Transplant Medicine

Nov. 12, 2021

Mayo Clinic's campus in Rochester, Minnesota, launched two new liver transplant programs, expanding patients' transplant possibilities. Both programs involve living donation:

• A nondirected liver program, which is liver donation to any needy patient — a stranger
• Paired exchange, also called paired-organ donation, in which a transplant center pairs donors who aren't matches for their chosen recipients with other donor and recipient pairs for whom they are a match

Living donation benefits

Timucin Taner, M.D., Ph.D., a transplant surgeon at Mayo Clinic's Minnesota campus, is excited about the potential these living-donor programs bring to patients needing liver transplants.

"There aren't enough livers to transplant," says Dr. Taner. "There's been a pretty steady large demand for livers to be transplanted into patients on the waiting list. Living donation gives loved ones a chance to be generous to another loved one."

In the U.S., most liver transplants come from deceased donors. Although the number of deceased donors has been increasing in recent years, it is still outpaced by the number of people added to the liver transplant waiting list every year.

Living-donor transplants are more popular in Asia, where the medical community has met the need for livers by encouraging this type of transplant, according to a 2013 article published in Nature Reviews Gastroenterology & Hepatology. U.S. transplant surgeons have been performing increasing numbers of living-donor liver transplants, with 5% of liver transplants nationwide currently coming from living donors.

Dr. Taner notes that some recipient complications may be slightly more common after living-donor liver transplants compared with deceased-donor liver transplants. Nonetheless, he feels that this type of transplant far surpasses alternatives for some patients.

"Receiving a living-donor transplant is simply lifesaving, because the alternative is dying," says Dr. Taner. "Patients who are considered for this type of transplant typically have lower Model for End-Stage Liver Disease (MELD) scores, so they're a low priority for receiving a deceased-donor liver. MELD score factors in only four blood tests, which excludes consideration of ascites or other concerning symptoms."

He explains that the MELD system especially disadvantages females needing livers, as their lower creatinine scores downgrade their priority scores.

Nondirected donation

Mayo Clinic is opening doors for nondirected liver donation, in which donor and recipient don't know each other. Dr. Taner explains that although transplant centers have accepted nondirected kidney transplant donations for years, this transplant type is newer for livers. The reason living kidney donation has been around longer is the lower risk involved compared with liver living donation. Liver donation incurs 10 times the risk of kidney donation, he explains.

Though the timing of the nondirected liver transplant program launch wasn't related to COVID-19, once Mayo Clinic implemented the program, the pandemic delayed nondirected donor requests.

Dr. Taner says nondirected liver transplant donors are amazing, altruistic people who want to do good for someone else. They typically are routine blood donors; many have already donated a kidney.

Before the transplant surgeries, nondirected donors and recipients do not meet. Dr. Taner explains that while the transplant center doesn't discourage these parties from meeting after their surgeries, the center doesn't facilitate meetings.

Paired liver exchange

Mayo Clinic also now offers paired liver exchange — sometimes involving several pairs — to solve donor and recipient mismatch challenges. This living-donor matching method provides a transplant avenue long before a recipient might receive a deceased-donor transplant. Family members or friends may desire to donate a liver to loved ones who need transplants, but they simply aren't a match.

To address this issue, United Network for Organ Sharing piloted a paired exchange program, bringing together a potential donor and recipient pair who don't match with a donor and recipient pair who make a match for each. Each pair's donor is compatible with the other pair's recipient. All paired exchange participants must approve the process before it can proceed. Usually, these pairs don't know one another.

"Let's say you are donating a liver to a friend and you two aren't compatible," says Dr. Taner. "Someone in New York wants to donate to his wife, but they are incompatible. This solves that problem by bringing together two donors and recipient sets so we can make a match."

Liver donation specifics

When individuals donate a liver, they can gift up to 70% of it: left or right lobe, or a left lobe section. Transplant surgeons recommend the liver amount and section for transplant, considering donor anatomy and recipient need. The liver regenerates in three weeks. Thus, a liver donor isn't living with less liver, which differs from a kidney transplant donor missing an organ permanently.

Mayo Clinic Transplant Center staff explains all this information along with the rest of the liver transplant process, including potential complications, to donors and recipients. The entire liver donation process takes about two months.

How to refer a patient or donor

Physicians caring for patients requiring liver transplants — including transplant centers that don't perform living-donor transplants for recipients with low MELD scores — may refer patients to Mayo Clinic. Physicians also may refer potential donors interested in exploring nondirected donation. To refer, physicians may call (800-533-1564) or complete an online referral.

For potential nondirected donors, the first step is filling out a health history questionnaire online.

Dr. Taner sees a referral to Mayo Clinic Transplant Center as the start of collaborative care for a patient. "Referred patients are mutual patients," he says. "We're in constant contact with their hometown referring physicians."

For more information

Chen, C-L, et al. Why does living donor transplant flourish in Asia? Nature Reviews Gastroenterology & Hepatology. 2013;10:746.

Online Health History Questionnaire. Mayo Clinic.

Refer a patient to Mayo Clinic.