Liver Transplants: How Do We Choose Who Should Live When Not All
Can?
by Gregory W. Rutecki
With a scarce, non-renewable resource such as livers for
transplantation, shouldn’t the individuals who receive organs be the
persons who need them most? If recipients could be selected based on
need, allocation finally could be divorced from onerous criteria
such as social value. Since need in this context can be equated with
death (if life-saving treatment is withheld), the manner in which
recipients are chosen becomes paramount. On an existential level,
the question may be reduced simply to choosing who should live when
not all can.
This hard reality is simply a case of demand far outstripping
supply. There has been and continues to be a scarcity of donated
livers. In fact, nearly 17,000 patients were waiting for one in 2002
(up from 1,676 a decade earlier), while only 5,000 livers were
donated that year. As sick as those in need have been, their average
wait has increased from 65 to 795 days over ten years! Without a
liver, these people die at a rate estimated to be 10% (approximately
1,300 individuals) per year. Addressing justice in life-and-death
allocation decisions calls for a frank evaluation of the ethical
criteria applied. Considerations include durable concepts, both
positive and negative, such as “first come--first served,” medical
benefit, social value, progress of science, and favored groups.
Recent data has once again suggested that US transplant surgeons are
not providing a “level playing field” for liver recipients.1
It has been demonstrated, furthermore, that surgeons are
prioritizing their own patients, even when these individuals are
less in need than others. Why is this happening?
The Department of Health and Human Services has characterized the
development of just criteria for donation as a “final rule mandate.”2
Strong emphasis should be placed on consistent fairness when sharing
the “Gift of Life.” In fact, the Department issued recent
regulations to ensure “that allocation of scarce organs would be
based on common medical criteria, not accidents of geography.” This
concern represents two contentious issues. First, in the past, the
assessment of illness severity unjustly has included subjective
criteria. Second, disparity in the fairness of allocation across
geographic regions continues to be an issue.
The problem of subjectivity in the assessment of illness severity
seems to have been solved. Medical need can be determined by an
evidence-based score, an objective marker of severity. The score,
the Model for End-stage Liver Disease (or MELD), is calculated from
parameters indicative of liver function (serum creatinine, INR, and
bilirubin). The goal of MELD is to provide an objective,
medical-benefit standard in order to allocate livers justly. Studies
have documented the score’s utility; it identifies those persons who
most need a liver. The strategic endpoint of MELD scoring is to
identify for transplantation patients who will die within three
months rather than those who have been on the waiting list the
longest. “First come” should not always be “first served” in the
context of liver transplantation, because people on the list the
longest are not always the sickest.
Although not perfect, MELD is probably the most objective measure
available to prioritize recipients based on need. Following a study,
the United Network of Organ Sharing adopted MELD in February 2002.3
Has it worked? The simple answer is that medical benefit criteria
per se are no longer at the root of the distribution problem. The
current dilemma, so-called “accidents of geography,” which are the
direct result of disparately sized Organ Procurement Organizations (OPOs),
has not been managed adequately.
In the United States, variation in the size of geographic organ
allocation “areas” is a reality. As a result, one might say that the
existing OPOs are “bimodal.” From a number of persons served
standpoint, they tend to be either very large or very small. Donated
organs stay close to the region in which they are procured even if
“sicker” patients in other geographic areas are in greater need.
Small OPOs have a greater “per capita” supply of organs and fewer
people on their list. As a result, less critical patients may
receive a transplant more expeditiously. Conversely, large OPOs—those
in big cities with large medical centers—often have many critically
ill people waiting. Without a timely donation, more of their
critical patients die.
The Institute of Medicine has made two recommendations that should
affect the contemporary allocation question as it works toward the
goal of fairness. Regarding criteria for selection, they caution
that an objective score of illness severity, such as MELD, be
applied to everyone. Concerning geographic disparity, they strongly
suggest that OPOs should serve a population base of 9 million
people. Geography should not be the issue; rather, there seems to be
an optimal population size that would serve as a better criterion.
Data has demonstrated that a census of 9 million would speed
transplantation for sicker individuals, without adversely affecting
the “less sick” when they later desperately need a transplant.
Liver transplant recipients from February 28, 2002, through March
30, 2003 (4,798 individuals) were stratified by MELD scores.4
Comparing smaller to larger OPOs revealed disturbing results. The
proportion of patients receiving liver transplants with a “higher”
MELD score (i.e., “sicker”) was lower for the smaller (n=43) than
for the larger (n=400) OPOs (19% versus 49%). The bottom line is the
numbers demonstrated that recipients in smaller OPOs received organs
although they were not in as great a need as individuals in larger
OPOs. Despite the availability of the MELD score, sicker individuals
were not transplanted because organs were not shared adequately.
The solution—standardizing the OPO populations served at 9
million—should be the next step. Are there ethical downsides to a
gerrymander of OPO size? Smaller transplant centers may have to
close. This is not a prohibitive price to pay when lives are at
stake. Another concern, that patients in smaller OPOs may have to
travel farther to get care, may have some merit. However, travel
issues are easier to address than the present geographically based
disparity.
In All I Really Need to Know I Learned in Kindergarten, Robert
Fulghum indicated that sharing, a fundamental lesson to be learned
early in life, is an unequivocal societal good. It appears this
lesson is one that OPOs and transplant surgeons have yet to learn.
If the MELD score is to work, sharing across size-consistent OPOs
must be implemented. The Institute of Medicine was right. Let’s not
waste MELD, a score that finally may end the wrong of social
valuation in organ transplant allocation decisions. In the scheme of
things, adversely affecting the viability of small transplant
centers pales in comparison to continuing the present alternative
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