Kidney transplantation is the removal of a healthy kidney from a living or recently deceased person and then its transfer into a person with end-stage kidney failure.
(See also Overview of Transplantation.)
For people of all ages who have irreversible kidney failure, kidney transplantation is a lifesaving alternative to dialysis. Kidney transplantation is the most common type of organ transplantation procedure.
Kidney transplantation is indicated when people have
Advanced, irreversible kidney failure
People in their 70s and sometimes 80s may qualify for transplants if the following apply:
They are healthy in other respects, can function independently, and have good social support.
They are expected to live a reasonably long time.
Transplantation is likely to substantially improve their ability to function and their quality of life beyond simply freeing them from dialysis.
People who also have type 1 diabetes may be candidates for simultaneous pancreas-kidney or pancreas-after-kidney transplantation.
Both donors and recipients undergo pretransplantation screening. This screening is done to be sure that the organ is healthy enough for transplantation and the recipient does not have any medical conditions that would prohibit transplantation.
Kidney transplantation is not done (is contraindicated) if people have certain disorders, such as a severe heart disorder or cancer. Some disorders that previously meant kidney transplantation could not be done (absolute contraindications) are now considered relative contraindications (meaning that transplantation may be possible with special precautions) because there are drugs to control them. For example, special precautions are carried out when people have poorly controlled diabetes (which can result in kidney failure) or certain viral infections (such as advanced hepatitis C) that may be made worse by taking the drugs required to prevent rejection after transplantation. These drugs inhibit the immune system and thus make it less able to defend the body against infection.
One year after transplantation, about 95% of kidney recipients are alive. The percentage of transplanted kidneys still functioning is
For kidneys from living donors: About 95%
For kidneys from deceased donors: About 90%
Each year thereafter, about 3 to 5% of kidneys from living donors and about 5 to 8% of those from deceased donors stop functioning. Transplanted kidneys sometimes function for more than 30 years.
People with successful kidney transplants can usually lead normal, active lives.
Donors
More than one half of transplanted kidneys come from previously healthy, deceased donors. About one third of these kidneys are damaged but are used because the demand is so great. The rest of transplanted kidneys come from living donors. Donation from a living donor is possible because the donor can live with one healthy kidney.
Procedure for Kidney Transplantation
The kidneys are removed from the donor, usually using thin instruments and a small video camera inserted through several tiny incisions (laparoscopic surgery). Occasionally, a larger incision (open surgery) is required. After removal, the kidney is cooled and transported quickly to a medical center for transplantation to a person who has a compatible blood and tissue type and who does not make antibodies to the tissues of the donor.
Kidney transplantation is a major operation. The person receiving the kidney is usually on dialysis in the months or years before the transplant procedure. The donated kidney is placed in the pelvis through an incision and is attached to the recipient’s blood vessels and bladder. Usually, the nonfunctioning kidneys are left in place. Occasionally, they are removed because infection develops and does not resolve.
Drugs to inhibit the immune system (immunosuppressants), including corticosteroids, are started the day of transplantation. These drugs can help reduce the risk that the recipient will reject the transplanted kidney.
Complications of Kidney Transplantation
Transplantation can cause various complications.
Rejection
Even if tissue types are closely matched, transplanted organs, unlike transfused blood, are usually rejected unless measures are taken to prevent rejection. Rejection results from an attack by the recipient's immune system on the transplanted organ, which the immune system recognizes as foreign material. Rejection can be mild and easily controlled or severe, resulting in destruction of the transplanted organ.
Despite the use of immunosuppressants, one or more episodes of rejection may occur after kidney transplantation.
Acute rejection occurs within 3 to 4 months of kidney transplantation. It can be accompanied by fever, decreased urine production with weight gain, pain and swelling of the kidney, and elevated blood pressure. Blood tests show deteriorating kidney function. Because these symptoms can also result from infections or use of a drug, the diagnosis of rejection sometimes needs to be confirmed with a needle biopsy of the kidney.
Chronic rejection that develops over many months to years is relatively common and causes kidney function to gradually deteriorate.
Rejection can usually be effectively treated with high doses of corticosteroids or antilymphocyte globulin. If these drugs are ineffective, they are gradually stopped, and dialysis must be started again. Dialysis is continued until another kidney transplant is available.
The rejected kidney may be left in place unless fever, tenderness, or blood in the urine persists. The chance of success with second transplants is almost as good as that with first transplants.
Cancer
Compared with the general population, kidney transplant recipients are about 10 to 15 times more likely to develop cancer, probably because the immune system helps defend the body against cancer as well as infections. Cancer of the lymphatic system (lymphoma) is 30 times more common among kidney transplant recipients than the general population, but lymphoma is still uncommon. Skin cancer is common.
