“The donor process is safer than some have previously thought,” says transplant surgeon Dorry L. Segev, M.D., Ph.D., an associate professor of surgery and epidemiology at the Johns Hopkins University School of Medicine and leader of the study published in the February issue of the journal Gastroenterology. “Live liver donation is a serious operation with serious risks. However, in this largest study ever conducted in the United States, we have shown that it is safer than many previously believed, with a risk of death of 1.7 per thousand donors.”
The only treatment for end stage liver disease is transplant. Without a functioning liver, patients in liver failure die. Safe live liver donation is possible because the liver is an organ that regenerates itself relatively quickly, Segev notes, allowing the harvest of a small portion of the organ which, when transplanted, grows into a liver large enough to perform its crucial roles in blood detoxification, digestion and metabolism. The regenerative ability also means donors can survive well with a smaller segment of their own livers until they, too, regrow.
A decade ago, surgeons across the United States performed an estimated 500 live liver transplants a year. In 2002, however, there was a highly publicized death of a live liver donor. Since then, live liver donation may have been perceived as more dangerous than it actually is, Segev says, and now only 200 to 300 of these surgeries are performed annually, compared to 6,000 live kidney donations in the United States each year.
More than 16,000 people are currently on the waiting list for a liver transplant in the United States, while only around 6,000 livers are available from deceased donors. “For many, the risk of dying on the waiting list is higher than the chance of getting a deceased donor transplant," Segev says. "For the right patients, with the right needs and the right donors, live donor transplantation can be the best treatment option, and this study reassures us that the risk of a catastrophic complication remains low.”
To determine the safety of live liver donation, Segev and his colleagues combed data from all 4,111 donors in the United States between April, 1994, and March, 2011, and followed patients for an average of 7.6 years. There were seven donor deaths over the period in the 90 days following surgery, but the researchers say the long-term survival rate for donors was overall equal to the long-term survival of live kidney donors and a healthy control group culled from the National Health and Nutrition Survey.
Although the rate of live liver donor death was relatively low, Segev says it is still five times that of the risk of death for live kidney donors. A study by Segev published in the Journal of the American Medical Association in March, 2010, found that the rate of death in live kidney donation in the United States is 3.1 in 10,000. However, kidney donation is a simpler process, Segev notes. The operation itself is less complicated and kidney donors are left with one completely intact healthy kidney, which is typically able to compensate for the function of the one that is removed. By contrast, if a donor does not have enough healthy liver remaining after donation, he or she may not have enough liver function to get through the regeneration process, and might actually need a transplant to survive.
Segev says he was particularly interested in studying the outcomes for donors because most of those who offer to give up part of an organ come to the process very healthy. “The ideal risk of death from donating an organ is zero and we work as hard as we can to seek that ideal,” says Segev, director of clinical research in transplant surgery at Hopkins. “But in these serious, major operations, it is unlikely the risk will ever be zero.”
Other Hopkins researchers involved in the study include Abimereki D. Muzaale, M.D., M.P.H.; Nabil N. Dagher, M.D.; and Robert A. Montgomery, M.D., D.Phil.
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