The organ transplantation is the moving of an organ from one body to another or from a donor site to another location on the person's own body, to replace the recipient's damaged or absent organ. Organs and/or tissues that are transplanted within the same person's body are called autografts. Transplants that are recently performed between two subjects of the same species are called allografts. Allografts can either be from a living or cadaveric source.
Organs that can be transplanted are the heart, kidneys, liver, lungs, pancreas, intestine, and thymus. Tissues include bones, tendons (both referred to as musculoskeletal grafts), cornea, skin, heart valves, nerves and veins. Worldwide, the kidneys are the most commonly transplanted organs, followed by the liver and then the heart. Cornea and musculoskeletal grafts are the most commonly transplanted tissues; these outnumber organ transplants by more than tenfold.
Organ donors may be living, brain dead, or dead via circulatory death. Tissue may be recovered from donors who die of circulatory death, as well as of brain death – up to 24 hours past the cessation of heartbeat. Unlike organs, most tissues (with the exception of corneas) can be preserved and stored for up to five years, meaning they can be "banked". Transplantation raises a number of bioethical issues, including the definition of death, when and how consent should be given for an organ to be transplanted, and payment for organs for transplantation.
Types of Transplants:
Autograft: Autografts are the transplant of tissue to the same person. Sometimes this is done with surplus tissue, tissue that can regenerate, or tissues more desperately needed elsewhere (examples include skin grafts, vein extraction for CABG, etc.). Sometimes an autograft 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). In a rotationplasty, a distal joint is used to replace a more proximal one; typically a foot or ankle joint is used to replace a knee joint. The person's foot is severed and reversed, the knee removed, and the tibia joined with the femur.
Allograft and Allotransplantation: An allograft is a transplant of an organ or tissue between two genetically non-identical members of the same species. Most human tissue and organ transplants are allografts. Due to the genetic difference between the organ and the recipient, the recipient's immune system will identify the organ as foreign and attempt to destroy it, causing transplant rejection. The risk of transplant rejection can be estimated by measuring the Panel reactive antibody level.
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 do not trigger an immune response.
Xenograft and Xenotransplantation: A transplant of organs or tissue from one species to another. An example is porcine heart valve transplant, which is quite common and successful. Another example is attempted piscine-primate (fish to non-human primate) transplant of islet (i.e. pancreatic or insular tissue) tissue. The latter research study was intended to pave the way for potential human use if successful. However, xenotransplantion is often an extremely dangerous type of transplant because of the increased risk of non-compatibility, rejection, and disease carried in the tissue.
Split Transplants: Sometimes a deceased-donor organ, usually a liver, may be divided between two recipients, especially an adult and a child. This is not usually a preferred option because the transplantation of a whole organ is more successful.
Domino Transplants: In people with cystic fibrosis, where both lungs need to be replaced, it is a technically easier operation with a higher rate of success to replace both the heart and lungs of the recipient with those of the donor. As the recipient's original heart is usually healthy, it can then be transplanted into a second recipient in need of a heart transplant.
Organs and Tissues Transplanted:
Heart (deceased-donor only)
Lung (deceased-donor and living-related lung transplantation)
Heart/Lung (deceased-donor and domino transplant
Kidney Transplant (deceased-donor and living-donor)
Liver Transplant (deceased-donor and living-donor
Pancreas Transplant (deceased-donor only)
Intestine Transplant (deceased-donor and living-donor)
Stomach Transplant (deceased-donor only)
Testis Transplant (deceased-donor and living-donor)
Tissues, cells and fluids
Hand (deceased-donor only)
Cornea (deceased-donor only)
Skin, including face replant (autograft) and face transplant (extremely rare)
Islets of Langerhans (pancreas islet cells) (deceased-donor and living-donor)
Bone marrow/Adult stem cell (living-donor and autograft)
Blood transfusion/Blood Parts Transfusion (living-donor and autograft)
Blood Vessels (autograft and deceased-donor)
Heart Valve (deceased-donor, living-donor and xenograft [porcine/bovine])