The problem of organ shortage for transplantation is urgent for all humanity as a whole. About 18 people die every day due to the lack of organ and soft tissue donors without waiting their turn. Organ transplantation in modern world for the most part, it is produced from deceased people who, during their lifetime, signed the appropriate documents indicating their consent to donation after death.
What is transplantation
Organ transplantation involves removing organs or soft tissue from a donor and transferring them to a recipient. The main direction of transplantology is organ transplantation - 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 replacement therapy. Today, organ transplantation offers great hope for prolonging human life. Transplantation is already being successfully practiced. These are the kidneys, liver, thyroid gland, cornea, spleen, lungs, blood vessels, skin, cartilage and bones to create a framework so that new tissues can form in the future. The first kidney transplantation operation to eliminate a patient's acute renal failure was performed in 1954; the donor was an identical twin. Organ transplantation in Russia was first performed by Academician B. V. Petrovsky in 1965.
What types of transplantation are there?
All over the world there is great amount terminally ill people in need of transplantation of internal organs and soft tissues, since traditional ways Treatments for the liver, kidneys, lungs, and heart provide only temporary relief, but do not fundamentally change the patient’s condition. There are four types of organ transplantation. The first of these - 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 case when tissue or organ transplantation is performed in or animals raised 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 includes autotransplantation - transplantation of tissues and organs within one organism.
Indications
As practice shows, the success of the operations is largely due to timely diagnosis and precise definition the presence of contraindications, as well as how timely the organ transplant was performed. Transplantation must be predicted taking into account the patient's condition both before and after surgery. The main indication for surgery is the presence of incurable defects, diseases and pathologies that cannot be treated with therapeutic and surgical methods, as well as life-threatening patient. When performing transplantation in children, the most important aspect is determining the optimal moment for the operation. As experts from such an institution as the Institute of Transplantology testify, postponing the operation should not be carried out for an unreasonably long period, since the delay in the development of a young organism can become irreversible. Transplantation is indicated in case of a positive life prognosis after surgery, depending on the form of the pathology.
Organ and tissue transplantation
In transplantology, autotransplantation is most widespread, as it eliminates tissue incompatibility and rejection. Most often, operations are performed on fatty and muscle tissue, cartilage, bone fragments, nerves, pericardium. Vein and vascular transplantation is widespread. This became possible thanks to the development of modern microsurgery and equipment for these purposes. A great achievement in transplantology is the transplantation of fingers from the foot to the hand. Autotransplantation also includes transfusion of one's own blood in case of large blood losses during surgical interventions. During allotransplantation, bone marrow and blood vessels are most often transplanted. This group includes blood transfusions from relatives. It is much rare to carry out operations on this because so far this operation faces great difficulties, however, in animals, transplantation of individual segments is successfully practiced. A pancreas transplant can stop the development of this serious illness like diabetes. IN last years 7-8 out of 10 operations performed are successful. In this case, not the entire organ is transplanted, but only part of it - the islet cells that produce insulin.
Law on organ transplantation in the Russian Federation
On the territory of our country, the transplantology industry is regulated by the Law of the Russian Federation of December 22, 1992 “On Transplantation of Human Organs and (or) Tissues.” In Russia, kidney transplantation is most often performed, and less often heart and liver transplantation. The law on organ transplantation considers this aspect as a way to preserve the life and health of a citizen. At the same time, the legislation considers the preservation of the life of the donor to be a priority in relation to the health of the recipient. According to the Federal Law on organ transplantation, objects can be the heart, lung, kidney, liver and other internal organs and tissues. Organ removal 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. Only legally capable persons who have undergone a medical examination can be donors. Organ transplantation in Russia is carried out free of charge, since the sale of organs is prohibited by law.
Donors for transplantation
According to the Institute of Transplantology, every person can become a donor for organ transplantation. For persons under eighteen years of age, parental consent is required for the operation. When you sign a consent to donate organs after death, a diagnosis and medical examination is carried out to determine which organs can be transplanted. HIV carriers are excluded from the list of donors for organ and tissue transplantation. diabetes mellitus, cancer, kidney disease, heart disease and other serious pathologies. Related transplantation is carried out, 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 leading to fatal outcome. All contraindications are divided into two groups: absolute and relative. The absolute ones include:
- infectious diseases in other organs on a par with those that are planned to be replaced, including the presence of tuberculosis and AIDS;
- disruption of the functioning of vital organs, damage to the central nervous system;
- cancerous tumors;
- the presence of malformations and birth defects that are incompatible with life.
However, during the period of preparation for surgery, thanks to 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, the donor does not experience disruptions in the functioning of the body that threaten his life. Due to the peculiarities of the blood supply, the transplanted kidney takes root well in the recipients. The first experiments on kidney transplantation were carried out in animals in 1902 by researcher E. Ullman. During transplantation, the recipient, even in the absence of supportive procedures to prevent rejection, foreign organ lived a little over six months. Initially, the kidney was transplanted onto the thigh, but later, with the development of surgery, operations began to transplant it into the pelvic area, a technique that is still practiced today. The first kidney transplant was performed in 1954 between identical twins. Then in 1959, an experiment was carried out on kidney transplantation of fraternal twins, which used a technique to counteract graft rejection, and it proved its effectiveness in practice. New agents have been identified that can block the body's natural mechanisms, including the discovery of azathioprine, which suppresses immune protection body. Since then, immunosuppressants have been widely used in transplantology.
Organ preservation
Any vital organ that is intended for transplantation is subject to irreversible changes without blood supply and oxygen, after which it is considered unsuitable for transplantation. For all organs, this period is calculated differently - for the heart, time is measured in a matter of minutes, for the kidney - several hours. Therefore, the main task of transplantology is to preserve organs and maintain their functionality until transplantation into another organism. To solve this problem, canning is used, which consists of supplying the organ with oxygen and cooling. The kidney can be preserved in this way for several days. Preservation of an organ allows you to increase the time for its examination and selection of recipients.
Each of the organs, after receiving it, must be preserved; for this, it is placed in a container with sterile ice, after which preservation 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 complete if a clean preservative solution without blood admixtures emerges from the mouths of the graft veins. After this, the organ is placed in a preservative solution, where it is left until the operation.
Graft rejection
When a transplant is transplanted into the recipient's body, it becomes the object of the body's immunological response. As a result of a defensive reaction immune system The recipient undergoes a number of processes at the cellular level that lead to rejection of the transplanted 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. At 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 surgery performed, blood type, donor-recipient compatibility, and the patient's condition. The least rejection is observed with related transplantation of organs and tissues, since in this case, as a rule, 3-4 antigens out of 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 prolonged interaction between the recipient and the transplant, microchimerism occurs, which allows the dose of immunosuppressants to be gradually reduced over time until they are completely abandoned.
VASCULAR SURE. VESSEL TRANSPLANTATION. VEIN OPERATIONS IN CHILDREN. COMPLETED: ALEXANDROVA O. A. 604 -4 GR. OM SURGERY TEACHER: ZHAKSYLYKOVA A. K.
ATRAUMATIC INSTRUMENTATION To perform operations on blood vessels, it is necessary to use special atraumatic instruments that ensure gentle handling of the vascular wall. Much of the credit for their development goes to American vascular surgeons at the Mayo Clinic, as well as Michael De. Becky. Vascular instruments include vascular forceps with atraumatic cutting, thin and well-knit vascular scissors, sharp vascular scalpels, soft vascular clamps with long ratchet clamps. The application of general surgical clamps to the main arteries leads to inevitable thrombosis of the latter. To temporarily clamp large vessels, you can use tourniquets (loops made of thin fragments of infusion systems, onto which pieces of thicker drainage tubes are placed). Various probes and catheters are widely used (for example, the Fogarty catheter for embolectomy).
ACCESS In modern vascular surgery, basic surgical approaches have been developed to all large vessels, mainly to the areas of forks. When performing access, it is necessary to observe the principles of atraumatic opening of the vessel's own fascial sheath: The vascular sheath is opened, as a rule, bluntly, using a dissector. Sometimes a solution of novocaine is injected into the vagina to avoid reflex spasm. The separation of the artery and vein is performed extremely carefully. Movements with the instrument are made “from the vein,” i.e., try not to direct the tip of the dissector towards the wall of the vein in order to avoid its rupture. The vessel must be separated from the surrounding tissue on all sides for the length necessary for convenient application of clamps. They try to remove sympathetic nerve fibers from the surface of the vessel. Thus, we perform periarterial sympathectomy and eliminate reflex vasospasm in the periphery.
PROJECTIONS OF THE MAIN NERVOVASCULAR BANDS OF THE LIMB OPERATIVE ACCESS TO THE VESSELS: DIRECT – carried out strictly along the projection line (to deep-lying formations) CIRCULAR – carried out outside the projection line (to superficially lying formations)
REQUIREMENTS FOR THE VASCULAR SUTURE: Creation of tightness along the anastomosis line; There should be no narrowing of the lumen along the suture line; The sutured ends of the vessel along the suture line should touch the inner membrane - the intima; The suture material should not be in the lumen of the vessel; There should be no obstacles to the blood flow in the area where the suture is applied; The edges of the vessel should be trimmed sparingly; The vessel should not dry out; The distance between stitches is 1 mm.
c VASCULAR SUTURE CLASSIFICATION: By method of application: manual suture; mechanical suture - performed using a vascular stapling device. In relation to the circumference: Lateral (up to 1/3); Circular (over 2/3); a) Wrapping (Carrel, Morozova seam); b) Everting (suture of Sapozhnikov, Braitsev, Polyantsev); c) Intussusception (Soloviev’s suture). b a HTTP: //4 ANOSIA. RU/
Currently for overlay vascular suture A polypropylene (non-absorbable) atraumatic thread is used. In adults, this is a continuous wrapping seam according to the pattern “from outside to inside - from inside to outside.” In young children, a U-shaped interrupted suture is used. Everting sutures, A. Carrel's suture, as well as mechanical (hardware) vascular suture are of historical importance.
SEAM OF F. BRIAN AND M. JABOULEI This is the so-called U-shaped, intermittent (knotted) everting suture. Such a suture will not impede the growth of the anastomotic zone if it is used in young body. The principle of adaptation of the intima with everting stitches, proposed by the authors, has found its application and further development in a large number of modifications (E.I. Sapozhnikov, 1946; F.V. Balluzek, 1955; I.A. Medvedev, 1955; E. N. Meshalkin, 1956; Yu. N. Krivchikov, 1959 and 1966; V. Dorrance, 1906; A. Blalock, 1945; I. Littman, 1954).
SUCH I. MURPHY J. Murphy in 1897 proposed a circular invagination method of vascular suture. At first, this modification attracted attention, since the problem of sealing the suture was solved quite simply, but the basic principle of vascular anastomosis - contact of intima with intima - was violated by simple invagination of one segment into another. Therefore, the suture used by the author and other researchers, as a rule, led to thrombosis, and Murphy’s original idea was forgotten for a long time.
A. CARREL'S SEAM Carrel's seam is an edge wrapping seam, continuous, between three knot holders, which are applied through all layers at an equal distance from each other. The frequency of stitches depends on the thickness of the vessel wall and varies from 0.5 to 1 mm. This technique has become widespread and is used most often, being the basis for the development of numerous modifications of vascular connections.
DORRANCE SEAM A - STAGE I; B - STAGE II The Dorrance seam (V. Dorrance, 1906) is marginal, continuous, two-story
SEAM L. I. MOROZOVA The seam A. I. Morozova (a simplified version of the Karell seam) is also a twisting, continuous one, but involves the use of only two holders. The role of the third holder is performed by the thread of the continuous seam itself.
APPLICATION OF MARGINAL SUTURES IN THE EVENT OF INCONSISTENCE IN THE CALIBER OF VESSELS A - METHOD OF N. A. DOBROVOLSKAYA; B METHOD Y. N. KRIVCHIKOV; B - METHOD OF SEIDENBERG, HURVIT AND CARDBOARD N. A. Dobrovolskaya in 1912 proposed an original seam for connecting vessels with different diameters (Fig. a). In order to ensure good adaptation of such vessels, the circumference of the smaller one is increased by applying two notches located 180° from each other. For the same purpose, Zaidenberg and his colleagues (1958) crossed a vessel with a smaller diameter in the zone of its division (Fig. c), and Yu. N. Krivchikov (1966) and P. N. Kovalenko and his colleagues (1973) ) cut off the end of the smaller vessel at an angle (Fig. b).
SUTURE OF N. A. BOGORAZ (SUTURNING OF A VASCULAR DEFECT WITH FIXATION OF A PATCH) Suture of N. A. Bogoraz (1915) is a plastic suturing large defect in the vessel wall by fixing the patch with a continuous wraparound edge suture after preliminary application of suture stays at the corners of the defect.
STRENGTHENING THE AREA OF VASCULAR ANASTOMOSIS A - V. L. KENKIN’S METHOD; B - METHOD SP. SHILOVTSEVA For better sealing of the line of vascular anastomosis, N.I. Bereznegovsky (1924) used a piece of isolated fascia. V.L. Khenkin proposed autovein and allograft for this purpose (Fig. a), and SP. Shilovtsev (1950) - muscle (Fig. b).
A. A. POLYANTSEV’S SEAM (WIRING, CONTINUOUS BETWEEN THREE U-SHAPED HOLDERS) A. A. Polyantsev’s seam was proposed by the author in 1945. It is winding, continuous, between three U-shaped everting holders.
E. I. Sapozhnikova's seam (CONTINUOUS WANTED BETWEEN TWO NODE HOLDERS) E. I. Sapozhnikov's seam (1946) - continuous, welt-like, between two nodal supports. A thread is used with two straight needles, which are injected towards each other at the base of the cuffs.
SUTURE OF THE POSTERIOR WALL IN THE IMPOSSIBILITY OF VESSEL ROTATION (I) AND INVAGINATION SUCHURE ACCORDING TO G. M. SOLOVIEV (II): I: A - L. BLELOCK METHOD, B - E. N. MESHALKIN METHOD, B VIEW OF THIS SUTURE AFTER TIGHTENING THE THREAD; II: A-B - STAGES OF SEAM FORMATION
METHOD Y. N. KRIVCHIKOV A - APPLICATION OF U-SHAPED SUTURES; B FORMATION OF THE CUFF; I - APPLICATION OF A CONTINUOUS SUIT; D - STRENGTHENING THE CUFF Yu. N. Krivchikov (1959) developed an original invagination suture (Fig. a-d) with a single cuff (everting, covered with a cuff created from the vessel itself). This modification, according to the author, ensures good adaptation of the intima and minimal protrusion of threads into the lumen of the vessel, creates a reliable seal and also allows the formation of a reinforcing cuff from any segment of the vessel.
I. I. PALAVANDISHVILI’S RING (STRETCHING THE HOLDERS WITH THE HELP OF SPRINGS) I. I. Palavandishvili (1959) to simplify the technique of applying a manual seam according to Carrel, created a metal ring with a diameter of 12 cm with three springs to which the holders are attached. Such a device gives the lumen of the vessel a triangular shape and frees up the assistant’s hands.
SEAM G. P. VLASOV (PREVENTION OF NARROWING OF THE ANASTOMOSIS ZONE) A feature of the proposed circular suture, in contrast to the continuous one with overlaps, is that both ends of the threads “walk” one after another and are connected to each other. The stitch formed resembles a machine stitch, only the longitudinal thread is located on one side. Advantages this method consist, firstly, in the fact that there is no corrugation of the walls of the stitched vessels between the stitches; secondly, the longitudinal arrangement of twisted threads along the roller between the stitches promotes close contact of the walls of the vessels and reduces the possibility of bleeding.
A. M. DEMETSKY’S SUMMER (PREVENTION OF NARROWING THE ANASTOMOSIS ZONE) A. M. Demetskiy (1959) proposed a suture that eliminates the narrowing of the anastomotic zone. The author cut off the ends of the sutured vessels at an angle of 45°, while the length of the suture and the flow hole in the anastomosis zone increased by 2 times.
N. G. STARODUBTSEV’S METHOD (PREVENTION OF NARROWING AND TURBULENCE IN THE ANASTOMOSIS AREA) N. G. Starodubtsev and co-workers (1979) developed and studied in detail a new type of anastomosis, in which its narrowing is eliminated and the conditions for the occurrence of turbulent blood flow are practically eliminated. This type of connection is called a “Russian castle” anastomosis.
SHOW J. N. GADZHIEV AND B. KH. ABASOVA (EVERTERING DOUBLE-SIDED CONTINUOUS MATTRESS) A - INITIAL STAGE; B - FINAL STAGE A peculiar modification of the vessel suture was developed by J. N. Gadzhiev and B. Kh. Abasov (1984). In order to increase the tightness and prevent bleeding from the anastomosis, prevent narrowing of the anastomotic zone and thrombosis of the reconstructed arteries, the authors proposed an everting bilateral continuous mattress suture.
I. LITTMAN'S SEAM (INTERRUPTED MATTRESS BETWEEN THREE U-SHAPED HOLDERS) Littman's seam (1954) is an intermittent mattress seam between three U-shaped supports, which are applied at an equal distance from each other.
RECONSTRUCTIVE OPERATIONS ARE PERFORMED WITH THE PURPOSE OF RESTORING THE MAIN BLOOD FLOW IN THE IMPAIRMENT OF VASCULAR patency Disobliterating operations are aimed at restoring the patency of an occluded segment of a vessel: Thrombus - or embolectomy: a) Direct (through an incision in the vessel) b) Indirect (with a Fogarty catheter from another vessel) Thrombendarterectomy – removal of a blood clot along with thickened intima. Plastic surgeries are aimed at replacing the affected vessel segment with an auto-, allo-, xenograft or vascular prosthesis. Bypass surgery - with the help of vascular prostheses or an autograft, an additional path for blood flow is created, bypassing the occluded segment of the vessel. HTTP: //4 ANOSIA. RU/
Option of endarterectomy with sewing in a patch angioplasty Plastic surgery of the deep femoral artery (profundoplasty) according to Martin. The superficial femoral artery is occluded. An autovenous patch is sewn into the mouth of the deep artery of the thigh. According to Yu. V. Belov
BYPASS A bypass to bypass the obstruction to blood flow. At the same time, the possibility of residual blood flow remains Femoropopliteal bypass Bifurcation aorto-femoral bypass (Lerisch operation), BABS According to Yu. V. Belov, Burakovsky-Bockeria
PROSTHETICS Application of a bypass path to bypass the obstruction to blood flow with complete exclusion of the affected area from the blood flow. Bifurcation aorto-iliac prosthesis for an aneurysm of the infrarenal aorta with transition to both aortas. According to Yu. V. Belov
STENTS In modern intravascular surgery, many techniques have become possible thanks to the use of intravascular stents. Stents - weeding tubes - holding devices located in the lumen of the vessel. They were first developed by Charles Dotter in the late 60s of the 20th century. Many modifications of stents have been proposed. Basically, they can be divided into three groups. 1. Balloon expandable. These are the stents used most often. The stent is placed on an inflating catheter balloon. Inflating the balloon causes stretching of the wire structure of the stent, the latter expands, cuts into the wall of the vessel and is fixed. 2. Self-expanding stents are guided to the area of interest inside the introducer catheter, and then pushed into the lumen with a mandrel. Expansion of the spring stent leads to its fixation in the vessel wall. 3. Thermally expandable stents.
Stents are used either independently as devices for permanent dilatation of a vessel, or together with intravascular prostheses to retain them. When treating false arterial aneurysms, a Dacron endoprosthesis with two stents at the ends is endovascularly applied to them and fixed by expanding the stents. The aneurysm cavity is switched off from the bloodstream. Surgeries on the aortic arch may require turning off the natural blood flow and require complex equipment. Stent with antiproliferative drug coating - intravascular prosthesis made of cobalt-chrome alloy with coating, releasing medicinal substance, preventing repeated narrowing of the vessel. The medicinal layer subsequently dissolves.
MODERN TECHNOLOGIES IN VASCULAR SURGERY Intravascular dilatation and stenting Balloon catheter with Palmaz stent Coronary angiogram before and after the procedure
TRUE FALSE ANEURYSMS (TRAUMATIC) Currently, operations are predominantly performed to exclude the aneurysm from the bloodstream or to remove it and replace it with a vascular prosthesis. TYPES: ARTERIAL VENOUS ARTERIO-VENOUS Three groups of operations: surgical interventions, the purpose of which is to cause a cessation or slowdown of blood flow in the aneurysmal sac and thereby contribute to the formation of a blood clot and obliteration of the cavity or a decrease in the volume of the aneurysmal sac. This is achieved by ligating the leading end of the artery proximally from the aneurysmal sac (Anel and Gunther methods); operations in which the aneurysmal sac is completely excluded from the circulation (Antillus method) or its removal like a tumor (Filagrius method); operations aimed at restoring completely or partially blood circulation by suturing the arterial fistula through the aneurysmal sac - endoaneurysmorrhaphy (methods of Kikutsi - Matas, Radushkevich - Petrovsky) HTTP: //4 ANOSIA. RU/
OPERATIONS FOR VARICOSE VEINS OF THE LOWER EXTREMITIES There are 4 groups of operations: removal of veins, ligation of the main and communicating veins, sclerosis of veins, combined. ACCORDING TO MADELUN - removal through an incision along the entire length of the BSVB ACCORDING TO BABCOCK - removal of the BSVB using a probe through 2 small incisions ACCORDING TO NARATU - ligation and removal of dilated veins on the lower leg through separate incisions ACCORDING TO TROYANOV-TRENDELENBURG - high ligation of the BSVB at the point of entry into the femoral ACCORDING TO COCKET – suprafascial ligation of the communicants ACCORDING TO LINTON - subfascial ligation of the communicants ACCORDING TO SHEDE, ACCORDING TO CLAP – percutaneous ligation of veins (for scattered veins) The Troyanov operation is more often performed. Trendelenburg-Babcock-Narata. HTTP: //4 ANOSIA. RU/
Transplantation(late lat. transplantatio, from transplanto- transplantation), tissue and organ transplantation.
Transplantation in animals and humans is the engraftment of organs or sections of individual tissues to replace defects, stimulate regeneration, during cosmetic operations, as well as for the purposes of experiment and tissue therapy. The organism from which the material for transplantation is taken is called a donor, the organism into which the transplanted material is implanted is called a recipient, or host.
Types of transplantation
Autotransplantation - transplantation of parts within one individual.
Homotransplantation - transplantation from one individual to another individual of the same species.
Heterotransplantation - a transplant in which the donor and recipient belong to different species of the same genus.
Xenotransplantation - a transplant in which the donor and recipient belong to different genera, families and even orders.
All types of transplantation, as opposed to autotransplantation, are called allotransplantation .
Transplanted tissues and organs
In clinical transplantology, autotransplantation of organs and tissues is most widespread, because With this type of transplantation there is no tissue incompatibility. Transplantations of skin, adipose tissue, fascia (muscle connective tissue), cartilage, pericardium, bone fragments, and nerves are more often performed.
Vein transplantation is widely used in vascular reconstructive surgery, especially large veins. saphenous vein hips. Sometimes resected arteries are used for this purpose - the internal iliac artery, the deep femoral artery.
With the introduction of microsurgical technology into clinical practice, the importance of autotransplantation has increased even more. Transplantations on vascular (sometimes nerve) connections of skin, musculocutaneous flaps, muscle-bone fragments, and individual muscles have become widespread. Important We acquired transplants of toes from the foot to the hand, transplantations of the greater omentum (fold of the peritoneum) to the lower leg, and segments of intestine for esophagoplasty.
An example of organ autotransplantation is a kidney transplant, which is performed for extensive stenosis (narrowing) of the ureter or for the purpose of extracorporeal reconstruction of the vessels of the renal hilum.
A special type of autotransplantation is the transfusion of the patient’s own blood during bleeding or deliberate exfusion (withdrawal) of blood from the patient’s blood vessel 2-3 days before surgery for the purpose of its infusion (administration) to him during surgery.
Tissue allotransplantation is used most often for transplantation of the cornea, bones, bone marrow, and much less often for transplantation of pancreatic b-cells for the treatment of diabetes mellitus, hepatocytes (for acute liver failure). Brain tissue transplants are rarely used (in processes accompanying diseases Parkinson's). Mass transfusion of allogeneic blood (blood of brothers, sisters or parents) and its components is a mass transfusion.
Transplantation in Russia and in the world
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For vascular reconstruction, many options for vascular grafts have been proposed: autovein, autoartery, vein umbilical cord human, xenoartery, alloven, synthetic prostheses, etc. Currently, autovenous grafts and synthetic prostheses are mainly used. The practical value of grafts used for arterial plastic surgery is determined by biological compatibility, mechanical properties, effect on thrombogenesis, and the frequency of complications in the immediate and long-term periods after surgery. In table 1 presents the modern international classification of grafts and vascular transplantation.
Table 1. International Classification of Organ and Tissue Transplantation (1973)
|
Graft material |
Type of transplant |
Name of graft |
||
|
Old name |
New name |
Old name |
New name |
|
|
Transplantation of non-living substrate |
Allotransplantation |
Explantation |
Allogeneic |
Explant |
|
Organs of a different kind |
Heterotransplantation |
Xenotransplantation |
Allogeneic |
Xenogeneic |
|
Organs and tissues of the same type |
Homotransplantation |
Allotransplantation |
Homogeneous |
Allogeneic |
|
The patient's own tissues and organs |
Autotransplantation |
Autotransplantation |
Autogenic |
Autolytic |
|
Genetically similar (identical twins) |
Isotransplantation |
Isotransplantation |
Isogenic |
Isogenic |
Autovenous plasty was first developed experimentally and used in the Carrel clinic (A. Carrel, 1902-1906). Lexer (Lexer, 1907) performed free plastic surgery of the axillary artery defect with a segment of the great saphenous vein of the thigh. J. Kunlin (1949) used the great saphenous vein of the thigh to bypass the occluded femoral artery. The use of an autovein for the reconstruction of medium- and small-diameter arteries remains the “gold standard” to date. Indications for performing autovenous bypass are most often occlusive-stenotic lesions of the femoral-popliteal-tibial segment, carotid system, renal arteries, visceral branches of the abdominal aorta, coronary arteries etc. In this case, the most successful graft is the great saphenous vein. Before surgery, it is recommended to investigate the suitability of the autovein for bypass grafting using duplex scanning. Bypass surgery using an autovein is possible in two options: reversed autovein and in situ. The reversed vein has been successfully used as a short bypass. For a long shunt, the vein must be of sufficient diameter throughout. Autovenous shunting using the in situ technique is less traumatic, more physiological, and uniform narrowing of the shunt ensures adequate blood flow and maintains its longer viability. The vein in the in situ position was first used in 1959 by the Canadian surgeon Cartier. Among domestic researchers A.A. Shalimov (1961) was the first to report the results of using this technique.
Homoplasty in humans was first used by Pirovano (Pirovano, 1910), but without success. And the first successful homotransplantation of the artery in the clinic was performed by R.E. Gross et al. (R.E. Gross et al., 1949). For arterial preservation, the authors used Tyrode's fluid, 4% formalin solution, 70% ethanol, plasma, etc. In 1951, lyophilization of vessels (freezing, drying) was proposed (Marrangoni and Cecchini). Homotransplantation of arteries was widely used in the 60s of the last century (N.I. Krakovsky et al., 1958). Homografts are a scaffold for the formation of a new vascular wall and connective tissue.
For bypass grafting of the femoral artery, umbilical veins (Ibrahim et al., 1977; B.C. Krylov, 1980) and heterovascular (bovine and porcine) veins were also used. carotid arteries) grafts (Rosenberg et al., 1964; Keshishian et al., 1971). The most promising methods for eliminating the antigenic properties of heterovascular grafts turned out to be methods of their enzymatic treatment, with the help of which autogenous proteins are dissolved.
Porous synthetic plastic prostheses made from Vignon were first proposed in 1952 (Voorhess, Jaretski, Blakemore). In the first half of the last century, tubes made of rubber, silver, glass, ivory, polyethylene, and plexiglass were used to replace vessels in experiments (F.V. Balluzek, 1955; B.S. Krylov, 1956; D.D. Venediktov, 1961 g., etc.).
A new and promising direction in arterial plastics is the use of porous vascular prostheses of woven, knitted, braided and monolithic construction made of polyamide (nylon, nylon), polyester (dacron, perylene, lavsan) and polytetrafluoroethylene (teflon, fluorlon) and other fibers. A prosthesis is a frame, which after some time is covered with a connective tissue capsule. Capsule formation goes through the following main phases:
- compaction of the prosthesis with the formation of a fibrin lining along its inner surface;
- ingrowth of the prosthesis frame with granulation tissue;
- organization of the connective tissue capsule of the vessel wall;
- degeneration or involution of the newly formed wall.
Vessels grow from the vascular bed through the pores of the graft 1-2 weeks after surgery. After 6-12 months, the formation of a connective tissue vascular wall around the prosthesis frame occurs. Outer and inner connective tissue capsules are formed. The internal lining (neointima) is gradually covered with endothelium, growing from the side of the anastomosis of the prosthesis with the vessels. Deposits of loose fibrin structures cause a narrowing of the lumen and lead to thrombus formation.
Prostheses should not be pathogenic and cause a strong protective reaction. They must be strong, elastic, flexible and reliably sterilized. S. Wesolowski et al. (1961-1963) introduced the concept of surgical and biological porosity.
Surgical porosity is an indicator of the bleeding of the prosthesis wall after its inclusion in the bloodstream. It is determined by specific water permeability (the amount of water seeping through 1 cm 2 of the vessel wall in 1 minute at a pressure of 120 mm Hg).
For the normal development and existence of neointima, porosity is necessary, at which after 1 cm 2 synthetic fabric in 1 minute at a pressure of 120 mm Hg. Art. 10,000 ml of water will pass through (biological porosity).
Surgical porosity is characterized by the following feature: with it, no more than 50 ml of water should pass through 1 cm2. Thus, biological porosity is 200 times greater than surgical porosity.
Biological porosity is an indicator of the germination of the prosthesis wall connective tissue from outer shell to the inner one. An increase in biological porosity leads to the threat of profuse bleeding through the wall of the prosthesis. The desire to combine these two opposing properties, i.e. large biological and low surgical porosity, led to the idea of creating combined semi-absorbable prostheses, consisting of absorbable and non-absorbable components.
Prostheses impregnated with gelatin (Carstenson, 1962), semi-biological, consisting of synthetic and collagen threads (A.M. Khilkin et al., 1966; S. Wesolowski, 1962), water-soluble synthetic fiber vinol (A.G. Gubanov, 1962), etc. In order to prevent thrombosis, prostheses with heparin and with braided silver thread have been proposed (V.L. Lemenev, 1975).
The causes of thrombosis in the long term are: altered neointima of the prosthesis; hemodynamic disorders; changes in the blood coagulation system.
A decrease in blood flow velocity is often caused by a narrowing of the distal anastomosis, an increase in peripheral resistance, blood turbulence, which depends on the difference in diameters of the prosthesis and the bypassed artery, and the progression of the main atherosclerotic process.
The most serious complication when using alloprostheses is wound suppuration. Infectious complications are observed during reconstruction of the aortoiliac zone in 0.7%, aortofemoral - in 1.6% and femoro-popliteal zone - in 2.5% of cases. When infected, the prosthesis becomes a foreign body with a rejection reaction, and a granulation shaft forms around it. In this case, arrosive bleeding from the anastomosis site may occur. In order to prevent surgical infection, it has been proposed to introduce materials containing antibiotics into the prosthesis.
As a result of changes in the physicochemical properties of prostheses, their strength, elasticity, and resilience decrease. Over the years, “fatigue” of polymer materials has been observed. So, after 5 years, the loss of strength is 80% for propylene and 60% for dacron. None of the used prostheses made of Teflon, Dacron, Fluorlon and Dacron are an ideal means of replacing blood vessels. In 1974, the textile company Gore (W.L. Gore et al.) developed a new synthetic prosthesis made of microporous polytetrafluoroethylene (PTFE) and named “Gore-Tech”. Due to their qualities, these prostheses quickly became widespread in the United States and then in other countries of the world.
In 1994, JSC Research and Production Complex Ecoflon in Russia developed a technology for the production of vascular prostheses from PTFE under the brand name Vitaflon. Samples of prostheses underwent comprehensive medical and biological tests in the polymer laboratory (head professor N.B. Dobrova) Science Center cardiovascular surgery of the Russian Academy of Medical Sciences and clinical trials in many vascular centers. The results of the experimental and clinical trials showed that prostheses have high biological inertness, good plastic properties, high thromboresistance, zero surgical porosity and reliable “implantability” into the recipient’s body. Prostheses are applicable not only for plastic surgery of arteries, including medium-sized ones, but also of veins, where there are more favorable conditions for thrombus formation. The high thromboresistance of the material is due to the fact that the inner wall of the prosthesis has a smooth hydrophobic surface, which improves the interaction of the prosthesis wall with blood, and this property is maintained during long periods of implantation. The development of thin-walled Vitaflon prostheses opens up the prospect of their use for plastic surgery of small-caliber arteries.
Selected lectures on angiology. E.P. Kokhan, I.K. Zavarina
CHAPTER 4. BASICS OF SURGICAL TRANSPLANTOLOGY
CHAPTER 4. BASICS OF SURGICAL TRANSPLANTOLOGY
4.1. GENERAL CHARACTERISTICS, TERMS
AND CONCEPTS OF TRANSPLANTOLOGY
The term "transplantology" is derived from the Latin word transplantare - to transplant and Greek word logos - teaching. In other words, transplantology is the study of organ and tissue transplants.
The Great Medical Encyclopedia defines transplantology as a branch of biology and medicine that studies the problems of transplantation, develops methods for preserving organs and tissues, and creating and using artificial organs.
Transplantology has incorporated the achievements of many theoretical and clinical disciplines: biology, morphology, physiology, genetics, biochemistry, immunology, pharmacology, surgery, anesthesiology and resuscitation, hematology, as well as a number of technical disciplines. On this basis, it is an integrative scientific and practical discipline.
The section of transplantology devoted to the use of organ and tissue transplantation in the treatment of human diseases is called clinical transplantology, and since such transplantations are, as a rule, surgical operations, it is appropriate to talk about surgical transplantology.
Transplantation- this is the replacement of the patient’s tissues or organs either with his own tissues or organs, or taken from another organism or created artificially. The transplanted tissue areas or organs themselves are called grafts.
Depending on the source and type of transplanted grafts, there are 5 types of transplantation:
Autotransplantation- transplantation of own tissues and organs.
Isotransplantation- transplantation between genetically homogeneous organisms. These are transplants between human twins in clinical transplantology or between individuals within genetically homogeneous lines of animals in experimental transplantology.
Allotransplantation- transplantation between organisms of the same species, but genetically dissimilar. This is an intraspecific transplant; in medicine, it is a transplant from person to person.
Xenotransplantation- transplantation of organs or tissues between organisms different types. This is an interspecies transplantation; in medicine, it is the transplantation of animal organs or tissues into humans.
Explantation(prosthetics) - transplantation of a non-living, non-biological substrate.
In transplantology, three outwardly similar terms are used: “plasticity,” “transplantation,” and “replantation.” It can be difficult to distinguish them absolutely, but nevertheless these terms can be defined as follows.
Plastic surgery is, as a rule, the replacement of a defect in an organ or anatomical structure with grafts without suturing blood vessels. The term is used to refer to the transplantation of tissues, but not entire organs.
A transplant is the transplantation (replacement) of an organ with stitching of blood vessels. Such a transplantation can be orthotopic, i.e. to the place usual for a given organ, and heterotopic, i.e. to a place not typical for this organ.
A transplant is the transplantation of a donor organ without removing the same organ from the recipient.
The term “replantation” stands somewhat apart in the system of basic terms of transplantology, which is understood as a surgical operation to engraft a section of tissue, organ or limb separated due to injury in its original place. The same term refers to the introduction of an extracted tooth into its own alveolus.
4.2. CLINICAL CHARACTERISTICS OF VARIOUS
TYPES OF TRANSPLANTATION
The types of transplantation named in section 1 of the chapter modern medicine and, above all, in surgery, they have different scope and breadth of use.
Autotransplantation
Autotransplantation ensures true engraftment of the transplanted substrate. With such transplants and plastic surgery there is no
immunological conflict in the form of transplant rejection. For this reason, autotransplantation is by far the most advanced type of transplantation.
In surgery, skin autoplasty is widely used: local and free autografts. To strengthen weak points and defects in the walls of cavities, dense fascia, such as the fascia lata, is used to replace tendon defects. Some bones are used for bone autoplasty: rib, fibula, iliac crest.
Some blood vessels can serve as autografts: the great saphenous vein of the thigh, intercostal arteries, internal mammary arteries. The most indicative here is coronary artery bypass grafting, in which a segment of the great saphenous vein of the patient’s thigh is used to create a connection between the ascending aorta and the coronary artery of the heart or its branch.
Autotransplantation is the use of autografts of the small intestine, colon, and stomach to restore the esophagus (after its resection for cancer or scar strictures). Autoplastic surgeries are performed on the urinary tract: ureter, bladder.
A very good auxiliary autoplastic material is the greater omentum.
Autotransplantation may also include: replantation of a tooth, traumatically severed limbs or their distal segments: fingers, hands, feet.
Allotransplantation
For allotransplantation, there are two sources of donor tissues and organs: a cadaver and a living volunteer donor.
In modern surgery, skin allografts from both corpses and volunteer donors, various connective tissue membranes, fascia, cartilage, bones, and preserved vessels are used. An important type of allotransplantation in ophthalmology is cadaveric cornea transplantation, developed by the largest Russian ophthalmologist V.P. Filatov. The first reports of allotransplantation of the complex of skin and soft tissues of the face appeared. Allotransplantation is the transfusion of blood as liquid tissue, which is widely used in medicine.
The largest area of allotransplantation is organ transplantation, which will be discussed in the next section of this chapter.
For the widespread use of allotransplantation, three problems are of primary importance:
Legal and moral support for organ retrieval from both a corpse and a living volunteer donor;
Preservation of cadaveric organs and tissues;
Overcoming tissue incompatibility.
In the legislative support of allotransplantation, the criteria for death, in the presence of which organ retrieval is possible, legislation regulating the rules for organ and tissue retrieval, and the possibility of using allografts from living volunteer donors are of key importance.
Preservation of donor organs and tissues allows transplantation material to be preserved and accumulated in tissue and organ banks for use for therapeutic purposes.
The following main conservation methods are used.
Hypothermia, i.e. preservation of an organ or tissue at a low temperature, at which a decrease in metabolic processes in tissues and a decrease in their need for oxygen occur.
Freezing in a vacuum, i.e. lyophilization, which leads to an almost complete stop of metabolic processes while preserving cells and other morphological structures.
Continuous normothermic perfusion of the bloodstream of the donor organ. At the same time, normal metabolic processes are maintained in the isolated organ by delivering oxygen and necessary nutrients to the organ and removing metabolic products.
Overcoming tissue incompatibility between donor and recipient tissues is essential for allotransplantation. This problem, first of all, relates to the selection of donors, donor organs and tissues that are most compatible with the recipient’s body. This is carried out during serological diagnosis by using special sets of sera. This selection is very important, as it allows you to select the most compatible pairs and count on successful engraftment of the allograft.
In addition, there are methods of immunosuppressive therapy, i.e. suppression of transplantation immunity, prevention
rejection reactions. Among them, a distinction is made between physical (for example, local X-ray irradiation), biological (for example, antilymphocyte serum) and chemical methods. The latter are the most diverse and are the main ones. These methods consist of using a whole group of immunosuppressive drugs (imuran, actinomycin C, cyclosporine, etc.), which reduce the immunity of the recipient’s body and prevent a rejection crisis.
It should be noted that allotransplantation and the problems associated with it are a very dynamic and rapidly developing area of clinical transplantology.
Xenotransplantation
In modern surgery, transplantation of animal organs and tissues to humans is the most problematic type of transplantation. On the one hand, an almost unlimited number of donor organs and tissues from different animals can be prepared. On the other hand, the main obstacle to their use is pronounced tissue immune incompatibility, leading to rejection of xenografts by the recipient's body.
Therefore, until the problem of tissue incompatibility has been resolved, the clinical use of xenografts is limited. In a number of reconstructive operations, specially treated animal bone tissue is used, sometimes blood vessels for combined plastic surgery, temporary transplants of the liver and spleen of a pig - the animal that is genetically closest to humans.
Attempts to transplant animal organs into humans have not yet led to lasting positive results. Nevertheless, this type of transplantation can be considered promising after solving the problems of tissue incompatibility.
Explantation
Explantation, or prosthetics, can be considered as a type of transplantation that is alternative to the use of living biological tissues and organs. With this type of transplantation, various artificial products and devices made of various materials are implanted into the patient’s body. These include synthetic blood vessel prostheses: woven, knitted, woven from various synthetic threads, heart valve prostheses, metal prostheses of large joints: hip, knee, implantable artificial heart ventricles.
Explantation is a rapidly developing type of transplantation associated with the development of new implantable devices and the use of new plastic materials. Technical sciences play an important role in its development: materials science, organic chemistry, radio electronics, etc.
4.3. TRANSPLANTATION OF INTERNAL ORGANS
Internal organ transplantation has been the most important branch of clinical surgical transplantology for more than 50 years. The beginning of scientifically based experimental development of this problem dates back to the first years and decades of the twentieth century. Among the surgeons and experimenters who made a significant contribution to the experimental substantiation of organ transplantation, one should name the French surgeon A. Carrel, Russian experimenters A.A. Kulyabko, S.S. Bryukhonenko, V.P. Demikhova.
Transplantation of large organs has a number of features. When removing an organ from a cadaveric donor, the timing of its removal after the fact of death has been established is of key importance. The time for maintaining viability varies for different organs after cessation of blood circulation: for the brain 5-6 minutes, for the liver 20-30 minutes, for the kidney 40-60 minutes, for the heart up to 60 minutes. Preservation of removed organs is of utmost importance, i.e. preservation of their tissues in a viable state, preservation of organs in tissue banks, the possibility of selecting them for the patient on the basis of the greatest immune compatibility of the donor organ and the recipient organism.
When transplanting an organ from a living volunteer donor, it is essential that the donor organ at the time of transplantation is subject to temporary ischemia, it is deprived of nerve connections with the body and lymphatic drainage pathways. It is also important that an organ transplant from a living volunteer donor is a simultaneous surgery in two patients: donor and recipient.
Living donors are usually close relatives of the patient: parents, brothers and sisters. This type of transplantation is only possible in relation to paired organs, specifically the kidneys.
The kidney was the first organ whose transplantation began to be used in clinical practice. The source of a donor kidney can be either a cadaver or a living volunteer donor.
The world's first human kidney transplant was performed in the USSR by surgeon Yu.Yu. Voronoi in 1934. In 1953 in the USA, Hume performed the first successful kidney transplant between twins.
In our country, regular kidney transplants to patients began to be performed in 1965 after the largest Russian surgeon, Academician B.V. Petrovsky performed a successful kidney transplantation on a patient.
Currently, kidney transplantation is performed for life-saving indications, which include: chronic renal failure due to glomerulonephritis, pyelonephritis, toxic lesions kidney and other irreversible kidney diseases leading to complete cessation of their function.
The technique for performing kidney transplantation is well developed, taking into account individual differences in its blood vessels, urinary tract, and topography of the organ in the retroperitoneal space.
It can be combined with simultaneous removal of the patient’s affected kidneys or performed as a transplant without removing the affected kidneys. Therefore, a donor kidney can be placed in the recipient’s body either orthotopically, i.e. into the retroperitoneal space at the site of the removed kidney, and heterotopically, for example, into the iliac fossa of the pelvis with anastomosis of the renal vessels (arteries and veins) with the iliac ones.
Human heart transplantation was first performed in December 1967 by Cape Town surgeon K. Barnard (South Africa). The patient was L. Vashkansky with severe heart failure. He lived with a transplanted heart for 17 days and died from developing severe bilateral pneumonia.
In January 1968, the same K. Barnard performed another heart transplant on dentist F. Bleiberg, who lived for 19 months with the transplanted heart.
The preferred method of heart transplantation is the Shumway technique, in which the ventricles of the heart are transplanted and sutured to the preserved atria of the recipient.
In our country, the clinical use of heart transplantation as a method of treating severe heart lesions (decompensated heart failure, cardiomyopathy, etc.) is associated with the name of the outstanding transplant surgeon V.I. Shumakova.
In addition to kidneys and hearts in a number of surgical clinics and organ transplantation centers different countries operations are performed on
transplantation of liver, lungs, endocrine glands. Thus, the Russian topographical surgeon I.D. Kirpatovsky, for the first time in the world, developed and carried out in the clinic pituitary gland transplantation in the form of a heterotopic graft on the anterior abdominal wall.
It should be noted that organ transplantation is an extremely dynamically developing area of modern transplantology. Within the framework of this direction, extensive experimental and clinical research is being carried out on the transplantation of a number of other organs: the pancreas, parts of the intestines, on the creation of artificial organs, and the use of embryonic organs for transplantation. Research on growing organs and tissues from stem cells and transgenic organs is promising.
For the development of organ transplantation and its widespread use as a treatment method in clinical medicine Economic, social and legal aspects are essential.
4.4. TRANSPLANTATION SITE
IN MODERN SURGERY
The fundamentals of transplantology presented above clearly indicate its key importance for reconstructive surgery.
