In the previous entry, we discussed the transplant process for heart and lung. Today, we will continue our discussion with liver and kidney transplants.
LIVER
The organ allocation policy currently in use went into effect in 2020.
MELD, the Model for End-Stage Liver Disease, is a numeric scale, ranging from 6 (less ill) to 40 (gravely ill). Used for transplant candidates aged 12 and older.
MELD scores can change over time based on the transplant candidate’s disease progression. Candidates will have their score recalculated over time to ensure it reflects their current condition. At higher levels of medical urgency, scores will be recalculated more frequently (every 30 days to every 7 days, depending on the most recent score).
Some liver transplant candidates have a medical condition that is highly likely to lead to death very soon without a transplant. The very sickest candidates are listed either in a Status 1A or Status 1B category. These statuses receive the highest priority for matching organs.
There are only a handful of Status 1A liver transplant candidates nationwide at any given time. These are candidates who are expected to live less than seven days without a transplant, and they must meet very specific criteria outlined in OPTN policy. Examples of Status 1A conditions are having no functional liver, having a sudden, severe onset of liver failure, or receiving a previous liver transplant that fails to function within seven days.
There may be a few dozen Status 1B liver transplant candidates nationwide at any given time. They are all younger than age 18 or were younger than 18 when listed for a transplant. They either have a specific diagnosis meeting requirements in OPTN policy or have a very high MELD score with severe complications. Policy changes to Liver allocation are taking effect in July 2023. A webinar reviewing those changes is available here: Patient Family Webinar
KIDNEY
Over 90,000 people are currently waiting for a kidney transplant in the United States. Updated kidney and pancreas policies took effect in 2021, but the policy is still undergoing changes.
Under the current policy deceased donor kidneys will be offered first to candidates listed at transplant hospitals within 250 miles of the donor hospital. Offers not accepted at any of these hospitals will then be made for candidates beyond the 250-mile radius.
Candidates will also receive proximity points based on the distance between the transplant center and the donor hospital. Proximity points are intended to improve the efficiency of organ placement by giving priority to candidates listed at transplant centers that are located closer to the donor hospital. Candidates within the initial 250-mile radius will receive a maximum of two proximity points, while those outside the initial circle will receive a maximum of four proximity points. Proximity point assignment will be highest for those closest to the donor hospital and will decrease as the distance increases.
In the new system, proximity points will be calculated into the total allocation score. Within the 250-mile radius, candidates will be ranked using a total score including a maximum of two proximity points. Once 250 NM classifications have been exhausted, candidates in national classifications will be ranked using a total score including a maximum of four proximity points. Candidates registered at transplant hospitals that are located more than 2,500 miles from a donor do not receive any proximity points. This graphic shows an example of how proximity points impact allocation for candidates inside and outside the circle: inside outside circle and proximity points (hrsa.gov)
Link to interactive map with visualization of 250-mile radius around selected transplant centers. KIDNEY ALLOCATION PROPOSAL MAPS
UNOS is currently working on a program to prioritize prior living donors in the organ allocation process for kidney recipients. This has already been implemented for lung recipients. You can read an excerpt of the UNOS statement, dated March 16, 2023, below:
“We wish to assure the community that the OPTN Kidney Transplantation Committee intends for both prior and future living donors to receive the same level of priority for a deceased donor organ in the new framework as they receive in the current allocation system. The final policy proposal for continuous distribution of kidneys is still being developed and we appreciate every public comment that we have received to aid in its creation. All feedback shared in public comment is considered in the overall policy development process. We are especially grateful for the patients, families, and living donors who take the time to share their perspectives . . . Being a prior living donor is a significant aspect of a person’s medical history, like being biologically harder to match. That’s why these characteristics are intended to be prioritized under continuous distribution of kidneys.”
Link to full statement: UNOS statement on kidney continuous distribution policy in development – UNOS
CONTINUOUS DISTRIBUTION – THE FUTURE FOR ALL ORGANS
The organ donation and transplant community is working together to introduce a new framework called continuous distribution. A continuous distribution framework will ensure that no single factor determines a patient’s priority on the waiting list. View a couple brief videos explaining continuous distribution here: How is continuous distribution different from the current system?
Continuous Distribution – Public
As mentioned in the previous post, the allocation of lungs has already migrated to the Continuous Distribution model, and kidneys will be the next organ to move to this system. Over time, it is expected that all remaining organs will be allocated in this manner.
Dawn Levitt, Author 