Liver Transplantation Trasplante de Hígado

Liver Transplantation

What is a liver transplant?

A liver transplant is a surgical procedure performed to replace a diseased liver with a healthy liver from another person. The liver 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 a portion of their liver. This type of transplant is called a living transplant. Individuals who donate a portion of their liver can live healthy lives with the remaining liver.

An entire liver may be transplanted, or just a section. Because the liver is the only organ in the body able to regenerate, a transplanted portion of a liver can rebuild to normal capacity within weeks.

Why is a liver transplant recommended?

A liver transplant is recommended for individuals who have serious liver dysfunction and will not be able to live without having the liver replaced. The most common liver disease for which transplants are done is viral hepatitis-induced cirrhosis. Other diseases may include the following:

  • Acute hepatic necrosis or fulminant liver failure

  • Biliary atresia and other congenital disorders

  • Metabolic diseases

  • Liver cancers or bile duct cancer

  • Autoimmune hepatitis, primary biliary cirrhosis, or sclerosing cholangitis

  • Liver damage from overdose of medications toxic to the liver, such as acetaminophen

How many individuals in the U.S. need liver transplants?

Visit the United Network for Organ Sharing (UNOS) website for statistics of patients awaiting a liver transplant, and the number of patients who underwent a transplant this year. There are about 17,000 people waiting and over 6000 liver transplants per year.

Where do transplanted organs come from?

The majority of livers that are transplanted come from organ donors who have died. These organ donors are adults or children who have become critically ill (often due to an accidental injury) and have died as a result of their illness. If the donor is an adult, he or 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 U.S. This type of transplant is called a deceased donor transplant.

An individual receiving a transplant may either get a whole liver, or a segment of one. If an adult liver is available and is an appropriate match for two individuals on the waiting list, the donor liver can be divided into two segments and each part is transplanted one for the adult and one for a child.

Living family members may also be able to donate a section of their liver. This type of transplant is called a living-related transplant. Individuals receiving a partial liver seem to do as well as those receiving a whole liver. Relatives who donate a portion of their liver can live healthy lives with the segment that remains.

How are transplanted organs allocated?

UNOS is responsible for transplant organ distribution in the U.S. 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 team is responsible for sending the data to UNOS, and updating it as your condition changes.

Criteria have been developed to ensure that all people on the waiting list are judged fairly as to the severity of their liver illness using the MELD score and the associated 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 with a MELD score. The people in most urgent need of a transplant are placed highest on the status list and are given first priority when a donor liver becomes available. The MELD score is calculated using measurements of bilirubin, creatinine, and an international normalized ratio (INR).

When a donor organ becomes available, a computer searches all the people on the waiting list for a liver and sets aside those who are not good matches for the available liver. 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 or she is not a good candidate, for whatever reason, the next person is considered, and so forth. Sometimes, people lower on the list might be considered before a person at the top because of the size of the donor organ or the geographic distance between the donor and the recipient. There is now a regional share for fulminant liver failure and a MELD score of over 35 in the United States.

How is an individual placed on the waiting list for a new liver?

Extensive testing must be done before an individual can be placed on the transplant list. Testing includes:

  • Psychological and social evaluation

  • Diagnostic tests for heart, lung, and other organ conditions

  • Blood tests. Blood tests are done to gather information that will help determine how urgent it is that an individual is placed on the transplant list, as well as to ensure the individual receives a donor organ that is a good match. These tests may include:

    • Liver enzymes. Elevated levels of liver enzymes can alert doctors to liver damage or injury, since the enzymes leak from the liver into the bloodstream.

    • Bilirubin. Bilirubin is produced by the liver and is excreted in the bile. Elevated levels of bilirubin often indicate an obstruction of bile flow or a defect in the processing of bile by the liver.

    • Albumin. Below-normal levels of proteins made by the liver are associated with many chronic liver disorders.

    • Clotting studies, such as an international normalized ratio (INR) formerly known as the prothrombin time (PT). Tests that measure the time it takes for blood to clot are often used prior to liver transplantation. Blood clotting requires vitamin K and proteins made by the liver. Liver cell damage and bile obstruction can both interfere with proper blood clotting.

    • Renal function. Creatinine reflects the liver function in critically ill people.

Other blood tests will help improve the chances that the donor organ will not be rejected. They may include:

  • Your 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 an individual's type of blood or an immune reaction will occur. The same immune reaction will occur if the blood contained within a donor organ enters an individual's body during a transplant.

  • Viral studies. These tests determine if the recipient has viruses that may increase the likelihood of infecting the donor organ, such as hepatitis B virus, hepatitis C virus, cytomegalovirus (CMV) and Epstein-Barr virus (EBV).

Diagnostic tests may include any of the tests that have been done to evaluate the extent of the disease, including the following:

  • Abdominal ultrasound (also called sonography). A diagnostic imaging technique which uses high-frequency sound waves and a computer to create images of blood vessels, tissues, and organs. Ultrasounds are used to view internal organs and to assess blood flow through various vessels.

  • Liver biopsy. A procedure in which tissue samples from the liver are removed (with a needle) from the body for examination under a microscope.

How long does it take to get a new liver?

There is no definite answer to this question. Sometimes, individuals wait only a few days or weeks before receiving a donor organ. If no living-related donor is available, it may take months or years on the waiting list before a suitable donor organ is available. Unfortunately, some people die, about 20%, before an acceptable donor organ can be found.

How is a person notified when a liver is available?

Each transplant team has its own specific guidelines regarding waiting on the transplant list and being notified when a donor organ is available. In most instances, you will be notified by phone or pager that an organ is available. You will be told to come to the hospital immediately so you can be prepared for the transplant.

What is rejection?

Rejection is a normal reaction of the body to a foreign object. When a new liver 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 liver 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.

What is done to prevent rejection?

Medications must be given for the rest of the individual's life to fight rejection and each transplant team has preferences for different medications. The anti-rejection medications most commonly used include:

  • Cyclosporine

  • Tacrolimus

  • Sirolimus

  • Prednisone

  • Azathioprine

  • Mycophenolate mofetil

The doses of these medications may change frequently, depending on your response. Because anti-rejection medications affect the immune system, individuals who receive a transplant are at higher risk for infections. A balance must be maintained between preventing rejection and making you very susceptible to infection. Blood tests to measure the amount of medication in the body are done periodically to make sure you do not get too much or too little of the medications. White blood cells are also an important indicator of how much medication you may need.

This risk of infection is especially great in the first few months after transplant because higher doses of anti-rejection medications are given during this time. You will most likely need to take medications to prevent other infections from occurring. Some of the infections you will be especially susceptible to include oral yeast infection (thrush), herpes, and respiratory viruses.

What are the signs of rejection?

The following are the most common symptoms of rejection. However, each individual may experience symptoms differently. Symptoms may include:

  • Fever greater than 100 degrees F

  • Jaundice. A yellowing of the skin and eyes.

  • Dark urine

  • Itching

  • Abdominal swelling or tenderness

  • Fatigue

  • Irritability

  • Headache

  • Nausea

The symptoms of rejection may resemble other medical conditions or problems. Consult your transplant team with any concerns you may have.

What is the long-term outlook after a liver transplant?

Living with a transplant is a lifelong process. Medications must be taken for the rest of your life to fight rejection. Other medications must also be taken to prevent side effects of the anti-rejection medications, such as infection. Frequent visits and contact with the transplant team are essential.

There is no good answer as to how long an individual can be expected to live after a liver transplant. Each person and every transplant is different. Results improve continually as doctors and scientists learn more about how the body deals with transplanted organs and search for ways to improve the success of transplantation.

Related Items