Jpn. J. Artif. Organs 11 (3), 767-771 (1982) To avoid the air embolism during cardiopulmonary bypass, various bubble trapps have been used. But there were few reports that compared their debubbling abilities quantitatively. We compared six bubble trapps with regard to debubbling ability, pressure drop and influences for blood cell components. Four bubble trapps have microfilter. A; 40μm polyester screen filter, B; 20μm nylon screen filter, E; dacron wool filter, F; 25μm nylon screen filter. And other two, C and D, have not microfilter mechanisms. Debubbling abilities were studied by TM-8 Microbubble Activity Monitor. Four bubble trapps with microfilter were superior in debubbling abilities but it could not be denyed that these bubble trapps might bring on damages of blood cell components. Two, without microfilter, were poor in debubbling abilities. Bubble trap should meet two factors that are good debubbling abilities and little blood cell damages. At present A, B and F bubble trap were comparatively good for clinical use, but other new and better one should be deviced.

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Jpn. J. Artif. Organs 11 (3), 772-777 (1982) Perfluorochemical emulsion (Fluosol-DA) was used as priming solution for 2-hour extracorporeal circulation under 37°C in three calves (C₇, C₆ and C₉). The cardiopulmonary bypass (CPB) was started after removal of 80-85% of autologous blood. Perfusion flow was 42.9, 75.6 and 52.0ml/kg/min, respectively. During CPB, the Hct and the Mb ranged between 3 and 12% and between 1.9 and 2.8g/dl respectively. Oxygen content, oxygen delivery, oxygen consumption and FDA concentration were measured at various stages of CPB, from which FDA proved to deliver 76 to 84% of the oxygen consumed by tissues. On the other hand, the contributions of Hb and plasma in carrying oxygen to tissues were minimal during the CPB with such extreme hemodilution. From the interrelation between O₂ delivery and O₂ consumption, the O₂ delivery of 5 ml/kg/min was thought to be required to supply sufficient oxygen, and O₂ demand was thought to be around 3.5ml/kg/min under the situations the experiments were performed. Therefore, it was demonstrated that one of the calves (C₈), which was perf used with an adequate flow of 75.6ml/kg/min had received sufficient oxygen from FDA. Hemolysis was observed in C₇ and C₉, which had an FDA retention of 11.5 and 16.6g/kg, respectively. As for chronic effects of FDA, the transaminase was revealed to elevate temporarily but to return to normal in a long term period. The C₇, which had an FDA retention of 11.5g/kg showed almost normal growth. The distributions of FDA in vars i pus organs were measured by gas chromatography, which showed the reticuloendothelial system had significant retention of FDA in an acute phase. In the calf, which was sacrificed 395 days after the CPB, only a trace level of FDA was demonstrated in the spleen, liver, lymph node and bone ma-row but not in other organs.

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Jpn. J. Artif. Organs 11 (3), 778-782 (1982) Factor assays of normal human citrated plasma following incubation with the surfaces of synthetic polymeric materials, that is, polyethylene, ethylene-butylene copolymer, ethylene-propylene copolymer, ethylene-ethylacrylate copolymer, ethylene-vinylacetate copolymer, polytetrafluoroethylene-hexafluoropropylene copolymer, ethylene-methyl-methacrylate sodium ionomer, nylon 12 and polyurethane, in high surface area-plasma volume ratios showed not only a significant pattern of enhancement in factor XI, with much enhancement of VII and VIII, but also marked pattern of reduction in factor XI activity, with lesser depression of X. In particular, no significant alteration of factor XII was observed.

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Jpn. J. Artif. Organs 11 (3), 783-785 (1982) For the purpose of the development of antithromboresistant polymers, factor assays of human citrated plasma following incubation with the surfaces of fillers such as bismuth trioxide, barium sulfate, titanium dioxide, calcium carbonate, aluminum oxide, silicon dioxide, trilead teroxide and stannic oxide were performed in high surface area-plasma volume ratios. Despite a wide variety, the activity of blood coagulation factor showed a marked siginificant pattern of reduction. Therefore, use of fillers for the antithrombogenic synthetics must be selected, taking account of the above-mentioned interaction with blood coagulation factors.

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Jpn. J. Artif. Organs 11 (3), 786-793 (1982) XAD-4 resin has been evaluated for its biocompatibility and performance. Because of significant white blood cell and platelet depletion, plasma filtration system utilizing polyacrylonitrile membrane was employed for direct perfusion of the ultrafiltrate through the resin in this study. Hepatic ischemia was produced by two stage operation in adult mongrel dogs. End-to-side portacaval anastomosis was performed following ligation of the gastroduodenal artery and occluder around the common hepatic artery was closed without anesthesia from outside of the body 48 hours later. Eight dogs tolerated the procedure. Four of them were control group who were treated by fluid replacement and general supportive care. Four dogs were treated group who were subjected to the plasma filtration system for 6 hours beginning at 2 hours after occlusion of the artery. Average and the longest survival time was 13±1 and 16 hours for control group, while 18±4 and 29 hours for treated group. In treated group, GOT and GPT level did not show abrupt increase. Neither white blood cell nor platelet counts showed significant depletion in the treated group. Efficacy and improved blood compatibility of this system learned by this study is interpreted to imply that this is ready for clinical application.

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Jpn. J. Artif. Organs 11 (3), 794-797 (1982) An in vivo test for evaluation of blood compatibility is described. The specimen is prepared as follows. A suture ranging from No. 2-0 to 1 (USP) with length of 10cm is coated with the polymer which will be tested. In the animal experiment, a 18-gauge needle is inserted into the peripheral vein (jugular andfemoral vein), under general anesthesia. The suture is introduced through the needle into the lumen of the vessel. After the needle is withdrawn, the edge of the suture is ligated to the connective tissue near the puncture site of vessel. After an adequate intervals for observation (1 hour to 14 days), the animal is sacrified by exanguination under general anesthesia and heparin administration. The vein in which the suture is inserted is opened and observation is carried out macroscopically and by means of light microscopy, scanning and ransmission electron microscopy. This method has more advantages as follows than other in vivo tests reported before. (1) The procedure is simple and easy. (2) The burden affecting the animal is minimum. (3) The injury of the blood vessel is negligible. (4) Four materials can be estimated at once in each animal. (5) The test is very exact, because the blood stream is slow in peripheral veins and formed thrombus is seldom carried away. (6) Special pre-treatment for coating material is unnecessary. (7) The test is excellent in reproducibility. (8) Specimens for light and electron microscopy can be obtained from one experiment

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Jpn. J. Artif. Organs 11 (3), 798-803 (1982) We made the cardiopulmonary bypass circuit inserted in the pulsatile assist device (PAD) which was developed by Dr. Pregman in the arterial line, and connected to the Datascope system 80 intraaortic balloon pump console. So we developed the photo-cell triggering device to get the signal of the movement of the roller pump and got the stable PAD pulsatile wave on the roller pump wave during complete cardiopulmonary bypass. We reported the mechanism of the photo-cell triggering device to get the signal of the roller pump and the clinical evaluation of the pulsatile cardiopulmonary bypass using PAD.

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Jpn. J. Artif. Organs 11 (3), 804-806 (1982) From the electromechanical standpoint, sensitivity of demand pacemaker is essentially equal during its nonrefractory period. Authors observed, however, QRS waves in the early diastolic phase is easily sensed by the demand pacemaker, though QRS in the late diastolic phase is poorly sensed. The sensitivity of demand pacemaker resulted in showing the highest in its earliest phase and the lowest in its latest period.

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