What Kind of Transplantation Is Available?
Doctors can perform kidney, heart, liver, lung, pancreas, and intestine
transplant surgeries.
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Kidney transplant surgery.
This procedure is the most common organ transplantation in the United
States: 14,775 people received a kidney transplant in 2002. Doctors
can transplant kidneys from living donors as well as from cadavers.
In most surgeries, doctors only replace one kidney. However, if
a person is extremely sick, two kidneys may be transplanted. |
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Heart transplant surgery.
Many people who undergo heart transplant surgery respond very well
to their new organ. About 85 percent of people who receive a heart
transplant are alive one year later. Among 4,409 people who received
heart transplants in 1997 and 1998, about 79 percent did not experience
rejection for at least three years afterward. |
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Liver transplant surgery. Liver
transplantation is the second most common transplant surgery; more
than 5,000 people received a liver transplant in 2002. Doctors can
transplant an entire liver from a cadaver. But because of the liver’s
ability to regenerate, doctors can transplant a partial liver from
a cadaver or from a living donor. After the operation, the livers
in both the recipient and the donor will grow to their full size. |
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Lung transplant surgery. Doctors around
the country performed about 1,042 lung transplant surgeries in 2002.
During this procedure, surgeons remove both lungs from a cadaver
at the same time. There are three different kinds of lung transplantation:
single-lung transplantation, double-lung transplantation (all from
the same donor), and heart-lung transplantation (all from the same
donor). |
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Pancreas transplant surgery. During this
procedure, doctors can transplant
part of a pancreas or the whole organ. There were 554 pancreas transplantations
in 2002. Doctors can transplant a kidney and pancreas at the same
time. |
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Intestine transplant surgery. Researchers
have recently developed this transplant surgery; people who undergo
this procedure must receive specialized nutrition and are at risk
for complications. Doctors performed 107 intestine transplant surgeries
in 2002. What Are the Risks Following Transplant Surgeries? Although
transplant surgery has become safer, people still face risks after
the operation. |
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Rejection. After the surgeon has completed
the operation, the body’s immune system may consider the new
organ to be foreign and try to attack it. People who have transplant
surgeries take immunosuppressive medication, which can help prevent
rejection up to 75 percent of the time. Depending on the person’s
body and his or her symptoms, a doctor may increase or change the
dosage of immunosuppressive medications to ensure that the new organ
is not rejected. |
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Cancer. Studies show that up to eight
percent of people with a transplant
will develop cancer; this risk is slightly higher than in people
without transplants. Skin cancer is the most common condition among
transplant recipients, but it can be treated effectively. Some cancers
result from the effects of the immunosuppressive medications. |
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Infection. Taking the powerful immunosuppressant
medications can increase
the risk for less serious conditions—like urinary tract infection—and
more serious infections, including pneumonia. |
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Receiving an Organ for
Transplantation
If you think you may need a transplant surgery, talk with your doctor.
Transplantation is usually considered only after all other treatments
have not worked.
1. If you need an organ transplant, your doctor will help you
get on the national waiting list.
2. To get on the waiting list, you need to visit a transplant
hospital.
3. A team of specialists at the hospital will give you an examination
and make sure you meet the criteria to be put on the list. You also
can get on the waiting list at more than one transplant hospital; each
hospital has its own standards for listing patients. If you meet their
criteria, they will add you to the list.
4. Your name will be added to the list. When an organ donor
becomes available, all people on the list are compared to the donor.
Doctors examine such criteria as blood type, tissue type, size of the
organ, your symptoms, time spent on the waiting list, and distance between
donor and the potential recipient.
The organ is offered first to the candidate who is the best match. The
organs are distributed locally first, and if no match is found, they
are offered regionally and then nationally until a recipient is found.
5. Wait. There is no way to know how long you will wait to receive
a donor organ.
Kidney Transplantation
A kidney transplant surgery is usually reserved for people who have irreversible
kidney failure. Doctors are able to perform successful kidney transplantation
on newborn infants, children, and adults, including people older than
70.
Heart Transplantation
Doctors may recommend a heart transplant to treat chronic, irreversible
heart failure. Other medical or surgical treatments for cardiac problems
have usually been tried before transplantation is considered. When a donated
heart becomes available, doctors remove it from the donor and it is transplanted
into the recipient.
Liver Transplantation
Doctors may recommend a liver transplant to treat liver failure, which
could be caused by hepatitis, excessive consumption of alcohol, metabolic
disease, or certain cancers. When a donated liver becomes available, surgeons
remove it from the donor and transplant it into the recipient. Because
the liver can regenerate, sometimes surgeons can remove a portion of the
liver from a living donor and transplant it into a recipient. In both
the donor and recipient, the livers will regenerate back to normal size.
Lung Transplantation
A lung transplant surgery can help treat lung failure, which is caused
by emphysema and pulmonary fibrosis. People with lung failure will not
live longer than two years without a transplant. Almost 1,700 people received
a lung transplant in 1997 and 1998; about 60 percent survived for at least
three years.
Pancreas Transplantation
Doctors may recommend pancreas transplant surgery to treat type 1 diabetes,
a condition in which the pancreas does not produce enough insulin, a chemical
that helps the body regulate blood sugar levels. Severe type 1 diabetes
is often associated with chronic renal failure; some people who need a
pancreas transplant also may need a kidney transplant.
There are three types of pancreas transplant operations:
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Combined kidney-pancreas transplant |
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"Pancreas-after-kidney"
transplant, in which the pancreas is transplanted after a kidney
has been transplanted. |
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Pancreas-alone transplant, for patients
with functioning kidneys. |
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Transplant Surgery
Time is critical during organ transplantation; most organs need to be
transplanted within a few hours after removal from the donor. Removing
an organ from a cadaver is carried out just like any other operation;
surgeons respect the body and will honor the donor’s wishes for
an open-casket funeral.
Heart Transplant Surgery
A heart must be transplanted into the recipient within five hours. After
surgeons remove the heart from the donor, the organ is preserved and packed
carefully for transport.
While surgeons remove the heart from the donor, officials on the national
waiting list search for the best possible recipient and prepare him or
her for surgery. As the heart is transported to the recipient’s
hospital, surgeons give the person anesthesia and place him or her on
a cardiopulmonary bypass machine. This equipment delivers oxygen to the
person ’s blood; the person remains hooked up to this machine until
the new heart is working.
After the new heart has been transplanted, surgeons may use electric
shock to stimulate the new organ to begin beating. When the heart is successfully
beating, the surgeons check for any signs of bleeding. Doctors may give
the recipient drugs to regulate the heart rate and blood pressure.
Kidney Transplant Surgery
If doctors find a close relative or a friend who will donate his or her
kidney to the recipient, the transplant surgery will be scheduled right
after doctors remove the kidney from the donor. During this process, the
recipient is prepared for surgery at the same time as the donor.
If the kidney is from a cadaver, transplantation must take place within
24 to 36 hours. After the kidney is removed from the donor, it is preserved
and packed for transport.
At the same time, officials on the national waiting list search for the
best possible recipient for the donor. Once a recipient has been found
and the kidney arrives, surgeons give the recipient anesthesia before
the operation begins.
After surgeons place the kidney in the recipient, they connect the blood
vessels from the kidney to the blood vessels of the person’s body.
After surgeons restore the blood flow to the new kidney, they attach the
ureter (a vessel that carries urine) to the person’s bladder. There
is usually room for the donor kidney to be transplanted and connected
without removing the original nonfunctioning kidneys.
Liver Transplant Surgery
If doctors find a close relative or a friend who will donate part of
his or her liver to the recipient, the transplant surgery will be scheduled
right after doctors remove the liver from the donor. During this process,
the recipient is prepared for surgery at the same time as the donor.
If a liver becomes available from a cadaver, the organ must be transplanted
within 12 to 18 hours. After the liver is removed from the donor, it is
preserved and packed for transport.
After surgeons locate the best possible recipient for the liver, they
begin the transplantation. First, surgeons remove the nonfunctioning liver.
When the new liver is transplanted, surgeons connect the blood vessels
from the liver to the person’s blood vessels. After blood flow is
restored, the bile duct—which carries the body’s waste from
the liver into the intestine—is connected. After the transplantation
is complete, the incision is closed.
The patient will begin recovery in the intensive care unit (ICU).
Lung Transplant Surgery
The lung must be transplanted into a recipient within four to six hours.
After the lung is removed from the donor, it is preserved and packed for
transport.
Typically, surgeons remove both lungs from the donor at the same time.
If a person needs a double-lung transplant, both lungs will be transplanted.
Otherwise, the lungs are usually separated after they are removed from
the donor and used for two different people who need a single-lung transplant.
As soon as a recipient is found, the person is given anesthesia and is
placed on an artificial respirator. Surgeons remove the nonfunctioning
lung and disconnect the blood vessels leading to the heart and the body’s
large airway. When the lung is placed within the recipient, the blood
vessels and airway from the donor lung are attached to the recipient's
corresponding blood vessels and bronchus. Surgeons then restore blood
flow and airflow.
During a double-lung transplantation, surgeons first replace the more
diseased lung, and then the less diseased lung is replaced.
Pancreas Transplant Surgery
The pancreas must be transplanted within 12 to 15 hours. After the pancreas
is removed from the donor, it is preserved and packed for transport.
As soon as a recipient is found, the person is given general anesthesia
and is placed on a ventilator during surgery. If only the pancreas is
being transplanted, the new organ can be placed on the left or the right
side. During a “pancreas-after-kidney” transplantation, the
pancreas is placed on the opposite side of the kidney. If the kidney and
the pancreas are being transplanted at the same time, doctors insert the
pancreas first, often on the right side. The kidney is then placed on
the left.
To restore blood flow to the new organ, surgeons reconnect a major artery
and a major vein to the new pancreas. Afterward, the duodenum (the beginning
of the small intestine) from the new pancreas is attached to the recipient’s
intestine or bladder. After all the connections have been completed, the
incision is closed.
Intestine Transplant Surgery
Although it is possible for a living donor to donate a segment of his
or her intestine, most intestine transplant surgeries involve a whole
organ from a deceased donor. In addition, most intestine transplant surgeries
are performed at the same time as liver transplantations.
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Current Research
Costimulatory Molecule Research
To increase long-term transplant survival rates, researchers have been
investigating mechanisms in the body that cause the immune system to attack
transplanted organs.
They have discovered a group of cells called costimulatory molecules
that boost immune tolerance. Currently, researchers are trying to develop
treatments that stimulate these cells—and the immune system—to
tolerate transplanted organs. Scientists have identified a molecule—called
CD28—on the surface of immune cells that is integral in the body’s
response to transplanted organs. By blocking CD28, scientists prevented
the immune system from rejecting new organs. Since then, scientists have
found that CD40, a similar molecule on the surface of immune cells, was
instrumental in rejecting organs.
Based on these discoveries, scientists from the National Institute of
Allergy and Infectious Diseases (NIAID) created animal models to determine
if blocking of CD28 and CD40 could prevent rejection within the animal’s
body. Researchers have used this approach to boost tolerance of heart
transplantation in mice and kidney transplantation in monkeys, without
the need for standard therapy that suppresses the entire immune system.
By blocking the signals of the costimulatory molecules, scientists can
prevent rejection without disabling the entire immune system, which decreases
risk for future infection.
Immunosuppressant Medication
Researchers have been studying a new immunosuppressant drug, CP-690,550,
that may reduce some of the common side effects associated with other
medications that curb the immune system.
Scientists tested CP-690,550 in mice with heart transplants and in monkeys
with kidney transplants. In both cases, animals that received the drug
survived much longer than untreated animals. In addition, none of the
animals had any of the side effects that usually occur after taking immunosuppressant
medication, including high cholesterol level, high blood sugar level,
high blood pressure, or a high white blood cell count. The animals also
showed no significant reduction in white blood cells or platelets, which
help the body fight infection.
CP-690,550 deactivates a chemical called Jak3, a protein found only in
immune system cells. Researchers found that blocking this enzyme could
help suppress the immune system without affecting other systems of the
body. Current immunosuppressant drugs target enzymes found in cells throughout
the body, resulting in the toxic side effects. The Jak3 inhibitor has
the advantage of selectively targeting a protein that only has effects
on immune cells.
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Towards the Future
Scientists continue to search for new ways to reduce organ rejection.
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Researchers are trying to manipulate
immune system molecules called cytokines to boost tolerance. Also,
they are trying to specifically target and destroy the cells that
would attack a transplant. Additional research is needed to determine
how long transplant survival can be extended by using these strategies. |
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The next goal for scientists is to
adapt to humans their successful research on animals. Promising
results in animal models and early human studies suggest that therapies
involving tolerance induction have the potential to prevent transplant
rejection without the use of immunosuppressive drugs. |
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References
1. “Organ
Donation and Transplantation,” The National Women’s Health
Information Center, August 2003.
2. “Transplantation
Primer: Introduction to Transplantation,” Scientific Registry
of Transplant Recipients, March 3, 2004.
3. “Twenty-five
Facts about Organ Donation and Transplantation,” National Kidney
Foundation, February 2002.
4. “Heart
Transplants,” Scientific Registry of Transplant Recipients,
March 3, 2004.
5. “During
the Transplant: Heart,” United Network for Organ Sharing (UNOS),
2004.
6. “Kidney
Transplants,” Scientific Registry of Transplant Recipients,
March 3, 2004.
7. “During
the Transplant: Kidney,” UNOS, 2004.
8. “Liver
Transplants,” Scientific Registry of Transplant Recipients,
March 3, 2004.
9. “During
the Transplant: Liver,” UNOS, 2004.
10. “Lung
Transplants,” Scientific Registry of Transplant Recipients,
March 3, 2004.
11. “During
the Transplant: Lung,” UNOS, 2004.
12. “Pancreas
Transplants,” Scientific Registry of Transplant Recipients,
March 3, 2004.
13. “During
the Transplant: Pancreas,” UNOS, 2004.
14. “During
the Transplant: Intestine,” UNOS, 2004.
15. “NIAMS
Researchers Collaborate to Produce Targeted Immunosuppressant Drug,”
National Institute of Arthritis and Musculoskeletal and Skin Diseases,
Oct. 30, 2003.
16. “Immune
Tolerance: Improving Transplantation Success,” National Institute
of Allergy and Infectious Diseases (NIAID), May 1999.
17. “Getting
a New Lung: Facts about Lung Transplants,” American Society
of Transplantation, Aug. 1, 2001.
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Writer: Andrea King
Clinical Reviewer: Patt Panzer, MD, MPH
Editors: Andrea King, Joanne Poeggel
Source of Material: Rockhill Communications, 14 Rock Hill Road Bala, Cynwyd,
PA 19004, (610) 667-2040, http://www.rockhillcommunications.com
Date Written: 3/22/04
Date Last Revised: 3/26/04
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