Kidney Transplantation

INFORMATION FOR PET OWNERS

The following is some general information about kidney transplantation. Each case is treated individually, and may not adhere to these guidelines. While every effort is made to keep this information accurate, it is by no means complete.
 

Kidney failure in cats

Chronic kidney failure (chronic renal failure, CRF) is one of the leading causes of disease in older cats, although it can occur in young cats also. It is caused by a variety of problems; one of the more common causes is an aging change where the functional units of the kidney, called the nephrons, one by one stop working. The other nephrons will do extra work up to a point, to make up for the nonfunctioning ones, but there comes a point when they can't keep up, and this is when signs of kidney disease become apparent. Other causes of kidney failure include infection, toxins, and cancer.
 

Chronic kidney failure treatment

Treatment of kidney failure includes many different aspects. In severe cases, hospitalization to give intravenous fluids is necessary, to "flush" out the kidneys. When the situation is more stable, fluid treatment can be given at home in the form of subcutaneous (under the skin) fluids. Other treatments include special diets with reduced protein and phosphorus, medications to prevent phosphorus absorption, hormone replacement to combat anemia, and anti-ulcer medications for nausea. These measures help the cat with kidney failure feel better and live longer, but the kidney disease continues to progress.
 

Transplantation as a treatment for CRF

Kidney transplantation can help treat the disease by providing a healthy kidney to perform all of the normal functions. After successful transplantation, only two medications are needed to prevent rejection of the kidney.
 

Who can have a kidney transplant?

Transplantation would be suitable for a cat who has kidney disease from aging or a birth defect, or several other types of kidney disease if they are not caused by infection or cancer. A cat being considered for transplantation will go through a battery of tests to make sure there are no hidden problems that would complicate this treatment.
 

Who cannot have a kidney transplant?

Cats who have infection cannot have transplants because they would infect the transplanted kidney and cause it to fail. The same holds true for most kinds of kidney cancer. Cats who are infected with the feline leukemia virus or the feline immunodeficiency virus are also not suitable because the immune suppression necessary to prevent them from attacking the new kidney makes them very ill. Cats who have other disease in addition to the kidney, especially heart or gastrointestinal disease, tend not to be strong enough to safely undergo the required surgery. Because of the difficulties in suppressing the immune system without excessive side effects, transplantation in dogs is not currently available.
 

Where does the new kidney come from?

Cats (and people and dogs, too) can have normal kidney function with only one half of one normal kidney, so a healthy cat can donate an entire kidney and still have twice as much kidney function as is necessary for a normal life. The family of the cat receiving the transplanted kidney are required to adopt the donor cat and give it a lifetime home. Our kidney donors are cats who need a home. They have been extensively screened for any disease or infection.
 
 
Surgical anatomy of transplanted kidney. The vessels of the transplanted kidney are attached to the aorta and cavdal venacava. The native kidneys are left in place
 

Getting ready for surgery

After determining that a cat is a good candidate for transplantation, the surgery is scheduled. Several days before the scheduled surgery, the cat should be admitted to the hospital for intravenous fluid therapy and to complete the final testing. A compatible kidney donor will be identified, and the final tests on the donor will be completed during these few days, also.
 

The surgery

The transplantation itself involves removing one kidney from a healthy donor cat, placing it in the abdomen near the groin region of the recipient, and attaching it to the blood vessels leading to the leg. The recipient's natural two kidneys are usually left in place. The recipient cat must then be placed on medications to prevent the immune system from rejecting the new kidney. A feeding tube is placed at the time of surgery, to help until the cat's appetite returns (usually within the month).
 
 

Aftercare in the hospital

Monitoring after surgery includes watching the kidney function, blood levels of the medications, level of anemia, and a variety of other aspects. Most cats will stay in the hospital for 1 to 2 weeks after surgery.
 

Long term care

Cats with a transplanted kidney must receive their medicines twice a day, every day, to prevent rejection of the new kidney. Immediately after surgery, weekly rechecks with the vet are required to check on the kidney values and the medication levels in the bloodstream. As time goes on, the rechecks are gradually decreased to once every 3 months.
 

Outcome

About 75% (three out of four) of cats who get a transplant surgery survive and are sent home from the hospital. Some cats will have complications in the first six months, and about 60% of transplanted cats live to 6 months after surgery. The rate of complications decreases after the first six months (although complications are possible at any point), and 40% of cats are still going strong after 3 years, and there are a few cats who are 6-10 years post surgery.
 

Cost

At the Animal Medical Center, the cost for the surgery and the time in the hospital around surgery is estimated to cost roughly $8000. Follow-up care, including medications and recheck visits is estimated to cost around $4000 for the first year, and probably $3000 per year thereafter.
 
Transplantation is not appropriate for all situations. Some cats have diseases that prevent it. It is an expensive procedure. Some owners do not have the time to bring the cat in for frequent follow-up examinations. Some cats do not have an attitude appropriate for lifelong twice daily pill administration and frequent trips to the vet for examination and blood testing. For those, however, which do meet all the requirements, kidney transplantation can be a procedure that gives a longer, healthier life that would not otherwise be possible.
 
If you are interested in having your pet evaluated for potential transplantation, make an appointment with a member of the transplantation team (appointment desk 212-838-8100). You may also contact the Renal Medicine Service at 212-329-8618 or e-mail us at hemodialysis@amcny.org.