who have been diagnosed in the earlier stages of renal failure
are the best candidates. The surgery is a considerable risk and
the patient's chances are enhanced by being in generally good
health, aside from the kidney failure itself. Although physical
condition is more important than age, a transplant may not be
the right choice for a patient whose life expectancy might be
just as long with aggressive supportive care. It should also be
recognized that an older cat is more likely to develop other life-threatening,
age-related problems which could shorten his post-transplant survival
time. A transplant does not make the patient invincible from other
diseases or problems and, in fact, could make those conditions
more serious because of the required immune suppression. A transplant
should be viewed not as a cure, but as one of several options
for the treatment of feline CRF.
qualify for a transplant, a thorough screening must be done to
rule out medical conditions or diseases that would threaten the
life of the patient during or after surgery. Cancer, heart disease,
diabetes, inflammatory bowel disease, infections, FeLV, FIV, and
kidney or bladder stones are some of the major conditions that
would be disqualifying. A series of tests will have to be done
prior to the surgery and any negative findings will disqualify
a potential candidate. Some or all of the following tests will
be required and additional ones may be necessary depending on
the patient's history and the surgeon's opinion:
culture and sensitivity
titer (IgG and IgM)
the transplant is done, the patient will be on antirejection drugs
which compromise the immune system. It is, therefore, critical
to screen for any problems that may take advantage of the patient's
somewhat reduced resistance to diseases, infections, etc.
primary objective of preoperative preparation and care is to get
the CRF patient in the best condition possible to undergo the
surgery. A key issue here is determining when the time is right.
Since the very early signs of renal failure are subtle and cats
hide their illnesses so well, most of us do not recognize the
problem until the more dramatic symptoms appear. At that point,
the patient has probably lost a considerable amount of weight,
is dehydrated and anemic, and has seriously elevated BUN and creatinine
levels. To stabilize the patient for surgery, these conditions
must and can be significantly improved with treatment (fluids,
medications, etc.). Supportive care can be so successful that
the patient feels good and appears healthy again, making the decision
to proceed with the surgery more difficult. The decision of how
long to wait should be made in conjunction with your local veterinarian
and the transplant surgeon.
patient will need to be in the hospital several days before the
surgery but the amount of time depends somewhat on the recipient's
condition. The patient will be started on antirejection drugs
prior to the transplant and IV fluids 24 to 48 hours before the
surgery. Since some blood will be lost during the surgery, the
patient's hematocrit must be well within the normal range. (It
is recommended that the patient's PCV be greater than 30%). Transfusions
are possible and one school of thought has suggested that this
might even be helpful in minimizing rejection. Although Epogen
can be used to raise the PCV, there is a risk of antibody formation
which can be avoided with transfusions.
you live in close proximity to the transplant facility, it is
likely that the surgeon will see the patient for the first time
just prior to the operation. This examination represents a final
screening and the potential for a last minute disqualification.
the surgery, the recipient will remain under intensive care for
one to three weeks. While in the hospital, the recipient is typically
kept on IV fluids, antibiotics and oral antirejection drugs (prednisolone
and cyclosporine). An ultrasound may be done to verify blood flow
through the new kidney and blood samples are taken frequently
to monitor cyclosporine level and kidney function.
rejection of the new kidney is not common but rejection episodes
are, and they are more likely to occur early than later on as
the body "gets used to" the presence of the foreign kidney. A
rejection episode is essentially the body's immune system attacking
what it perceives as an invasion by the new kidney. When this
occurs, the patient feels sick and may vomit, stop eating, run
a fever and/or become depressed. An immediate response is essential
so that the antirejection medication can be increased to suppress
this immune system activity.
case is different, but it is typical for the new kidney to show
some signs of function three to ten days after the surgery. Generally,
the three major kidney functions return at different rates, with
the production of erythropoietin often being the last to return.
The surgeon will determine when the patient is stabilized enough
to go home. There is no set formula nor test numbers that must
be reached before the patient is discharged. BUN and creatinine
levels may or may not have fallen into the normal ranges by the
time the patient leaves the hospital.
discharged, the patient will be stable and active but still in
a recuperation period. For the first month, the transplant cat
must be restrained from any excessive movements, such as jumping.
During this time it is also advisable to kennel the recipient
when he is not being closely monitored. These precautions are
to allow sufficient time for the new kidney to become firmly set
in the transplant cat's body and for the surrounding tissue to
solidly heal around the new organ.
surgeon will provide detailed instructions for administering medications,
for recognizing rejection episodes and for scheduling follow-up
visits and tests. You may also be required to have a scale to
monitor the patient's weight and, initially, it might be necessary
to give the patient sub-Q fluids and/or Epogen shots to support
the new kidney. You may be given a vial of IV cyclosporine to
keep with the patient at all times so that any vet can treat a
Visits with the Surgeon
the surgeon is in a distant city, he will eventually turn over
the follow-up visits to your local veterinarian but maintain telephone
contact with you for some elements of continuing care. Be sure
you have made the necessary arrangements for you or your local
vet to be able to contact the surgeon in case of an emergency.
sure that any vets that you will be seeing have a copy of the
instructions you were given, particularly those explaining the
protocol for dealing with rejection. At first the follow-up visits
will be frequent but the length of time between visits will gradually
become longer as the patient further stabilizes. Visits are generally
every two weeks for the first several months, then monthly for
the next four to five months. The frequency after the first six
months will depend somewhat on how the patient is doing and how
consistent the cyclosporine level checks become. The equipment
needed to assay cyclosporine is very specialized and generally
found only at hospitals that perform human transplants or at veterinary
schools that perform feline transplants.
primary purpose of these maintenance visits is to check the patient's
condition and draw blood to monitor BUN, creatinine, PCV, Total
Protein and cyclosporine levels. Urine samples are also required
periodically to check the specific gravity as an indication of
how well the new kidney is functioning. It is best to free-catch
a urine sample since the new kidney's proximity to the bladder
makes cystocentesis more difficult (ultrasound guidance is recommended).
hundreds of transplants have been performed, it is highly unlikely
that your local general practice veterinarian will have any experience
with post-transplant care and the possible complications. It is
advisable to locate and contact a board-certified internist or
kidney specialist in your area in case more than routine follow-up
care is ever required.
patient generally is given a course of antibiotics for the first
few weeks. Cyclosporine and prednisolone will be required for
life. In some cats, prednisolone may inhibit fur growth, slowing
the replacement of fur that was shaved for the surgery. Cyclosporine
is used to suppress the immune system (T cells) and is the very
potent drug that has made human and animal transplants possible.
It is an oily liquid that must be measured and put into a gel
cap. This is a simple procedure that you can do yourself or you
can arrange to have the capsules made by a pharmacist. (Since
the dosage will frequently change, it is not helpful to make up
too many capsules ahead of time.) The patient must take cyclosporine
for the rest of his life and generally these pills must be given
every 12 hours. Some transplant surgeons combine cyclosporine
with ketoconazole and the medication protocol will differ slightly.
The patient may also need Epogen shots for some period of time
and should be weighed every few days. Weight maintenance is essential
and if the patient is not eating enough, the stomach tube can
the patient develops a problem unrelated to the transplant, no
other treatments or tests are required and there are no special
dietary requirements. At the point when it is felt that the patient
is eating and drinking sufficiently, the stomach tube can be removed
(without anesthesia). The recipient is at a somewhat greater risk
of disease or infection but there is no reason for isolation,
assuming that other cats in the household are healthy. The recipient
can continue to get yearly vaccinations since the cyclosporine
should not interfere with the body's ability to process immunization
shots. In general, your cat will return to a normal, active life
with virtually no restrictions.