The problem of shortage of organs for transplantation is urgent for all mankind as a whole. About 18 people die every day due to the lack of organ and soft tissue donors, without waiting for their turn. Organ transplants in the modern world are mostly performed from deceased people who, during their lifetime, signed the relevant documents on their consent to donation after death.
What is a transplant
Organ transplantation is the removal of organs or soft tissues from a donor and their transfer to a recipient. The main direction of transplantology is the transplantation of vital organs - that is, those organs without which existence is impossible. These organs include the heart, kidneys, and lungs. While other organs, such as the pancreas, can be replaced by replacement therapy. To date, great hopes for prolonging human life are given by organ transplantation. Transplantation is already successfully practiced. This is a transplant of the heart, kidneys, liver, thyroid gland, cornea, spleen, lungs, blood vessels, skin, cartilage and bones to createscaffold in order to form new tissues in the future. For the first time, a kidney transplant operation to eliminate acute renal failure of a patient was performed in 1954, an identical twin became a donor. Organ transplantation in Russia was first performed by Academician Petrovsky B. V. in 1965.
What are the types of transplants
All over the world there is a huge number of terminally ill people who need transplantation of internal organs and soft tissues, since traditional methods of treating the liver, kidneys, lungs, heart give only temporary relief, but do not fundamentally change the patient's condition. There are four types of organ transplants. The first of them - allotransplantation - takes place when the donor and recipient belong to the same species, and the second type includes xenotransplantation - both subjects belong to different species. In the case when tissue or organ transplantation is performed in identical twins or animals grown as a result of consanguineous crossing, the operation is called isotransplantation. In the first two cases, the recipient may experience tissue rejection, which is caused by the body's immune defense against foreign cells. And in related individuals, tissues usually take root better. The fourth type is autotransplantation - transplantation of tissues and organs within the same organism.
Indications
As practice shows, the success of the operations performed is largely due totimely diagnosis and accurate determination of the presence of contraindications, as well as how timely the organ transplant was performed. Transplantation should be predicted taking into account the patient's condition both before and after the operation. The main indication for the operation is the presence of incurable defects, diseases and pathologies that cannot be treated by therapeutic and surgical methods, as well as threatening the life of the patient. When performing transplantation in children, the most important aspect is to determine the optimal moment for the operation. As experts of such an institution as the Institute of Transplantology testify, postponing the operation should not be carried out for an unreasonably long period, since a delay in the development of a young organism may become irreversible. Transplantation is indicated in case of a positive life prognosis after surgery, depending on the form of pathology.
Organ and tissue transplantation
In transplantology, autotransplantation is most widely used, as it eliminates tissue incompatibility and rejection. Most often, operations are performed to transplant skin, adipose and muscle tissue, cartilage, bone fragments, nerves, and pericardium. Transplantation of veins and vessels is widespread. This became possible thanks to the development of modern microsurgery and equipment for these purposes. A great achievement of transplantation is the transplantation of fingers from the foot to the hand. Autotransplantation also includes a transfusion of one's own blood.with large blood loss during surgical interventions. With allotransplantation, bone marrow, blood vessels, and bone tissue are most often transplanted. This group includes blood transfusions from relatives. Brain transplantation operations are performed very rarely, since so far this operation encounters great difficulties, however, in animals, transplantation of individual segments is successfully practiced. Pancreas transplantation can stop the development of such a serious disease as diabetes mellitus. In recent years, 7-8 out of 10 operations performed have been successful. In this case, not the entire organ is transplanted, but only part of it - islet cells that produce insulin.
Law on Organ Transplantation in Russia
On the territory of our country, the transplantation industry is regulated by the Law of the Russian Federation of December 22, 1992 “On transplantation of human organs and (or) tissues”. In Russia, transplantation of the kidneys is most often performed, less often of the heart, liver. The law on organ transplantation considers this aspect as a way to preserve the life and he alth of a citizen. At the same time, the legislation considers the preservation of the life of the donor as a priority in relation to the he alth of the recipient. According to the Federal Law on organ transplantation, the objects can be bone marrow, heart, lung, kidney, liver and other internal organs and tissues. Organ retrieval can be carried out both from a living person and from a deceased person. Organ transplantation is carried out only with the written consent of the recipient. Donors can only be able-bodied persons who have passed a medical examination. Organ transplantation in Russiais carried out free of charge, as the sale of organs is prohibited by law.
Transplant donors
According to the Institute of Transplantology, each person can become a donor for organ transplantation. For persons under the age of eighteen, parental consent is required for the operation. When signing the consent to organ donation after death, a diagnosis and medical examination are carried out, which allows you to determine which organs can be transplanted. Carriers of HIV, diabetes mellitus, cancer, kidney disease, heart disease and other serious pathologies are excluded from the list of donors for organ and tissue transplantation. Related transplantation is performed, as a rule, for paired organs - kidneys, lungs, as well as unpaired organs - liver, intestines, pancreas.
Contraindications for transplantation
Organ transplantation has a number of contraindications due to the presence of diseases that can be aggravated as a result of the operation and pose a threat to the patient's life, including death. All contraindications are divided into two groups: absolute and relative. Absolute include:
- infectious diseases in other organs on a par with those that are planned to be replaced, including the presence of tuberculosis, AIDS;
- violation of the functioning of vital organs, damage to the central nervous system;
- cancerous tumors;
- presence of malformations and congenital defects,incompatible with life.
However, in the period of preparation for the operation, due to the treatment and elimination of symptoms, many absolute contraindications become relative.
Kidney Transplant
Kidney transplantation is of particular importance in medicine. Since this is a paired organ, when it is removed from the donor, there are no violations of the body that threaten his life. Due to the peculiarities of the blood supply, the transplanted kidney takes root well in recipients. For the first time, experiments on kidney transplantation were carried out in animals in 1902 by research scientist E. Ulman. During transplantation, the recipient, even in the absence of supporting procedures to prevent rejection of a foreign organ, lived for a little more than six months. Initially, the kidney was transplanted to the thigh, but later, with the development of surgery, operations began to be performed to transplant it into the pelvic area, this technique is practiced to this day. The first kidney transplant was performed in 1954 between identical twins. Then, in 1959, a kidney transplantation experiment was carried out on fraternal twins, using a technique to resist transplant rejection, and it proved to be effective in practice. New drugs have been identified that can block the body's natural mechanisms, including the discovery of azathioprine, which suppresses the body's immune defenses. Since then, immunosuppressants have been widely used in transplantology.
Organ preservation
Any vital organwhich is intended for transplantation, without blood supply and oxygen, is subject to irreversible changes, after which it is considered unsuitable for transplantation. For all organs, this period is calculated differently - for the heart, time is measured in minutes, for the kidney - several hours. Therefore, the main task of transplantation is to preserve organs and maintain their performance up to transplantation into another organism. To solve this problem, conservation is used, which consists in supplying the organ with oxygen and cooling. The kidney can be preserved in this way for several days. The preservation of the organ allows you to increase the time for its study and selection of recipients.
Each of the organs after receiving it must be subjected to conservation, for this it is placed in a container with sterile ice, after which conservation is carried out with a special solution at a temperature of plus 40 degrees Celsius. Most often, a solution called Custodiol is used for these purposes. Perfusion is considered completed if a pure preservative solution without blood impurities protrudes from the orifices of the graft veins. After that, the organ is placed in a preservative solution, where it is left until the operation.
Transplant rejection
When a graft is transplanted into the recipient's body, it becomes the object of the body's immunological response. As a result of the protective reaction of the recipient's immune system, a number of processes occur at the cellular level, which lead to rejectiontransplanted organ. These processes are explained by the production of donor-specific antibodies, as well as antigens of the recipient's immune system. There are two types of rejection - humoral and hyperacute. In acute forms, both mechanisms of rejection develop.
Rehabilitation and immunosuppressive treatment
To prevent this side effect, immunosuppressive treatment is prescribed depending on the type of operation performed, blood type, degree of compatibility of the donor and recipient, and the condition of the patient. The least rejection is observed in related organ and tissue transplantation, since in this case, as a rule, 3-4 out of 6 antigens coincide. Therefore, a lower dose of immunosuppressants is required. Liver transplantation demonstrates the best survival rate. Practice shows that the organ demonstrates more than a decade of survival after surgery in 70% of patients. With prolonged interaction between the recipient and the graft, microchimerism occurs, which allows, over time, to gradually reduce the dose of immunosuppressants until they are completely abandoned.
