An organ transplant is a surgery in which an organ is removed from a donor's body and then placed into the recipient's body to replace a damaged or missing organ. The donor and recipient may be in the same location, or organs from a donor in a different region may be transplanted into a recipient in a different location.
Organs or tissues for transplantation can be taken from living bodies or cadavers. Transplant medicine is one of the most complex and complex areas of modern medicine. Organs that can be successfully transplanted today include the heart, kidneys, liver, lungs, pancreas, intestines, thymus, and uterus. A global study of medical data shows that the most frequently transplanted organs are the kidneys, followed by the liver and heart.
A key problem in organ transplantation is the problem of transplant rejection, such as the body's immune response to the transplanted organ, based on the possible failure of transplantation, and the need for immediate removal of the organ from the recipient. If necessary, serotyping should be performed to determine the most appropriate donor-recipient match to minimize the possibility of graft rejection. In addition, the use of immunosuppressants may reduce the chance of transplant rejection.
Tissues that can be transplanted include bones, tendons, corneas, skin, heart valves, nerves, and vessels. Bone and tendon grafts are called musculoskeletal grafts. Corneal and musculoskeletal transplants are the most commonly transplanted tissues, and these transplants are much more common than organ transplants.
Organ donors can be people, living, dead, or brain-dead, whose life is supported by machines. It is possible to use organs removed from the body for transplantation within 24 hours after cardiac arrest or brain death. Most types of tissues, except for the cornea, can be preserved and stored in special tissue "banks" for up to five years, unlike organs.
Organ transplantation raises several ethical questions, including the medical definition of death, when and how consent must be given for an organ transplant, donor consent, and whether there is monetary compensation for organs taken for transplant.
Other ethical issues associated with this situation include transplant tourism and, more broadly, the socio-economic conditions in which organ harvesting or transplantation can be created or considered as a solution.
Organ and tissue transplantation can be carried out in several ways, depending on who the recipient is. If the same person is both the recipient and the donor, then an organ or tissue transplant within the same body is called an autograft. Grafts between two individuals of the same species are called allografts. Allografts can be either living or cadaveric.
An autograft is a transplant of tissue into the same person. In some cases, this procedure is performed on excess, regenerated tissue, or tissue that is badly needed elsewhere for survival. Examples of this are skin grafts or the removal of coronary artery bypass vessels. In some cases, tissue removal is performed to treat the tissue alone or to treat an individual without that tissue, and then the tissue is added back to the individual.
Examples of this are auto stem cell transplant and blood storage before surgery. As another example, in rotational play, instead of more proximal, that is, closer, distal, i.e. distant joint. As a rule, the foot or ankle joint is used instead of the knee joint. The person's foot is amputated and turned over, the knee is removed, and the tibia is reattached to the femur.
Allograft and allograft
An allograft is a procedure for transplanting an organ or tissue between two genetically non-identical members of the same species. Tissue and organ transplants performed in humans are usually allografts.
However, due to genetic differences between the organ and the recipient, the recipient's immune system may recognize the organ as a foreign body in the body and attempt to destroy it, causing transplant rejection. The risk of transplant rejection can be assessed by measuring panel reactive antibodies.
An isograft is a subset of allografts in which organs or tissues are transplanted between a genetically identical donor and recipient, such as an identical twin. Although isografts are similar to allografts in terms of anatomical procedures, they generally do not elicit an immune response, unlike other types of transplantation.
Xenotransplantation and xenotransplantation
Xenograft and xenotransplantation This is the name given to the transplantation of tissues and organs between two different types of organisms. An example of this is the very common and successful porcine heart valve transplant. However, xenotransplantation is often an extremely dangerous type of transplant due to the increased risk of compatibility, rejection, and disease due to cross-species transmission.
To minimize these risks and eliminate the problem of shortage of organs for transplantation, research is ongoing on transplanting organs from the human body to humans after they have been cultured in various animals.
Domino transplants are multiple transplants performed in a chain for different reasons.
For example, a liver that secretes a protein that causes long-term damage to the body can be transplanted from a younger person to an older person whose diseased liver will not have much of an impact on life expectancy due to the slow progression of liver disease. and a healthy liver taken from an old man can be given to a young man.
As another example, in cases where two lungs need to be replaced, it is technically easier to remove the heart along with the lungs and insert a completely new lung/heart system. However, since the removed heart will still be healthy in such cases, the originally removed heart may be implanted in another patient in need of a heart transplant.
Very young children, usually under 12 months of age, may receive organs from donors with whom they are normally incompatible because their immune systems are not yet fully developed. This state is known as an ABO incompatible transport, or ABOi for short.
There has also been limited success with ABO-incompatible heart transplantation in adults. In these cases, it has been proven necessary that adult recipients have low levels of anti-A or anti-B antibodies. In these cases, kidney transplantation is more successful and long-term survival rates are similar to ABOc transplantation.
Transplanted organs and tissues
The types of donors who have successfully transplanted tissues and organs under normal conditions are as follows.
Heart (cadaveric donor only)
Lung (cadaver and live donor)
Kidney (cadaver and living donor)
Liver (either a cadaveric donor or multiple living donors if a whole liver is required, a cadaveric donor and a living donor if a partial liver transplant is sufficient)
Pancreas (deceased donor only; very severe diabetes occurs when the pancreas of a living person is removed)
Intestine (cadaveric and living donor; usually occurs in the small intestine)
Stomach (cadaveric donor only)
Testicle (cadaver and living donor)
Penis (cadaver donor)
Tissues, cells, and body fluids.
Arm (cadaveric donor only)
Cornea (cadaveric donor only)
Including skin graft, face autograft, and very rarely face transplant.
Islets of Langerhans, ie. pancreatic islet cells (cadaver and living donor)
Bone marrow/Adult stem cells (living donor and autograft)
Blood transfusion/transfusion of blood products (Living donor and autograft)
Blood vessels (cadaveric donor and autograft)
Heart valve (living donor and xenograft [pig/bovine])
Bone (cadaver and living donor).
Almost anyone can donate tissue or organs, thereby saving one or more lives. Organ donors can be people who are still alive or people who are brain dead.
Brain death refers to the cessation of brain function, usually due to damage to the brain caused by traumatic or pathological causes, or the cessation of the blood supply to the brain due to causes such as suffocation.
In such cases, breathing or pulse can be maintained artificially with the help of means. Criteria for brain death vary from country to country. But overall, brain death represents a very low proportion of conventional deaths, meaning that the vast majority of deaths are unsuitable for organ donation.
If a person who is expected to have or has experienced brain death has previously donated organs, he or she may be placed in a suitable organ transplant operating room to give life to others.
Tissue can also be transplanted from people who have died of the brain or circulatory death. As a rule, tissue repair is possible within 24 hours after the cessation of the heartbeat. Unlike organs, most tissues, except for the cornea, can be preserved and stored for up to five years. However, one tissue donor can donate enough grafts to give life to more than 60 recipients. Because of these factors, tissue transplantation is much more common than organ transplantation.
Living donors can be organ donors if they survive and after the organ has been partially or completely removed, and the body can healthily continue other functions. Examples of such organ donations are single kidney donation, partial liver donation, lung lobe donation, and small intestine donation.
Deceased (Corpse) Donor:
Cadaveric donors are people who have been declared brain dead and whose bodies continue their organic activities with ventilators or other mechanical mechanisms until their organs are removed for transplantation.
Before the medical acceptance of the concept of brain death in the 1980s, organ transplants were performed with organs taken from the bodies of donors whose circulatory systems had completely stopped. Organs taken from donors with a completely stopped circulatory system are less successful than organs taken from a donor who has died of a brain, but the body's activity is supported by machines.