[Experimental study of the relationship of the level of blood hemolysis and the design of artificial heart valves]. / Eksperimental'noe issledovanie zavisimosti urovnia gemoliza krovi ot konstruktsii iskusstvennykh klapanov serdtsa.

The paper deals with experimental studies into the level of hemolysis that accompanies the performance of artificial cardiac valves (ACV). The studies were conducted by two ways. The first study determined the level of hemolysis when artificial cardiac valves worked and donor blood performed. The second one was that a polymer was added to the model physiological fluid, the degree of hemolysis was determined by the changes occurring in the time of relaxation of elastic stress in the model fluid samples taken during tests. The experiments showed polyethylene oxide break-down to be the most accurately modelling process of hemolysis.

Comparative hemolysis tests of rotary blood pumps.

At present, hemolysis is one of the most important characteristics used to evaluate rotary blood pumps. However, the conditions of testing procedures in various research centers differ considerably. We proposed to conduct the experiments under conditions similar to those from clinical applications of arterial pumps in extracorporeal perfusion. Proceeding from these considerations, the following parameters of Hemolysis (H) testing were adopted: output, 6 L/min; difference of pressure, 300 mm Hg; initial hematocrit, 30 mg%; and initial hemolysis (PHbo) < 5 mg%. The channel pump IBP80 designed on the basis of the BP80 was tested using fresh human blood. The experimental results indicate that the H level due to the use of the IBP80 is 2-3 times less than H for the BP80. H dependence on the difference of pressure in the range between 200 and 300 mm Hg was noted for the BP80, which can be accounted for by the transition of the laminar conditions of flow to turbulence. According to the results of the hydrodynamic efficiency evaluation, the IBP80 is twice as efficient as the BP80.

[Centrifugal blood pumps (new possibilities of design improvement)]. / Tsentrobezhnye nanosy dlia krovi (novye vozmozhnosti uluchsheniia konstruktsii).

Based on an analysis of 300 world information sources, 19 types of centrifugal blood pumps were ascertained. Five new designs suggested have an idea in common: combination of the inlet of the disk pump and of the outlet of the impeller pump. This allows uniting the merits of the above pumps and excluding their shortcomings. The designs suggested make it possible to solve the two basic problems: hemolysis and thrombogenesis inside the pumps. The use of the pumps designed on such a basis will afford a simple and reliable approach to heart function replacement.

Present and future of the artificial heart driving system.

The totally artificial heart (TAH) is now in development in two trends. First, there is the development of a bridge system for temporary support of cardiac function. The TAH with the extracorporeal pneumatic driving system Sinus-IS is more efficient and safer. Parallel with this, a portable pneumatic driving system has been developed. That can be considered a stage in the development of the second trend: a totally implantable TAH. This article reviews problems of building of the Micron energy system to be used in implantable TAH designs.

[Anesthesiologic management of clinical orthotopic liver transplantation]. / Anesteziologicheskoe obespechenie ortotopicheskoi transplantatsii pecheni v klinike.

The first clinical experience of anesthesiological management during 6 orthotopic liver transplantations (5 primary operations and 1 retransplantation) in 2 males and 3 females, aged 20 to 52 years, is presented. The method of general anesthesia is described--the use of veno-venous bypass without systemic heparinization and rapid infusion system. Hemodynamic, temperature, metabolic and coagulologic homeostasis disturbances are analysed at different stages of orthotopic liver transplantation, especially upon reperfusion of the donor organ. The tactics of infusion-transfusion therapy, as well as correction of electrolyte disturbances and blood coagulation disorders are being discussed. Different intraoperative complications are characterized. It is concluded that anesthesiological management of liver transplantations is one of the most complex problems of modern anesthesiology which takes joint effort of a large team of specialists: surgeons, anesthesiologists, perfusiologists, transfusiologists, and laboratory assistants specializing in different areas.

Centrifugal blood pumps--a brief analysis: development of new designs.

Analysis of 350 different sources of information from leading countries of the world enabled us to determine the availability of 20 different designs of centrifugal and rotary blood pumps. Most of them are for extracorporeal applications with radial pumping wheels of disc or vane type. The prospect of improving these designs was suggested by a combination of these two types. Five new designs based on the Biomedicus have been produced. Basic calculations are given for one of these with respect to limitations for shear stresses. It is proposed that the suggested designs will allow reductions in thrombosis and haemolysis which are the main problems for these pump designs.

[The first clinical experience with orthotopic transplantation of the liver]. / Pervyi opyt ortotopicheskoi transplantatsii pecheni v klinike.

The article deals with material concerning the performance of 4 operations for orthotopic liver transplantation (OLT). The operations were carried out on 2 males and 2 females whose ages ranged from 20 to 52 years. The indications for OLT were as follows: ++hemangioendothelioma of the liver, hepatocellular carcinoma, cirrhosis-carcinoma of the liver, and metastatic affection of the liver. One male patient died immediately after the end of the operation, another patient died 3 days after the operation due to nonfunctioning of the transplant. In 2 female patients the operations were carried out successfully. One of them was discharged from the clinic in 62 days in a satisfactory conditions and a well functioning transplant. The other patient died from a complication which was not connected with the operation--perforation of the small intestine 69 days after OLT. The technical aspects of and the provision for the operation and the postoperative management of patients are discussed. The encountered complications are analysed.

[A portable, movable pneumatic drive for an artificial heart with an autonomous electrochemical source of energy]. / Portativnyi perenosnoi pnevmaticheskii privod iskusstvennogo serdtsas avtonomym élektrokhimicheskim istochnikom énergii.

The authors have designed a pneumatic drive, which differs from the known ones in that it contains two electromagnetic two-linear and two-positioned air distributors while the motor operates in the mode excluding the change of its axis direction. This affords using a standard crank mechanism as a transformer of rotary motion to translational motion and reducing several times the power consumed. Besides, the two-linear and two-positioned air distributors allow a possibility of exercising a separate control over the time of the systole-diastole phases of the left and right ventricles. In this case both ventricles can work at 100% filling whereby maintaining the capacity of the artificial heart without additional energy consumption.

[Centrifugal pumps for forcing blood: technical aspects (review)]. / Tsentrobezhnye nasosy dlia nagnetaniia krovi: tekhnicheskie aspekty (obzor).

The paper is concerned with one of the trends in the design of outfits for blood forcing, namely with centrifugal pumps. Advantages and shortcomings of such pumps are assessed as compared to roller and other type pumps for blood. Unsolved problems are outlined. Based on a comparative analysis, six main designs are distinguished, the principles of the action, the scope of uses and characteristics are depicted. The conclusion is made that this type of pumps holds promise for the use in cardiosurgical clinics of the USSR.

Use of an ellipsoid artificial heart.

Experiments with the Poisk model of an ellipsoid artificial heart are reported. With a modified model of the diaphragm type made from polyurethane, calves survived for a mean of 55 days, with a maximum survival of 3 months. With adequate anticoagulation therapy, no thrombogenesis was observed in the blood chamber (except for the inlet valves); a low level of plasma hemolysis was observed postoperatively. Good correlation was demonstrated between the stroke volume and left and right atrial pressures. Changes in the blood coagulation indices are reported. Implantation of a clinical variant of this prosthesis into human cadavers demonstrated no difficulties in placing the heart in the pericardial cavity. Developmental efforts are continuing.