Mini Medical School
The Heart Of Kidney Transplants
INDIANAPOLIS - Each one the pair weighs only six
ounces and is less than five inches long. Yet, kidneys provide a
highly sophisticated pump and filtration system, eliminating poisons,
regulating acid concentration and maintaining water balance in the
human body. When the two organs don't work, transplantation is an
option that can restore function and in many cases improve the quality
of life for patients.
Kidney transplants are the second most common transplant
operation in this country (corneal transplants rank first) with
more than 9,000 procedures annually. Each year, more than 120 kidney
transplants are performed at the Indiana University School of Medicine.
"The renal transplant is easier than all other major
organ transplants and the patient can be treated with dialysis until
a suitable donor can be matched," said Mark D. Pescovitz, M.D.,
an IU School of Medicine surgeon who specializes in renal (kidney),
pancreatic and liver transplants. Dr. Pescovitz revealed the world
of transplant surgery and its latest developments for participants
attending the Feb. 20 session of IU School of Medicine's Spring
Mini Medical School.
Candidates for kidney transplants usually are those
who have kidney failure caused by severe and uncontrollable high
blood pressure (hypertension), infections or diabetes mellitus.
The procedure is not recommended for patients who have heart or
liver disease, metastatic cancer, AIDS and other life- threatening
diseases.
"The major pre-operative obstacle is finding a suitable
donor," said Dr. Pescovitz. While most organs for transplants have
come from deceased donors in the past, the number of living kidney
donors is on the increase. A recent annual report by the United
Network for Organ Sharing found that patients receiving kidneys
from live donors are more likely to survive than those receiving
organs from cadavers.
"That's largely because blood relatives (ideally a
parent or sibling) make the best donors, and they can be more carefully
screened and matched to the patient," said Dr. Pescovitz. About
600 living donor transplants have been performed at IU School of
Medicine since 1980.
"It's an extremely safe procedure for the donor,"
said Dr. Pescovitz. Medical statistics show complications occur
in less than 5 percent of donors, and less than .01 percent result
in death. The post-operative renal function for donors is between
80 percent to 90 percent of the function they had with two kidneys.
The environment for the living donor procedure is
more controlled because there is little time lag between harvesting
the kidney and transplanting it; the donor and recipient are in
adjacent operating rooms. The donor kidney is transplanted into
the patient's lower abdomen (the damaged kidneys remain intact and
eventually wither) and stitched into place within the pelvis. In
most cases, the transplanted kidney begins to function immediately.
The next obstacle is fighting the body's rejection
of the new organ. Dr. Pescovitz said there are three categories
of rejection: hyperacute (within two days), acute (the most common
and occurring after seven days) and chronic, where scarring within
the transplant organ occurs over months or years.
Immunosuppressant drugs, many of which have been researched
and used in clinical trials at IU School of Medicine, help fight
infection. In 1998, the antibody Zenapax, which blocks immune cells
from attacking the new kidney, showed significant results in transplant
patients at IU Hospital and James Whitcomb Riley Hospital for Children.
That drug was administered with standard anti-rejection drugs during
the first eight weeks following the transplant-the riskiest period
in which organ rejection can occur.
The average hospital stay for kidney transplant patients
is about a week with a recovery period of about a month. "We encourage
patients to resume normal activities as soon as they are able,"
Dr. Pescovitz said.
Perhaps the biggest challenge in transplant surgery
is the simple law of economics: supply meeting the demand. According
to UNOS, the number of patients awaiting organ transplants has grown
five times faster than the supply. Currently, there are more than
72,000 on national transplant waiting lists-three times as many
as there were in 1990.
Looming ahead is the controversial transplantation
of organs from animals, into humans. Xenotransplantation researchers
are investigating the possibility of developing transgenic "miniature"
pigs, which express a human gene. The belief is held that these
pigs will develop organs adaptable for human transplantation. Current
federal laws prohibit xenotransplants.
The IU Medical Group and Indianapolis radio station
WIBC sponsor Mini Medical School, which is offered by the Indiana
University School of Medicine Faculty Community Relations Committee
through the IUPUI Division of Continuing Studies. For registration
information, call 317-278-7600.
