Xenotransplantation is the transplantation of cells, tissue or other organs between phylogenetically different species. The process of grafting organs or tissues between members of different of different species. It is any procedure that involves the transplantation, implantation or infusion into a human recipient of either live cells, tissues or organs from a non human animal source or human body fluids, cells, tissues, or organs that have had ex-vivo contact with live non human animal cells, tissues or organs. The development of xenotransplantation is driven by the fact that the demand for human organs for clinical transplantation far exceeds the supply.
Currently main problem is the long waiting list, according to World Health Organization (WHO), more than 114,000 organs transplantation are performed every year worldwide, which is only the 10% of the actual need currently.
The main advantage of xenotransplant is that they would provide an easily available animal source with an unlimited supply of donor organs. Ethically, pigs are an acceptable option for an alternative organ source. However, this solution is immunologically less desirable than non human primates, due to genetic distance between pigs and humans. Pig xenotransplant in non human primates have progressed a great deal, and the first clinical trials of complete organ xenografts will likely involve patients with renal failure. These patients could be selected because they have a high degree of sanitisation, which prevents them from easily obtaining an allograft.