Transplantation medicine is one of healthcare’s newest disciplines. It has transitioned from the stuff of science fiction to reality in a few short decades. Solid organ and tissue transplantation rests on three legs: Technical, immunological, and ethical.
Technical The surgical version of robbing Peter to pay Paul requires many hands and teams, especially if both the tissue donor and recipient are alive and meant to stay so post-op. In 1954, Joseph Murray* performed the world’s first successful living related kidney transplant between the identical Herrick twins at the Brigham and Woman’s Hospital in Boston (top image), an operation that lasted five and a half hours.
*Murray received the 1990 Nobel Prize in Physiology or Medicine for his work in organ transplantation.
In the years that followed that seminal event, transplantation targets became increasingly ambitious and what was formerly regarded as impossible, became reality. The 1960s saw the successful transplantation of lungs, pancreas, hearts and livers. The 1980s was the decade of the doubles with heart/lung, heart/liver and double lung transplants being performed at Stanford, Pittsburgh and Toronto, respectively. Transplantation firsts in the 1990s included laparoscopic and robotic nephrectomies, knee joint, living donor partial pancreas and partial liver transplantations, hands and a tissue-engineered urinary bladder.
Transplantation procedures performed in 21st century have already surpassed the imagination of the most creative Hollywood screenwriters. Transplanted tissues of 21st century vintage include small bowel, arms, legs, penises (the correct plural is penes), uterus and ovaries, from each of which normal fetuses/infants have been conceived and born, and yes, even complete facial transplants* (bottom image).
*The image is from the same-themed Hollywood film, Face/Off which was regarded as fiction when it was released in 1997.
Immunological All of the surgical and procedural pyrotechnics noted above would have been for nought had it not been for the burgeoning art of immunosuppression, without which the recipient will almost invariably reject the donor tissue. These agents fall into one of several categories:
• Calcineurin inhibitors Cyclosporin, tacrolimus
• Corticosteroids Methylprednisolone, dexamethasone, prednisolone
• Cytotoxic immunosuppressants Azathioprine, chlorambucil, cyclophosphamide, mercaptopurine, methotrexate
• Immunosuppressant antibodies Antithymocyte immunoglobulins, basiliximab, infliximab
• Sirolimus, everolimus
Ethical The most uncomfortable issue related to transplantation is that of illicit or quasi-illicit procurement. In the darker regions of the world there are thriving black markets for organs. Virtually all developed countries have put the kibosh on the organ trading by making it illegal. Singapore’s reasoning for outlawing the practice is to prevent the exploitation of poor and socially disadvantaged donors who are unable to make informed choices and suffer potential medical risks.
Other countries, notably China which claims to have stopped using it prisoners as voluntary donors, are thought to have continued harvesting organs for transplantation, ethics be damned.