transplantation, special considerations must be taken when transplanting children based on the underlying etiology of kidney disease, previous surgical procedures, anatomical limitations and necessary technical adjustments. Additionally, the choice of donor must be measured to ensure optimal graft survival given a longer post-transplant life expectancy. Those topics as well as frequently encountered postoperative complications are also discussed in this publication.

Donation After Cardiac Death in Children

The wait list for organ transplant exceeds the rate of organ donation, especially in children. The solid-organ transplant rate has remained stable over time, despite increased demand. Although donation after cardiac death has helped to expand the donor organ pool for the adult population, this option remains scarce for children in need of transplant. Because long-term graft survival is more important in the pediatric group than in adults, we should reconsider the common notion that donation after cardiac death is inferior to donation after brain death. Herein, we review the literature to extract and analyze data regarding donation after cardiac death for solid-organ transplant in children.

Survival Benefit of Donation After Circulatory Death Kidney Transplantation in Children Compared With Remaining on the Waiting List for a Kidney Donated After Brain Death

BACKGROUND

Kidneys donated after circulatory death (DCD) are increasingly being used for transplantation in adults to alleviate organ shortage. Pediatric data on survival benefits of DCD transplantation compared with remaining on the waitlist for a kidney donated after brain death (DBD) offer are lacking.

METHODS

We used Scientific Registry of Transplant Recipients to identify 285 pediatric (<18 y) DCD kidney transplants performed between 1987 and 2017. Propensity score matching was used to create a comparison group of 1132 DBD transplants. We used sequential Cox analysis to evaluate survival benefit of DCD transplantation versus remaining on the waitlist and Cox regression to evaluate patient and graft survival.

RESULTS

DCD transplantation was associated with a higher incidence of delayed graft function (adjusted odds ratio: 3.0; P < 0.001). The risks of graft failure (adjusted hazard ratio [aHR], 0.89; P = 0.46) and death (aHR, 1.2; P = 0.67) were similar between DCD and DBD recipients. We found a significant survival benefit of DCD transplantation compared with remaining on the waitlist awaiting a DBD kidney (aHR, 0.44; P = 0.03).

CONCLUSIONS

Despite a higher incidence of delayed graft function, long-term patient and graft survival are similar between pediatric DCD and DBD kidney transplant recipients. DCD transplantation in children is associated with a survival benefit, despite pediatric priority for organ allocation, compared with remaining on the waitlist.

Should We Be Utilizing More Liver Grafts From Pediatric Donation After Circulatory Death Donors? A National Analysis of the SRTR from 2002 to 2017

BACKGROUND

Rates of withdrawal of life-sustaining treatment are higher among critically ill pediatric patients compared to adults. Therefore, livers from pediatric donation after circulatory death (pDCD) could improve graft organ shortage and waiting time for listed patients. As knowledge on the utilization of pDCD is limited, this study used US national registry data (2002-2017) to estimate the prognostic impact of pDCD in both adult and pediatric liver transplant (LT).

METHODS

In adult LT, the short-term (1-year) and long-term (overall) graft survival (GS) between pDCD and adult donation after circulatory death (aDCD) grafts was compared. In pediatric LT, the short- and long-term prognostic outcomes of pDCD were compared with other type of grafts (brain dead, split, and living donor).

RESULTS

Of 80 843 LTs in the study, 8967 (11.1%) were from pediatric donors. Among these, only 443 were pDCD, which were utilized mainly in adult recipients (91.9%). In adult recipients, short- and long-term GS did not differ significantly between pDCD and aDCD grafts (hazard ratio = 0.82 in short term and 0.73 in long term, both P > 0.05, respectively). Even "very young" (≤12 y) pDCD grafts had similar GS to aDCD grafts, although the rate of graft loss from vascular complications was higher in the former (14.0% versus 3.6%, P < 0.01). In pediatric recipients, pDCD grafts showed similar GS with other graft types whereas waiting time for DCD livers was significantly shorter (36.5 d versus 53.0 d, P < 0.01).

CONCLUSIONS

Given the comparable survival seen to aDCDs, this data show that there is still much scope to improve the utilization of pDCD liver grafts.

Neonatal organ donation: Ethical insights and policy implications

In the realm of clinical ethics as well as in health policy and organizational ethics, the onus of our work as ethicists is to optimize the medical care and experience of the patient to better target ethical dilemmas that develop in the course of care delivery. The role of ethics is critical in all aspects of medicine, but particularly so in the difficult and often challenging cases that arise in the care of pregnant women and newborns. One exemplary situation is that when a pregnant woman and her partner consider neonatal organ donation after receiving news of a terminal diagnosis and expected death of the newborn. While a newer, less practiced form of organ donation, this approach is gaining greater visibility as an option for parents facing this terminal outcome. The aim of our paper is to highlight some of the key ethical issues associated with neonatal organ donation and identify clinical and logistical aspects of implementing such an approach to facilitate organ donation.

Donation after cardiac death kidneys are suitable for pediatric recipients

Despite the high number of children listed for kidney transplantation and shortage of deceased organ donors, there is reluctance to utilize DCD kidneys in pediatric recipients. We examined outcomes in pediatric kidney transplant patients who received a DCD kidney allograft. UNOS database was queried to examine outcomes in all pediatric kidney transplant recipients from 1994 to 2017. Pediatric status was defined as <18 years at the time of transplantation. Recipients were divided by DBD or DCD allograft status. Donor and recipient demographic data were examined. Patient and allograft survival was calculated, and Kaplan-Meier survival curves were generated. A P-value of <0.05 was considered to be significant. A total of 286 pediatric kidney transplant recipients received a DCD allograft. The donors in the DCD group were significantly younger than those in the DBD group (21.7 vs 23.3 years), with a higher KDPI (26.5% vs 22.9%). In the DCD group, the average age at transplant was younger (11.6 vs 12.9 years), with no difference in cold ischemia time or length of stay between the two groups. Rates of delayed graft function were higher in the DCD group, but despite this, there were no significant differences in allograft or patient survival between the groups. There is no difference in allograft survival in pediatric kidney transplant recipients who receive a DCD kidney allograft. DCD kidney allografts are suitable for transplantation in pediatric patients and can greatly expand the donor pool.

Should more donation after cardiac death livers be used in pediatric transplantation?

INTRODUCTION

There is a mismatch that exists in donor liver organ supply and demand. DCD livers represents a potential source to increase the number of liver grafts available for use in pediatric recipients; however, there has been hesitancy to use such organs. We evaluated patient and allograft outcomes in pediatric liver transplant recipients of DCD livers.

METHODS

The UNOS database was queried to examine outcomes in all liver transplant recipients from 1993 to 2017. Patients were then divided according to adult and pediatric status, DBD or DCD allograft status, and era of transplant. Donor and recipient demographic data were examined, and patient and allograft survival were calculated. A P-value of <0.05 was considered to be significant.

RESULTS

A total of 57 pediatric recipients received a DCD liver allograft. DCD recipients were older than DBD recipients. There was no difference in the final PELD score between the groups. There were no differences in causes of allograft failure between the DCD and DBD groups. Importantly, the overall allograft survival in the DCD and DBD groups was similar, as was allograft survival based on era.

CONCLUSION

Pediatric liver transplant recipients of DCD allografts have comparable patient and allograft survival when compared to DBD allograft recipients. Use of DCD allografts in the pediatric liver transplant population should be strongly considered to increase the donor organ pool.

UK National Registry Study of Kidney Donation After Circulatory Death for Pediatric Recipients

BACKGROUND

Donation after circulatory death (DCD) kidney transplantation has acceptable renal allograft survival in adults but there are few data in pediatric recipients. The aim of this study was to determine renal allograft outcomes for pediatric recipients of a DCD kidney.

METHODS

Data were collected from the UK Transplant Registry held by National Health Service Blood and Transplant. Kidney transplants performed for pediatric recipients (age, <18 years) in the United Kingdom from 2000 to 2014 were separated into DCD, donation after brain death (DBD), and living donor (LD) transplants, analyzing 3-year patient and renal allograft survival.

RESULTS

One thousand seven hundred seventy-two kidney only transplants were analyzed. Twenty-one (1.2%) of these were from DCD donors, 955 (53.9%) from DBD donors, and 796 (44.9%) from LDs. Patient survival is 100% in the DCD group, 98.7% in the DBD group, and 98.9% in the LD group. Three-year renal allograft survival was 95.2% in the DCD group, 87.1% in the DBD group, and 92.9% in the LD group. There was no significant difference in 3-year renal allograft survival between the DCD and DBD groups (P = 0.42) or DCD and LD groups (P = 0.84). For DCD, the primary nonfunction rate was 5% and delayed graft function was 25%.

CONCLUSIONS

Children receiving a DCD kidney transplant have good renal allograft survival at 3-year follow-up, comparable to those receiving a kidney from a DBD donor or a LD. This limited evidence encourages the use of selected DCD kidneys in pediatric transplantation, and DCD allocation algorithms may need to be reviewed in view of this.

Global lessons in graft type and pediatric liver allocation: A path toward improving outcomes and eliminating wait-list mortality

Current literature and policy in pediatric liver allocation and organ procurement are reviewed here in narrative fashion, highlighting historical context, ethical framework, technical/procurement considerations, and support for a logical way forward to an equitable pediatric liver allocation system that will improve pediatric wait-list and posttransplant outcomes without adversely affecting adults. Where available, varying examples of successful international pediatric liver allocation and split-liver policy will be compared to current US policy to highlight potential strategies that can be considered globally. Liver Transplantation 23:86-95 2017 AASLD.

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

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

Renal transplantation in infants

Renal transplantation (RTx) has become an accepted mode of therapy in infants with severe renal failure. The major indications are structural abnormalities of the urinary tract, congenital nephrotic syndrome, polycystic diseases, and neonatal kidney injury. Assessment of these infants needs expertise and time as well as active treatment before RTx to ensure optimal growth and development, and to avoid complications that could lead to permanent neurological defects. RTx can be performed already in infants weighing around 5 kg, but most operations occur in infants with a weight of 10 kg or more. Perioperative management focuses on adequate perfusion of the allograft and avoidance of thrombotic and other surgical complications. Important long-term issues include rejections, infections, graft function, growth, bone health, metabolic problems, neurocognitive development, adherence to medication, pubertal maturation, and quality of life. The overall outcome of infant RTx has dramatically improved, with long-term patient and graft survivals of over 90 and 80 %, respectively.

The evolving potential for pediatric ex vivo lung perfusion

Despite the rise in the number of adult lung transplantations performed, rates of pediatric lung transplantation remain low. Lung transplantation is an accepted therapy for pediatric end-stage lung disease; however, it is limited by a shortage of donor organs. EVLP has emerged as a platform for assessment and preservation of donor lung function. EVLP has been adopted in adult lung transplantation and has successfully led to increased adult lung transplantations and donor lung utilization. We discuss the future implications of EVLP utilization, specifically, its potential evolving role in overcoming donor shortages in smaller children and adolescents to improve the quality and outcomes of lung transplantation in pediatric patients.

An echocardiographic measurement of superior vena cava to inferior vena cava distance in patients<20 years of age with idiopathic dilated cardiomyopathy

In normal pediatric echocardiograms, the distance from the junction of superior vena cava (SVC) and right atrium to inferior vena cava (IVC) and right atrium is linearly related to height. We examine this relation in children listed for heart transplant with idiopathic dilated cardiomyopathy (IDC) compared with the previously defined normal distribution of SVC-IVC to improve matching of heart sizes. Measurements of SVC-IVC and left ventricular end-diastolic diameter in 55 pediatric patients with IDC were correlated with height, weight, and body surface area. Regression analyses were performed to find the best-fit equation and correlation coefficient. Generalized linear modeling compared SVC-IVC in patients with IDC with normal SVC-IVC values from 254 patients. There was a strong linear relation in patients with IDC between SVC-IVC and height (R2=0.84) and a logarithmic relation to weight (R2=0.80). Left ventricular end-diastolic diameter did not correlate with SVC-IVC or any other parameter. In 87% of patients with IDC, SVC-IVC was over 2 SDs above predicted normal values (mean z-score=4.3±2.1). In conclusion, predicted SVC-IVC in patients with IDC was different from published norms (p<0.001). SVC-IVC in pediatric patients with IDC, although linearly related to height, is consistently above normal values.

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.

Pediatric organ donation and transplantation

BACKGROUND AND OBJECTIVES

There is increasing unmet need for solid organ donation. Alternative donor sources, such as donation after circulatory determination of death (DCDD), are needed. The objective of this study was to examine the impact of DCDD on trends in pediatric organ donation and transplantation.

METHODS

Data were obtained from the Organ Procurement and Transplantation Network for US organ recipients and donors from 2001 to 2010 stratified according to age, organ, and deceased donor type (DCDD or donation after neurologic determination of death). Additional data included transplant wait-list removals due to death.

RESULTS

From 2001 to 2010, pediatric organ transplant recipients increased from 1170 to 1475. Organs from DCDD donors were transplanted into children infrequently but increased from 1 to 31. Pediatric donation after neurologic determination of death decreased by 13% whereas DCDD increased by 174% (50 to 137). Recipients of pediatric grafts decreased from 3042 to 2751. Adults receiving grafts from pediatric donors decreased from 2243 to 1780; children receiving pediatric grafts increased from 799 to 971. Transplant recipients receiving pediatric DCDD grafts were few but increased annually from 50 to 128 adults and 0 to 9 children. Pediatric candidates dying waiting for an organ decreased from 262 to 110.

CONCLUSIONS

From 2001 to 2010, children received more solid organ transplants and fewer children died waiting. Organ recovery from pediatric and adult DCDD donors increased. The number of pediatric recipients of DCDD grafts remains small. Adults primarily receive the direct benefit from pediatric DCDD but other changes in organ allocation have directly benefited children.

ABO-incompatible lung transplantation in an infant

Waitlist mortality continues to be a limiting factor for all solid-organ transplant programs. Strategies that could improve this situation should be considered. We report the first ABO-incompatible lung transplantation in an infant. The recipient infant was ABO blood group A1 and the donor group B. The recipient was diagnosed with surfactant protein B deficiency, which is a fatal condition and lung transplantation is the only definitive therapy. At 32 days of age, a bilateral lung transplantation from a donation after cardiac death (DCD) donor was performed. Intraoperative plasma exchange was the only preparatory procedure performed. No further interventions were required as the recipient isohemagglutinins were negative before transplant and have remained negative to date. At 6 months posttransplant, the recipient is at home, thriving, with normal development. This outcome suggests that ABO-incompatible lung transplantation is feasible in infants, providing another option to offer life-saving lung transplantation in this age range.