A living-donor transplant is a surgical procedure to remove an organ or portion of an organ from a living person and place it in another person whose organ is no longer functioning properly.

The popularity of living-organ donation has increased dramatically in recent years as an alternative to deceased-organ donation due to the growing need for organs for transplantation and shortage of available deceased-donor organs. About 6,000 living-organ donations are reported each year in the U.S.

People can donate one of their two kidneys, and the remaining kidney is able to perform the necessary functions. Living-kidney donation is the most common type of living-donor procedure.

Living donors can also donate a portion of their liver and the remaining liver regenerates, grows back to nearly its original size, and performs its normal function.

Kidney and liver are the most common types of living-donor organ procedures, but living people may also donate tissues for transplantation, such as blood, skin and bone marrow.

Living-organ donation types

There are two types of living-organ donation.

Directed donation

This is the most common type of living-donor organ donation. In this type of living-organ donation, the donor is directing the organ to a specific recipient for transplant.

The recipient may be:

  • A first-degree relative, such as a parent, brother, sister or adult child
  • A biologically unrelated person who has a connection with the transplant candidate, such as a spouse or significant other, a friend, or a coworker
  • A person who has heard about the transplant candidate's need

Nondirected donation

In nondirected donation, also known as good Samaritan or altruistic donation, the donor does not name the recipient of the donated organ. The match is based on medical need and compatibility.

In some cases, the donor may choose not to know the recipient. In other cases, they may meet if both the donor and recipient agree and the transplant center policy allows it.

Paired donation and donation chains

Living donors often play an important role in paired donation and donation chains. Paired-organ donation (also known as paired exchange) may be an option when a donor and intended recipient have incompatible blood types, or when the recipient has unacceptable antibodies against the donor's tissue antigens.

In paired donation, two or more organ-recipient pairs trade donors so that each recipient gets an organ that is compatible with his or her blood type. A nondirected living donor also may participate in paired-organ donation to help match incompatible pairs.

More than one pair of incompatible living donors and recipients may be linked with a nondirected living donor to form a donation chain in order to receive compatible organs. In this scenario, multiple recipients benefit from a single nondirected living donor.

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