As More in US Need Kidney Transplants, the Process is Refined

With the first kidney transplant performed nearly a half century ago, the medical profession has increasingly refined the process, which has resulted in a high rate of success.

The kidneys are crucial because they filter and re-process our blood - about 200 quarts a day - to screen out two quarts of waste products and excess water. The waste products and water are converted to urine. The kidneys also generate hormones that strengthen our bones and make blood. But if the kidneys fail to function properly, waste products such as urea and creatinine remain in the blood stream and the body retains the excess fluids. This is called kidney failure.

Kidney failure can be caused by many things, but presently in the US it is caused mostly by diabetes and high blood pressure.

Gap Between Need and Availability
The increasing success of kidney transplants has provided hundreds of thousands with new hope for restoring their normal lives. Yet there is a persistent and growing gap between the number of people needing transplants and the quantity of kidneys available, says Mark B. Adams, MD, MS, Professor and Chairman of the Medical College of Wisconsin Department of Surgery.

Dr. Adams practices at both the Froedtert & The Medical College of Wisconsin Transplant Center and the Children's Hospital of Wisconsin Transplant Clinic.

Given present trends, Dr. Adams is very concerned about the future. "As the nation gets older and fatter, we will see more diabetes," Dr. Adams warns. "I would expect the number of people with kidney disease to double in the next 10 years." At the same time, the process of kidney transplantation has become safer and more effective.

To be a candidate for a kidney transplant, the patient needs to be carefully evaluated, with the heart and lungs functioning well as determined by a thorough examination. If the patient is a good candidate, they will be placed on a waiting list which typically takes five years or so.

Each year, Froedtert Hospital carries out approximately 150 kidney transplants. A bit more than half of the donated kidneys come from living donors. Nationally, most kidneys used in transplants are from deceased donors, drawn from people who recently died and wanted to donate their organs so others could live better lives. (The situation is different locally, as noted above, where less than half of the donated kidneys are from deceased donors.) A deceased donor kidney is normally transplanted within 24 hours, although it might be as long as 36 to 48 hours before a transplant.

Complex Matching Required
Adding to the complexity of the kidney transplant is the need for "matching" between the donor and recipient. Their blood types must be compatible; their 'antigens" (markers on the surface of the white blood cells) must match up as much as possible; and the recipient's immune system must not already be resistant to some element of the donor's tissues. A thorough assessment of each patient's characteristics is maintained on the national waiting list so that a transplant can take place as soon as a kidney becomes available.

Multiple Advantages of Live Donation
The transplant process is much easier when a living donor provides a kidney, according to the doctor.

Dr. Adams stresses that kidney donations from live donors have five principal advantages:

• A family member is usually a better match, lessening the problems associated with rejection. The donor does not need to be a family member.
• A live donation permits relatively rapid planning for the transplant. "It's much easier, instead of waiting five or so years on the transplant waiting list," he says.
• Living donations may allow the patient to avoid dialysis. While dialysis provides maintenance of life, it takes a toll on the patient's overall health. "The patient doesn't stay healthy while being maintained on dialysis. Their health will have changed as they wait for the transplant, in terms of their heart, lung, and bones."
• "Kidneys from living donors all work right away, while not all kidneys from deceased donors can start functioning," says Dr. Adams. "Sometimes, it can take several weeks."
• "Kidneys from living donors work longer and better," improving both the recipient's quality of life and extending it.

At the same time, a donation from a living donor carries risks. "Donors must undergo a major operation, so they need to go through an extensive screening to make sure that they are healthy and are not putting themselves at risk," Dr. Adams cautions. But if the donor is healthy and both kidneys are functioning normally, the transplant can take place.

With a live donor, the transplant involves two parallel surgeries on the donor and the diseased patient. First, using a "laparoscopic" procedure where a tiny incision is made and small-scale surgical equipment inserted, the healthy kidney is extracted from the donor after the connecting artery and vein are tied off and the kidney is removed from the donor. The new kidney is then inserted in the diseased patient's lower right abdomen, with the key steps "hooking up" the new kidney to a nearby artery and vein, and also the ureter, which will carry urine to the bladder.

In most cases, the diseased kidneys do not need to be removed, says Dr. Adams. While the new kidney will take over all the functions of the diseased kidneys, the "native" kidneys may continue to function to a limited extent.

The transplant takes about two hours under general anesthesia, and we have the patient up and walking around the same day," he explains. A four- to five-day hospital stay is normally required.

But adjusting the body to the new "foreign" kidney becomes the next challenge, since the transplant triggers the body's natural immune reactions. "We work to adjust medications to the right level, and patients are seen by their doctor frequently for the first two months, Dr. Adams says. "This is to monitor the side effects of the medications given to neutralize the autoimmune system.

The side effects of medication vary from individual to individual. As time goes on the need for visits becomes less, so that a year after the transplant most patients are having lab work done monthly and seeing their doctor once a year. This depends on which of the many medications the patient is taking. The doctor will closely scrutinize the effects of various medications and their effects, and adjust them to minimize unwelcome impacts.

Kidney Disease Widespread
The incidence of kidney disease is widespread, with 20 million Americans having some form of the problem and another 20 million at a somewhat higher degree of risk, according to the National Kidney and Urologic Disease Information Clearinghouse. There are already some 200,000 to 300,000 Americans undergoing the inconvenience and discomfort of dialysis.

There are two forms of dialysis: hemodialysis and peritoneal dialysis. Hemodialysis, the more common technique, essentially involves allowing blood to flow through a dialysis machine that filters out wastes and excess fluids, then returns clean blood to the body. Hemodialysis typically requires visiting a clinic for three 3-5 hour sessions each week. There have been many improvements since its introduction in the 1960s, but hemodialysis remains an inconvenient and cumbersome substitute for working kidneys.

Peritoneal dialysis works differently, and involves flushing solutions in and out of the abdominal cavity. The dialysis solution circulates in the abdominal cavity and then is drained from the body, removing waste products via this exchange. There are three different types of peritoneal dialysis, chiefly distinguished by the schedule of exchanges. Peritoneal dialysis may offer less disruption of daily life.

Prevention Is Crucial
Clouding the future is the growing prevalence of diabetes, which is likely to sharply increase the number of people with kidney disease. The incidence of kidney disease is estimated to be three times higher among African-Americans, Latinos, and Asian-Americans due to the high rates of diabetes and high blood pressure among these groups.

To head this off, Dr. Adams urges people to be pro-active about maintaining their health. As Dr. Adams says, "Most of the time, there aren't symptoms until you are already pretty far down the line."

Instead of reacting to symptoms, patients with high blood pressure or diabetes should make sure they are seeing their doctor for particular blood and urine tests on a regular basis. Being careful about following any medication regime is also crucial.

MCW Health News presents up-to-date information on patient care and medical research by the physicians of the Medical College of Wisconsin.