Save the Children: The Ethical Argument for Preferential Priority to Minors in Deceased Donor Liver Allocation

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Abbreviations

ET

Eurotransplant

MELD

Model for End‐Stage Liver Disease

NOTA

National Organ Transplant Act

PELD

Pediatric End‐Stage Liver Disease

UNOS

United Network for Organ Sharing

In 1984, the US Congress passed the National Organ Transplant Act (NOTA), which required that the US organ allocation system “assure equitable access by patients to organ transplantation and assure the equitable allocation of donated organs among transplant centers and patients medically qualified for an organ transplant.” ¹ NOTA specifically called for the “identification of barriers to donation of organs to patients (with a special emphasis upon pediatric patients).” The moral theory of organ allocation in our society is primarily focused around the core ethical principles of maximizing utility (efficiency) and just distribution of consequences (equity). ²

Ethical Principles of Pediatric Allocation

Although living donation has increased in recent years in the United States, ³ it remains insufficient to address the current demand. Without a robust nationalized health care system and widespread support of overall community health, any reliance on a living donation program would favor well‐resourced families and pose a significant dilemma from an equity perspective. For this reason, children continue to require consideration in deceased donor liver transplantation policy. In Transplantation Ethics, ethicists Robert Veatch and Lainie Ross ² summarize ethical justifications for prioritizing children on transplant wait lists (Table 1). Under the principle of medical utility, children should be prioritized because they would benefit from an organ for longer than many adults.

TABLE 1.

Ethics and Logistics of Pediatric Organ Allocation

Ethical Principle	Description
Prudential life span	In a situation with limited resources, resources should be “invested” in times of greatest development to yield greatest benefit (i.e., investing in earlier stages of life to benefit from schooling, training, starting a family)
Maximin principle	Resources should be allocated to those most vulnerable and giving the maximum benefit to those who have the least
Utility	Children have superior survival, extending the life‐years gained from transplant
Fair Innings	Children are deserving of the opportunity to experience more years of life

From the viewpoint of justice, using the benefit‐over‐a‐lifetime argument (Prudential Lifespan Account) and the maximin principle, children are worse off because they have developed end‐organ failure at a younger age. The youngest children with end‐stage liver disease have size limitations for organ acceptance, and they are less able to receive treatment for life‐threatening portal hypertensive bleeds. Due to their size, transjugular intrahepatic portosystemic shunt or endoscopic variceal band ligation may not be options. From the argument for “slice‐of‐time,” the end‐stage liver failure interferes with neurological development, nutritional development, and socialization, which is never recovered. In the white paper “Ethical Principles of Pediatric Organ Allocation,” published by the Ethics and Pediatric Transplant Committees of the United Network for Organ Sharing (UNOS) in November 2014, specific ethical principles underlying the necessity of pediatric priority in allocation are outlined. ⁴ In addition to the arguments specified earlier, the “Fair Innings” principle is described, which states that children should not be denied opportunities of reaching adulthood and completing their education, establishing a career, and having a family. It does follow that the “Justice‐over‐a‐Lifetime” argument would support that the younger the age of the person needing an organ, the higher their claim to it, and that the cutoff of 18 years of age creates an arbitrary dichotomy (Table 1). However, in the United States, there is established legal precedent for the designation of who qualifies as a child and specific policies in place for the protection of this vulnerable population. On moral and ethical grounds, there is little to argue against the prioritization of children in deceased donor liver allocation.

There are benefits to prioritizing children on the liver wait list for deceased donor liver allocation and clear ethical reasons in favor of doing so. Several countries and transplantation organizations worldwide have established a clear and organized practice of pediatric priority in liver allocation since the creation of their centralized organ transplantation systems. In some systems, this has resulted in increased organ utilization through technical variant grafts and collaborative splitting of liver grafts. There is a lack of consistent and clear prioritization of children awaiting liver transplantation worldwide. As opportunities to build infrastructure for deceased liver transplantation programs grow, attention toward identifying gaps in the application of ethical principles of pediatric organ allocation is of critical importance. Pediatric transplantation advocates worldwide have the obligation to study allocation systems and work toward equitable treatment of children worldwide.

Pediatric priority is an issue that deserves close attention and examination because of the nature of the strong ethical arguments in its favor. In this review, we will highlight specific ways in which children worldwide continue to be systematically stripped of priority as they fight to survive on the liver wait list.

Pediatric Priority Realized: The International Experience

Outside of the United States, pediatric liver transplantation and deceased donor liver allocation to children take place on all populated continents to varying degrees. Eurotransplant (ET), ScandiTransplant, Canada, Brazil, and independent programs in the United Kingdom have deemed the use of Pediatric End‐Stage Liver Disease (PELD) alone to be inadequate in giving priority to children on the liver waiting list. These organizations have modified Model for End‐Stage Liver Disease (MELD)/PELD assignment and allocation algorithms to adequately prioritize children. This priority recognizes the vulnerable status of children and the necessity for prompt transplantation in wait‐listed children.

In ET countries, a “pediatric MELD score” is calculated for each child. Additional priority is maintained for high‐urgency statuses: acute hepatic failure, graft failure following transplant, urea cycle defects, and nonmetastatic hepatoblastoma. The remaining patients younger than 12 years are assigned a score that corresponds to 35% wait‐list mortality risk in 3 months, and this score is upgraded every 90 days, to correspond to a 15% increased risk for 3‐month wait‐list mortality until transplant. The same process occurs for patients 12 to 16 years of age, but the point score corresponds to 15% wait‐list mortality rate and is increased by 10%. ⁵ Within the ET system, this reduced their mortality from 4 children/year to 1 child/year. ⁶ In Canada, France, and the United Kingdom, systems uniformly prioritize children above adults on the wait list. ⁷ Similar efforts in Brazil, where children younger than 12 years have their calculated PELD score multiplied by 3, led to increased rates of split‐liver transplantation and decreased wait‐list time. ⁸ In terms of utility, this ability to benefit both the small child and an adult via liver splitting further emphasizes the role that prioritizing children can accomplish.

A Work in Progress: Pushing For Pediatric Priority in Allocation in the United States

In the United States, liver allocation has significantly evolved over the last four decades. The system is overseen by UNOS, which has contracted with the Organ Procurement and Transplantation Network to oversee the allocation of deceased donor organs for transplantation. On February 27, 2002, the MELD and PELD scoring system was implemented, with the goal of using an objective formula to predict wait‐list mortality. The allocation algorithm, which prioritized local and regional adults over critically ill children, resulted in 25% of pediatric donor livers being offered to adults without ever being offered to a child, despite a persistent 7% rate of mortality on the pediatric wait list. ⁹ Although this rate of mortality is lower than that of all adults (13%), inclusive of the >70% of recipients who are listed as older than 50 years, ³ this rate of preventable pediatric mortality is unacceptably high, particularly when more than 300 grafts from pediatric donors are transplanted into adults every year (Fig. 1). Multiple studies using national registry data have been published that have shown that the PELD score does not adequately represent risk for wait‐list mortality in comparison with adults. Despite this knowledge, the PELD score has not been modified since it was instituted in 2002. ¹⁰ , ¹¹

FIG 1.

Recipients of liver grafts from deceased donors younger than 18 years, 2010 to 2018. Scientific Registry of Transplant Recipients, queried July 2020. Courtesy Dr. James Perkins, Clinical and Bio‐analytics Transplant Laboratory (CBATL), University of Washington School of Medicine.

In February 2020, with the implementation of Acuity Circles for all deceased donor liver allocation, a new allocation algorithm for deceased donor livers from children was introduced. After offers to children within a 500‐nm circle, the donor is offered to all children on the list nationally before being allocated to adults again within the circle. ¹² Although an improvement in favor of pediatric priority for pediatric deceased donor livers, this update does not address the inadequacy of the PELD score in predicting wait‐list mortality in comparison with the MELD score for adults, nor does it prioritize children on the wait list for deceased donor livers from adult donors. With the advent of technical variant graft use, these deceased donors are optimal up to 40 years of age.

Immediately prior to this change, after almost two decades of linear increase of exception applications for pediatric recipients on the wait list, ¹³ a National Liver Review Board for Pediatrics was implemented to replace the Regional Review Board review of applications (Table 2). ¹⁴

TABLE 2.

Opportunities to Provide Pediatric Priority to Children on the Liver Wait List Within the US Organ Allocation System

Proposal	Status
Prioritizing pediatric wait‐list candidates nationally for pediatric‐aged deceased donor livers	Implemented by UNOS February 4, 2020
Prioritizing pediatric wait‐list candidates for deceased donor livers <40 years of age	Not implemented
Adjusting PELD score for equivalent risk for mortality to adults	Not implemented
Continuous distribution: weight given to pediatric wait‐list candidates	Currently under discussion

The Role of Children in Shaping Societal Attitudes Toward Organ Donation

Organ donation attitudes and decisions, particularly in the case of parents who are making these decisions on behalf of their deceased child, can be influenced by the age of the potential recipient. In one US study of parents of pediatric deceased organ donors, although the majority of parents were satisfied with the decision to donate their child’s organs, those who regretted consenting reported being angry that one or more of their child’s organs were transplanted into an elderly recipient, or when the recipient of their child’s organ had died. ¹⁵ Societal attitudes toward organ allocation worldwide are often weighted to save as many lives as possible by maximizing success for organ transplantation, which favors priority for children not only from a utility perspective but also as a vulnerable population that requires special protections. ¹⁶

A Path Forward

The international pediatric liver transplant community continues to propose and support pediatric priority while promoting a variety of increased organ‐utilization strategies (Table 3), including: (1) mandatory liver splitting, (2) extended criteria donors, (3) donation after circulatory determination of death, and (4) living donation. Another critical opportunity to develop more clear priority within the US allocation system will be to determine the appropriate weight given to pediatric patients within a “Continuous Distribution” framework for organ donation. In the United States, the continuous distribution framework has been approved as a principle for more transparent/outcome‐driven and less geography‐based organ allocation. To protect and serve future generations of children on the liver wait list, it will be critically important for pediatric advocates to highlight the established ethical principles of pediatric organ allocation and raise their collective voice in this moment. ¹⁷

TABLE 3.

Strategies Used to Prioritize Children for Liver Transplantation: The International Experience

System	Strategy for Pediatric Prioritization
Eurotransplant	Children <16 years of age receive allocation score equivalent to 35% 3‐month mortality rate with automatic 15% monthly increase until transplanted 6
Canada	Children with chronic liver disease assigned 24 points, with an additional 3 points assigned every 3 months to a maximum of 39 points (or calculated score, whichever is greater) 18
Brazil	Calculated score is multiplied by 3 if the candidate is <12 years of age 8