Share 35 was implemented by the United Network of Organ Sharing (UNOS) in 2013 to offer livers to both local and regional patients on the waitlist with MELD scores of 35+, those considered to be most in need. During Saturday’s Transplant Surgery Workshop, David Goldberg, MD, MSCE, Assistant Professor of Medicine and Epidemiology at the University of Pennsylvania, discussed some of the latest research about the Share 35 program.
“[Share 35] was implemented because there was data showing that highest waitlist mortality was for patients with the highest MELD scores,” Dr. Goldberg said. Based on published data, a model predicted that with a cut point of 35 there would be 80 fewer waitlist deaths with this program. In addition, the goal was to minimize excess travel of surgeons and organs.
Data has shown that Share 35 seems to have achieved its stated goal of increasing regional shares to patients with the highest MELD scores. A 2015 study showed that, prior to Share 35, sharing of adult deceased donor liver transplants was 77.9% locally and 19.1% regionally compared with 65.6% locally and 30.7% regionally post-Share 35 (P < .001 for both). Share 35 has also increased the number of organ offers to patients with the highest MELD scores. However, Dr. Goldberg noted that the increase in transplants had nothing to do with Share 35 itself, but rather an increased number of transplants across all organ groups in the United States.
Despite these benefits, there has also been some harm from the program, according to Dr. Goldberg. Although the goal was to have 80 fewer waitlist deaths, the 2014 Scientific Registry of Transplant Recipients’ Annual Report showed that the number of waitlist deaths has increased every year.
“This increase may not be from Share 35, but clearly there has not been a decrease in waitlist deaths under Share 35,” Dr. Goldberg said.
Under the new plan there has also been a lot of travel for organ donation for minimal difference in severity of illness. A 2016 study by Chow et al showed that, for example, in California, organs or surgeons were being flown for a difference in MELD score of only two points.
“This is important because while 35+ are the sickest [patients], it is arguable that a MELD 33 person is still quite ill,” Dr. Goldberg said.
That means that there may have been some unintended consequences for patients with MELD scores of 30 to 34. Chow et al also looked at what happened to the highest local patient who was passed over because there was a regional MELD 35+. In Regions 2 and 11, there was a very high mortality rate for the MELD 30-34 patients because of the higher prioritization of the regional candidate.
“Share 35 was a national policy that led to a lot of changes for all centers but really benefited only a very small number of centers,” Dr. Goldberg said. Recently presented data at the American Society of Transplant Surgeons Winter Symposium showed that two-thirds of the increase in MELD 35+ transplants were concentrated to only 10 centers.
Early analysis of post-transplant survival showed that there was no change in survival post-Share 35, but these data were limited, he noted. Additional research has shown that on a national level survival is not different in the post-Share 35 era, but this is not uniform. In regions 4 and 10, there was significantly worse survival for MELD 35+ patients, suggesting that “we have comprised post-transplant outcomes with this policy.”
Finally, data suggest that post-Share 35 changes in physician behavior has led to decreased organ acceptance rates for the sickest patients.
“In the pre-Share 35 era surgeons were more likely to accept organs for the MELD 35+ patients because a limited number of organs were being offered,” Dr. Goldberg said. “After Share 35 things went the complete opposite direction with surgeons less likely to accept organs even though the organs that they ultimately transplanted were the same quality.”