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Basic definitions

When a graft is taken from one place and put in another there are four possible scenarios.

Autograft
within the same animal
Isograft
between genetically identical (syngenic) individual, eg monozygotic twins and inbred experimental animals
Allograft
between genetically non identical individuals of the same species
Xenograft
between individuals of differing species

Examples of autografs include; autologous skin grafting, where skin is taken from one place and moved to another, most commonly as a split skin graft. Using a vein from the leg to make a new arterial conduit in bypass surgery is another example when one tissue is used to provide the function of another. In the abdomen a piece of intestine may be used to replace the bladder or the stomach.

Isografts would in the main represent grafts between identical twins. For instance one of the milestones in transplantation was the grafting of a kidney in 1954 from a healthy twin to the sybling dying from renal failure.

Allografts are the most common graft when it comes to major organ transplantation. Cadaveric kidneys, liver, pancreas, heart and lung would fall into this category.

Xenografts are in the main experimental.

An orthotopic graft is a graft placed in the usual anatomic location of the organ and a hetertopic graft is placed in another location.

Renal transplantation is the practice of transplanting a kidney. In the context of the above definitions, it is usually an allograft and it is grafted into the iliac fossa in a so called hetero-topic location. In the main renal transplantation is for patients in end stage renal failure from a variety of causes, (See 5). When in renal failure the patients survival depends on renal replacement therapy.


next up previous contents index
Next: History of transplantation Up: Introduction Previous: Introduction   Contents   Index
Adrian P. Ireland