<P> The heart was a major prize for transplant surgeons . But over and above 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 was prepared to attempt a human heart transplant in 1964, but when a premature failure of comatose Boyd Rush's heart caught Hardy with no human donor, he used a chimpanzee heart, which beat in his patient's chest for approximately one hour and then failed . The first partial success was achieved on 3 December 1967, when Christiaan Barnard of Cape Town, South Africa, performed the world's first human - to - human heart transplant with patient Louis Washkansky as the recipient . Washkansky survived for eighteen days amid what many saw as a distasteful publicity circus . The media interest prompted a spate of heart transplants . Over a hundred were performed in 1968--1969, but almost all the people died within 60 days . Barnard's second patient, Philip Blaiberg, lived for 19 months . </P> <P> It was the advent of cyclosporine that altered transplants from research surgery to life - saving treatment . In 1968 surgical pioneer Denton Cooley performed 17 transplants, including the first heart - lung transplant . 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 on to riskier fields, including multiple - organ transplants on humans and whole - body transplant research on animals . On 9 March 1981, the first successful heart - lung transplant took place at Stanford University Hospital . The head surgeon, Bruce Reitz, credited the patient's recovery to cyclosporine - A . </P> <P> As the rising success rate of transplants and modern immunosuppression make transplants more common, the need for more organs has become critical . Transplants from living donors, especially relatives, have become increasingly common . Additionally, there is substantive research into xenotransplantation, or transgenic organs; although these forms of transplant are not yet being used in humans, clinical trials involving the use of specific cell types have been conducted with promising results, such as using porcine islets of Langerhans to treat type 1 diabetes . However, there are still many problems that would need to be solved before they would be feasible options in people requiring transplants . </P> <P> Recently, researchers have been looking into means of reducing the general burden of immunosuppression . Common approaches include avoidance of steroids, reduced exposure to calcineurin inhibitors, and other means of weaning drugs based on patient outcome and function . While short - term outcomes appear promising, long - term outcomes are still unknown, and in general, reduced immunosuppression increases the risk of rejection and decreases the risk of infection . The risk of early rejection is increased if corticosteroid immunosuppression are avoided or withdrawn after renal transplantation . </P>

Which is the least likely tissue or organ to be transplanted