[THE ROLE OF INTESTINE ISCHEMIA IN METABOLIC DISORDERS DURING THE AORTIC CLAMPING ABOVE THE CELIAC TRUNK.]

THE AIM: To identify the role of the intestine in the development of metabolic disorders with operations in the thoracoabdominal aorta developing after clamping of the aorta above the celiac trunk Materials and methods. The study was conducted in pigs (n = 6) with similar body weight (m = 35-39 kg). After the intoduction of animal anesthesia, surgery was performed by access to the visceral veins (upper and lower mesenteric kidney, liver spleen andfemur), from which the Blood samples to determine the concentration of lactate, glucose, as well as indicators of acid-base status. Then placing the clamp on the aorta above the level of discharge of the celiac trunk. Blood sampling and laboratory diagnosis carried out twice: before clamping the aorta and blood flow before the start after 60 minutes of ischemia. Histological study intestinal tissue also conducted. RESULTS: It is shown that the aorta cross-clamping develops pronounced metabolic disorders, manifested in the form of increased levels of lactate and glucose concentrations in all investigated parts of the splanchnic region. The most pronounced increase in lactate after clamping the aorta was observed in the blood samples flowing from the intestine. The results of histological studies show that intestinal hypoperfusion leads to severe pathological changes, that is a predisposing factor leading to the translocation of bacterial agents into the systemic circulation, to the process of expression of systemic inflammatory response and a powerful oxidative stress. CONCLUSION: Our experimental data show that when aortic clamping above the celiac trunk (ischemia mesenteric region) the greatest quantitative contribution to metabolic disorders the body of the animal created in a pathophysiological situation contributes to intestinal hypoperfusion. In this regard, one of the main tactics of the anaesthetist in the perioperative period should be the protection of the intestine against ischemia and its consequences.

[Sevoflurane optimal dosage estimation for myocardium pharmacological postconditioning: an experimental study].

We estimated the optimal dosage of inhalation anesthetic sevoflurane, for the maximum cardioprotective effect with minimal angioparalytic action. 25 pigs were included in this study, they were divided into 5 groups, depending on the sevoflurane dosage used for pharmacological postconditioning (PPC): control group - PPC has't been conducted, a group of PPC 0.5 - sevoflurane PPC in a dose of 0.5 V%, a group of PPC 1.0 - sevoflurane PPC in a dose of 1.0 V%, a group of PPC 1.5 - sevoflurane PPC in a dose of 1.5 V%, a group of PPC 2.0 - sevoflurane PPC in a dose of 2.0 V%, a group of PPC 2.5 - sevoflurane PPC in a dose of 2.5 V%. Ischemia was simulated by left coronary artery crossclamping. Further PPC was held according to the following Protocol: 20 min before left coronary artery clamp off and first 20 min of reperfusion sevoflurane was given into CPB circuit. Myocardial ischemia period was 60 min in all groups. It was found and experimentally proved that the optimal sevoflurane dosage for PPC is 2 V%

[The transplantation of revascularized thyroid-trachea-lung complex: the experimental study].

The osteoplastic tracheobronchopathy affects the trachea, main, lobar and smaller bronchi, causing their stenosis. Nowadays the mainstay of the treatment of such patients is the cryodestruction, laser destruction and the endoscopic buginage of the trachea and bronchi. The palliative nature and low efficacy of these procedures forces to search new ways of treatment. The traditional lung transplantation or separate trachea and lung transplantation is inappropriate because of the complex affection of both trachea and bronchi. The experimental study aimed the possibility of thyreotracheolung revascularized donor complex transplantation.

[Tissue equivalent for the closure of extended urethral defects].

The aim of the present work was to develop a method for culturing epidermal keratinocytes to be used in a tissue equivalent for the closure of extended urethral defects. The experiment was carried out using 15 rabbits. Skin biopsies were obtained from the inner surface of the ear. The tissue equivalent consisted of collagen gel with embedded fibroblasts and epidermal keratinocytes grown on its surface; lavsan-mesh endoprosthesis served as the framework. Prefabrication of the neourethral plate was performed on the superficial fascia of m. rectus abdominis. The neourethral tube was formed after engraftment which was complete in all 15 animals. A histological study revealed morphological similarity of the neourethral tube thus engineered and the normal urethra.

[Brain cryodestruction in mammals in vivo].

26 animals (13 pigs and 13 rabbits) were involved in the study. Liquid nitrogen cryodestruction experimental  machine was used. The following measurements and investigation were performed: invasive temperature measurement, intraoperative ultrasound, magnetic resonance imaging and pathomorphologic assessment. An ice sphere was hypoechogenic with hyperechogenic  contour by ultrasound.  Postoperative MRI showed signs of local ischemic oedema in cryodestruction zone, no signs of bleeding were detected. Morphologically zones of total necrosis, oedema and minor dystrophic changes were recognized. Cryodestruction proved to be a reliable technique of cold brain necrosis.

[Effect of perfusion volume of the Custodiol solution on the efficiency of cardioplegia in experiment].

The purpose of the present study was to compare the efficiency of small and standard volumes (1.5-20 and 7-10 ml/g of the myocardium, respectively) of Custodiol solution in myocardial ischemia lasting 2 and 4 hours. Experiments were carried out on 24 mongrel dogs weighing 22-36 kg under extracorporeal circulation (EC) with bicaval cannulation under moderate general hypothermia and balanced general intravenous anesthesia. According to the solution volume and cardioplegia (CP) duration, all the animals were divided into 4 groups: 1) 2-hour CP (standard volume); 2) 2-hour CP (small volume); 3) 4-hour CP (standard volume); 4) 4-hour CP (small volume); of them Groups 1 and 3 served as a control. Antegrade CP was accomplished by the conventional procedure. In Groups 1 and 3, the volume of Custodiol solution was 1000-2000 ml; in Groups 2 and 4, that was 300-600 ml depending on myocardial mass. In Groups 1 and 3, the mean duration of myocardial perfusion was 9.8+/-2.8 and 8.4+/-1.4 min, respectively; and in Groups 2 and 4, that was 4.2+/-0.7 and 4.5+/-1.4 min. Groups 3 and 4 animals received additional myocardial perfusion with Custodiol solution in a volume of 400-500 and 200-250 ml, respectively. The efficiency of myocardial protection was evaluated from the course of a reperfusion period (RP) and from central hemodynamic changes, the concentrations of glucose, lactate, malonic dialdehyde, medium-weight molecules, and blood gas and electrolyte composition of the coronary sinus. The studies were performed in stages: outcome, launch of blood flow (5-10 in); RP (30 min); complete loading (30 min); disconnection from an extracorporeal circulation apparatus. The experiment has indicated that the use of Custodiol solution in the standard volumes ensures an effective cardioplegic protection within 4 hours. Reductions in the volume and time of perfusion to the values characteristic of extracellular-type solutions cause a lower efficiency of this protection. Moreover, myocardial damage progresses as the duration of CP increases. The used Custodiol solution dose of 1.5-2.0 ml/g of the myocardium is apparent to be insufficient to set an ionic balance between cardioplegic solution and intracellular fluid, which reduces the duration of CP effect and the efficiency of myocardial protection. It may be assumed that lower perfusion volume lowers the efficiency of the buffer system of the solution and the metabolic effects of substrates. The authors consider that the decreased volume and time of perfusion of intracellular Custodial solution are unjustified and may result in the development of complications associated with inadequate cardioplegic myocardial protection.

[Intraoperative myocardial protection with extracellular cardioplegic solutions in patients with cardiac valve diseases].

A hundred patients operated on under extracorporeal circulation (EC) with bicaval cannulation in the moderate general hypothermia mode were intraoperatively examined. According to the used cardioplegic solution, all the patients were divided into three groups: 1) Konsol; 2) Konsol MF; 3) St. Thomas (a control group). All the groups were matched by age, gender, the duration of myocardial ischemia (MI) (37-128 min), that of EC (52-186 min), and the nature of surgical interventions, of which mitral valve replacement amounted to 72-78%. To prepare a modified solution, 20 ml of 40% glucose, 20 units of insulin, and 200 mg of creatine phosphate (Neoton) were added to a flask containing 400 ml of Konsol. The efficiency of myocardial protection was evaluated by the data characterizing cardiac arrest and cardiac performance resumption, as well as by heart rate and the use of inotropic support in the reperfusion period. The parameters of central hemodynamics and systemic coronary blood flow, the concentrations of glucose and lactate, the blood gas and electrolyte composition of the coronary sinus (CS), myocardial oxygen consumption and the oxygen-utilizing coefficient were monitored. The cardioplegic solutions Consol and Consol MF were found to have a more effective cardioprotective activity in patients with cardiac valvular disease, operated on under EC and moderate hypothermia that St. Thomas'solution. Modification of the Consol solution by adding glucose, creatine phosphate, and insulin improves the protective effect of the solution, promoting a rapider transition of the myocardium from anaerobic to aerobic metabolism.

[Comparative evaluation of clinical use of cardioplegic solutions custodiol and konsol in the correction of cardiac valvular diseases].

The efficiency of myocardial protection with cold crystalloid cardioplegia (CC) during operations on the heart under total ischemia and extracorporeal circulation was studied. Two hundred and fifty patients who underwent prosthetic or plastic repair of the aortic and mitral valves or plastic repair of the tricuspid valve were examined. Group 1 comprised 218 patients in whom the myocardium was protected with Konsol solution ("Biofarm "research-and-production enterprise, Russia); Group 2 included 32 patients in whom Custodiol solution ("Dr Franz Kohler Chemia GMBH", Germany). The volume of the Konsol solution required for CC was 400-2000 ml, with the duration of myocardial ischemia (MI) being 75 +/- 33 min; that of the Custodiol was 2000-4000 ml, with the duration of MI being 80 +/- 22 min. The used algorithm of administration of the solutions provided a persistent cardioplegic effect in both groups. After aortic declamping, there was a spontaneous recovery of cardiac performance in 84 and 40% in Groups 1 and 2, respectively. In the reperfusion period (RP), no significant differences were found in the basic hemodynamic parameters (heart rate, blood pressure, and central venous pressure) in both groups. After defect correction, cardiac output equally increased in both groups. The groups did not differ in the rate of inotropic support either. In RP, transient cardiac rhythm and conduction disturbances occurred in 19 and 28% in Groups 1 and 2, respectively.

[Study of the revascularizing properties of the greater omentum for creating prefabricated complex autografts under experimantal conditions].

The revascularizing properties of the greater omentum used as a vascular pedicle for the prefabrication of skin, skin/cartilage or skin/ bone autografts, and their viability after rotation and recipient zone infection were studied in rat experiments. The experiment showed that complexity factor did not have a significant effect on the revascularizing properties of the greater omentum, and required only an insignificant prolongation of prefabrication period. Skin/omental, skin/cartilageous, and skin/bony autografts based on the greater omentum formed by day 7, 14, and 21, respectively. After these periods prefabricated autografts remained viable upon rotation. In case of infection, the survival rate of prefabricated skin/bone autografts, revascularized with two-layer greater omentum, is lower than that of skin/cartilage ones. The technique of prefabrication of autografts including skin, cartilage, and bone, is a promising method for closure of vast multicomponent defects in complicated clinical situations.

[Experimental rationale for possible clinical use of biodialysis].

At biodialysis, the bloods of a patient and a donor simultaneously pass through the individual mass exchangers. The cavities of the dialyzing fluid of both mass exchangers hydraulically interconnected with recurculating transport medium. The metabolites accumulating in the patient's blood pass through the membrane to the transport medium and then the second membrane to the donor's blood and they are eliminated via his/her liver and kidney. At the same time, regression occurs: the substances required for normal vital activity move from the donor's body to the patient's one. Experiments on pigs in one of which both kidneys were removed yielded clearances of major toxic metabolites by approximately 2 times less than that at routine dialysis. Daily sessions of biodialysis ensured a satisfactory state and stable levels of metabolites. At biodialysis, the state did not deteriorate. In the other series of experiments, choledochus was ligated in one of the pigs and sessions of biodialysis were initiated following 24 hours. Daily sessions could achieve stabilization of the level of bilirubin within 135 micromol/l. In the donor pig, the level of bilirubin slightly increased. Its condition remained to be satisfactory.

[Hemodialysis with biological object].

The essence of the method of biodialysis (hemodialysis with biological object) developed and suggested by the authors for clinical use consists in that the healthy organism exerts, through a system of mass transfer, a therapeutic action on the sick organism. Blood from the affected and healthy organisms is perfused through individual mass exchangers (dialyzers, hemodiafilters and hemofilters), which are hydraulically connected by a circulating transport medium. Metabolites that accumulate in blood of the affected organism diffuse into the transport medium and, from there, into blood of the healthy organism, which metabolizes them. The reverse process occurs simultaneously: substances, whose concentration in blood of the sick organism is less versus the healthy organism, diffuse from blood of the healthy organism to blood of patient. The method suggested by us can be used in clinical practice for normalizing a variety of parameters in patients with hepatic and renal insufficiency. Besides, a number of substances can be transferred from the healthy donor to patient in the process of biodialysis, which opens promising potentialities for the treatment of many diseases.

[The initial trial of the clinical use of FK-1 glue in surgical interventions]. / Pervyi opyt klinicheskogo primeneniia kleia FK-1 pri operativnykh vmeshatel'stvakh.

The article presents results of a comparative clinical trial of the preparation "fibrinous glue" (FK-1) and "Beriplast" in operations on the lungs for hermetization of the wound and the lung as well as in reconstructive plastic gynecological operations. Intraoperative hermetization in operations on the lungs was obtained in 67% of the cases when using "FK-1" and in 64% with "Beriplast". In all the cases the lung was spread during 12 hours after operation. The visual intraoperative assessment of using "FK-1" and control laparoscopy on the 4th-5th days after operation showed its good effect in gynecological procedures. Clinical trials of the new domestic fibrinous glue "FK-1" in surgical and gynecological clinics confirmed its high medical effectiveness.

[Anatomic orthotopic heart transplantation: the surgical characteristics and the advantages of the method]. / Anatomicheskaia ortotopicheskaia transplantatsiia serdtsa: khirurgicheskie osobennosti i dostoinstva metodiki.

Standard technique of establishment of interatrial anastomoses allows to carry out orthotopic transplantation of the heart quickly and reliably. However the accumulation of collective experience evidences about a number of unavoidable shortcomings of such operation: rhythm disturbances, worsening of hemodynamics in discordant atrial contractions of recipient and donor, atrio-ventricular valve insufficiency, thromboembolism, coronary fistulas. Since 1990 in RRCS 25 operations were carried out with the use of standard technique and we also met with the risk of developing the above complications. In experiment on 30 mongrel dogs the technique of anatomical, truly orthotopic transplantation of the heart with six anastomoses was developed: left pulmonary veins with a common cuff, separate anastomoses of the superior and inferior caval veins, anastomoses of aorta and pulmonary artery. Particular attention was paid to developing of original surgical modes for prophylaxis of stenoses in the area of anastomoses of pulmonary and caval veins. In 1997 the anatomical technique of heart transplantation was successfully introduced by us into clinical practice. Clinical electrophysiological, echocardiographic and functional examinations have confirmed the results of the experiments and have evidenced for substantial advantages of the anatomical technique of orthotopic transplantation of the heart. By reliability the new operation is not inferior to standard method of N. Shumway.

Simultaneous separate assessment of the cardiac and LVAD output.

The electroimpedance indicators' dilution (EIID) technique was used to study the possibility of a simultaneous separate assessment of the biological heart and LVAD performance in the position of LVB. The experimental part of the research was performed on 5 dogs; an artificial ventricle of the pulsing type (USA) with cusps was used as a pump. The clinical part of the work was conducted on 5 patients after open-heart surgery who had the clinical picture of postcardiotomy cardiogenic shock; a centrifugal pump "Biopump" (Medtronic, USA) was used. The authors have shown a principally important possibility of applying the EIID, technique for studying the performance curves which are the integral derivatives of the work of a specific hybrid system--"the biological heart-assist device". From the practical viewpoint the EIID technique permits in the read time mode to control continuously the part of the pumping function which is assumed by the patient's own heart. This information can serve as the basis for making the prognosis and determining the further tactics of treatment; the restoration of the heart performance or its replacement by transplantation.

[The system of hemostasis in experimental liver transplantation]. / Sistema gemostaza transplantatsii pecheni v eksperimente.

The status of haemostatic factors in 28 pigs after orthotopic liver transplantation was evaluated. The major changes took place in fibrinolytic system during the "non-liver" stage: rapid increase of fibrinolytic activity, plasmin activity, plasmin activator activity. From the moment of blood supply restoration to a transplanted liver the tendency to normalisation of fibrinolysis was detected. The deficiency of plasma haemostatic factors and platelets has increased during all the follow-up period and should be corrected in time. The following principles of corrective therapy are formulated: inhibition of fibrinolysis, correction of antithrombin-3 and blood clotting factors. Correction of haemostasis should be done in "pre-non-liver" period and later in "non-liver" reperfusion periods.

[Role of membrane protectors and antioxidants in the process of perfusion and preservation of donor lungs]. / Rol' membranoprotektorov i antioksidantov v protsesse perfuzii i konservatsii donorskikh legkikh.

Comparative study of the effect of four perfusion and preservation solutions on lung function, conducted in experiments on 69 inbred dogs, revealed the following regular features. Euro-Collins and electrolyte solutions cause a marked increase of the capillary-hydrostatic pressure, a significant decrease of colloido-osmotic pressure of the plasma, and, as a result, reduction of the ient between them. This is manifested by edema of the lungs. The use of LPD solution is attended by moderate edema of the lungs in moderately increased capillary hydrostatic pressure and mildly reduced colloido-osmotic pressure of the plasma. Perfusion and preservation of the lungs with the LPD solution, containing membrane protectors and antioxidants, for 12 hours is marked by practically unchanged indices of capillary-hydrostatic pressure, plasma coloido-osmotic pressure, and the gradient between them. Edema of the lungs does not develop in this case.

[Orthotopic liver transplantation: surgery research center's experience]. / Opyt ortotopicheskoí transplantatsii pecheni v Nauchnom Tsentre Khirurgii RAMN.

From 1990 to 1996, 178 patients with severe diffuse and advanced focal liver diseases with grave prognosis were observed for indications to orthotopic liver transplantation (OLT). According to the revealed indications and contraindications, 95 patients were enrolled for the procedure. Eighteen patients underwent 19 OLTs, including 1 urgent retransplantation and 3 living related graftings. Surgical techniques were conventional; with these, intraoperative mortality and biliary complications could be avoided. Long-term survival (6 to 68 months) was achieved in 8 recipients, including in those after liver retransplantation. Double or triple suppressive regimens were used. These included corticosteroids, cyclosporin A, azathioprine, antithymocytic globulin. The life quality of recipients promoted restoration of their working capacities. Two recipients gave birth to healthy babies.

[Disorders of hemostasis in orthotopic liver transplantation in an experiment]. / Narusheniia gemostaza pri ortotopicheskoi transplantatsii pecheni v éksperimente.

The study was undertaken to examine blood coagulative parameters in experimental orthotopic liver grafting. Plasma hemostatic parameters were studied in animals undergone successful and unsuccessful surgery. The preservation of a graft, anesthetization, and blood-substitute therapy were found to substantially affect the severity of hemostatic disorders. The liver-free period was characterized by changes in the fibrinolytic system and the activity of a plasma coagulation, by enhanced hypocoagulation, and thrombocytopenia. The findings suggest that timely correction of blood coagulative disorders is highly essential in orthotopic liver grafting. Prevention and prompt correction of hypocoagulation and thrombocytopenia are the most urgent.