"EX VIVO" MACHINE PRESERVATION OF THE ABDOMINAL ORGANS OF A PIG.

The aim of the study is to test the developed perfusion machine for long-term preservation of the liver, to evaluate the perfusion scheme that provides two different (arterial and venous) flows, and to evaluate hemodynamic of parallel perfusion of the liver together with the kidney. We have developed a perfusion machine to enable simultaneous perfusion of the liver and kidney, based on clinically proven constant flow blood pump. In the developed device, constant blood flow is converted into pulsed blood flow using a device of its own design - a pulsator. The device was tested on 6 pigs, whose liver and kidney were explanted for preservation. Organs were explanted along with the aorta and caudal vena cava on a common vascular pedicle and perfused through the aorta and portal vein. With a constant flow pump, part of the blood was directed through a heat exchanger, an oxygenator, and a pulsator and delivered to the organs through the aorta. The other part was sent to the upper reservoir, from which the blood gravitationally entered the portal vein. The organs were irrigated with warm saline. Blood flows were regulated by gas composition, temperature, blood flow volume and pressure. One experiment was put to an end due to technical problems. In 5 experiments, during the 6-hour perfusion, all physiological parameters remained within the normal range. During the conservation process, slight, correctable changes in gas exchange parameters affecting pH stability were noted. The production of bile and urine was noted. Results of the experiments with the achievement of a stable 6-hour perfusion preservation with confirmed physiological activity of the liver and kidney, make it possible to consider the design capabilities of the applied device with pulsating blood flow. It is possible to assess the original perfusion scheme, which provides two different flows, by one blood pump. The possibility of increasing the duration of liver preservation with further improvement of the perfusion machine and methodological support was noted.

[IMPROVING THE PERFUSION FLOW OF BLOOD PUMPS].

Research in recent years has shown that pulsating flow during cardiopulmonary bypass can prevent the development of a number of perfusion complications inherent in continuous blood flow. On the other hand, attempts to pulsate with roller and centrifugal pumps, which are structurally DC pumps, are fraught with complications. However, these pumps are clinically tested and are successfully used for the implementation of direct blood flow. The aim of the study was to develop and create a preclinical apparatus that transforms the flow of DC pumps into a pulsating one. We have developed an electronically controlled device (pulsator) that transforms the direct blood flow generated by roller or centrifugal pumps into a pulsating flow synchronized by the cardiogram. The pulsator was tested on the bench in various load modes. Cardiosynchronized pulsating blood flow with circulatory support is able to effectively relieve the ventricular myocardium both in volume and pressure. The pulsator can be easily and easily installed on the operating table or on the perfusion device stand. The ability to control the pulsation frequency, systolic-diastolic duration, clear cardiosynchronization and the ability to control the onset and termination of the impulse can provide unloading of the myocardium in volume and pressure in experiments on animals in the mode of auxiliary circulation.

MORPHOLOGICAL CHANGES IN THE LIVER AFTER 8 HOURS OF PRESERVATION BY MACHINE PERFUSION.

Patients with refractory cardiac arrest, who have undergone Extracorporeal Life Support (ECLS) for resuscitation, but have not achieved cardiac recovery, can be considered as potential donors (Cardiac Death Donors). In such cases, it takes time to notify and obtain the principle consent of the relatives and finalize the clinical and legal documents. During this time, prior to obtaining consent for the removal of organs, ECLS can be extended. In this case, the extracorporeal circulation implies organ preservation "in situ" until the ethical, religious and organizational problems should be decided. Correspondingly, the identification of safe time terms during which the donor organs do not suffer by the changes not compatible with transplantation is extremely important. We aimed to study the morphological changes in the liver after 8 hours of extracorporeal circulation in experiments. The investigation was performed on 6 sheep with simulated cardiac arrest and undergone 8-hours extracorporeal circulation with own blood by using of new portable perfusion apparatus, made on the basis of a universal volumetric blood pump of our own design. The device was connected to the body through the femoral artery and vein with special cannulas. The biopsy of the liver was performed before the starting of perfusion, and on 4 and 8 hours of the experiment. The histological slices were stained by H&E and were assessed by standard criteria: level of steatosis (large-droplet macrovesicular steatosis [ld-MaS] and/or small-droplet macrovesicular steatosis [sd-MaS]); mononuclear portal inflammatory cell infiltrates; bile ductular proliferation; cholestasis; venous congestion; hepatocellular necrosis. Before the perfusion, no venous congestion, hepatocellular necrosis or ld-MaS were observed; Less than 3% of cells were suffered by sd-MaS; mononuclear portal inflammatory cell infiltrates were found only in several areas. Mild mixed ld-MaS and sd-MaS was found in less than 5 % and 10% of the cells accordingly on the 4 and 8 hours after in vivo Machine perfusion. Similarly the mild venous congestion was present in 1 out of 6 livers after 4-hours perfusion and in 2 out of 6 livers after 8-hours Perfusion. The number of necrotic hepatocytes and portal triads infiltrated with mononuclear cells did not exceed 10% and 15% accordingly. However, there were no differences in the degree of biliary damage - cholestasis or ductular proliferation - correlating with the terms of the experiment. Taking into the consideration all internationally accepted criteria of donor liver histological assessment, 8-hour in vivo perfusion of the liver in Cardiac Death Donors by using of the machine of own design providing the pulsatile blood flow guarantees the satisfactory preservation of liver making it useful for successful transplantation.

[PRESERVATION OF ORGANS VIABILITY BY THE HEART-LUNG BYPASS MACHINE IN THE NON-HEART-BEATING DONORS (REVIEW)].

In a wide range of acute, debatable problems of transplantology, the problem of donation should be highlighted. It includes the selection and management of the donors, ethical and religious aspects and issues on the prevention, treatment and rehabilitation of the organ before its transplantation. Among the many methods of organ preservation, in the last decade, machine perfusion methods are on the forefront. They are designed to minimize or repair the ischemic-reperfusion damages in tissues and cells. This became possible in conditions of technical progress and the introduction of artificial circulation systems that provide adequate tissue microcirculation in non-heart-beating donors. However, this approach should take into account the complexity of the perfusion machines design, its various connection schemes and the nature of the perfusion parameters - the composition and temperature of the perfusion liquor. Experimental studies confirm that the use of machine perfusion is a technology whose possibilities will radically change the approaches to organ transplantation.

[THEORETICAL BACKGROUND OF FINDING ORGANS FOR TRANSPLANTATION AMONG NON-HEART BEATING DONORS UNDER UNSUCCESSFUL EXTRACORPOREAL RESUSCITATION (LITERATURE REVIEW)].

The number of patients who are in the "Transplant Waiting List" is increasing each year. At the same time, as a result of the significant shortage of donor organs, part of the patients dies without waiting till surgery. According to the Maastricht classification for non-heart beating donors, the patients, who had cardiac arrest outside the hospital (in the uncontrolled by medical staff conditions) should be considered as a potential donors of category II. For these patients, the most effective resuscitation is recommended. The extracorporeal life support (ECLS) considers the connection to a special artificial perfusion system for the restoration of blood circulation out-of-hospital with further transportation to the hospital. If restoration of independent cardiac activity does not occur, in spite of the full range of resuscitative measures, these patients may be regarded as potential donors. The final decision should be received in the hospital, by the council of physicians, lawyers and patient's family members. Until the final decision, the prolongation of ECLS and maintaining adequate systemic and organic circulation is recommended.

Abdominal organ donation: surgical aspects and recommended practice guidelines for controlled donation of brain-dead donor.

The shortage of organ donors along with the increased number of waiting recipients have created the need for new strategies to expand the organ pool from donations after brain death. Organ procurement from brain-dead deceased donors is a complex task. Multiple, complicated operations are performed simultaneously. Very often, this involves numerous physicians and transplant coordinators. An extensive coordination between the thoracic and abdominal surgical teams is crucial for the successful procurement of all suitable organs. The quality of donor organs and the successful recovery therefore depends on a good communication. Organ procurement for transplantation should generally be performed in a calm and dignified atmosphere. The last wishes of the organ donor itself or the relatives must be respected unconditionally. In general, a dignified and respectful treatment of the organ donor is a condition sine qua non for each person involved in the process of organ procurement. The purpose of this article was to focus on the surgical aspects of organ donation after brain death. The proposed recommendations, in cases where they are applicable, are acceptable, however, one should never forget the importance of the ethical side of the issue with respect to the doctor-donating side relationship.

New model of veno-venous bypass for management of anhepatic phase in experimental study on dogs.

Blood is shunted from the inferior vena cava and portal vein to the superior vena caval system to prevent congestion in the lower parts of the body during the anhepatic phase (AP) of liver transplantation. It leads to overload in the superior vena caval system retarding cranial outflow due to a nonphysiological blood redistribution. To overcome this problem, we developed a new bypass in dogs: blood is shunted from the inferior (caudal) vena cava and portal vein to the suprahepatic inferior (caudal) vena cava. This model was compared with traditional one with or without a pump. Blood pressure and flow parameters were estimated during 3 hours of AP in four groups of four dogs each. The current study showed that a nontraditional scheme of venous bypass reduced circulatory complications during AP, especially in the cranial vena caval system, although a low rate of congestion remains in the caudal vena cava and portal vein systems. Whereas the same scheme using a pump effectively prevented congestion in all of the systems: cranial, caudal, and portal. We concluded that application of a nontraditional bypass scheme, providing venous blood return into suprahepatic part of caudal vena cava, can be considered to be a method of choice for experimental liver transplantation.

Experimental liver autotransplantation with novel scheme of veno-venous bypass as a model of liver denervation and delymphatization.

The impact of denervation and delymphatization (DD) on liver tissue remains a topic of major interest in liver transplantation, as the organ or its part continues to function well. Various chemical and/or surgical interventions have been developed to achieve in situ liver denervation and delymphatization, but it is evident that DD can be achieved only through "ectomia", ie, complete isolation of the organ from adjacent and connected structures. This Study describes a liver DD model based on a technique of autotransplantation (replantation), maximally preventing ischemia in the transplanted (replanted) graft and dyscirculatory complications in the recipient. Experiments were performed on eight male mongrel dogs. Venous reservoir and roller pumps were used in a forced nontraditional bypass scheme. Autotransplantation was performed by step-by-step dissection of the suprahepatic, infrahepatic, and portal structures, leading to DD, with subsequent recovery of the blood vessel and bile duct. DD was achieved successfully with stable hemodynamic parameters during all surgery periods. All animals survived. This model of liver autotransplantation lead to DD of the organ. It was characterized by hemodynamic stability of the liver as well as of the whole body at every stage of the surgery, proffering liver DD for experimental studies.

[Optimization of the venous return during experimental hepatectomy in rabbits].

A traditional bypass pattern applied in hepatectomy (venous return in superior vena cava system) is frequently attended by blood congestion in cranial veins. The study objective is the maintenance of hemodynamic indices in normal physiological ranges via application of the new bypass scheme in the experimental model of the anhepatic period. 12 rabbits of Chinchilla breed were involved in the experiments, with weight ranging between 3,0-3,5 kg, which were divided into three groups (with 3 animals in each): I control group - hepatectomy under the condition of non-compulsory liver bypass with the return of the venous flow in brachiocephalic vein. II group - hepatectomy with the compulsory bypass, with an in-take of blood in the apparatus and injection in the brachiocephalic vein. III group - hepatectomy via non-traditional method of compulsory bypass in suprahepatic vena cava. The outcomes of the experiments indicated that blood congestion in cranial venous system occurred only in I and II groups, which was verified by the pressure rise (5,9+/-1,2 mmHg and 4,7+/-0,5 mmHg, respectively) and diminished blood flow rate (3,0+/-1,8 ml/min and 2,0+/-0,7 ml/min) in external jugular vein. These indices corresponded with the levels of 0,6+/-0,2 mm Hg and 9,0+/-2,5 ml/min respectively in the III group. Application of the artificial, compulsary bypass circuit has been established to be reasonable in anhepatic period, for achieving the blood return to the heart through portal vein and from the lower parts of the body. During blood return in suprahepatic portion of vena cava, the congestion in cranial venous system is prevented. Maintenance of the pressure and volume indices between normal physiological limits in venous system provides the opportunity of safe prolongation of the anhepatic period.

Experimental study of the new blood pump for the heart-lung bypass machine.

The functioning of the rolling pump in the system of artificial blood circulation is associated with a number of complications. For avoiding these complications, virtually new perfusion system is developed, in which the functions of a blood reservoir and a pump are united in hermetic cardiotomy reservoirs. The technical aspects of connecting this system to experimental animals are described. In comparison with the traditional machines the system has minimal volume of filling and does not damage blood corpuscles. Constructive pumping system and entire perfusion system are quite simple and the control system allows achievement of hemodynamic characteristics maximally close to physiological ones. In addition, the system could be applied on both, large and small experimental animals.

[Use of Plaferon LB for cardiac preconditioning during experimental ischemia/reperfusion injury in rabbits].

The main goal of research was to study potential of Plaferon LB for cardiac preconditioning during experimental ischemia/reperfusion injury in rabbits. 30 rabbits (2.5-3.0 kg) were used in experiment. They were divided in 3 groups and 6 subgroups (n=5). In I group experimental design of m/i was performed by proximal ligation of left coronary artery (LCA) (2-6 hours). In II group on the 2 and 6 hour ligature was removed - reperfusion during 1 hour. In III group before ligation of LCA animals was administered Plaferon LB (0.2 mg/kg). The animals were under electrocardiographic monitoring. Troponin I was measured in blood. In II group after 1 hour of reperfusion Troponin I concentration was higher than in I group after 2 and 6 hours. In II group electrocardiographic data was worsened (rhythm and heart rate). In III group these changes were less marked. Obtained data confirm enhancement of myocardial injury during the reperfusion. Cardiac preconditioning by Plaferon LB significantly decreased pathologic indices.

[Effects of early vocational guidance of students at medical faculty of institute of higher education].

Despite the intensive clinical application of the scientific and technological innovations, the effect of the human factor in surgical intervention remains decisive. The existing model of training highly qualified specialists in the residency program does not always render positive results. For this reason, the issue of early orientation and specialization of prospective specialists, starting from the Bachelor's stage, has received considerable attention. The experience of colleagues at the department of human anatomy, topographic anatomy and operative surgery of the medical faculty of Tbilisi State University is based on the example of early professional orientation of the students, and their active attraction in the specialized surgery groups within the department's "student scientific-practical laboratory." The laboratory has united the abdominal, thoracic, microvascular surgery, plastic surgery, anaesthesiology groups and the group of artificial life support. Teaching was carried out on the basic and specialized stages of preparation in the duration of 5 years in conjunction with regular classes at the faculty. The results of this approach included: significantly higher level of knowledge of theoretical foundations and practical skills in various fields of surgical specialty; positive influence on learning process in general, with improved academic performance of students in every surgical discipline; popularisation and promotion of research with active engagement of students in research activities of the department; "painless" adaptation of students in the clinical departments of city hospitals.

New type of pulsate flow system for artificial heart-lung bypass.

In the artificial system of heart-lung bypass, used during the surgery on stopped heart, a com-mon problem-causing device is a roller pump. Inexpensive, simple, yet dependable device is in the process of development, with characteristics maximally approximated to the physiologic parameters of the organism's natural heart. Substituting for the roller pumps, this device consists of two reservoirs. Hermetic reservoirs are interconnected in parallel. They also connect to other parts of the system with blood tubing. A pneumo console for artificial ventricles represents the control system and ensures pulsate blood flow in the bio-models. The developed device provided not only an opportunity to assign frequency of a pulsation, but also an opportunity of control in each output volume. For fulfillment of maximum physiologic blood flow, it is necessary to provide cardio-synchronized mode of perfusion.

Aspects of aging in georgian traditional medicine.

The goal of the investigation was studying Georgian medicinal manuscripts of X-XVIII centuries in order to find out ideas of ancient authors regarding peculiarities of healthy lifestyle from the moment of birth till the elderly age. Results of analysis of Georgian medieval medicinal manuscripts allow us to conclude, that Caucasian longevity is determined not only by genetic, ecological, social and hygiene factors, but also by rational diet, proper treatment, remedies of plant origin and healthy lifestyle, existing in Caucasian cultural anthropology. Original schemes of diets and recipes, based on humoral theory and balanced by main characteristics of natural material are described.

[Treatment of total diverticulosis of the small intestine]. / Lechenie total'nogo divertikuleza tonkoi kishki.

Results of treatment of diverticulosis of the small intestine in 59 patients are presented. Operations for urgent indications were performed on 12 patients. In 12 patients diverticulosis was associated with other surgical diseases of organs of the abdominal cavity. Planned operations were performed on 35 patients, 3 of them having total diverticulosis. The authors describe their tactics and original methods of treatment of total diverticulosis.

Long-term circulatory and respiratory support using two artificial ventricles and a fluorocarbon oxygenator.

Using a new heart-lung machine developed at our Institute, experiments were conducted on dogs, donkeys, and monkeys, providing complete and assisted artificial circulation, assisted oxygenation, and perfusion preservation of the heart. The new apparatus consists of two sequentially mounted artificial ventricles working in an antiphase mode; blood oxygenation is accomplished by a reusable oxygenator with a fluorocarbon preoxygenator. Experimental results indicate that clinical use of the apparatus is promising and deserves consideration. The conditions of perfusion were close to physiological conditions and provided long-term survival of the animals. Performance in left ventricular bypass was optimized by monitoring myocardial PO2 and the state of the quick-connect/cut-off assemblies.