Kidney transplant is a surgical procedure performed to replace a diseased kidney with a healthy kidney from another person. The kidney may come from a deceased organ donor or from a living donor. Family members or individuals who are unrelated but make a good match may be able to donate one of their kidneys. This type of transplant is called a living transplant. Individuals who donate a kidney can live healthy lives with the remaining kidney.
A person receiving a transplant usually receives only one kidney, but, in rare situations, he/she may receive two kidneys from a deceased donor. In most cases, the diseased kidneys are left in place during the transplant procedure. The transplanted kidney is implanted in the lower abdomen on the front side of the body. A kidney transplant is recommended for children who have serious kidney dysfunction and will not be able to live without dialysis or a transplant.
Where do transplanted organs come from?
The majority of kidneys that are transplanted come from deceased organ donors. Organ donors are adults or children who have become critically ill and will not live as a result of their illness. If the donor is an adult, he/she may have agreed to be an organ donor before becoming ill. Parents or spouses can also agree to donate a relative's organs. Donors can come from any part of the United States. This type of transplant is called a cadaveric transplant.
A child receiving a transplant usually receives only one kidney, but, in rare situations, he/she may receive two kidneys from a cadaveric donor. Some experimentation with splitting one kidney for two recipients is underway. Family members or individuals who are unrelated but make a good match may also be able to donate one of their kidneys. This type of transplant is called a living transplant. Individuals who donate a kidney can live healthy lives with the kidney that remains. While most children requiring kidney transplants weigh more than 15 kilograms, or 33 pounds, some transplant centers are able to transplant adult kidneys into children and infants weighing only 5 kilograms, or 11 pounds.
How are transplanted organs allocated?
The United Network for Organ Sharing (UNOS) is responsible for transplant organ distribution in the United States. UNOS oversees the allocation of many different types of transplants, including liver, kidney, pancreas, heart, lung, and cornea. UNOS receives data from hospitals and medical centers throughout the country regarding adults and children who need organ transplants. The medical transplant team that currently follows your child is responsible for sending the data to UNOS, and updating them as your child's condition changes.
Criteria have been developed to ensure that all people on the waiting list are judged fairly as to the severity of their illness and the urgency of receiving a transplant. Once UNOS receives the data from local hospitals, people waiting for a transplant are placed on a waiting list and given a status code. The people in most urgent need of a transplant are placed highest on the status list, and are given first priority when a donor kidney becomes available.
When a donor organ becomes available, a computer searches all the people on the waiting list for a kidney and sets aside those who are not good matches for the available kidney. A new list is made from the remaining candidates. The person at the top of the specialized list is considered for the transplant. If he/she is not a good candidate, for whatever reason, the next person is considered, and so forth. Some reasons that people lower on the list might be considered before a person at the top include the size of the donor organ and the geographic distance between the donor and the recipient.
How is my child placed on the waiting list for a new kidney?
An extensive evaluation must be completed before your child can be placed on the transplant list. Testing includes:
- Blood tests
- Diagnostic tests
- Psychological and social evaluation of the child (if old enough) and the family
Tests are done to gather information that will help determine how urgent it is that your child is placed on the transplant list, as well as ensure the child receives a donor organ that is a good match. These tests include those to analyze the general health of the body, including the child's heart, lung, and kidney function, the child's nutritional status, and the presence of infection. Blood tests will help improve the chances that the donor organ will not be rejected. These tests may include:
- Blood chemistries - these may include serum creatinine, electrolytes (such as sodium and potassium), cholesterol, and liver function tests.
- Clotting studies, such as prothrombin time (PT) and partial thromboplastin time (PTT) - tests that measure the time it takes for blood to clot.
Other blood tests will help improve the chances that the donor organ will not be rejected. They may include:
- Your child's blood type - Each person has a specific blood type: type A+, A-, B+, B-, AB+. AB-, O+, or O-. When receiving a transfusion, the blood received must be a compatible type with your child's own, or an allergic reaction will occur. The same allergic reaction will occur if the blood contained within a donor organ enters your child's body during a transplant. Allergic reactions can be avoided by matching the blood types of your child and the donor.
- Human leukocyte antigens (HLA) and panel reactive antibody (PRA) - These tests help determine the likelihood of success of an organ transplant by checking for antibodies in your child's blood. Antibodies are made by the body's immune system in reaction to a foreign substance, such as a blood transfusion or a virus. Antibodies in the bloodstream will try to attack transplanted organs. Therefore, children who receive a transplant will take medications that decrease this immune response. The higher your child's PRA, the more likely that an organ will be rejected.
- Kidney, liver, and other vital organ function tests
- Viral studies - These tests determine if your child has antibodies to viruses that may increase the likelihood of rejecting the donor organ, such as cytomegalovirus (CMV).
- The diagnostic tests that are performed are extensive, but necessary to understand the complete medical status of your child. The following are some of the other tests that may be performed, although many of the tests are decided on an individual basis:
- Enal ultrasound - a non-invasive test in which a transducer is passed over the kidney producing sound waves which bounce off of the kidney, transmitting a picture of the organ on a video screen. The test is used to determine the size and shape of the kidney, and to detect a mass, kidney stone, cyst, or other obstruction or abnormality.
- Kidney biopsy - a procedure in which tissue samples are removed (with a needle or during surgery) from the kidney for examination under a microscope.
- Intravenous pyelogram (IVP) - a series of x-rays of the kidney, ureters, and bladder with the injection of a contrast dye into the vein; to detect tumors, abnormalities, kidney stones, or any obstructions, and to assess renal blood flow.
The transplant team will consider all information from interviews, your child's medical history, physical examination, and diagnostic tests in determining whether your child can be a candidate for kidney transplantation. After the evaluation and your child has been accepted to have a kidney transplant, your child will be placed on the United Network for Organ Sharing (UNOS) list.
What is involved in kidney transplant surgery?
Once an organ becomes available to your child, you and your child will be immediately called to the hospital. This call can occur at any time, so you should always be prepared to go to the hospital, if needed. Once at the hospital, the child will have some more final blood work and tests to confirm the match of the organ. The child will then go to the operating room. The transplant surgery may require several hours, but will vary greatly depending on each individual case. During the surgery, a member of the transplant team will keep you informed on the progress of the transplant.
Post-operative care for kidney transplant:
After the surgery, your child will go to the intensive care unit (ICU) to be monitored closely. The length of time your child will spend in the ICU will vary based on your child's unique condition. After your child is stable, he/she will be sent to the special unit in the hospital that cares for kidney transplant patients. Your child will continue to be monitored closely. You will be educated on all aspects of caring for your child during this time. This will include information about medications, activity, follow-up, diet, and any other specific instructions from your child's transplant team.
What is rejection?
Rejection is a normal reaction of the body to a foreign object. When a new kidney is placed in a person's body, the body sees the transplanted organ as a threat and tries to attack it. The immune system makes antibodies to try to kill the new organ, not realizing that the transplanted kidney is beneficial. To allow the organ to successfully live in a new body, medications must be given to trick the immune system into accepting the transplant and not thinking it is a foreign object.
What is done to prevent rejection?
Medications must be given for the rest of the child's life to fight rejection. Each child is unique, and the transplant team has preferences for different medications. Some of the anti-rejection medications most commonly used include the following:
- Mycophenolate mofetil
- Antithymocyte Ig (ATGAM)
New anti-rejection medications are continually being approved. Physicians tailor drug regimes to meet the needs of each individual child. The doses of these medications may change frequently as your child's response to them changes. Because anti-rejection medications affect the immune system, children who receive a transplant will be at higher risk for infections. A balance must be maintained between preventing rejection and making your child very susceptible to infection. Blood tests to measure the amount of medication in the body are done periodically to make sure your child does not get too much or too little of the medications. White blood cells are also an important indicator of how much medication your child needs.
What about infection?
This risk of infection is especially great in the first few months because higher doses of anti-rejection medications are given during this time. Your child will most likely need to take medications to prevent other infections from occurring. Some of the infections your child will be especially susceptible to include oral yeast infection (thrush), herpes, and respiratory viruses.
Living with a transplant is a life-long process
Medications must be given that trick the immune system so it will not attack the transplanted organ. Other medications must be given to prevent side effects of the anti-rejection medications, such as infection. Frequent visits to and contact with the transplant team are essential. Knowing the signs of organ rejection (and watching for them on a daily basis) is critical. When the child becomes old enough, he/she will need to learn about anti-rejection medications (what they do and the signs of rejection), so he/she can eventually care for himself/herself independently.
Every child is unique and every transplant is different. Results continually improve as physicians and scientists learn more about how the body deals with transplanted organs and search for ways to improve transplantation.