Transplantation of organs and tissues. Organ transplantation in Russia
The problem of organ deficiency for transplantationis essential for all mankind as a whole. About 18 people die daily because of the lack of organ donors and soft tissues, without waiting for their turn. Organ transplants in the modern world are mostly made from deceased people who, during their lifetime, signed relevant documents about their consent to donate after death.
What is transplantation?
Organ transplantation is an exceptionorgans or soft tissues from the donor and transferring them to the recipient. The main direction of transplantology is the transplantation of vital organs - that is, those organs without which existence is impossible. These organs are the heart, kidneys, lungs. While other organs, such as the pancreas, can replace substitution therapy. To date, a great hope for the extension of human life is organ transplant. Transplantation has already been successfully practiced. This is a transplantation of the heart, kidneys, liver, thyroid, cornea, spleen, lungs, vessels, skin, cartilage and bones to create a framework with the goal that in the future new tissues will form. For the first time, an operation on kidney transplantology to eliminate acute renal failure of the patient was carried out in 1954, the donor was an identical twin. Organ transplantation in Russia was first carried out by academician Petrovsky BV in 1965.
What are the types of transplantation?
There is a huge number ofterminally ill people who need to transplant internal organs and soft tissues, since the traditional methods of treating the liver, kidneys, lungs and heart give only temporary relief, but do not change the patient's condition at the root. Organ transplantation exists in four types. The first of them - allotransplantation - occurs when the donor and recipient belong to the same species, and the second type includes xenotransplantation - both subjects belong to different species. In the event that the transplantation of tissues or organs is performed in identical twins or animals grown as a result of bloodbreeding, the operation is called isotransplantation. In the first two cases, the recipient may encounter tissue rejection, which is due to the immune defense of the body against foreign cells. And in related individuals, tissues usually get better. The fourth type includes autotransplantation - transplantation of tissues and organs within one organism.
As practice shows, the success of theoperations is largely due to timely diagnosis and accurate determination of the presence of contraindications, as well as the timing of organ transplantation. Transplantation should be predicted taking into account the patient's condition both before surgery and after. The main indication for the operation is the presence of incurable defects, diseases and pathologies that can not be treated by therapeutic and surgical methods, as well as life-threatening patients. When carrying out transplantation in children, the most important aspect is determining the optimal time for the operation. As the specialists of such an institution as the Institute of Transplantology testify, the postponement of an operation should not be carried out for an unreasonably long period, since a delay in the development of a young organism can become irreversible. Transplantation is indicated in case of a positive life prediction after the operation, depending on the form of pathology.
Transplantation of organs and tissues
In transplantology, the most widespreadreceived autotransplantation, as it excludes tissue incompatibility and rejection. Most often, skin, fat and muscle tissue, cartilage, bone fragments, nerves, pericardium are transplanted. Transplantation of veins and vessels is widespread. This became possible due to the development of modern microsurgery and equipment for these purposes. A major achievement of transplantology is the transplantation of fingers from the foot to the hand. Autotransplantation also includes transfusion of one's own blood with large blood loss during surgical interventions. When allotransplantation is most often transplanted bone marrow, vessels, bone tissue. This group includes transfusion of blood from relatives. Transplantation of the brain is rarely performed, since this operation faces 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. In recent years, 7-8 out of 10 operations performed have been successful. In this case, not completely the whole organ is transplanted, but only part of it is the islet cells that produce insulin.
Law on Organ Transplantation in the Russian Federation
On the territory of our country, the industryTransplantology is regulated by the Law of the Russian Federation of 22.12.92 "On transplantation of organs and (or) tissues of a person". In Russia, most often kidney transplantation, less often the heart, liver. The law on organ transplantation considers this aspect as a way of preserving the life and health of a citizen. At the same time, the legislation considers the preservation of the life of the donor in relation to the health of the recipient as a priority. According to the Federal Law on organ transplantation, the objects can be bone marrow, heart, lung, kidney, liver and other internal organs and tissues. The removal of organs can be carried out both with a living person and with a deceased person. Organ transplantation is carried out only with the written consent of the recipient. Donors can only be capable persons who have undergone medical examination. Organ transplantation in Russia is free of charge, as the sale of organs is prohibited by law.
Donors for transplantation
According to the Institute of Transplantology, eacha person can become a donor for organ transplantation. For persons under the age of eighteen, consent of the parents to the operation is necessary. When signing consent to the donation of organs after death, diagnosis and medical examination is carried out, which allows to determine which organs can be transplanted. The carriers of HIV, diabetes mellitus, cancer, kidney disease, heart disease and other serious pathologies are excluded from the list of donors for transplantation of organs and tissues. Related transplantation is usually performed for paired organs - kidneys, lungs, as well as unpaired organs - liver, intestine, pancreas.
Contraindications to transplantation
Organ transplantation has a number ofcontraindications due to the presence of diseases that may worsen as a result of the operation and pose a threat to the life of the patient, including death. All contraindications are divided into two groups: absolute and relative. The absolute are:
- infectious diseases in other organs on a par with those that are planning to replace, including the presence of tuberculosis, AIDS;
- violation of the functioning of vital organs, damage to the central nervous system;
- cancerous tumors;
- the presence of malformations and birth 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.
Particular importance in medicine iskidney transplantation. Since this is a paired organ, when it is removed from the donor, there are no disturbances in the functioning of the organism that threaten its life. Due to the peculiarities of the blood supply, the transplanted kidney is well established in recipients. For the first time, experiments on kidney transplantation were carried out in animals in 1902 by researcher E. Ulman. At transplantation, the recipient, even in the absence of supporting procedures to prevent the rejection of the alien organ, lived for slightly more than six months. Initially, the kidney was transplanted to the thigh, but later with the development of surgery, operations on transplantation into the pelvic region began, this technique has been practiced to this day. The first kidney transplantation was carried out in 1954 between identical twins. Then, in 1959, a kidney transplantation experiment was performed on the rabbits' twins, using a technique to resist graft rejection, and it proved effective in practice. New agents were discovered that can block the natural mechanisms of the body, including the discovery of azathioprine, which suppresses the body's immune defense. Since that time, immunosuppressants have become widely used in transplantology.
Preservation of organs
Any vital organ that is intendedfor 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 in different ways - for the heart time is measured in minutes, for the kidney - several hours. Therefore, the main task of transplantology is the preservation of organs and maintenance of their working capacity up to transplantation into another organism. To solve this problem, canning is used, which consists in supplying the body with oxygen and cooling. The kidney in this way can be kept for several days. Preservation of the organ allows increasing the time for its study and the selection of recipients.
Each of the organs after receiving it is compulsoryare subjected to conservation, for this, it is placed in a container with sterile ice, followed by conservation with a special solution at a temperature of plus 40 degrees Celsius. Most often for these purposes, a solution called Custodiol is used. Perfusion is considered to be complete, if from the mouths of the transplant veins appears a pure preservative solution without any blood impurities. After that, the organ is placed in a preservative solution, where it is left until the operation is performed.
When transplant is transplanted into the recipient's bodyhe becomes the object of the immunological response of the organism. As a result of the protective reaction of the immune system of the recipient, a number of processes take place at the cellular level, which lead to the rejection of the transplanted organ. These processes are explained by the development of donor-specific antibodies, as well as antigens of the immune system of the recipient. There are two types of rejection - humoral and super-fast. In acute forms, both mechanisms of rejection develop.
Rehabilitation and immunosuppressive treatment
To prevent this side effectprescribe immunosuppressive treatment depending on the type of operation performed, the blood group, the degree of compatibility of the donor and recipient, and the patient's condition. The smallest rejection is observed in the related transplantation of organs and tissues, since in this case, as a rule, 3-4 antigens from 6 coincide. Therefore, a lower dose of immunosuppressive drugs is required. The best survival rate is demonstrated by liver transplantation. Practice shows that the organ demonstrates more than ten years of survival after surgery in 70% of patients. With long-term interaction between the recipient and the transplant, microchimerism occurs, which allows gradually decreasing the dose of immunosuppressants down to complete rejection with time.