The number of donor livers thrown away in the U.S. has increased since 2004 due - in part - to a population growing older and heavier, according to a new study that also points to changes in medical practice that may make some donor livers less viable.
"The rationale for looking at this question in the first place is that the number of liver transplants done in the U.S. has gone down," said the study's lead author Dr. Eric Orman, a fellow at the University of North Carolina at Chapel Hill.
To identify factors that might explain the trend, Orman and his colleagues used a national database of all organ donations beginning in late 1987 to see how many livers from donors of at least one organ were discarded, and why.
They found that the proportion of unused livers fell dramatically, from 66 percent in 1988 to 15 percent in 2004. After that, however, the percentage of unused livers began to rise again, hitting 21 percent in 2010.
Between 1988 and 2010, about 107,000 people donated their livers. Nearly 42,000 of those were after 2004. Of those post-2004 donations, about 33,900 livers were used and about 7,600 were not.
When the researchers, who published their results in the journal Liver Transplantation, looked at the differences between the livers that were used and those that weren't, they found a few possible links.
Specifically, livers from older, heavier and sicker patients were more likely to be thrown out between 2004 and 2010.