Rom Harre is Emeritus Professor of Philosophy at Linacre College, Oxford, and Adjunct Professor of Philosophy at Georgetown University, Washington, DC. In his book, Pavlov’s Dogs and Schrodinger’s Cat: Scenes from the Living Laboratory, we get an enlightening look at the use of plants and animals–including humans–in scientific experiments. In the excerpt below we see how dogs were essential to figuring out heart transplants.
By coincidence, two men, one living in the seventeenth century and one in the twentieth, who both used dogs as models and whose work led to major breakthroughs in medicine bore the same name. The first Richard Lower used dogs to perfect blood transfusion techniques, while the second Richard Lower used the same species of animals to perfect heart transplantation methods.
History, as presented in the media and so in popular belief, credits the beginning of heart transplantation techniques to Christiaan Barnard. Digging a little deeper we come across the most successful practitioner of this art, Norman Shumway. However, using dogs as experimental apparatus – as pilot plants- to perfect the surgical techniques required to carry out transplant operations on human beings. Christiaan Barnard did forty-eight trial transplants with dogs before he undertook such an operation with a human being. He acknowledges that what he uses ‘was a technique built on that developed by Shumway and Lower, who had experimented on more than 300 dogs… With their findings joined to mind there was little point in continuing to further sacrifice of animals.’
Richard Lower studied at the Medical School at Cornell but moved for his residency period to the University of Washington in the northwest of the United States. One autobiographic snippet suggests that the American northwest suited his love of the outdoors. Finding things not to his liking there he moved south to Stanford were he could qualify more quickly. Working in very primitive conditions in the training section of the hospital he eventually met up with Norman Shumway and forged a remarkable partnership with him.
Norman Shumway (1923-2006) studied medicine at Vanderbilt University, moving on to a doctorate at the University of Minnesota in 1956. He was appointed as a surgery instructor at Stanford University in 1958, where he remained for the rest of his career. He seems to have been a somewhat paradoxical character. Reticent and wary of publicity, yet he was famous for his witty and jocular conversation, particularly during the course of long and demanding surgical procedures. The persistence with which he pursued his goal of successful himan heart transplantation suggests a dogged streak.
Lower began his experimental programme as an assistant to Shumway working on the techniques for open heart surgery, including the possibility of cooling a living heart so as to stop its beating. Under this condition surgical repair would be greatly facilitated. The heart could then be warmed up and restarted with a fibrillator. Perhaps the heart could be removed completely from the patient’s body for delicate surgical work and replaced when the repair was done. This is the procedure known as ‘auto-transplantation’.
Dogs were already in regular use at Stanford University Medical School for training surgeons. …Lower and Shumway continued their use of dogs as experimental apparatus, pilot plants for the ultimate transfer of the techniques to the human case. Despite his skill in surgery Lower was unable to achieve successful autotransplantation. The reason was simple. To remove the heart from the dog the aorta and pulmonary vessels had to be cut in such a way that there was sufficient length on each side of the incision for sewing the heart back in. Lower simply could not manage to retain enough of the vessels on either side of the severing cut to meet this essential condition. However, it then ocurred to him that in implanting a ‘homologous heart’ – one from another dog – the problem could be overcome. By cutting the aorta of the first dog close to the heart a substantial section of the aorta remained in the cavity of the chest. By cutting the aorta of the donor dog to leave a substantial length from the heart, enough ‘tubing’ was left to make successful suturing possible. The same held for other cardiac blood vessels. This technique proved to be entirely successful. The first operation transplanting a heart from one dog to another was carried out in 1959.
The results of the project were reported in the Surgical Forum of 1960. In the discussion section of the paper the authors report that the dogs died within a few days and at best survived for as much as three weeks. The cause of death was found to be adverse immunological reactions rather than heart failure. ‘If the immunological mechanisms of the host were prevented from destroying the graft, in all likelihood it would continue to function adequately for the normal life span of the animal.’ Lower carried out other experiments, include a bizarre xenotransplant, inserting a human heart into a chimpanzee. A newspaper report described the result euphemistically: ‘the heart functioned until Lower euthanized the chimp and terminated the experiment.’
Lower eventually moved to Richmond, Virginia, where among his visitors was a South African surgeon, Christiaan Barnard. Barnard also visited Shumway whom he had know previously at the University of Minnesota. Back in Stanford it was not until 1967 that Shumway was ready to go ahead with confidence to a programme of human transplantations. During the preceding eight years he had continued his use of the bodies of living dogs as the essential apparatus for his transplantation experiments. It was a great surprise to him to learn that on December 23 his old acquaintance and recent visitor, Christiaan Barnard, had carried out a successful human heart transplantation operation on Louis Washkansky. The use of the necessary immunosupprressing drugs left often the possibility of fatal infection. Washkansky contracted pneumonia and died after only 18 days. After a few more operations Barnard abandoned his programme because the immunosuppresing drugs available at that time for preventing the rejection of the transplant also left the patient vulnerable to common and simple infections…
Shumway began his own programme of transplantations on 6 January 1968. While his patients survived the operation for increasing lengths of time, and given immunosuppressing drugs, continued on the path to recovery, the life expectancy of the recipients of healthy hearts was subject to the danger of infections with which the damped immune system could not cope… All this changed when a new drug, ‘cyclosporine’, was introduced. While suppressing the body’s efforts to expel the alien heart tissue it allowed resistance to common infections to remain robust.