What is Organ Transplantation?
Organ transplantation is an operation in which an organ is removed from the donor body and then placed in a recipient body to replace a damaged or missing organ. The donor and recipient can be in the same location, or organs from a donor located in a separate region can be transplanted to a recipient located elsewhere.
Organs or tissues to be transplanted can be taken from living bodies or cadavers. Transplantation medicine is one of the most challenging and complex areas of modern medicine. Organs that can be successfully transplanted today include the heart, kidneys, liver, lungs, pancreas, intestine, thymus, and uterus. When medical data are examined globally, it is seen that the most commonly transplanted organs are the kidneys, followed by the liver and heart.
The key to organ transplantation is the problems of transplant rejection, such as the body showing an immune response to the transplanted organ, based on this possible transplant failure and immediate removal of the organ from the recipient.
Where appropriate, serotyping should be performed to determine the most appropriate donor-recipient match to minimize the possibility of transplant rejection. In addition, the use of immunosuppressant drugs can reduce the possibility of transplant rejection.
Tissues that can be transplanted include bones, tendons, cornea, skin, heart valves, nerves, and vessels. Bone and tendon transplants are called musculoskeletal grafts. Cornea and musculoskeletal grafts are the most frequently transplanted tissues, and such transplants are much more common than organ transplants.
Organ donors can be individuals who are alive, dead or brain dead, and whose lives are maintained by machines. It is possible to use organs removed from the body for transplantation within 24 hours after heartbeat stops or brain death occurs. Most types of tissue, with the exception of corneas, can be preserved and stored in special tissue "banks" for up to five years, unlike organs.
Organ transplantation raises a number of ethical issues, including the medical definition of death, when and how consent must be given for an organ to be transplanted, the donor's consent, and whether there is a monetary compensation for organs taken for transplantation.
Other ethical issues related to this situation include transplant tourism and, more broadly, the socio-economic conditions that organ harvesting or transplantation may pose or be seen as a solution.
What are the Types of Organ Transplantation?
Organ and tissue transplants can take place in several ways, depending on who the recipient is. If the same person is both a recipient and a donor, that is, organ or tissue transplantation within the same body is called autograft. Transplants between two individuals of the same species are called allografts. Allografts can be of living body or cadaver origin.
autograft
Autograft is a tissue transplant to the same person. In some cases, this procedure is done with tissue that is surplus, regenerable, or that is more desperately needed elsewhere for survival.
Examples of this are skin grafts, or vessel extraction for coronary bypass treatment. In some cases, tissue removal is performed to treat the tissue separately or to treat the individual without that tissue, and then the tissue is added back to the individual.
As an example of this stem cells autograft and blood storage can be given before surgery. As another example, during rotationplasty, a distal, i.e. distant joint is used instead of the more proximal, that is, the closer one. Typically, a foot or ankle joint is used to replace the knee joint. The person's foot is amputated and turned over, the knee is removed, and the tibia is joined to the femur.
Allograft and allotransplantation
Allograft is the 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 estimated by measuring the panel reactive antibody level.
isograft
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 the same as allografts in terms of anatomical procedures, they generally do not trigger an immune response, unlike other types of transplantation.
Xenograft and Xenotransplantation
Xenograft and xenotransplantation It is the name given to tissue and organ transplants between two different species 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 interspecies transmission.
In order to minimize these risks and to eliminate the problem of the scarcity of the number of organs to be transplanted, studies are continuing on the transplantation of human body organs to humans after they are grown on various animal subjects.
Domino Transplants
Domino transplants are multiple transplants performed in a chain for various reasons. For example, a liver that secretes a protein that causes long-term damage to the body can be transplanted from a younger individual to an older person whose diseased liver will not have much effect on life expectancy due to the slow progression of the diseased liver, and a healthy liver taken from an old individual can be given to a young person.
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 whole new lung/heart system. However, since the removed heart will still be healthy in such cases, the originally removed heart can be implanted in another patient who needs a heart transplant.
ABO Incompatible Transplants
It is possible for very young children, usually under 12 months, to receive organs from donors with whom they would normally be incompatible, as their immune system is not yet well developed. This condition is known as ABO incompatible transport, or ABOi for short.
There has also been limited success in ABO-incompatible heart transplants in adults. In these cases, it appeared necessary for adult recipients to have low levels of anti-A or anti-B antibodies. In these cases, kidney transplantation is more successful and long-term survival rates appear to be similar to ABOc transplantations.