Online Aspen Webinar (Part 7) -Liver Organ Allocation

Below I’ve included a few slides and some notes from recent Aspen Webinars; my notes may have errors of omission or transcription.

Key Points:

  • The new allocation policy tries to make liver organ allocation more equitable in terms of disease acuity at time of transplantation and access to allografts
  • The changes, based on some preliminary data, appear to improve the likelihood of children receiving needed organs. Dr. Bondoc specifically cited the work of Dr. John Bucuvalas in pointing out some of the systemic ways that the previous system disadvantaged children.
    • Infants are at the greatest risk on the wait list.  Yet, successful transplantation in children could be beneficial for many decades
    • PELD underestimates mortality risk
    • 25% of pediatric donors have historically gone to adults


Related blog posts:

Pediatric Livers Bypassing Needy Children

A recent study (J Ge, EK Hsu, J Bucuvalas, JC Lai. Hepatology 2019; 69: 1231-41) provides data showing that current liver allocation policy allow pediatric donor organs to bypass desperately ill children in favor of adult liver transplant recipients. The authors utilized national registry data over a 5-year period to follow the allocation of pediatric liver donor organs.

Key points:

  • About 60 children (~12% of waitlist candidates) die awaiting liver transplantation each year
  • From 2010-2014, 3318 pediatric donor livers were transplanted; 45% of these organs went to adults.
  • 390 of the 1569 adult recipients received a pediatric organ that was NEVER offered to a child
  • In this group of 390, 71% of these adults were lower acuity with MELD <35 and non-status 1A.

These data identify a deviation from the policy goal that pediatric organs are offered first to pediatric recipients.

My take: this study adds more data showing that children <12 years of age are disadvantaged with current allocation policies.  This is despite the fact that children have lower posttransplant mortality, indicating that organ transplantation is more likely to be truly life-saving in children.

Related blog posts:

Near Chattahoochee River, Atlanta

More on It’s Past Time to Split

In followup to this morning’s post, Pediatric Liver Transplantation: It’s Past Time to Split, one reader pointed out an abstract by Emily R. Perito et al.presented at this year’s AASLD which showed that pediatric deaths would decrease if more livers were split.


Increasing split liver transplantation in the U.S. could decrease pediatric deaths on the liver transplant waiting list

Emily R. Perito1,3, Garrett Roll2, Jennifer L. Dodge2,

Background: In the United Kingdom, defaulting to split liver transplantation (LT) with suitable deceased donor grafts has virtually eliminated pediatric waitlist (WL) mortality. In the US, only <2% of LTs are split, but 1 in 10 infants die on the WL.

Methods: Using UNOS STAR data, livers for potential split LT were identified from all transplanted, deceased-donor livers 2010-15 who fit strict criteria: age 18-40y, BMI<30, recovered in US after donor brain death, 0-1 vasopressors, a <155meq/L, AST/ALT<100IU/L, bilirubin<3mg/dL, <7d hospitalized, cardiac arrest≤30min, HBV/HCV neg, not CDC high-risk, steatosis≤10% if biopsied, not multi-organ transplant, and no bloodstream infection. Livers allocated to patients high-risk for split LT were also removed: status 1A or MELD/PELD≥40 at WL removal, re-transplant, in the ICU, BMI>34, or >300mi from donor hospital. Pediatric WL deaths included deaths and removals for too sick to transplant, never relisted.

Results: Of 35,461 livers transplanted 2010-15, 6.7% were potentially utilizable for split LT based on donor characteristics. Of these, 95% were transplanted whole (n=2,253). 50% went to recipients deemed possibly high-risk for split LT. This left 1,116 potential livers for split LT (FIGURE); 78% of their primary recipients were listed as willing to accept a segmental liver, and 97% to accept cold ischemia time≥6h (CIT, median 12h). Median donor risk index for this subset was 1.06 (max 1.67). During the same 5y, 261 children died after ≥3d on the WL (median 57d, IQR 15-161)—87% of all pediatric WL deaths. Of these, 56% were <2y of age, 26% 2-12y, 18% 13-18y. Median weight was 9.2kg (IQR 5.9-29.4kg). 36% died at centers that reported doing no pediatric split LTs (15%) or ≤1/year (22%).

Conclusions: Increased utilization of split LT could decrease US pediatric WL mortality—without decreasing LT access for adults. Barriers are significant, but changes to  allocation policy, increasing centers with splitting experience, and splitting on normothermic perfusion could increase access and reduce WL mortality.

Jose Garza, Chelly Dykes, Elvis, and Jay Hochman at Cincinnati Children’s Reception

Lack of Survival Benefit With MELD Exception Points in Hepatocellular Carcinoma

Briefly noted:

Another study also looks at transplant utility by showing the use of MELD exception points for hepatocellular carcinoma provides almost no survival benefit: K Berry, GN Ioannou. Gastroenterol 2015; 149: 669-80, editorial 531-34.    The article states that the “survival benefit of patients with HCC was similar to that of patients without HCC who had the same actual MELD score…a much lower mean 5-year survival benefit was achieved by providing liver transplants to patients with HCC (0.12 years/patient) than patients without HCC (1.47 years/patient).”

How is this possible?

When patients are transplanted at lesser illness acuity, it takes longer to achieve a transplant benefit because they can live longer without a transplant.  In essence, the survival clock starts ticking much later than the transplant date.

Why this is important (from editorial):

The proportion of patients undergoing liver transplantation for HCC has increased from “4.6% before the introduction of MELD exception to 16.5% currently.” And, “the results, put simply, suggest that allocating donor livers and performing liver transplantation in patients with HCC MELD exception points produces almost no survival benefit.”

My take: Liver allocation policies need to be modified.  This study suggests that prioritizing HCC patients does not make much sense.

Atlanta Botanical Garden

Atlanta Botanical Garden