Liver transplantation might become more equitable under an allocation program being considered by the United Network for Organ Sharing (UNOS) and the Organ Procurement and Transplantation Network (OPTN).

The proposed plan, which will be released for public comment on Aug. 17, would change the geographic regions in which livers are allocated throughout the U.S. Under the current system, the country is divided into 11 different regions, and organs are allocated within each region based on how sick the patients on the transplant list are.

However, the regions vary greatly in terms of size and also vary a lot in terms of how many patients are waiting for transplants and how many potential donors there are, explained Ryutaro Hirose, MD, chair of the Liver and Intestinal Committee at OPTN, on a call with reporters.

In addition, the degree of illness that's required to get a transplant -- which is determined based on a 40-point scale known as a MELD score -- varies greatly from region to region. "In some areas of the country, you have to reach MELD score of 35 -- those are patients who are extremely ill and usually will die within a week," explained Hirose, who is also an organ transplant surgeon at the University of California San Francisco.



"Whereas in some areas, you have to have a score of 23, and those folks are sitting at home and we have to call them in for a transplant." As a result, there is as much as a 60% difference by geographic area in the rates of death within 3 months among patients who don't receive a transplant.

From 11 Regions to Eight
Under the proposed changes, the country would be divided up into eight regions. The sickest patients would continue to have the highest priority, Hirose said. "When we re-draw the lines, it actually matches better with organ supply and demand, and encourages better access." UNOS and OPTN employed a firm that used mathematical modeling "to select the best solutions that met the goals of decreasing this inequity within certain boundaries ... and to help with practical issues such as decreasing the amount of transport time to get a liver from one part of a district to another, and to make sure that any solution we came out with did not increase the number of waitlist deaths."

The map was also modified so that in places where a donor hospital is located, transplant candidates who are in a 150-mile "proximity circle" will get more priority on the list, "and that will keep organs from flying long distances for very small differences in the MELD score," Hirose explained.

If no patient in the geographic region needs or wants the liver, then UNOS and OPTN will prioritize the sicker patients nationwide by their MELD score, "from 40 all the way down to 29," to see if any of them could use it, Hirose said. "Then we would go back to more local distribution for less sick patients and then go back to a wider district and national distribution should no one want that liver or [if there were] nobody who could use that liver within the higher categories."

The model found that the variance in median MELD score required for a transplant would be cut in half by the new system, from 6.2 points to 2.9 points. It also found that pre-transplants deaths would not increase, and that 95% of transplants would take place within the assigned geographic area. Researchers did find that there would be an overall 2% decrease in the number of transplants performed, but "[they] have told us this was probably a very low reliability number," Hirose added.

Less Transplant Travel?
Hirose told MedPage Today that the new map could potentially reduce the issue of having some patients get an unfair advantage by moving from one area of the country -- where a higher MELD score is needed for a transplant -- to another area that has a lower required MELD score, something that the late Apple CEO Steve Jobs did.

"There are a fair number of patients who have the resources to move from one area of the country to another," he noted. "In some areas you only have to have a MELD score of 20 or 23, while within others, like where Steve Jobs came from, you have to have a score of 35. It's completely legal and within our policy to have folks multiple list ... [But] that really disadvantages folks without resources that can't travel."

In addition, there is also the insurance issue. "Folks with Medicaid are never going to be covered to have a transplant done somewhere else where the liver supply is much better, so you have an exacerbation of a very two-tiered system," said Hirose. "That's a different disparity -- not just where you live, but how much money you make and how well-insured you are."

The new map would mean that patients in some regions would need higher MELD scores than before in order to receive a transplant, so some people have raised the issue of whether more livers will be wasted on sicker patients who will end up dying even with a transplant. "Right now that hasn't happened in any of the allocation policies that could potentially do that; we haven't seen that yet," he said. Instead, "we've had better and better outcomes since the MELD score was put in place" to determine patient priority.

Other Issues Being Considered
The committee is also looking at several other issues; one involves the review boards in each region that decide whether to grant exceptions to the priority system to allow liver transplants for patients whose severity of illness might not be accurately reflected by their MELD score. The regional boards vary in the number of cases they get, how they review them, and how often they approve exceptions.

"So a related but separate proposal we are putting forth is the creation of a national review board to make more consistent, across the board and across the country, how these practices are done," said Hirose.

Another thing the committee is looking at is adjusting the number of MELD points patients with liver cancer get, he added. "Right now, patients with liver cancer are a little more advantaged than folks that don't have liver cancer, and we want to make sure we're giving everyone a fair opportunity to go ahead and get a liver transplant."

The comment period on the proposals will remain open until Oct. 14; final proposals will then be drafted and another comment period opened in January.