Types of transplants

Autograft

A transplant of tissue from one to oneself. Sometimes this is done with surplus tissue, or tissue that can regenerate, or tissues more desperately needed elsewhere (examples include skin grafts, vein extraction for CABG, etc.) Sometimes this is done to remove the tissue and then treat it or the person, before returning it (examples include stem-cell autograft and storing blood in advance of surgery).

Allograft

An allograft is a transplanted organ or tissue from a genetically non-identical member of the same species. Most human tissue and organ transplants are allografts.

Isograft

A subset of allografts in which organs or tissues are transplanted from a donor to a genetically identical recipient (such as an identical twin). Isografts are differentiated from other types of transplants because while they are anatomically identical to allografts, they are closer to autografts in terms of the recipient's immune response.

Xenograft

A transplant of organs or tissue from one species to another. Examples include porcine heart valves, which are quite common and successful, a baboon-to-human heart (failed), and piscine-primate (fish to non-human primate) islet (i.e. pancreatic or insular tissue), the latter's research study directed for potential human use if successful. See: xenotransplantation.

Split transplants

Sometimes, a deceased-donor organ (specifically the liver) may be divided between two recipients, especially an adult and a child. This is uncommon, as the outcomes are worse for both patients than had they received the whole organ.

Domino transplants

This operation is usually performed for cystic fibrosis as both lungs need to be replaced and it is a technically easier operation to replace the heart and lungs en bloc. As the recipient's native heart is usually healthy, this can then itself be transplanted into someone needing a heart transplant. That term is also used for a special form of liver transplant, in which the recipient suffers from familial amyloidotic polyneuropathy in which the liver (slowly) produces a protein that damages other organs; their liver can be transplanted into an older patient who is likely to die from other causes before a problem arises.