一项肝移植前后的比较报告(2005.2)

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From Alimentary Pharmacology & Therapeutics

A Comparison of Liver Transplantation Outcomes in the Pre- vs Post-MELD Eras

F. Kanwal; G.S. Dulai; B.M.R. Spiegel; H.F. Yee; I.M. Gralnek

Summary and Introduction
Summary
Background: The model for end stage liver disease (MELD)-based organ
allocation system is designed to prioritize orthotopic liver transplantation
(OLT) for patients with the most severe liver disease. However, there are no
published data to confirm whether this goal has been achieved or whether the
policy has affected long-term post-OLT survival.
Aim: To compare pre-OLT liver disease severity and long-term (1 year)
post-OLT survival between the pre- and post-MELD eras.
Methods: Using the United Network of Organ Sharing database, we compared two
cohorts of adult patients undergoing cadaveric liver transplant in the
pre-MELD ( n = 3857) and post-MELD ( n = 4245) eras. We created
multivariable models to determine differences in: (i) pre-OLT liver disease
severity as measured by MELD; and (ii) 1-year post-OLT outcomes.
Results: Patients undergoing OLT in the post-MELD era had more severe liver
disease at the time of transplantation (mean MELD = 20.5) vs. those in the
pre-MELD era (mean MELD = 17.0). There were no differences in the unadjusted
patient or graft survival at 1 year post-OLT. This difference remained
insignificant after adjusting for a range of prespecified recipient, donor,
and transplant centre-related factors in multivariable survival analysis.
Conclusions: Although liver disease severity is higher in the post- vs.
pre-MELD era, there has been no change in long-term post-OLT patient or
graft survival. These results indicate that the MELD era has achieved its
primary goals by allocating cadaveric livers to the sickest patients without
compromising post-OLT survival.

Introduction
Although the model for end stage liver disease (MELD)-based organ allocation
system is designed to prioritize orthotopic liver transplantation (OLT) for
patients with the most severe liver disease, there are no published data to
confirm that this goal has been achieved. Specifically, there has been no
previous attempt to measure whether liver disease severity at the time of
OLT is higher in the post- vs. pre-MELD era. Nonetheless, assuming that the
MELD era has indeed allowed sicker patients to be transplanted sooner,[1,2]
a plausible assumption would be that post-OLT outcomes are now worse
compared with the pre-MELD era. However, recent data do not bear this out as
they demonstrate unchanged 3-month patient and graft survival in the post-
vs. pre-MELD eras.[1] Given that pre-OLT liver disease severity is the most
important determinant of post-OLT outcomes,[3,4] there appears to be a
disconnect between the purported increase in pre-OLT severity and the lack
of change in post-OLT outcomes. The source of this apparent disconnect is
unclear. Potential explanations might include: (i) pre-OLT liver disease
severity is not a predictor of post-OLT outcomes; (ii) transplant recipients
are, in fact, not sicker in the post- vs. pre-MELD eras; (iii) post-OLT
outcomes have indeed worsened but have not yet been detected as reported
outcomes have been limited to only 3-month post-OLT.

The first explanation is unlikely given the extensive validation to the
contrary.[3,4] The remaining two explanations are plausible and have not
been systematically appraised. The MELD based system prioritizes patients
with more severe liver disease. The MELD system also prioritizes patients
with renal insufficiency, and patients with hepatocellular carcinoma. All
these factors are associated with decreased patient and graft survival.[3-6]
In light of these, our aim was to reassess the contention that sicker
patients are receiving cadaveric livers and that the post-OLT outcomes are
stable in the post-MELD era. We therefore sought to test the hypotheses
that: (i) pre-OLT liver severity is higher; and (ii) post-OLT patient and
graft survival are lower in the post- vs. pre-MELD era. To test our first
hypothesis, we performed a multivariable analyses in over 8000 orthotopic
liver transplant recipients using the United Network of Organ Sharing (UNOS)
liver transplant database to determine whether the mean pre-OLT liver
disease severity increased in the post-MELD era compared with the pre-MELD
eras. To test our second hypothesis, we conducted a multivariable survival
analysis to determine whether 1-year patient and graft survival worsened in
the post-MELD era compared with the pre-MELD eras.

FULL TEXT: http://www.medscape.com/viewarticle/498545_1