Organs and allocation

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 also can agree to donate a relative’s organs. Donors can come from any part of the U.S. This type of transplant is called a cadaveric 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. This procedure is more often done in children than adults.

Living family members also may 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?

The United Network for Organ Sharing 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 them 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 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 liver becomes available.

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/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 distance between the donor and the recipient.