The function of the kidneys is to filter the blood in the
body and to purify it by ridding it of soluble waste
products and excess water (which is then eliminated in
the form of urine).
Total kidney failure, which may be gradual or sudden in
onset, results in the accumulation of these waste
products in the blood. These waste products can poison
you unless removed.
The causes of kidney failure include:
- infection and inflammation of any part of the kidney structure
- nephrosclerosis (replacement of ordinary kidney tissues with scar tissue following disease), damage to kidney tissue through disease (high blood pressure, diabetes) or injury
- polycystic kidneys (an inherited condition in which the tissues of the kidneys are gradually destroyed by cysts)
- failure of normal kidney development from before birth
Kidney transplantation reestablishes the function of
organs that are not working. This procedure is successful
in about 85 percent of all cases, and is repeatable in
cases of failure, provided that a suitable second donor
can be located. This operation allows a patient to lead
an independent existence instead of being reliant on
regular kidney dialysis. It also allows a liberating return
to a normal diet.
Regular kidney dialysis is a short-term solution to kidney
failure: the blood is artificially filtered through a machine
or by diverting the bloodstream through another
permeable membrane in the body itself. The ideal
treatment for total kidney failure is kidney
transplantation.
One-third to one-half of all patients with end-stage renal
(kidney) disease are suitable for transplantation.
Two-thirds of all kidney transplants are recieved from
cadaveric donors, and one-third are recieved from living,
related donors.
Kidney Transplantation Surgery
The aim of the surgery is to supply a single, fully
functioning kidney. One kidney provides more than
enough filtration and regulating capacity for all purposes
and is grafted into its own position while the existing
(non-functioning) kidneys remain in place. The existing
kidneys are removed only if they cause persistent
infection or high blood pressure, and they will not
interfere with the transplant procedure or functioning of
the new organ. As soon as the transplanted kidney is
connected to the blood vessels, it will begin purifying the
blood of waste products.
Patients are required to take medications such as
corticosteroids, cyclosporine, and/or azathioprine to
suppress their immune system in order to prevent
rejection of the transplanted kidney.
Post-operative Effects
More often than not, the first week after kidney
transplantation is a grace period when things keep
getting better. However, the clear sailing can be
misleading, since many kidney recipients spend time in
the hospital soon after discharge when the functioning of
their new kidney diminishes. These episodes are almost
always successfully treated by adjusting the medication
regimen.
By far the two most common causes of diminished renal
function are rejection and the toxic effects of
cyclosporine. About 70 percent of all recipients will
manifest some signs of organ rejection, and most will
also have some evidence of cyclosporine toxicity. Both
problems manifest themselves as decreasing urinary
output and rising laboratory values of blood BUN (Blood
Urea Nitrogen) and creatinine (a component of urine).
These problems are usually treated simultaneously by
adding extra doses of steroids.
Managing Rejection
Immediately after kidney transplant surgery, the
mainstays of drug therapy are prednisone and
cyclosporine, and sometimes azathioprine. It should be
emphasized that cyclosporine is enormously beneficial
for two reasons: first, in improving long-term survival of
the kidney; and second, in permitting the rapid tapering
off of the prednisone. Nevertheless, it is critically
important that, as long as the transplanted organ is
functioning, some level of maintenance
immunosuppression (suppression of immunologic
response, usually with reference to grafts or organ
transplants) is necessary. If at any point a recipient
stops taking the medications, rejection can occur - even
ten or fifteen years after the transplant.
The important point to remember is that most recipients
can expect to have some problems getting adjusted to
their new organ, and that after the initial discharge it
may be necessary to return to the hospital for one or
more additional short stays. New drugs may be needed,
and the doses of the anti-rejection medications will
probably require adjustment. This fine-tuning is a
normal part of recovering.
The vast majority of renal transplants are successful.
Thus, the statement that someone is suffering rejection,
which understandably sounds disturbing, is not cause for
undue alarm. Most cases of rejection can be reversed,
and the other causes of abnormal renal function also can
be corrected. Well over 80 percent of recipients leave the
hospital with a kidney functioning sufficiently to keep
them off of dialysis.
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