Terminology

The definitions of flaps and grafts used above describe the vas­cular basis of the tissue transfer and the constituents of the transferred tissue. Most tissue transfer is from one place to another in the same person. However, there are other forms of transfer and further terminology is needed to explain the genetic basis of these transfers. An autograft is tissue trans­ferred from one location to another on the same patient. An isograft is tissue transferred between two genetically identical individuals, such as the first successful renal transplant that was between identical twins. An allograft is tissue transferred between genetically different members of the same species. Most solid organ tissue transplantation involves this type of transfer. Rejection of the transplanted tissue will occur unless immunosuppressant drugs are used. A xenograft is tissue trans­ferred from a donor of one species to a recipient of another species. Xenografts are usually small amounts of tissue rendered acellular before implantation to prevent rejection.