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  Wikipedia: Organ transplant

Wikipedia: Organ transplant
Organ transplant
From Wikipedia, the free encyclopedia.

An organ transplant is the transplantation of an organ (or part of one) from one body to another, for the purpose of replacing the recipient's damaged or failing organ with a working one from the donor.

Blood transfusion and bone marrow transplants are special cases of a transplant where the transplanted part of the body is renewable; in other cases, the organ donor either has another of the same organ (such as lungs or kidneys), or has been declared brain dead.

Organs that can currently be transplanted include:

The heart and lungs are sometimes transplanted together, in a heart-lung transplant.

Organ transplants that can not be performed today include

History

Successful inter-human transplants have a relatively long history, the operative skills were present long before the necessities for post-operative survival were discovered. Rejection was, is, and may always be the key problem.

The third century saints Damian and Cosmas are recorded as performing the first medical transplant - replacing the gangrenous leg of a white man with the leg of a dead Moor. Less miraculous was the work of French surgeon Alexis Carrel, in the 1900s, with the transplantation of arteries or veins. His skillful anastomosis operations, the new suturing techniques, laid the ground for later transplant surgery. From 1902 Carrel performed transplant experiments on dogs. Surgically successful in moving kidneys, hearts and spleens, he was one of the first to identify the problem of rejection.

Autotransplants, transfer of material on the same patient, was successfully demonstrated by Jean Casimir Guyon with skin in 1869. Slightly later, Jacques Reverdin used a similar technique to aid wound healing. Major steps in skin transplants occurred during WW I, notably in the work of Harold Gillies at Aldershot. Among his advances was the tubed pedicle graft, maintaining a flesh connection from the donor site until the graft established its own blood flow. Gillies' assistant, Archibald McIndoe, carried on the work into WW II as reconstructive surgery. In 1962 the first successful replantation surgery was perofrmed - re-attaching a severed limb and restoring (limited) functioning and feeling.

The first successful cornea transplant, a keroplastic operation, was performed by Eduard Zirm in Austria in 1906, for all other transplants rejection seemed an insurmountable problem. In the late 1940s Peter Medawar, working for the National Institute for Medical Research, improved the understanding of rejection. Identifying the immune reactions in 1951 Medawar suggested that immunosuppressive drugs could be used. Cortisone had been recently discovered and the more effective azathioprine was identified in 1959, but it was not until the discovery of cyclosporine in 1970 that transplant surgery found a sufficiently powerful immunosuppressive.

The first successful human organ transplant was the kidney in December 1954 in Boston by Joseph Murray and J. Hartwell Harrison. The kidney was the easiest organ to transplant, tissue-typing was simple, the organ was relatively easy to remove and implant, live donors could be used without difficulty, and in the event of failure kidney dialysis was available from the 1940s. Tissue-typing was essential to the success, early attempts in the 1950s on sufferers from Bright's disease had been very unsuccessful. The 1954 transplant was between identical twins.

The success with the kidney led to attempts with other organs. There was a successful cadaveric lung transplant into a lung cancer sufferer in June 1963 by James Hardy in Jackson, Mississippi. The patient survived for eighteen days before dying of kidney failure. Thomas Starzl of Denver attempted a liver transplant in the same year, he was not successful until 1967.

The heart was a major prize for transplant surgeons. But, as well as rejection issues the heart deteriorates within minutes of death so any operation would have to be performed at great speed. The development of the heart-lung machine was also needed. Lung pioneer James Hardy attempted a human heart transplant in 1964, but a premature failure of the recipient's heart caught Hardy with no human donor, he used a chimpanzee heart which failed very quickly. The first success was achieved in December 1967 by Christiaan Barnard in Cape Town, Louis Washkansky survived for eighteen days amid a distasteful publicity circus. The media interest prompted a spate of heart transplants, over a hundred were performed in 1968-69, almost all the patients died within sixty days.

As mentioned, it was the advent of cyclosporine that altered transplants from research surgery to live-saving treatment. In 1968 surgical pioneer Denton Cooley performed seventeen transplants, fourteen of his patients were dead within six months. By 1984 two-thirds of all heart transplant patients survived for five years or more. With organ transplants becoming commonplace, limited only by donors, surgeons moved onto more risky fields, multiple organ transplants on humans (first successful heart-lung in 1981) and whole-body transplant research on animals. Other researchers moved onto the use of artificial, animal or trans-genic organs.

See also: Artificial organ

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From Wikipedia, the free encyclopedia. 
Modified by Geona