The list of people waiting for a lifesaving organ transplant is more than 113,600 names long,1 and every 10 minutes, another person is added to the list.2 Many people will wait months or years for a suitable organ, and some will not survive long enough to get a transplant. According to data from the U.S. Department of Health and Human Services, each year, the number of people listed for transplant continues to be much larger than both the number of donors and transplants.3 This is why innovative ways to not only widen the available pool of organ donors, but also keep people waiting for transplants alive longer, are so important.
Kidneys are the most commonly transplanted organ, and the number of people on the wait list for a donor kidney far surpasses that of any other organ. Nearly 95,000 are waitlisted for a kidney,4 and most of these people will wait about four years to receive a kidney from a deceased donor.5 People waiting for a kidney transplant are often treated with dialysis while they wait.
Living kidney donation
Each person is born with two kidneys, but our bodies can function normally with just one. Because of this, living kidney donation is the main way to make more kidneys available for transplant.
A donor does not need to be biologically related to the recipient in order to donate. Compatibility is based on blood and tissue type, as well as antibody profile. When a living kidney donor match is secured for a transplant candidate, other candidates move up on the wait list.
“Education is so important,” said Michael Zimmerman, MD, an abdominal transplant surgeon at Froedtert & the Medical College of Wisconsin Froedtert Hospital. “Most people do not realize they can donate a kidney, or they do not realize that donating a kidney is safe.”
According to the National Kidney Foundation, most people who donate kidneys do not have health problems later in life associated with donating an organ.6 One of the largest studies on the topic, published in the New England Journal of Medicine, found the life expectancy of a living kidney donor is similar to that of a non-donor; and living kidney donors are not at an increased risk for kidney failure.7
Additionally, kidneys received through living donation have a 15 percent higher ten-year organ survival rate than kidneys received from a deceased donor, according to the U.S. Organ Procurement and Transplantation Network (OPTN) and the Scientific Registry of Transplant Recipients (SRTR).8
Kidney exchange programs
Even with a willing donor, nearly a third of kidney transplant candidates do not match their intended donor due to blood type or tissue incompatibility. In this case, paired exchange programs are a viable option.
“Paired exchange programs allow recipients and their incompatible donors to match with other donor-recipient pairs,” Dr. Zimmerman said. “There have been exchanges between more than a dozen different pairs, which significantly widens the donor pool.”
Global kidney exchange is a new strategy to expand the donor pool. A handful of these paired exchanges have taken place with donors and recipients across international borders. The Froedtert & MCW End-Stage Kidney Disease and Kidney Transplant Program participated in a global kidney exchange in 2018.
While dialysis can buy kidney transplant candidates more time, there are no alternative therapies for liver failure. Livers are the second most in-demand organ for transplant. The most commonly performed liver transplant surgery is one where the organ is from a deceased donor.
“Many livers from deceased donors are not suitable for transplant with the current organ preservation process,” said Johnny C. Hong, MD, director of the Solid Organ Transplant Program, a joint program of Froedtert & MCW Froedtert Hospital and Children’s Hospital of Wisconsin. “But, it is crucial to find ways to use all available livers. I am leading research to develop a technique that could rehabilitate or resuscitate livers that would generally be discarded. This could make a real difference in the number of lifesaving liver transplants we can do.”
Living liver donation
In a living donor liver transplant, a portion of a donor’s liver is removed (up to 60 percent) and is implanted in the recipient.
“The caveat is the longer a liver patient waits for a transplant, the sicker they become,” Dr. Hong said. “If their liver disease is categorized as severe, they will have a better outcome with a whole liver than a partial liver because a partial liver needs time to regenerate. Their body would not have the ability to nurture that liver to full size.”
Split-liver transplant is a technique that expands the available pool of donor organs by using one liver for two people. This procedure divides the deceased donor liver into two parts, which are implanted into two different recipients. This is possible because of the liver’s unique ability to regenerate. The liver is the only organ in the body that can replace damaged tissue with new cells. When a liver is split, it is able to regrow to its normal size within three months.
“Less than 2% of liver transplants in the United States are done using this technique because it requires the highest level of expertise and care,” Dr. Hong said. “The Froedtert & MCW Transplant Center is one of only a handful of centers able to offer this procedure, which further increases our patients’ access to lifesaving organs.”
For people with end-stage lung disease, a lung transplant is the only lifesaving treatment. Unfortunately, most donor lungs cannot be used for transplant. According to the American Lung Association, only 28 percent of donor lungs meet transplant criteria.9
“Lungs are uniquely fragile organs,” said Lucian Durham, MD, cardiothoracic surgeon at Froedtert & MCW Froedtert Hospital. “They are particularly susceptible to inflammation and damage in the transplant process.”
Ex vivo lung perfusion
Ex vivo lung perfusion (EVLP) is a leading-edge technique to improve the quality of donor lungs so they meet the criteria for transplant, and it extends the distance they can be transported. Donor lungs are placed on a device that includes a ventilator to inflate and deflate the lungs and a pump to circulate the blood, while maintaining them at normal body temperature. The lungs are treated with nutrients and drugs to improve their quality for transplant.
“EVLP removes some of the limitations with lung transplant,” Dr. Durham said. “It allows more donor lungs to be rehabilitated for transplant, and it also keeps donor lungs viable for an extended period of time.”
Only a few centers in the world have the expertise to offer EVLP, including Froedtert & MCW Froedtert Hospital.
Heart failure is a disease that affects more than six million Americans.10 It is one of the most common conditions in people over the age of 65, and according to the American Heart Association, about 10% of people with heart failure are in the advanced stage.
For the majority of end-stage heart failure patients, a heart transplant is the treatment of choice, but only a small subset of the population can get a heart transplant because of a dire shortage of donor hearts. The wait time for a donor heart depends on the severity of a person’s heart failure.
“In the past, many people would die waiting for a heart transplant,” said David Joyce, MD, cardiothoracic surgeon at Froedtert & MCW Froedtert Hospital. “Now, we have many new therapies and technologies that can buy people more time while they wait, and mechanical circulatory support is an essential alternative for many people as the number of people on the wait list grows exponentially.”
Ventricular assist device
A ventricular assist device, also known as a VAD, pumps blood from the lower chambers of the heart to the rest of the body. Different types of VADs are used depending on an individual’s needs. VADs allow some people to survive up to ten years while waiting for a donor heart to become available. The devices can be used as a bridge to transplant, or, for people who are not good transplant candidates, VADs can be used as destination therapy. In this case, the device is a permanent treatment.
Total artificial heart
A total artificial heart (TAH) is a pump that replaces both of the heart’s ventricles and pumps blood out of the heart to the rest of the body. An external, rechargeable driver delivers compressed air through tubes that come out of a person’s side, which help blood flow to the heart. The driver is portable and can be carried around in a backpack.
Froedtert & MCW physicians are participating in a national clinical trial to see if people can live permanently with a total artificial heart.
“This is the only FDA-approved biventricular device that can support the patient, but it is only approved as a bridge to transplant,” said Dr. David Joyce, who is the primary investigator of the study at Froedtert & MCW Froedtert Hospital. “This trial evaluates the device as ‘destination therapy’ for patients who are not eligible for a transplant or a left ventricular assist device.”
David Joyce’s father, Lyle Joyce, MD, was on the team that implanted the first total artificial heart in 1982. Dr. Lyle Joyce is now a cardiothoracic surgeon at Froedtert & MCW Froedtert Hospital.
Extracorporeal membrane oxygenation
In addition to VADs and TAHs, extracorporeal membrane oxygenation (ECMO) is another treatment that serves as a bridge to heart transplant. People who need ECMO are in severe and life-threatening condition. The ECMO machine offers life support by taking over heart and lung function and pumps blood through an external circuit.
“Of the menu of options that are available in the management of advanced heart failure, our program is one of the only ones in the country with deep expertise and experience in every strategy that exists,” said Dr. David Joyce. “We are also innovators in our field. When our patients require something extraordinary, we have the expertise and vision to identify strategies to address problems that would otherwise be unsolvable.”
Educating people to become organ donors will widen the donor pool, but Dr. Joyce said the only way to increase the number of heart transplants is to increase the number of acceptable donor organs.
“We are making plans to use technology that will allow us to preserve donor hearts for longer periods of time and therefore travel greater distances to retrieve them,” Dr. David Joyce said. “We are also exploring how to adapt a technique that is very important in England and Australia to increase transplant rates, which uses donor hearts that would typically be discarded.”
The bottom line
In 2018, there were more organ transplants in the United States than ever before. According to the United Network for Organ Sharing (UNOS), the nonprofit organization under contract by the government to manage the country’s transplant system, there were more than 36,500 transplants nationwide and nearly 6,900 living donor transplants — the highest total of living donor transplants in more than a decade11 — and despite this, there is still a shortage of donor organs. Registering to be an organ donor is an important step to bridge this gap and help saves lives.
For more information about organ donation, visit: froedtert.com/donatelife.