abstracts from the japanese journal of artificial organs (jinkozoki) published by the japanese...

Artificial Organs 14(4):29&317, Raven Press, Ltd., New York 0 1990 International Society for Artificial Organs

Communications This journal welcomes comments from all those involved in H c i a l organs, as researchers, developers, or users. We would like to hear of your experiences. Please send all Communications to the editorial office.

Abstracts from the Japanese Journal of Artificial Organs (Jinkozoki] Published by the Japanese Society of Artificial Organs and Tissues

Volume 15 Number 2, 1986

RECONSTRUCTION OF PULMONARY ARTERY A PORCINE MONOCUSP PERICARDIAL PATCH. T. Abe, K . Sugiki. Y . Asai, and S. Komatsu. Jinkozoki 15(2):708-711, 1986.

Between 1981 and 1985, 26 patients, ages 11-48 years (mean 19), with complex congenital heart disease (total repair of tetralogy of Fallot:13, Fontan operation of single ventricle: 4, double- outlet right ventricle (DORV): 2 and tricuspid atresia: 1, central palliation: 4, total repair of DORV and pulmonary atresia: 1). There were one operative and one late deaths. Postoperative cardiac catheterization data at 1 month revealed that there was no significant residual stenosis at anastomotic sites. Pulmonary diastolic pressure was maintained at the level of 9.4 2 1.7 mm Hg after the total repaus of tetralogy of Fdllot, but one patient with DORV required reoperation at 3 years after the reconstruction of RVOT with a Rygg patch. This monocusp was markedly degen- erated with partially calcified appearances. Therefore, all of these patients with a Rygg patch should be carefully followed up by echocardiogram and plain chest x-ray film at a long-term postoperative period. Key Words: Rygg monocusp patch-Fontan operation4entral palliation-Reconstruction of right ventricular outflow tract.

BASIC STUDY OF TRANSCUTANEOUS TRANSFORMER FOR MECHANICAL DRIVEN ARTIFICIAL HEART. Y. Abe, T. Chinzei, K . Mabuchi, M . Nakajima, K . Imachi, I . Fujimasa, and K . Atsumi. Jinkozoki 15(2):692-4, 1986.

To charge the battery that is necessary for the totally implantable artificial heart, a transcutaneous transformer was made. A couple of cored coils formed a transformer, which coupled the electric power (5 W in practical use, 20-W peak) by being driven with switching pulses. Its total efficiency was 1040% and coil- to-coil efficiency was 40-80%. Key Words: Transcutaneous transformer-Totally implantable artificial heart-Cored coil- Switching pulses.

A STUDY OF POLARITIES IN DDD PACEMAKERS. H . Aida, T. Shimizu, J . Matsubara, H . Iwanami, S . Sakamoto, Y . Anzai, K . Yuasa, Y. Kanero, H . Hosaka, M . Nagasue, H . Shirakawa, K . Narita, T. Toyoda, H . Chikuda, and M. Douniwa. Jinkozoki 1x2): 825-8, 1986.

Until now unipolar DDD pacemakers have been mainly used because of technological problems, but recently bipolar DDD pacemakers have been made and their use is recommended because of the avoidance of far field noise detection. In this study, comparisons between unipolar and bipolar DDD pacemakers were done. There were no differences in the pacing and sensing thresholds, but from the aspects of myopotential interference

and diaphragmatic twitch, the bipolar system was superior to the unipolar system. In case of myocardial leads the unipolar system is simpler, because the bipolar system needs four fixations of electrodes compared with two fixations in the unipolar system, and the unipolar DDD pacemakers that generators locate in the abdominal wall can avoid myopotential interference. The DDD pacemaker, in which polarity can be externally programmed, was very useful because the proper polarity could be selected in each case. Key Words: DDD pacemaker-Unipolar pacemaker- Bipolar pacemaker-Myopotential interference-Electrornag- netic interference.

HEMOCONCENTRATION DURING AND AFTER CARDIO- PULMONARY BYPASS WITH ASCITES-CONCENTRATOR (AHF-UN). H . Akagawa, Y . Isamoto, H . Shirna, I . Yanagi, K . Hisatomi, K . Ohno, H . Hara, K . Ohishi, and M . Koga. Jinko- zoki 15(2): 1105-8, 1986.

A polyacrylonitrile hollow fiber concentrator (AHF-UN), hemofilter, was employed in 58 patients to control water balance during cardiopulmonary bypass and to reinfuse the concentrated blood in the circuit after bypass. The amount of fluid removed during bypass averaged 968 t 568 ml. After bypass, the hemoconcentration resulted in increases of hernatocrit (1.5 x ) and total protein ( 1 . 9 ~ ) . There was no loss of protein in the filtrate. Al- though free hemoglobin was also increased, no problems associated with reinfusion (758 2 411 ml) were found. Hemoconcen- tration during and after pumping is a useful means of conducting a safe extracorporeal circulation and conserving blood. Key Words: Hemoconcentration-Hemofilter-Plasma separator- Blood conservation.

FLOW CHARACTERISTICS IN CANNULA AND AIR DRIVE LINE FOR ARTIFICIAL HEART. T. Akamatsu and H . Fuku- masu. Jinkozoki 15(2):682-5, 1986.

In extracorporeal circulation, it is desirable to be small, for reduction of invasion at the inserted blood vessel. For the diverging withdrawal cannula in nonpulsatile mode and the con- verging return cannula in pulsatile mode, relations of pressure difference, flow rate, and inner diameter were theoretically calculated. In the implanted artificial heart, it is desirable for the diameter of the air drive line to be throttled, for prevention of infection in penetrated skin. Energy transfer efficiency from bel- low-phragm cylinder to artificial ventricle was calculated by simulation of a closed-type air driver plus blood pump plus circulatory system. The throttled inner diameter of 3 mm proved to be allowable over the length of 10 mm of air line of 2 m in whole length and 10 rnm in diameter. Key Words: Diverging withdrawal cannula4onverging return cannula-Drive air line.

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COMMUNICATIONS 291

POSSIBILITY OF APPLICATION OF PARTIAL ARTIFICIAL

EARLY DEATHS AFTER CARDIAC SURGERY. Y. Akino, M. Miura, N . Uchida, N . Sato, T. Hongo, Y . Kagawa, T. Horiuchi, S . Nirra, and Y. Karahira. Jinkozoki 15(2):638-41, 1986.

During the period from 1982 to 1985, there were 20 early postoperative deaths among 185 cases of infants and children who underwent cardiac surgery. Seven cases were dependent on extracorporeal circulation and 11 cases fell into severe LOS. In 12 cases, there were some doubts about complete surgical repair of complex cardiac anomalies or surgical indications. Assisted circulation was performed in five cases, but in vain because of interstitial edema or bleeding problems. From this analysis, seven cases seemed to be candidates for a partial artificial heart. Key Words: Congenital heart disease-LOS-Assisted circulation-Partial artificial heart.

HEART FOR INFANTS AND CHILDREN-ANALYSIS OF

LONG-TERM EVALUATION OF SLLICON BALL VALVE FOR AORTIC VALVE REPLACEMENTS. Y. Asai, T. Kazui, T . Abe, and S . Komarsu. Jinkozoki 15(2):790-3, 1986.

The long-term prognosis of aortic valve replacement by silicon ball valve was investigated in 18 patients receiving a Starr- Edwards valve (SE group) and in 28 patients receiving a Smeloff- Cutter valve (SC group). The actuarial survival rates were 65% in the SE group after 22 years and 83% in the SC group after 18 years. Anticoagulant or antiplatelet therapy was necessary in 83.3% of the patients in the SE group and all of those in the SC group. In the SC group, thromboembolism occurred in two patients each receiving either antiplatelet drugs or warfarin. Con- cerning postoperative hemolysis, the haptoglobin value was significantly (p < 0.05) lower in the ball valve than in the tilting disk valve. In conclusion, the durability of the silicon ball valve was excellent, and these valves are expected to improve the prognosis of patients also receiving anticoagulant therapy. Key Words: Starr-Edwards valve-Smeloff-Cutter valve-Anticoagu- lant-Antiplatelet-Thromboembolism.

DEVELOPMENT OF COMPUTER BASED CARDIOPULMO- NARY BYPASS (CPB) CONTROL SYSTEM4CREENING AL- GORITHM FROM PARAMETER DISTURBANCES. T . Beppu, K. Soejima, S . Hoshino, Y. Nagase, Y. Imai, K . Tsuchiya, and Y. Fukui. Jinkozoki 15(2):1155-8, 1986.

A newly developed cardiopulmonary bypass control system maintains blood flow and pressure at preset points automatically with microcomputers. For the practical use of the system, we have developed a data screening algorithm that detects artificial pressure disturbances caused by surgical manipulations. To de- tect artifacts, the algorithm calculates the sum of absolute differences of each sample (0.3-s interval) and compares it with that of each control interval (3.0 s). The algorithm was confirmed by animal experiments and detected all artifacts. Key Words: Com- puter control-Cardiopulmonary bypass (CPB)-Automatic control-Screening algorithm.

DEVELOPMENT OF AUTOMATIC CONTROL SYSTEM OF

WITH MULTIPARAMETER. T. Chinzei, Y. Abe, K . Mabuchi, M. Nakajima, K . Imachi, I . Fujimasa, A . Kouno, T. Ono, and K . Arsumi. Jinkozoki 15(2):665-8, 1986.

An automatic control system for the pneumatic artificial heart driver was constructed that can respond rapidly to the living body’s demands by changing multidriving parameters simultaneously. This system has high flexibility in control logic and high controllability of driving parameters, such as driving pressure, systolic duration, and heart rate. The control program is mainly written with “Prolog,” which makes it easy to realize the complicated logical program with multidriving parameter control.

PNEUMATIC ARTIFICIAL HEART DRIVER-CONTROL

With this system, progress in the analysis of the circulatory control mechanism of the artificial heart can be expected. Key Words: Total artificial heart-Automatic control-Multipa- rameter-Artificial intelligence-Prolog.

EXPERIMENTAL AND CLINICAL EVALUATION OF NEW MODEL BOVINE PERICARDIAL XENOGRAFT’S. N. Fujii, M . Umezu, T. Tanaka, K . Kawazoe, and T . Fztjita. Jinkozoki 132): 745-8, 1986.

Value characteristics were compared between old-model prosthetic heart values and new-model bovine pericardial xenografts. New-model xenografts were improved using flexible ring and low-profile stent. Experimental data reveal the superior value performance of the new xenografts, especially in the aortic position. Clinical data showed almost the same tendency as the experimental data, but not as obviously. Key Words: Bovine pencardial xenograft-Value testing c i r c u i t r a r d i a c catheterization data-Mean pressure gradient-Effective orifice area.

DEVELOPMENT OF HOLLOW-FIBER OXYGENATOR FOR ECMO. H . Fukasawa, K . Hagiwara, S. Kawaguchi, 0. No- mura, D . Terai, A . Nogawa, Y . Karsura, and A . Takahashi. Jinkozoki 15(2):920-3, 1986.

We have developed a hollow-fiber oxygenator for ECMO using a combined membrane. Micropores of hollow fibers were filled with silica and a fluoropolymer was coated on the inner surface of the hollow fibers. The performance of this oxygenator with 1.6 m of surface area was an 0, transfer rate of 75 mumin and CO, transfer rate of 83 mUmin at a blood flow rate of 1,500 mumin. Gas transfer of this oxygenator was stable and plasma leakage did not occur during 30 h ventriculoatrial (V-A) bypass in dogs. Platelet count maintained 88% of the initial value at the 30-h point of V-A bypass. This oxygenator was found to be useful for the ECMO procedure, especially for ECC02R. Key Words: Hollow-fiber oxygenator-Combined rnembrane- Fluoropol ymer-ECMO-ECC02R.

EFFECTS OF LVAD ON THE RIGHT VENTRICULAR FUNC- TION OF NORMAL HEARTS. S . Fukuda, H . Takano, T. Naka- tani, H . Noda, S. Adachi, T. Tanaka, M . Umezu, and T. Akutsu. Jinkozoki 1x2): 563-6, 1986.

Right ventricular (RV) function during left ventricular assist device (LVAD) pumping was studied in five dogs and three goats. No significant change was found in overall RV hemodynamic parameters at any bypass rate. However, the RV stroke volume had a slight tendency to increase, whereas the max RVdpldt decreased with the increase in bypass rate. This finding indicates a slight increase of RV contractility but decrease in its preload. However, because the normal RV had a good distensibility, the right atrial pressure and RV end-diastolic pressure remained within normal range. This result suggests that the LVAD pumping will not affect the normal RV function in acute phase. Key Words: LVAD-RV function-maxRVdp/dt-Sono- micrometer-RV distensibility .

LIMITED FUNCTIONS OF VENTRICULAR-ASSIST HEART WITH AN ATRIAL WITHDRAWAL METHOD. H . Fukumasu, A . Yamazato, Y . Fujiwara, J . Soneda, Y. Okamoio, T. Ban, H. Hirose, and S . Yuasa. Jinkozoki 15(2):473-7, 1986.

Pulsatile ventricular assist devices (VADs) have successfully been in clinical use according to the Pierce’s criteria. However, there are many cases with more critical cardiac functions. An atrial withdrawal cannula cannot eliminate blood flow into the ventricle. The ventricular myocardium can minimize volume load but cannot reduce pressure afterloads. Subendocardial infarction found at autopsy after transatrial VAD in the animal

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292 COMMUNICATIONS

heart created more critical myocardial dysfunction. Key Words: Pulsatile heart-Transatrial withdrawal-Subendocardial infarction.

PHYSIOLOGICAL AND PHARMACOLOGICAL EXAMJNA- TIONS OF ISOLATED PERIPHERAL VASCULAR SYSTEMS IN V N O WITH A TAH. H. Fukumasu, T. Ban, and S . Yuasa. Jinkozoki 15( 2):463-8, 1986.

An animal with a total artificial heart underwent acute studies for characteristics of the peripheral vascular system. Treadmill exercise significantly reduced the function of the peripheral vascular system. Psychological stress did not change vascular resistance (PVR). Effects of cardiac drugs were observed just as the textbooks describe. Peripheral vascular resistance changed sud- denly to below normal when the animal pushed her head back for >25 s. Blood pH below 6.9 remarkably dilated the vascular bed. Key Words: Total artificial heart-Vascular resistanceaardiac drugs-Psychological stress.

MYOCARDIAL METABOLISM AND HEMODYNAMICS DUR- ING EXERCISE IN PATIENT WITH CARDIAC PACEMAKER

MODE AND VII MODE. H . Fukumoto, R . Koike, H . Sato, H . Muraki, H . Ohmori, T. Nishimoto, K . Asada, S . Shiguma. T. Inoue, M . Ohzeki, S . Sasaki, and A . Takeuchi. Jinkozoki 15(2): 829-32, 1986.

Hemodynamic superiority in DDD mode pacing was demonstrated both at rest and during exercise, compared with VVI mode. A higher atrioventricular O2 difference and serum lactate concentration indicating the presence of anaerobic state was observed during exercise in VVI mode. VVI mode showed a higher oxygen extraction ratio and insufiicient increase in coronary flow during exercise. Left ventricular work for a given oxygen consumption was greater in DDD mode. The differences in hemodynamics and myocardial metabolism mode were related to the physiologic response of pacing rate and atrioventricular syn- chronicity during exercise in DDD mode. Key Words: Cardiac pacemaker-Exercise test-Myocardial metabolism-coronary flow-Pacing mode.

FOR COMPLETE A-V BLOCK-A COMPARISON OF DDD

ARTIFICIAL HEART DRIVER USING LINEAR-PULSE MO- TOR. S. Fukunaga, J . Murashita, Y. Hamanaka, G . Takezawa, and H . Yamada. Jinkozoki 15(2):6614, 1986.

A portable artificial heart driver has been developed using a flat-type linear-pulse motor. Two polyurethane sacs are placed at both ends of a mover of the linear motor, which generate compressed air and vacuum alternately to create systole and diastole for left and right artificial hearts at the same time in alternate phase. Pressure relief valves and air intake valves are installed to adjust the driving pressure and suction vacuum. Mock circulation tests were performed using a pair of diaphragm-type artificial hearts of 140 ml designed for implantation in a calf. The heart rate reached 76 beatshin at driving pressure of 190 and 72 mm Hg for left and right artificial hearts, respectively. The maximum value of aortic pressure was 120 mm Hg and that of pulmonary arterial pressure was 40 mm Hg. Key Words: Artificial heart- Linear motor-Pneumatic driver-Portable driver-Pulse motor.

STUDIES IN PLATELET AND FIBRINOGEN AFTER CAR- DIAC VALVE REPLACEMENT. T . Fukutomi, M. Hirose, M . Kokkubo, K . Azuma, K . Inada, and K . Murase. Jinkozoki 15(2): 700-3, 1986.

Thromboxane B, (TXB,), p-thromboglobulin (P-TG), fibrinopeptide A (FPA), fibrinopeptide B p1542 (FPBP), and platelet size and population were investigated in 116 patients with car-

diac valve replacement. TXB, and p-TG were slightly elevated in the patients. It was suggested that platelet function activity increased in the patients. FPA and FPBp were at normal levels in the majority of patients, but some patients had high levels. It was suggested that increased coagulation system and fibrinolytic activity careful control of the patients is essential. Key Words: Cardiac valve replacement-Thromboxane B,-P-Thrombo- globulin-Fibrinopeptide A-Fibrinopeptide B p15-,,-Platelet size and population.

THE CHANGES OF BLOOD COAGULATION AND FIBRINO- LYSIS DURING EXTRACORPOREAL CIRCULATION. M . Fukuyama, C. M . Wei, M . Imura, R . Hattori, K . Saito, 1. Yada, H . Yuasa, and M . Kusagawa. Jinkozoki 15(2):993-5, 1986.

The changes of blood coagulation and fibrinolysis during extracorporeal circulation (ECC) were studied in 20 cases. Fibri- nopeptide A, a sensitive and specific factor of blood coagulation activity, did not increase during ECC, but elevated after heparin neutralization with protamine. FDP increased remarkably during ECC. Antithrombin 111, cx2 plasmin inhibitor, plasminogen, and fibrinogen decreased during ECC. These data suggested that blood coagulation was well controlled by heparin, but that fibri- nogenolysis was activated during ECC. Key Words: Extracorpo- real circulation-Fibrinopeptide A-Blood coagulation-Fibri- nogenolysis.

LIVER DYSFUNCTION AFTER OPEN-HEART SURGERY. M . Funami, T . Takaba, A. Murakami, T . Watanabe, M . Yamada, T . Mushiake, N . Yamamoto, K . Inoue, and J . Ishii. Jinkozoki 15(2): 1137-40, 1986.

Ninety-eight patients who underwent open-heart surgery from 1979 to 1984 were divided into a liver dysfunction group (13-1) in 11 patients (1 1.2%) and a normal group (G-2) in 87 patients. The incidence of postoperative liver dysfunction (non-A, non-B hepatitis) increased with the number of units of blood transfused, the prolonged operative time, the extracorporeal circulation time, the aortic cross-clamping time, and the postoperative complications. The importance of follow-up of liver function during the postoperative period at least -1 year was emphasized. Key Words: Posttransfusion hepatitis-Liver dysfunction- Extracorporeal circulation-Non-A, non-B hepatitis.

CLINICAL EXPERIENCE OF BENTLEY HOLLOW-FIBER OX- YGENATOR BOS CM40. H . Furukawa, T . Sasaki, S . Horikoshi, S . Suzuki, T . Kozukue, M . Nakano, H . Emoto, A. Mizuno, H . Takayasu, Y. Mochizuki, K . Karashima, and T. Arai. Jinkozoki 15(2):884-7, 1986.

Bentley hollow-fiber oxygenator BOS CM40 was used for open-heart surgery in seven adult patients and was compared with TMO in eight patients. The following results were obtained: (a) Blood-gas analysis data of BOS showed higher Paot and lower P,co, than that of TMO with the same conditions. (b) At the end of bypass, the platelet count in BOS showed a lower value than that in TMO, but immunoglobulin was well maintained, and the complement value was higher than that in TMO throughout bypass also. (c) Plasma free hemoglobin levels were almost the same in BOS and TOM. (d) The oxygenator pressure drop in BOS was slightly high compared with that in other plate membrane oxygenators. Key Words: Hollow-fiber oxygenator- Blood-gas analysis-Platelet count-Plasma free hemoglobin- Pressure drop.

A NEW LEFT VENTRICULAR ASSIST DEVICE WITH THE

STUDIES ON MOCK CIRCULATION. H . Furukawa, Y . Naka- gawa, M . Shibairi, M . Masuda, K . Yamamoto, M . Kitagawa, H . Shiihara, Y. Tsuruta, F . Kashiwagi, and K . Okui. Jinkozoki 15(2):469-72, 1986.

USE OF PULSATILE BYPASS PUMP-ITS HYDRODYNAMIC

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A new left ventricular assist device using pulsatile bypass pump was developed. Experiments were performed on mock circulation. Results were as follows. (a) Maximum pumping flow was 4.3 Urnin with the single unit and 6.7 L h i n with the double unit. (b) Under optimal balloon driving pressures, and in the range of 40-140 mm Hg of afterload, output of the single unit was 3.5-3.7 L/min whereas the double unit achieved 3 .94 .9 L/min of output. (c) Under the lower driving rate, the double unit could produce more stable output as compared with the single unit. Key Words: Pulsatile bypass pumpPBP-Left ventricular assist device-Mock circulation.

EXPERIMENTAL STUDY OF TEMPERATURE-SENSITIVE PACEMAKER DURING EXERCISE. Y. Harada, T . Yasmagu- chi, K . Yoshimura, T . Sugiura, M . Kimura, and S . Mizushina. Jinkozoki 15(2):852-5, 1986.

The effect of a temperature-sensitive pacemaker on the pacing rate during treadmill exercise was studied in animal experiments. During exercise, the blood temperature in both normal and pacemaker groups slowly elevated and reached the peak level at the end of running. The heart rate and cardiac output of normal dogs made a temporary and rapid increase by emotional effect in the 1st 10 s. Except for the initial change, the relation between blood temperature and heart or pacing rate appeared to be similar. Key Words: Temperature-sensitive pacemaker-Blood temperature-Exercise-Pacing rate.

HEMODYNAMIC EVALUATION OF MITROFLOW BOVINE PERICARDIAL VALVE IN MITRAL POSITION. H . Harada, T. Kazui, T. Tanaka, 0. Yamada, H. Yokoyama, and S . Komatsu. Jinkozoki 15(2):749-52, 1986.

Hemodynamic studies at rest and during exercise were performed in patients who had mitral valve replacement using the Mitroflow valve. The valve function of the Mitroflow valve es- timated by mitral valve gradient was almost the same as that of the Liotta valve. The mitral valve area was 2.03 cm2 at rest and 1.50 cm2 during exercise in the Mitroflow valve, and 1.64 cm2 at rest and 1.83 cm2 during exercise in the Liotta valve. Cineangio- graphic studies of the cusp movement showed synergic opening and closing of the three cusps and maximum opening of each cusp. Long-term follow-up is mandatory to evaluate the durability of the Mitroflow valve. Key Words: Mitroflow bovine pericardial valve-Mitral valve replacement-Mitral valve gradient-Mitral valve area-Liotta low-profile bioprosthesis valve,

CONTINUOUS Po2 and Pco2 MONITORING DURING EXTRA- CORPOREAL CIRCULATION. S. Hashimoro and A . Kohama. Jinkozoki 15(2):114&9, 1986.

A blood gas monitoring system during extracorporeal circulation (ECC) was made and tested. This system was composed of a Po, electrode (mnt Po,) and Pco, electrode (mnt Pco,). Two systems were to monitor blood gas during ECC, one for arterial blood and the other for venous blood. The value of the correlation coefficient between mnt Po, and P,02 was 0.988 and that of mnt Pco, and P,co, was 0.904. This ECC monitoring system is very promising. Key Words: mnt Po2-mnt Pco,-Po, electrode-Pco, electrode-Extracorporeal circulation.

EFFECT OF VELOCITY GRADIENT ON HEMOLYSIS: VE- LOCITY GRADIENT APPLYING TIME. S. Hashimoro, Y. Su- giura, and T. Sasada. Jinkozoki 15(2):617-20, 1986.

The effect of the velocity gradient applying time on hemolysis was investigated quantitatively in vitro. Velocity gradients [max. 1,500 s-’; (1) constant, (2) sinusoidal periodic] were applied to

heparinized canine blood contained in a concavoconvex type of testing machine for 0-120 min at 24°C. The results show that the hemolysis ratio (plasma hemoglobin count per whole blood hemoglobin count) increases with the increase of the velocity gradient applying time in both ( I ) and (2), and that the hemolysis ratio is larger in the constant velocity gradient of 500 s - ’ than in the sinusoidal periodic (period: 10 s) variation (between 0 and 500 s-’) of the velocity gradient. Key Words: Hemolysis- Velocity gradient-Velocity gradient applying time-Concavo- convex testing machine.

EXPERIMENTAL STUDY OF RENAL AND HEPATIC BLOOD FLOW DURING LEFT HEART FAILURE AND LVAD IN DOGS. H . Hata, N . Ohhashi, Y. Okada, S . Nishiuchi, and T. Shohmura. Jinkozoki 15(2):579-82, 1986.

Hemodynamic effectiveness, especially renal and hepatic flow, of the left ventricular assist device was evaluated in 19 mongrel dogs in which left ventricular failure was induced by coronary artery ligation. Nonoliguric renal failure was observed in dogs that were assisted 4 h with the left ventricular assist device. Key Words: L V A b H e p a t i c flow-Renal flow-Renal failure-Free water clearance.

A COMPARATIVE STUDY BETWEEN ASCENDING AND DE- SCENDING AORTIC PERFUSION IN LEFT VENTRICULAR ASSIST DEVICE. H . Hata, A. Yamazaki, T. Hasegawa, A . Miyamoto, M . Shiono, K . Ogasawara, Y . Orime, Y . Namiki, K . Kurihara, S . Yagi, K . Yamamoto, Y . Sezai, and T. Sairoh. Jinkozoki 15(2):5W3, 1986.

Hemodynamic effectiveness of two perfusion modes in left ventricular assist devices was evaluated against acute left ventricular failure in swine. Renal blood flow was increased in descending aortic perfusion mode, but the coronary sinus flow and endocardial viability ratio was increased more markedly in ascending aortic perfusion mode. These results suggested that the ascending mode appears to be the more promising method of assisting the failing heart complicated with acute myocardial infarction. Key Words: LVAD-Ascending aortic perfusion- Descending aortic perfusion2oronary sinus flow-Renal artery flow.

DEVELOPMENT OF AN EXTRACAPILLARY BLOOD FLOW

REAL MEMBRANE OXYGENATION. R. Hattori, C. M . Wei, M . Imura, K . Sairo, M . Fukuyama, K . Miyamura, I . Yada, H. Yuasa, M . Kusagawa, K . Kamiya, K . Kuwana, and H . Naka- nishi. Jinkozoki 15(2): 924-7, 1986.

We have newly developed the extracapillary blood flow type hollow fiber oxygenator for clinical use in extracorporeal membrane oxygenator (ECMO). Two types of oxygenators, the polypropylene hollow fiber (PPHF) and silicone hollow fiber (SHF) oxygenator, have been developed. The PPHF oxygenator probed highly efficiently in gas transfer and had minimum effects on the blood components, but it was thought to be inappropriate to use PPHF oxygenator in ECMO because of serum leakage in long-term use. The SHF oxygenator probed satisfactorily efficiently in oxygen transfer in vitro. In conclusion, the SHF oxygenator couId have utility for ECMO. Key Words: ECMO- Hollow fiber oxygenator-Serum leakage-Silicone hollow fiber-Polypropylene hollow fiber.

TYPE MEMBRANE OXYGENATOR FOR EXTRACORPO-

COMPARATIVE CLINICAL STUDIES ON MAXIMA AND CA- PIOX I1 MEMBRANE OXYGENATORS. S. Higashi, I. Kiso, T. Maehara, C . Naito, I . Suzuki, H . Kumamaru, S . Suzuki, H . Aeba, T. Shiora, and S. Usune. Jinkozoki 15(2):902-5, 1986.

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The Maxima is an outside flow type membrane oxygenator. It contains a heat exchanger and 2,800 hollow fibers with an effective membrane surface area of 2.0 m2. The hollow fiber has a 400 pm inner diameter and a 460 pm outer diameter and its pore size is 0.03 pm. The Maxima and Capiox I1 were applied to open- heart surgery. In Maxima, the platelet count was significantly higher and plasma-free hemoglobin was significantly lower than in Capiox I1 at 30, 60, and 90 min of cardiopulmonary bypass. Blood gas exchange was maintained stable within physiological limits throughout bypass in both oxygenators. At a flow rate of 3.5 Umin, a mean pressure drop of 30 mm Hg in Maxima and 80 mm Hg in Capiox I1 was observed. As for protection of platelet, hemolysis, and pressure drop, Maxima seems to be superior to Capiox 11. Key Words: Hollow fiber oxygenator-Hemoly- sis-Platelet count-Pressure drop.

THE USE OF THE RATE-RESPONSIVE PACEMAKER USING RESPIRATORY RATE AS A SENSOR. T. Hiranaka, H . Hirose, S . Nakano, H . Matsuda, R . Shirakura, T . Sakakibara, H . Kishi- moto, T . Kawamofo, M. Sakurai, H . Imagawa, T . Miura, and Y. Ka was hima. Jinkozoki 15(2):8447, 1986.

The rate-responsive pacemaker using respiratory rate as a sensor was implanted in four patients-three patients for ventricular pacing and one patient for atrial pacing. The level of exercise achieved with this system was higher than that with a fixed ventricular pacing rate. The fluctuations in the ventricular paced rate during daily activities were documented by ambulatory monitoring. When DDD pacing is not indicated, the use of the rate- responsive respiratory-dependent pacemaker allows more physiological pacing. Key Words: Rate-responsive pacemaker- Pacemaker sensor-Respiratory rate.

APPLICATION OF PARTIAL ARTIFICIAL HEART FOR THE

MENTALSTUDY. T . Hongo, Y. Kagawa, N . Sato, N . Uchida, M . Miura, Y. Akino, S . Nitta, Y. Katahira, and T . Horiuchi. Jinkozoki 15(2):600-3, 1986.

In most cases, the partial artificial heart (PAH) was used for the left side of the heart and isolated use for the right side of the heart was very rare. The patient was a 59-year-old woman with Ebstein’s anomaly. TVR, plication of atrialized right ventricle, and closure of ASD were carried out and PAH was applied for profound right ventricular failure. An outflow canula was inserted via the right ventricle. The patient was weaned from the PAH 7 days after surgery but died of acute renal failure in the 18th postoperative day. Results of an experimental study using goats to confum the safety and reliability of this cannulation technique were reported. Key Words: Partial artificial heart- Right ventricular failure-Ebstein’s anomaly-cannulation technique.

RIGHT SIDE OF THE HEARTXLINICAL AND EXPERI-

OUR EXPERIENCE WITH BJORK-SHILEY MONOSTRUT VALVE. R. Hoshino, R . Kuribayashi, T . Sakurada, H . Atsumi, S . Sekine, S . Saito, and T. Abe. Jinkozoki 15(2):753-5, 1986.

Thirty-eight patients underwent valve replacement operations with the Bjork-Shiley monostrut valve (13 AVR, 16 MVR, and 9 DVR). There were two cases of valve malfunction during operation (one in the mitral position and the other in the aortic position). In both cases, monostrut valves were removed and re- placed with other valve prostheses. There were two early deaths not related to the valve prosthesis. There was no late death or late mechanical failure. A thromboembolic episode occurred in one patient with double valve replacement. A postoperative hemodynamic study showed almost satisfactory results. Key Words: Bjork-Shiley monostrut valve-Valve malfunction- Thromboembolism.

DEVELOPMENT OF FREE DIAPHRAGM BLOOD PUMP FOR MECHANICALLY DRIVEN ARTIFICIAL HEARTS. K. Imachi, I. Fujimasa, T. Chinzei, M. Nakajima. K . Mabuchi, Y. Abe, K . Maeda, K . Orime, A . Kouno, T . Ono, and K . Atsumi. Jinkozoki 15(2):6734, 1986.

To eliminate a compliance chamber from the totally implantable artificial heart, a newly designed blood pump, in which the free diaphragm is moved back and forth without volume change for the outside of the pump, was designed. The performance of a prototype model was examined in a mock circulatory system and acute left heart bypass animal experiment. The pump output increased proportionally with pulse rate and the maximum output was 8 Wmin. In both experiments, the pump had good performance and has a promising future development. Key Words: Artificial heart-Blood pump-Compliance chamber-Perfor- mance.

HEMODYNAMIC EVALUATION OF THE CENTRAL OPEN- ING BIOPROSTHESIS (C.O.B.). E. fmamura, M . Kitamura, Y . Tomizawa, H . Nishida, Y. Yagi, and H . Koyanagi. Jinkozoki 15(2):765-8, 1986.

Ten patients receiving the C.O.B. were studied. Eight patients with mitral C.O.B. showed a mean diastolic gradient of 4.1 + 1.81 mm Hg and mean valve area of 2.53 + 0.78 cm. Two patients with an aortic C.O.B. showed a peak gradient of 0 mm Hg and a mean valve area of 2.54 cm. These results indicated that the hemodynamic function of the C.O.B. compared favorably with the conventional designs of the porcine xenograft. Key Words: Central opening bioprosthesis-Porcine xenograft- Hernodynamic function.

THE EFFECTS OF HOLLOW-FIBER HEMOCONCENTRATOR ON DILUTED BLOOD AFTER CARDIOPULMONARY BY- PASS (CPB). N . Inoue, H . Doi, A . Sasaki, S . Kikuchi, H . Yokoyama, T . Kazui, and S . Komatsu. Jinkozoki 15(2): 103942, 1986.

Both polypropylene and polyamide hollow-fiber hemoconcentrators (MPF-Mand BC-140) were used for concentrating and reusing diluted blood after CPB. The effects of hemoconcentrat- ing blood components were almost equivalent between both hemoconcentrators. The number of platelets after hemoconcentration revised based on hematocrit decreased significantly compared with preuse in MPF-M and BC-140. The sieving coefficient of albumin and free hemoglobin was 20-25% in MPF-M and 1- 3% in BC-140, respectively. The hemoconcentrator would be a useful device for concentrating diluted blood after CPB, but after transfusion of concentrated blood a bleeding tendency should be watched for. Key Words: Hemoconcentrator-Hollow fiber- Cardiopulmonary bypass-Sieving coefficient.

AN EXPERIMENTAL STUDY OF ECMO WITH INTERMIT- TENT ADMINISTRATION OF OP41483 (PGI, DERIVATIVES). Y. Ishibashi, T . Sakairi, T . Makoto, R . Yamazaki, H . Takeda, K . Sakai, and T. Tanabe. Jinkozoki 15(2):946-9, 1986.

Studies were made on dogs with severe respiratory failure induced by transtracheal administration of linoleic acid. The dogs were separated into four groups: GI-respiratory failure, GII-pumpless atrioventricular bypass, GIIT-ventriculoatrial bypass, and GIV-ventriculoatrial bypass with administration of OP41483 (PGI, derivatives). The dogs in which extracorporeal membrane oxygenation (ECMO) was done maintained good blood gas and survived significantly longer than did GI. GI11 survived significantly longer than did GII. TxA, increased and the PGI,/TxA, ratio decreased after linoleic acid administration. OP-41483 dilated the vessels of lung, and then intrinsic PGI,

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increased significantly and the PGI,/TxB, ratio increased after adminstration of OP-41483. However, significant difference was observed in survival time between GI11 and GIV. Key Words: ECM&OP-41483-PGI~-TxB,.

PUMPLESS ECMO BY A-V BYPASS FOR RESPIRATORY IN- SUFFICIENCY. T. Itaoka, J . Wada, K . Chino, Y. Kasagi, and M . Yokoyama. Jinkozoki 15(2):9414, 1986.

Pumpless extracorporeal membrane oxygenation (ECMO) with a microporous polypropylene hollow-fiber lung (Capiox 11) was used in treatment of three patients with respiratory distress due to hypercapnea. Improvement in blood gas data was significant and then clouding of conciousness disappeared after ECMO. Key Words: Pumpless ECMO-A-V bypass-Hyper- capnea.

A PORTABLE PNEUMATIC DRIVING UNIT FOR AN ARTI- FICIALHEART. N . Kabei, T . Murayama, A . Noda, H . Imai, T. Takagi, K . Satoh, E. Shimemura, Y . Sakurai, and K . Tsuchiya. Jinkozoki 15(2): 650-3, 1986.

A new type of portable pneumatic driving unit was developed. In this unit, the pressure level was regulated by varying the output flow rate of the compressor. A one-board microcomputer and pressure sensors were used to control the pressure level. This computer was also used for protection against energy short- age of the battery, pressure sensor breakdown, and computer runaway. The total weight of this unit was 9.5 kg. It was con- f m e d that the unit could drive the blood pump continuously for more than 2 h under the following conditions: output flow rate of the blood pump was 5 L/min and output pressure was 100 mm Hg. Key Words: Portable pneumatic driving unit-Micro- computer-Artificial heart.

AUTOMATIC CONTROL OF THE CARDIOPULMONARY BY- PASS (CLINICAL STUDY). H . Kaizuka, T. Hino, T . Itaoka, Y. Kasagi, H . Nagara, M . Yokoyama, and J . Wada. Jinkozoki 15(2):1159-62, 1986.

Although many approaches to automatic control of cardiopulmonary bypass (CPB) have been tested, there have been few technics or devices that can perform a completely controlled CPB in open-heart surgery. We devised a new system for automatic regulation of CPB. After many experimental studies, we introduced it into clinical cardiac surgery in four cases. The system functioned sufficiently even in the clinical cases. Therefore, there is one problem for getting stational and enough amount of the venous return whole through the cardiopulmonary bypass to continue the automatic regulation. Key Words: Cardiopulmonary bypass-Automatic regulation-CVP triggering.

COMPARISON OF THE EFFECT OF BIO-PUMP AND ROLLER PUMP ON HEMOLYSIS. H . Kaneko, K . Suma, Y . Takeuchi, K . Inoue, K . Shiroma, Y . Koyama, J . Narumi, T. Takahama. S . Nishiyama, Y. Kohri, Y. Terada, H . Yokomuro, 5’. Torii, K . Imnnishi, T . Ban, T . Tsuji, and T. Togawa. Jinkozoki 15(2):541- 4, 1986.

The effect of the biopump and roller pump on hemolysis was compared by measuring free hemoglobin (hb) concentration in the circulatory blood. In the experiments, bovine blood was cir- culated in the closed circuit by using each of the pumps. After 2-h circulation, the free Hb concentration was lower in the group using the biopump than that of roller pump group. During 24 h, free Hb concentration was gradually increased in both groups, and after 24-h circulation, there was no significant difference of free H b concentration between the groups. The biopump was used in five patients undergoing open-heart surgery. In clinical

use, there was no significant difference in free Hb concentration between the group using biopump and the group using the roller pump. However, the biopump was considered one of the effi- cient pumps applicable to clinical use. Key Words: Nonpulsatile pump-Centrifugal pump-Autoflow mode-Free Hb.

ANALYSES OF THE FLOW WITHIN THE ARTIFICIAL HEART USING THE FLOW VISUALIZATION TECHNIQUE. Y . Katahira, S . Nitia, T . Yambe, M . Tanaka, Y . Kagawa, T . Hongo, and T . Horiuchi. Jinkozoki 15(2):478-81, 1986.

The flow behavior within an artificial heart (AH) in the various driving conditions were analyzed with a numerical method based on quantitative flow visualization techniques. The velocity vec- tor distribution, the streamlined configuration, and the vorticity distribution within the AH were obtained with this method. In this study, the flow velocity within the A H showed the parallel changes with the stroke volume, but showed the sudden decrease in the flow velocity and the sudden change in the distribution pattern beyond a certain driving condition. Because this critical point was thought to be a minimum stroke volume, the driving condition should be avoided in this area to protect the AH from thrombus formation. Key Words: Flow visualization- Tracer method-computer analysis-Artificial heart-ventricular assist device.

NINE- TO 18-YEAR FOLLOW-UP OF PATIENTS UNDERGO- ING THE STARR-EDWARDS HEART VALVE REPLACE- MENT. Y. Kawachi, et al. Jinkozoki 15(2):794-7, 1986.

Between December 1964 and November 1976, 36 patients underwent valve replacement with several models of the Starr- Edwards prothesis: 19 aortic, 16 mitral, and 1 double. The overall operative mortality was 16.7%. Current follow-up was 100% complete. The actuarial survival ( 2 standard error) was 89 2 4.7% at 5 years after operation, 79 * 7.6% at 10 years, and 69 5 11.2% at 15 years. The overall incidence of thromboembolic and anticoagulant-related hemorrhagic complications was 4.6%/ patient-years (P-Y) with a total follow-up of 327.8 P-Y. In three patients with valve dysfunction (0.9%/P-Y), valve replacement was performed and all survived. Endocarditis never occurred. Total valve-related morbidity and mortality was 7.2%/P-Y, and its actuarial free rate was 73 ? 8.1% at 5 years, 58 ? 8.5% at 10 years, and 44 2 14.2% at IS years. Key Words: Starr-Edwards valve prosthesis-Actuarial survival-Valve-related morbidity and mortality.

THE CHANGES OF PLATELET FUNCTION DURING CAR- DIOPULMONARY BYPASS WITH MEMBRANE OXYGEN- ATOR. COMPARISON OF BIOPLJMP AND ROLLER PUMP. T. Kawada, S . Funaki, T . Mieda, T . Okada, T . Hiekaia, and T. Noguchi. Jinkozoki 15(2):999-1002, 1986.

Qualitative and quantitative studies of platelets were performed to evaluate the difference between the effects of centrifugal pump and the roller pump on platelets during short-term cardiopulmonary bypass with the membrane oxygenator. There was no significant difference between the two pump systems in regard to the levels of platelet loss and increased rate of PTG and PF4. It is believed that the degree of prebypass platelet aggregation of each patient contributes to the degree of the consumption of platelets during bypass. Key Words: Biopump- Membrane oxygenator-Platelet-~TG-PF4.

PROSTHETIC VALVE DYSFUNCTION OF KAY-SHILEY MI- TRAL VALVE PROSTHESIS 15- TO 18-YEAR FOLLOW-UP STUDY. T. Kawamoto, H. Hirose, S . Nakano, H . Matsuda, R . Shirakura, H . Kishimoto, T . Hiranaka, S. Watanabe, N . Sakaki, and Y. Kawnshima. Jinkozoki 15(2):78&9, 1986.


296 COMM UNICA T I 0 NS

We evaluated the causes of prosthetic valve dysfunction of Kay-Shiley disk valve prostheses that were implanted 15-18 years ago. The most characteristic feature of prosthetic valve dysfunction was valve-related stenosis, which was caused by tissue ingrowth. Not only the orifice area but also the frustum area of a prosthetic valve were reduced by tissue ingrowth. To diagnose the valve-related stenosis, it was mandatory to measure the valve area by cardiac catheterization. Key Words: Kay- Shiley valve prosthesis-Tissue ingrowth-Prosthetic valve dysfunction-Mitral valve area.

UNSUCCESSFUL CASES WITH POSTOPERATIVE INTRA- AORTIC BALLOON PUMP ASSIST. M. Kawauchi, 0. Tanaka, K . Tanaka, K . Wake, T. Takahama, K . Sudo, A . Mizuno, and A . Asano. Jinkozoki 1 S(2): 5 13-5, 1986.

From April 1981 to March 1985, Intraaortic balloon assist was installed in 30 adult patients (ages 26-69 years old, mean 50.6 years old; male:female ratio 15:15). Sixteen patients (ages 26-69 years old, mean 51.3 years old; male:female ratio 7:9) died in the hospital. Ten patients died of insufficient support, two of too- early weaning from the intraaortic balloon pump (IABP), and four of other lethal reasons. There were two reasons for insufficient support: one was unsuccessful repair and the other was extremely low cardiac output. The necessity for >800 ml/min/m2 circulatory assist at the time of ECC weaning and progressive renal failure in the early period of IABP were recognized as insufficient support. No relation was proved between the prognosis and blood pressure, left atrial pressure, or cardiac index in the early period of IABP assist. Key Words: IABP-Heart surgery.

AN EXPERIMENTAL STUDY ON PHYSIOLOGICALLY CON- TROLLED DIAPHRAGM PACEMAKERS. M . Kimura, Y . Harada, T. Sugiura, and K . Yoshimura. Jinkozoki 15(2):848-51, 1986.

Diaphragm pacemakers that can be controlled by body temperature or heart rate were developed. They were applied to mongrel dogs. The metabolic rate was increased by the administration of 2-4-dinitrophenol. The physiological effectiveness of the pacemakers was ascertained when the body temperature was <38"C. Key Words: Diaphragm pacemaker-Metabolic rate- Temperature-Heart rate-Telemeter.

CLINICAL APPLICATION OF ATS (AUTOLOGOUS TRANS- FUSION SYSTEM, SORENSON RESEARCH). I . Kiso, T. Mae- hara, S . Higashi, S . Suzuki, T. Shioda, H . Aeba, and S . Usune. Jinkozoki 15(2):985-7, 1986.

Hemothorax ATS (Sorenson) is a very simple autotransfusion system, consisting of a suction tube, canister, disposable liner assembly, and suction regulator. We applied this system in 28 open-heart surgery and 8 aneurysmal operations for clinical availability. This system was very easy to use; however, hemolysis was observed often, especially in surgery using cardiopulmonary bypass. This system was very useful, especially in aneurysmal operations for reducing the amount of blood transfusion. Key Words: ATS (Sorenson)-Autotransfusion-Free plasma hernoglobin.

CHANGES IN THE RENIN-ALDOSTERONE SYSTEM IN CARDJAC OPERATION-COMPARATIVE STUDY IN AOR- TIC VALVULAR DISEASE AND ISCHEMIC HEART DIS- EASE. M. Kitagawa, Y. Nakagawa, M . Shibairi, M. Masuda, K . Yamarnoto, H . Shiihara, H . Furukawa, Y. Tsuruta, F . Kashi- waga, and K . Okui. Jinkozoki 15(2): 11 18-21, 1986.

Renin-aldosterone system was comparatively studied in aortic valvular disease (group A, 10 cases) and ischemic heart disease

(group ACB, 8 cases). Group ACB (53.9 t- 5.2 years old) was significantly older than group A (42.8 5 13.4 years old). Plasma renin activity and plasma aldosterone were significantly higher in group A than in group ACB during and after operation. Cardiac index, urinary volume, creatinine clearance, free water clearance, FENa, S-Na, S-K, and U - N m - K were not significantly different between these two groups. In operations for ischemic heart disease, the renin-aldosterone system was only slightly activated. We concluded that the secretion of renin and aldosterone might be decreased in group ACB, probably because of the more advanced age. Key Words: Renin-aldosterone system- Aortic valvular disease-Ischemic heart d i s e a s d a r d i a c function-Renal function.

A NEW CIRCULATORY MODEL FOR THE EVALUATION OF VENTRICULAR ASSIST DEVICES WAD). Y. Koh, S. Kita- mura, C . Oyama, K . Kawachi, H . Kobayashi, R . Morita, T. Nishii, S. Taniguchi, T. Seki, T. Inoue, and S . Yuasa. Jinkozoki 15(2):508-1 I , 1986.

Piggyback heart circulatory assist model. The right and left artificial hearts (AH) were used and driven as the patient's sick heart and were connected to a copy type of the Donovan mock circulatory system with two or four chambers. The VAD of 40 ml was then connected to the main AH resembling the failing heart. Hemodynamic tests of the piggyback VAD (TMG-40-N) were performed with the four-chambered circulatory system. By controlling the driving condition of the main AH, a left-heart failure model was produced as follows: mean arterial pressure (MAP) 43-73 mm Hg, total flow 1.8-2.6 L/min. The VAD was driven in the counterpulsation mode for assisting this left-heart-failure model using a PBP-20 with a driving pressure of 180 mm Hg and a rate of 100/min. The following hemodynamic changes were obtained: maximal flow assist of 1.5 L/min, maximal MAP arise of 32 mm Hg, maximal mean PAP decrease of 11 mm Hg and maximal LAP decrease of 19 mm Hg. This new model of the circulatory system can be useful for the quantitative evaluation of VAD function. Key Words: VAD-Donovan mock circulation-Hemodynamic test-Artificial heart (Thomasu)-PBP-20.

COMPARISON OF HEMATOLOGY BETWEEN BIO-PUMP AND ROLLER PUMP. K . Koja, Y. Kuniyoshi, F . Ikemura, K . Iha, A . Kusaba, M. Shirnabukuro, T . Kamizato, and Y . Toyoda. Jinkozoki 15(2):545-8, 1986.

This study was done to determine the effects on blood components during extracorporeal circulation of Bio-Pump and Roller-pump. During 6 h bypass, plasma free hemoglobin increased somewhat in the control group (1.88 mg/dl/h) and in the Bio-Pump group (1.85 mgldl/h). It increased significantly in the Roller-pump group (12.60 mg/dl/h). Lactate dehydrogenase values showed the same change in free hemoglobin. Key Words: Extracorporeal circulation-Bio-Pump-Roller-pumpPlasma free hemoglobin.

AN EXPERIENCE WITH THE RATE-RESPONSIVE PACE- MAKER. M . Kokubo, M. Hirose, H . Tanabe, K . Azuma, and K . Znada. Jinkozoki 132):s 18-20, 1986.

The patient was a 28-year-old man. He underwent MVR and AVR at age 26. Complete atrioventricular block developed eventfully after DVR, so a VVI pacemaker was implanted. Recently he had complained of dyspnea on exertion and a chest- oppressive feeling. His exercise tolerance was poor. An activity- related rate-responsive pacemaker was implanted. Exercise tolerance had remarkably improved. It was concluded that if a dual-chamber pacemaker cannot be implanted, a rate-responsive pacemaker is very useful. Key Words: Rate-responsive pacemaker-Complete A-V block after open heart surgery- Activitrax.

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CLINICAL EVALUATION OF DUROMEDICS BILEAFLET CARDIAC VALVE. T. Kozukue, S . Horikoshi, S . Suzuki, T . Sasaki, S . Miyazawa, K . Mashiko, H . Emoro, K . Suzuki, Y. Mochizuki, and T. Arai. Jinkozoki 15(2):760-3, 1986.

Mitral-valve replacement with the Duromedics bileaflet cardiac valve has been done in 12 patients from October 1984 to September 1985. There were no early or late deaths, and the postoperative improvement of NYHA functional class and CTR were good. The Duromedics valve had lower hemolysis than the SJM, ISU, and ISLM valves. The hemodynamics of the early postoperative phase was more excellent in Duromedics valve than in the SJM, BS, ISU, and ISLM valves. The mean mitral gradients of the Duromedics valve were the lowest (0.7 5 0.1 mm Hg), and this was confirmed by Doppler ultrasound. The flow pattern of the Duromedics valve showed central flow, but the other mechanical valves showed a slightly stenotic pattern. Key Words: Duromedics valve-Hemod ynamics-Hemol ysis-Mean mitral gradients-Doppler ultrasound.

EXPERIENCE WITH WILLIAM HARVEY HF-4OOO HOLLOW- FIBER MEMBRANE OXYGENATOR. A COMPARISON OF PULSATILE AND NONPULSATILE PERFUSION. K . Kudoh, Y. Hosoda, A . Tanaka, Y. Ohse, Y. Hirooka, M . Watanabe, M . Ozeki, K . Yamamoto, and H . Takahasi. Jinkozoki 15(2): 1029-33, 1986.

William Harvey HF-4000 oxygenator device uses the inside of a hollow fiber for gas passage and the outside for blood passage. The HF-4000 oxygenator was used for 39 AC-bypass cases. Fourteen AC-bypass cases using pulsatile perfusion were compared with 25 AC-bypass cases using nonpulsatile perfusion in regard to hemolysis, platelet count, and amount of postoperative chest-tube drainage. An average peripheral pulse pressure during complete bypass was 29 2 5.6 mm Hg mean value (n = 84) and 33 +- 5.1 mm Hg maximum value (n = 14) in pulsatile groups. There were no significant differences in the values of platelet count during cardiopulmonary bypass and postoperative chest- tube drainage between the two groups. The higher urine output was observed in pulsatile perfusion group during cardiopulmonary bypass. Key Words: HF-4000-Membrane oxygenator- Hollow-fiber oxygenator-Pulsatile flow-Pulsatile pump.

CLINICAL EXPERIENCES OF HI-FLEX D-700 BABLE OXY- GENATOR FOR OPEN-HEART SURGERY. T. Kudoh, M . Ishikawa, H . Tsuchida, and Y. Yao. Jinkozoki 15(2):1072-4, 1986.

A new bable oxygenator (HI-FLEX D-700) was used in 10 clinical cases of cardiac surgery. The increase in oxygen-blood flow ratio corresponded well with the increase in oxygen rate; however, there was a slight decrease in the carbon dioxide transfer rate. During and after cardiopulmonary bypass using the D- 700, platelet counts, fibrinogen, FDP, and haptoglobin were measured. The results of these factors showed a similar change with use of the membrane oxygenator (TMO). Key Words: Bable oxygenator-HI-FLEX D-700-Platelet counts-Fibrino- gen-haptoglobin.

BASIC STUDY AND CLINICAL APPLICATION FOR ELIMI- NATION OF SERUM FREE HEMOGLOBIN DURING OPEN- HEART SURGERY. H. Maeda, T. Hashegawa, A . Miyamoto, S . Kitamura, H . Hagiwara, S . Shindo, H . Rikukawa, M . Shiono, S. Niino, M . Ichiwata, K . Suzuki, Y. Sezai, H . Nakanishi, and M . Suzuki. finkozoki 15(2): 1097-1 100, 1986.

Elimination of serum free hemoglobin was studied with a plasma filter (P-F) after extracorporeal circulation blood which was made of polypropylene membrane hollow-fiber tubes. Se- rum free hemoglobin and protein were decreased -25% after

1,000 ml was fdtrated and then the P-F was applied to use in valve disease and congenital heart disease (ASD). In conclusion, the concentration of free hemoglobin was decreased successfully, but that of protein IgG and platelets was not decreased. Key Words: Serum free hemoglobin-Plasma fdter-C-P bypass.

EFFECT AND LIMITATION OF CELLSAVER FOR CARDIO- VASCULAR SURGERY. M . Matsuda, R . Sakata, T. Ban, J . Soneda, and K . Nishirnura. Jinkozoki 15(2):1109-12, 1986.

The use of Cellsaver decreased the volume of transfused blood during and after cardiac surgery and the incidence of posttransfusion hepatitis. On the first postoperative day, however, high hematocrit and hypoglobulinemia were seen in the patients whose operations were performed with Cellsaver. Hypopro- teinemia influences the healing of wounds and postoperative infection. It seems that postoperative infection increased after introduction of Cellsaver for cardiac surgery. The effect and limitation of this instrument in the point of hematological and biochemical examination were discussed in this report. Key Words: Cellsaver-Hepatitis-Blood transfusion-cardio- vascular surgery-Hypoglobulinernia.

MECHANISTIC ASPECTS OF SYSTEM’S ANTITHROMBO- GENICITY OF ASSIST DEVICE. T. Matusda, H. Iwata, H . Takano, T . Nakatani, Y . Taenaka, H . Noda, S. Fukuda, S . Ada- chi, and T. Akutsu. Jinkozoki 15(2):6214, 1986.

The short- to long-term antithrombogenic mechanisms of the assist device inner-coated with segmented polyurethane were proposed in conjunction with controlled management of thrombogenic potential, especially focusing clinical cases with the weaning process. The thrombogenic potential was controlled by bypass flow rate. The bypass flow rate dependency was gradually decreased as the implantation period proceeded, which was rationalized by a proposed multilayered passivation mechanism. Key Words: System’s antithrombogenicity.

CLINICAL EXPERIENCE WITH THE PULSATILE ROLLER PUMP DURING CARDIOPULMONARY BYPASS. M . Matsui, Y. Nakamura, K . Hashimoto, R . Koike, and A. Matsui. Jinko- zoki 15(2):10134, 1986.

The pulsatile roller pump (Sarns 7400 MDX) was used in 52 cases of open heart surgery: pulsatile perfusion in 26 cases, nonpulsatile perfusion in 26 cases. The pulse wave contour of the radial artery during pulsatile perfusion very closely resembled the physiological pulse wave contour. Water balance during cardiopulmonary bypass of the pulsatile group was 0.7 * 1.7 ml/kg (mean 5 SD), significantly lower than that of the nonpulsatile group, 9.7 5 1.9 ml/kg. This pulsatile roller pump system may be used to produce effective pulsatile perfusion, safely and easily. Key Words: Pulsatile roller pump-Pulsatile perfusion- Cardiopulmonary bypass.

CRITICAL POINT OF PERFUSION PERIOD ON EXTRACOR- POREAL CIRCULATION BY STEPWISE DISCRIMINANT ANALYSIS. H. Matsukura, T . Tachiki, H . Takeda, K . Sakai, and T. Tanabe. Jinkozoki 15(2): 11 14-7, 1986.

The influence on extracorporeal circulation with core cooling was studied in 106 patients by stepwise discriminant analysis. The critical point of perfusion period was decided on metabolic changes at the end of extracorporeal circulation. The following results were obtained: (a) The critical point of perfusion period was 65 min, because a different pattern of the metabolic changes at the end of bypass was recognized in this period. (b) Blood sugar nonesterified fatty acid, venous base excess, and arterial



oxygen partial pressure were significant coefficient factors in the critical point of perfusion period. Key Words: Extracorporeal circulation-Stepwise discriminant analysis-Perfusion penod- Blood s u g a r a x y g e n partial pressure.

EVALUATION OF A HOLLOW-FJBER PLASMA SEPARATOR FOR HEMOCONCENTRATION IN EXTRACORPOREAL CJR- CULATION. K . Matsusaki, S. Kitagawa, Y . Nonami, M . Ya- masaki, S. Izumi, T. Yamashiro, T. Tamiya, A . Sueoka, and S . Horibata. Jinkozoki 15(2): 1052-5, 1986.

Hemoconcentration performance was compared among three models of Kuraray’s new hollow-fiber plasma separator, made of an ethylene-vinyl alcohol copolymer. The models were the 1A (80 A maximum pore size), the 2A (100 A) and the 3A (200 A), and a mock circuit primed with 2,000 ml of diluted human blood (21 2 2-in height) was used for evaluation. The sieving coefficient (SC) of model 1A was 19 2 2% for albumin and 30 ? 1% for free hemoglobin, under 250 ml of flow rate and 200 mm Hg of transmembrane pressure. The SC was thus significantly higher for free hemoglobin than for albumin. Filtration performance of the IA was 49 2 2 mVmin and hemoconcentration rate for 10 min was 168 ? 5%; such capacities were suggestive of sufficiency for clinical use. The SC and concentration performance of the model 2A (or the 3A) were nearly identical for both albumin and free hemoglobin (in each model), and the loss of globulin was domi- nant in the 3A. In conclusion, the model 1A was optimal because of minimal loss of albumin in face of relatively milder concentration of free hemoglobin in the perfusate. Its clinical use was also satisfactory. Key Words: Plasma separator-UltrafiI- tration-Ethylene-vinyl alcohol copolymer-Sieving coefficient-Free hemoglobin.

RIGHT VENTRICULAR (RV) PERFORMANCE DURING

LOAD. Y. Matsuyama, T. Nitta, A . Harada, M. Gomibuchi, M. Ikeshita, S . Tanaka, N . Yamate, T. Shoji, and T. Takano. Jinko- zoki 15(2):60111, 1986.

Right ventricular (RV) failure has been recognized as a com- plication of LHB. The purpose of this study was to characterize RV functional change that occurred during varying left ventricular (LV) volume load. Eight dogs were subjected to roller pump LHB while RV pressure, its first derivative (dp/dt), and contrac- tile force [strain gauge (SG)] were evaluated. The venous return to the right atrium (RA) (CO) was maintained at 100 mlikg/min with the second roller pump, while both cavae were interrupted from the RA. AoP, LAP, RAP, RV dp/dt, RVSG, and flows in both pumps were recorded. All measurements were compared before and after the ligation of the septa1 perforator (SP). Con- clusions: (a) The more complete the LV decompression the more detrimental the effect on RV function. (b) Increased volume load to the LV produces an increase in RV dp/dt, but a decreased SG. (c) After ligation of the SP, RV dp/dt was unaffected despite the increased LV volume. (d) These results suggest that RV dp/dt was influenced by the contractility of the septum. The detrimental RVSG, however, resulted from the change of LV geometry. Key Words: Left-heart bypass-Left-heart volume load- Right-heart function.

LEFT-HEART BYPASS (LHB) OR LEFT HEART VOLUME

ECHOCARDIOGRAPHIC AND SURGICAL FINDING OF PORCINE VALVE DYSFUNCTION. T. Misaki, H . Futamata, M. Endo, S . lida, K . Mukai, M. Tsuboia. Y. Matsunaga, M. Kawasuji, and T. Iwa. Jinkozoki 15(2):7247, 1986.

To determine the clinical value of echocardiographic evaluation of porcine valves, the finding in all nine patients who had reoperation 25-105 months after operation were analyzed. Echo- cardiographic evaluations including the pulsed Doppler method were of value in identifying dysfunctioning valves and also were

good guides for re-operation. Key Words: Valve dysfunction- Echocardiographic examination-Pulsed Doppler-Porcine xenograft.

CERAMIC HEART VALVE. Y. Miiamura, T . Mikami, and T. Yuta. Jinkozoki 15(2):73740, 1986.

A durable and thrombo-resistant flat disk-type valve (opening angle: 75”) was developed. It comprises a thin (0.6 mm) single- crystal alumina ceramic disk and titanium nitride housing. The housing was milled from a single piece of titanium and was coated with titanium nitrode. The single-crystal alumina and titanium nitride showed excellent results in vena cava ring tests. The opening time of the valve disk was measured by an optical sensor. It was the least in the ceramic valve compared with the Bjork-Shiley and Omni-Science valve. Key Words: Artificial heart valve-Ceramics-Alumina-Titanium nitride.

EXTRAPULMONARY ARTERIAL BALLOON PUMPING

MONARY HYPERTENSION. J . Miya, H . Maeta, T. Asakura, and M . Hori. Jinkozoki 15(2):516-20, 1986.

The efficacy of extrapulmonary arterial balloon pumping (EPABP) as a circulatory assist for the failing right side of the heart was evaluated experimentally using dogs with acute pulmonary hypertension (PHI caused by disseminated pulmonary emboli from polymethyl methacrylate beads. EPABP immedi- ately improved hernodynamics in the failing heart; decrease in RVP and CVP and increase in PAP and AoP were obtained and CO increased by 22.4% in the severe PH group. However, associated with surgical invasion on fixation and removal, EPABP has excellent advantages because of extrapulmonary arterial application: less arrhythmia was induced and less thrombus formed. In chronic PH, e.g., in mitral valvular disease, EPABP of the dilated main pulmonary artery trunk will also bring a certain assisting effect. Key Words: Right-heart failure-Extrapul- monary arterial balloon pumping (EPABPtRight-heart assist- Pulmonary hypertension.

(EPABP) FOR RIGHT-HEART FAILURE CAUSED BY PUL-

CLINICAL APPLICATION OF LEFT VENTRICULAR ASSIST DEVICE. A . Miyamoto, T. Hasegawa, S . Kiiamura, S . Umeda, K . Kawano, S. Shindou, H . Rikukawa, M. Shiono, K . Oga- sawara, Y . Namiki, Y . Orime, Y . Sezai, K . Aisumi, I . Fujimasa, and K . Imachi. Jinkozoki 15(2):604-7, 1986.

Three postoperative cases with low-cardiac-output syndrome were treated by left ventricular assist device (LVAD). Two of them were weaned from the LVAD but none of them survived. The indication for the LVAD has been established and the effect of the LVAD was remarkable. Therefore, the application of the LVAD and modification of the LVAD system were discussed in these cases. Key Words: Left ventricular assist device-Artificial heart-clinical use.

EFFECT OF METHYLPREDNISOLONE ON COMPLEMENT ACTrVATION DUIUNG CARDIOPULMONARY BYPASS. Y . Miyarnoto, H . Hirose, H . Matsuda, S . Nakano, R . Shirakura, S . Nakaia, M . Ohtani, K . Kadoba, N . Ohkubo, S. Kuki, F. No- mura, and Y. Kawashima. Jinkozoki 15(2):96171, 1986.

In-vitro experiment, methylprednisolone inhibited complement activation via both pathways, especially the alternative pathway. In clinical cardiopulmonary bypass, methylprednisolone significantly inhibited complement activation via the alternative pathway. Key Words: Complement activation-cardiopulmonary bypass-Methylprednisolone-Alternative pathway-Anaphylatoxin.

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COMMUNICATIONS 299

METHOD FOR THE ELlMINATION OF MICROBUBBLES IN

SONIC STANDING WAVE. Y. Mori, S. Murala, M . Kawasuji, T. Misaki, and T. Iwa. Jinkozoki 15(2):105741, 1986.

A method for the elimination of microbubbles in extracorporeal circulation applies ultrasonic standing wave to the blood, in which microbubbles are combined into a larger-size bubble. The large bubble can be eliminated easily by the bubble eliminator. The mechanism by which microbubbles are gathered together was analyzed theoretically. When the ultrasonic power was from 2.2 to 5 W, the effect of the elimination was best and microbubbles could be eliminated completely. Key Words: Microbub- bles-Extracorporeal circulation-Ultrasonic standing wave- Bubble eliminator.

EXTRACORPOREAL CIRCULATION BY APPLYING ULTRA-

ACTIVE APPLICATION OF PULSATILE FLOW INDUCED BY IABP TO A SERIOUS CARDIAC DYSFUNCTION. H. Moro, K . Togachi, T. Yokosawa, U . Okazaki, and S. Eguchi. Jinkozoki 15(2):1025-8, 1986.

In this paper, we studied the effect of pulsatile cardiopulmonary bypass on renal function in comparison with nonpulsatile cardiopulmonary bypass. Pulsatile flow was induced by intraaortic balloon pump (IABP) and nonpulsatile flow was delivered by a roller pump. Renal function study included systemic vascular resistance, free water clearance, NAG P,MG, and renin- angiotensin I1 and urine volume. Blood and urine samples were taken before IABP, and during and after bypass. A decrease in the level of GFR and an increase in the level of proximal tubular involvement were lower in pulsatile flow perfusion than in nonpulsatile perfusion. Pulsatile cardiopulmonary bypass is useful from the point of minimizing organ damage from extracorporeal circulation. Therefore, active population of pulsatile flow induced by IABP to a serious cardiac dysfunction, to a serious renal dysfunction, and to long-term cardiopulmonary bypass is useful. Key Words: Pulsatile cardiopulmonary bypass- NAG-P2 MG-Renin-Angiotensin 11.

USEFULNESS OF RATE-RESPONSIVE ATRIAL PACING. M . Murase, M. Tanaka, E. Takeuchi, K . Yoshida, A . Usui, and T. Abe. Jinkozoki 15(2):821-4, 1986.

The increase in heart rate of exercising AAI patients was slower than that of a normal population. In seven cases, rate- responsive atrial pacing by activity sensor was performed. On treadmill exercise, there was a better response of heart rate observed with rate-responsive pacing. Blood lactate and plasma noradrenalin after exercise showed lower levels in rate- responsive pacing than in AAI. Rate-responsive atrial pacing was considered to be the most physiologic pacing for sick-sinus syndrome currently. Key Words: Rate-responsive pacing-Atrial pacing-Plasma noradrenalin-Blood lactate-Treadmill exercise.

LOCAL DISTRIBUTIONS OF FLOW VELOCITY AND SHEAR STRESS IN THE AORTIC ARCH IN RESPONSE TO THE VALVE ORIENTATION OF PROSTHETIC HEART VALVES. K . Murota, H . Minamitani, E. Okoda, H . Yano, T. Inoue, Y. Imamura, and Y . Umezu. Jinkozoki 15(2):76%72, 1986.

Local velocity profile and shear stress distribution downstream from the aortic valve and in the model of human aorta were measured by using laser Doppler velocitimetry. BSS and LK valves provide high velocity and high shear stress in the outer curve region of the ascending aorta for OCO while just downstream from the major orifice and the inner curve region of the ascending aorta for ICO. However, less effect of the valve orientation can be observed in the descending aorta. The CE valve provides a high level of turbulence intensity and shear

stress in the annular region between the outflow surfaces of the leaflets and the flow channel wall as well as the top of aortic arch. Key Words: Flow velocity-Valve orientation-Shear stress-LDV.

CLINICAL EVALUATION OF ADVANTAGES OF EXTRA- CORPOREAL ULTRAFILTRATION METHOD DURING CAR- DIOPULMONARY BYPASS. Y . Nagata, M . Kobayashi, K . Shioi, T . Sahara, H . Tsuchioka, and E. Terasawa. Jinkozoki 15(2): 1 0 9 3 4 1986.

We used the extracorporeal ultrafidtration method during cardiopulmonary bypass so as to filtrate excessive water requiring large quantity of cardioplegic solution and to confirm the effect of ECUM in control of water balance. The advantages of two systems, Crystalflo made of polypropylene (C group) and Hemo- con made of cellulose-acetate (H group), were compared. In the results, serum Mb, thrombocytes, electrolytes, and serum os- motic pressure remained well in both groups and serum protein decreased in C group as compared with H group, but not very significantly. These systems are recognized as effective devices for hemoconcentration during cardiopulmonary bypass. Key Words: Extracorporeal circulation-Cardioplegic solution- Ultrafiltration.

THE EFFECT OF ULTRAFILTRATION DURING CARDIO- PULMONARY BYPASS. I . Nakada, K . Soejima, E. Imamura, M . Endo, H . Koyanagi, and S . Suzuki. Jinkozoki 15(2):1035-8, 1986.

Ultrafiltration during cardiopulmonary bypass (CPB) was evaluated in 3 1 patients undergoing open cardiac operations (ASD 9, ACBG 11, MVR 11); they were divided into two groups, S group being ultrafiitrated, C group being nonultrafiltrated. The postoperative urine volume was low in the S group compared with the C group (p < 0.05), but the cardiac index, P,o, (controlled ventilation, FIO, = 0.4), and serum creatinine levels were the same between the two groups. It was concluded that the ultrafiltration during CPB decreased fluid overload during CPB. Key Words: Ultratiltration-Fluid overload-Cardiopulmonary bypass.

HEMODYNAMIC AND HORMONAL STUDY OF TOTAL AR- TIFICIAL HEART (TAH). M . Nakajima, I . Fujimaso, K . Ima- chi, K . Mabuchi, T. Chinzei, Y. Abe, N . Takido, and K . Atsumi. Jinkozoki 15(2):68&91, 1986.

The hemodynamic and hormonal course of TAH-implanted goats was studied. The right atrial pressure elevated in 1-2 postoperative weeks and the arterial pressure increased more gradually, while left atrial and pulmonary arterial pressures were within the normal range. Renin-angiotensin system, catechola- mines, and ADH were almost normal after 2-3 postoperative weeks. The correlation between the hemodynamic and hormonal value did little to explain the hemodynamic abnormalities. Key Words: Total artificial heart-Hemodynamics-Renin-angiotensin system-catecholamine-Hypertension.

MICROPROCESSOR-CONTROLLED MOTOR-DRIVEN IM- PLANTABLE CARDIAC ASSIST DEVICE-DESIGN OF DRIVING AND CONTROL ALGORITHM. T . Nakamura, K . Hayashi, and J . Seki. Jinkozoki 15(2):66%72, 1986.

A pulse-width modulation algorithm with fixed duty ratio and variable voltage has been developed to drive and control the motor of an implantable artificial heart actuator. Rotation of the motor is converted into linear motion by a ball screw. Eight-bit and 16-bit microprocessors were used to drive the motor and to control the whole system, respectively. The torque performance

Artif Organs, Vol. 14, No. 4 , 1990


of the motor assembled in the actuator was studied in detail for the development of software to control the motor speed, and the results indicate that the pump fulfils the specified performance. Key Words: Cardiac assist device-Microprocessor-Torque- Pulse-width modulation-Duty ratio.

CARDIAC DYNAMICS DURING LEFT VENTRICULAR AS- SIST-EVALUATION OF MECHANICAL WORK OF ISCH- EMIC LEFT VENTRICLE. T. Nakamura, K . Hayashi, J . Seki, T . Nakatani, H . Noda, S . Fukuda, H. Takano, and T. Akutsu. Jinkozoki 15(2):575-8, 1986.

Bulk and regional mechanical work of the left ventricle during cardiac assist were studied by in-vivo acute experiments on mongrel dogs with ischemic hearts. The left ventricular assist device (LVAD) reduced bulk work both in the ischemic and normal hearts. The regional work in the normal region of the ischemic heart was significantly decreased by the LVAD pumping, while that in the ischemic area remained at near zero regardless of pumping or nonpumping. These results indicate that LVAD re- duces left ventricular work, developing no local forces or expan- sion in the ischemic region of the ventricle. Key Words: Left ventricular assist device-Bulk work-Regional work-Ische- mic heart.

AN EXPERIMENTAL STUDY OF POLYPROPYLENE HOL- LOW-FIBER OXYGENATOR FOR INFANTS. Y. Nakamura, M. Marsui, K . Hashimoto, R . Koike, and A . Matsui. Jinkozoki 15(2):8714, 1986.

We evaluated the gas transfer performance of a 0.6 m2 polypropylene hollow-fiber oxygenator and sizes of some drainage catheters. Gas transfer performance of 0, transfer and CO, removal were evduated with effective pulmonary flowltotal blood flow ratio (QJQ,), and arteriovenous CO, content difference/ arterial CO, tension ratio (ACO,/P,co,). SuSficient 0, transfer obtained under oxygen-blood flow ratio (V/Q) was 1 .O, but for CO, removal three times the oxygen flow was necessary. Exper- iments were done with some catheters for drainage. We obtained 300 mumin flow with a trocar catheter 8F size, and 500 mumin flow with 10F size under - 100 mm Hg. Key Words: Polypropyl- ene hollow-fiber oxygenator-Extracorporeal lung assist for infants.

TRICUSPID ANNULOPLASTY WITH A FLEXIBLE LINEAR REDUCER. M . Nakao, S . Yamamoio, H . Tsuruia, and K . Ogawa. Jinkozoki 15(2):70&7, 1986.

From November 1983 to June 1985,22 tricuspid annuloplasties were performed in association with mitral value or atrial septa1 defect procedures. As tricuspid annuloplasty, Bex’s method was used in 6, and Kay’s method in 16 patients. Bex’s method with a flexible linear reducer (FLR) was a reliable and effective method, especially in the cases with pulmonary hypertension. Key Words: Flexible linear reducer ( F L R t K a y .

THERAPEUTIC EFFECT OF LEFT VENTRICULAR ASSIST DEVICE (LVAD) ON PROFOUND HEART FAILURE (PHF) AFTER OPEN-HEART SURGERY. T. Nakaiani, T. Takano, M . Umezu, S . Adachi, H . Noda, S . Fukuda, T. Tanaka. H . Iwata, T . Matsuda, K . Kumon, T . Uiani, Y . Naiio, T. Fujita, T. Akutsu, and H . Manabe. Jinkozoki 15(2):588-91, 1986.

We have evaluated the therapeutic effect of LVAD on PHF in experimental study (PHF induced by aortic clamping under nor- mothermia in goats) and in clinical cases. In conclusion, LVAD can provide the failing heart with sufficient recovery time to regain its function while maintaining almost normal circulation. The recovery process is associated with increase of LV volume

and heart rate, and effective use of energy produced by residual myocardium after change of impaired muscle to connective tissue. The time required for LV assist depends on the severity of myocardial damage. Key Words: LVAD-Profound heart failure-Biventricular failure-Therapeutic effect.

HEART ASSIST EFFECT OF LEFT WN‘MUCULAR ASSIST

NUCLEAR MAGNETIC RESONANCE (NMR). T. Nakarani, H . Takano, H . Noda, S . Fukuda, S. Adachi, T. Nishimura, Y. Ya- mada, and T . Kozuka. Jinkozoki 15(2):5834, 1986.

Acute LVAD experiments (left atrium-descending aorta) were performed in five mongrel dogs to evaluate the heart-assist effect on the ischemic heart using NMR (Magnetom, superconductive type, 1.5 T). For enhancement of the infarcted area, gadolinium- DTPA was injected. With the LVAD on, the enhanced area and signal intensity of the infarcted area decreased. Also, MR con- trast (infarct image intensity minus normal myocardial image intensity divided by normal myocardial intensity) decreased with LVAD on. In conclusion, LVAD effectively decreased the ischemic area and the ischemic damage of the myocardium. Key Words: Nuclear magnetic resonance-LVAD-Gadolinium- DTPA-Heart-assist effect.

DEVICE (LVAD) ON ISCHEMIC HEART-EVALUATION BY

GAS EXCHANGE PERFORMANCE OF NEWLY DEVELOPED ARTIFICIAL LUNGS. T. Nakatani, M. Umezu, S . Adachi, T. Tanaka. H . Noda, S . Fukuda, and H . Takano. Jinkozoki

Gas exchange performance of 13 artificial lungs including nine newly developed ones was studied using mongrel dogs. 0, exchange performance of Bard HF-4000 was the same at various blood flows. 0, exchange performance of Shiley M-2000 and CO, performance of Dideco D-700 were not as good. Ube- Junken sheet type required to improve its gas exchange performance and ease of operation. Gambro G-10, Bentrey Bio-10, Cobe CML, Merasilox HSO-2.5, and Cobe VPCML had good performance. VPCML and D-700 had reliable performance for various blood flows. Key Words: Artificial l u n g d a s exchange performance-control index.

15(2): 1062-7, 1986.

CLINICAL AND HEMODYNAMIC RESULTS WITH DURO- MEDICS BILEAFLET CARDIAC VALVE PROSTHESIS. S . Na- kazawa, J . Hayashi, Y . Fujira, T. Yokozawa, Y . Yamazaki, S. Eguchi. and S . Ohrani. Jinkozoki 15(2):75&9, 1986.

Duromedics artificial valves were implanted in 19 patients from 1984 to 1985. Ten patients who underwent AVR with this prosthesis were reviewed. There was neither early death nor late death. No thromboernbolic phenomenon or severe hemolysis was encountered. Cardiac catheterization was performed on three patients postsurgery. A 25-mm Duromedics valve had small pressure gradients with a wide effective orifice area. How- ever, a 23-mm valve had a residual systolic gradient of 2c-30 mm Hg. Further observation and study should be continued. Key Words: Duromedics valve prosthesis-Aortic valve replacement.

EXPERIMENTAL STUDY IN OPTIMAL FLOW RATE OF LVAD FOR CORONARY SINUS FLOW. Y. Namiki, A. Ya- mazaki, T. Hasegawa, A . Miyamoio, M. Shiono, K . Ogasawara, Y. Orime, H . Hara, K . Kurihara, S. Yagi, K . Yamamoto, Y . Sezai, and T . Saiio. Jinkozoki 15(2):491-4, 1986.

Hemodynamic changes, including coronary sinus flow and carotid and renal artery flow, were evaluated in the model of acute left ventricular failure with complicated myocardial infarction in swine when the pump flow rate was changed from 10 to 60% of total cardiac output. The results showed that the left ventricular

Arrif Organs, Vol. 14, NO. 4, 1990

COMMUNICATIONS 301

assist device could improve hemodynamics at any flow rate. However, coronary sinus flow rate revealed a maximum value at the assist rate of 40%, and carotid and renal artery flow rate showed a plateau state when the pump flow rate was >40%. Key Words: Left ventricular assist device-coronary sinus flow- Carotid artery flow-Renal artery flow-optimal flow rate.

CLINICAL EVALUATION OF MICROPOROUS POLYPROPYL- ENE HOLLOW-FIBER OXYGENATOR. J . Narumi, K . Suma, Y. Takeuchi, K . Inoue, K . Shiroma, Y . Koyama, H. Kaneko, S . Nishiyama, T. Takahama, Y . Kohri, Y. Terada, H. Yokomuro, and T. Ban. Jinkozoki 15(2):893-6, 1986.

A microporous polypropylene hollow-fiber oxygenator (H.F.O.) was used in more than 600 cases of open-heart surgery with safety. Gas exchange performances of the oxygenator were excellent. However, tendency of Pco, accumulation in the blood in the outlet of the oxygenator was observed at the end of the total CPB. Pulmonary shunting flow in the patients treated with a H.F.O. was greater than in those with B.O. just after the operation. This might be due to the two-pump system adopted in our extracorporeal circuits. However, recovery of the pulmonary function of the patients perfused with H.F.O. was more rapid than in those with B.O. Key Words: Microporous polypropylene hollow-fiber oxygenator-Pulmonary shunting- Pulmonary function.

DEVELOPMENT OF A NEW HOLLOW-FIBER MEMBRANE OXYGENATOR. H . Natori, A . Miyamoto, S. Kitamura, T . Oka- zaki, K . Ohmori, Y. Ishii, H . Shinohara, 0. Nishimura, Y. Sezai, M . Suzuki, K . Kamiya, K . Kuwana, and H. Nakanishi. Jinko- zoki 15(2):1080-3, 1986.

We developed a new type of hollow-fiber membrane oxygenator. It consists of a polypropylene hollow-fiber bundle 20 cm long, and 4 cm in diameter. Oxygen flows within the lumen of the fiber and blood passes around the fiber bundles. The surface area available for gas transfer was 3.3 m2. This oxygenator had an excellent gas exchange capability and pressure drop was minimal. We applied this membrane oxygenator to two cases undergoing open-heart surgery. The results were satisfactory. Key Words: Hollow-fiber membrane oxygenator.

EVALUATION OF THE RESULTS AND CAUSES OF UNSUC- CESSFUL CASES AFTER ASSISTED CIRCULATION (IABP,

VER). S. Nawa, Y . Kioka, T. Komoda, A . Shimizu, Y . Miyachi, K . Ebara, H . Tsuji, Y . Nakayama, T . Murakami, H . Uchida, Y. Senoo, and S . Teramoto. Jinkozoki 15(2):549-53, 1986.

In congenital heart diseases, almost all assisting methods were not effective, and the results were mainly dependent on the operative indication, techniques, and procedures. In acquired valvular heart diseases, prophylactic use of the intraaortic balloon pump (IABP) for postoperative low cardiac output syndrome would improve the operative outcome. By the cases, in that the bypass flow rate above 2.4 L/midm2 and bypass time more than 100 min were needed, the prognosis was very poor. As for the combined use of IABP and V-A bypass or extracapillary membrane oxygenator (ECMO), the combination therapy was considered effective, and particularly, early introduction of IABP for weaning from the extracorporeal circulation was most effective. However, even by the combination assist some cases could not be improved as in almost all cases of ECMO. Thus, some other more effective and active assisting methods, such as the left ventricular or biventricular assist devices, and/or heart trans- plantation will be indicated when a high bypass flow rate is needed for many hours. Key Words: Assisted circulation- IABP-V-A bypass-ECMO.

V-A BYPASS, ECMO AND THE COMBINATION MANEU-

NEW TRANSATRIALSEPTAL CANNULA FOR LEFT-HEART BYPASS. H . Nishida, T . Ichihara, R . Seino, K . Soejima, M. Endo, and H . Koyanagi. Jinkozoki 15(2):625-8, 1986.

We developed a new transatrialseptal cannula that can be inserted safely and quickly applying a Seldinger-like technique. This cannula has a stylet in which a 0,038-in guidewire is pass- able. In a dog weighing 15-20 kg, 100-120 mlikgirnin flow was obtained using this 24 Fr (ID = 6 mm) cannula. After I week of insertion in the left atrium, we pulled back this cannula to the right atrium. At that time no meaningful interatrial shunt was detected. Moreover, an interatrial hole was repaired and completely closed 2 weeks after decannulation. Key Words: Trans- atrial septal cannula-Left-heart bypass-Seldinger technique- Guidewire-Interatrial shunt.

RIGHT VENTRICULAR PRESSURE-DIMENSION RELA- TIONSHIP DURING LEFT-HEART BYPASS IN DOGS. K . Nishigaki, H . Hirose, H . Matsuda, S. Nakano, T. Sakakibara, M . Ohtani, A . Kawaguchi, Y . Sasako, R . Matsuwaka, F . No- mura, and Y. Kawashima. Jinkozoki 15(2):567-70, 1986.

We analyzed the hemodynamic change and right ventricular pressure-dimension relationship during left-side-of-the-heart bypass in dogs. Eighteen mongrel dogs (body weight = 11.8 t 1.9 kg) were divided into the following three groups-I: normal control, n = 5 ; 11: right ventricle free wall ischemia, n = 5 ; 111: interventricular septum ischemia, n = 8. During complete bypass of the left side of the heart, right ventricular failure was detected only in group 111. The right ventricular pressure- dimension curve did not change in group I. In group I1 the curve moved slightly to the right at 30 min after ischemia. In group 111, the curve moved to the right and upper side as time passed after ischemia. Key Words: Left-heart bypass-Right ventricular function-Right ventricular pressure-dimension relationship-Ultra- sonic dimension crystal.

LONG-TERM RESULTS OF VALVE REPLACEMENT WITH THE BJORK-SHILEY TILTING DISK VALVE. K . Nishimura, T, Ban, J . Soneda, M. Matsuda, K . Hirata, S . Hanada, T. Tskeuchi, T . Oda, and T . Miyamoto. Jinkozoki 15(2):798-801, 1986.

Valve replacement with the Bjork-Shiley spherical valve was performed in 384 patients from 1975 to 1983. The 5-year actuarial survival rates were 89% after mitral, 83% after aortic, 80% after mitral and aortic valve replacement, including the early mortality rates. The incidence of systemic emboli was 1.0% patient years for mitral, 0.3% for aortic, and 0.5% for mitral and aortic valve replacement with anticoagulation therapy. Three patients developed valve thrombosis for an incidence of 0.1 % patient-years for mitral, 0.2% patient-years for aortic, and 3.3% patient-years for tricuspid valve prosthesis. All three patients underwent successful rereplacement. The long-term results of valve replacement with the Bjork-Shiley spherical valves were excellent. Adequate functional performance and minimal thromboembolic complications could be anticipated in patients with optimal anticoagulant therapy. Key Words: Bjork-Shiley valve-Late results- Thromboembolism-Thrombosed valve.

DEVELOPMENT AND EVALUATION OF MICROSENSORS

LAR ASSIST DEVICE. S. Nitta, Y . Katahira, T. Yambe, M . Tanaka, Y. Kagawa, T . Hongo, T . Horiuchi, N . Uchida, M. Miura, and A . Takahashi. Jinkozoki 15(2):64&9, 1986.

Piezoresistive pressure sensors and ISFET microsensors (pH, Pco,) for the use of the information from circulatory conditions during left ventricular assist device (LVAD) pumping have been developed and evaluated. These microsensors were built in the

FOR AN AUTOMATIC CONTROL SYSTEM OF VENTRICU-



intlow and outflow cannulae. Micropressure sensors and ISFET sensors were coated with antithrombogenic materials such as cardiothane and hydrophilic polyurethane, respectively. In the chronic animal study, enough sensitivity and reliability for an automatic control system of LVAD have been obtained. Key Words: Microsensor-ISFET-Piezoresistive pressure sensors-LVAD-Automatic control system.

EFFECTIVENESS OF ECCOZ-R WITH LOW-FLOW BYPASS UTILIZING RECIRCULATION CIRCUIT-EXPERIMENTAL STUDY. F. Nomura, H . Hirose, H . Matsuda, S . Nakano, M. Ohtani, K . Tamura, K . Kadoba, K . Nishigaki, Y. Miyamoto, N . Ohkubo, H . Takami, and Y. Kawashima. Jinkozoki 15(2):9634, 1986.

The ECC0,-R system including a recirculation circuit was studied with low-flow venovenous bypass for hypoventilated dogs. In view of arterial PCO, and hemodynamics, bypass flow set as 10% of cardiac output was effective when recirculation was combined. Key Words: ECC0,-R-Low-flow bypass- Recirculation circuit-Respiratory support.

A STUDY OF SPLANCHNIC HEMODYNAMICS DURING

nami, M. Yamasnki, K . Matsuzaki, S . Kitagawa, T. Matsumoto, T . Yamashiro, and T. Tamiya. Jinkozoki 15(2):100&12, 1986.

Hemodynamic effects of pulsatile perfusion to the splanchnic organs were investigated in adult mongrel dogs. Pulsatile perfusion was performed by use of the PAD and blood flow was measured by the ultrasonic transit time flow meter. Comparisons were made between the pulsatile and nonpulsatile total perfusion with regard to flow rates of 60, 80, and 100 ml/kg/min, respectively, under cardiac arrest. A difference of hemodynamic state between the two was noted in only those pulsated at a flow rate of 100 ml; significantly lower peripheral vascular resistance and significantly higher renal and portal blood flow were found in the pulsatile group. Key Words: Pulsatile extracorporeal circulation-Splanchnic hemodynamics.

PULSATILE EXTRACORPOREAL CIRCULATION. Y. NO-

EXPERIMENTAL AND CLINICAL STUDY IN OPTIMAL

TANCE. K . Ogasawara, T. Hasegawa, A . Miyamoto, M. Shiono, Y. Orime, Y. Namiki, H . Hata, T . Yamamoto, S . Yagi, K . Kurihara, and Y. Sezai. Jinkozoki 15(2):558-61, 1986.

An experimental study was planned for the purpose of dem- onstrating the optimal driving condition of the left ventricular assist device (LVAD) and the effectiveness of a combination of the intraaortic balloon pump (IABP) and LVAD under acute left ventricular failure with left ventricular infarction in swine. The results showed that the recovery of left ventricular function was much more effective in counterpulsation. The combination method of IABP and LVAD was as effective as individual LVAD (counterpulsation method), but renal artery flow was significantly reduced. However, in a case of clinical application of LVAD, individual LVAD could not improve hemodynamics and its combination with IABP could improve remarkably. Key Words: IABP-LVAMounterpulsation-Driving condition.

DRIVING CONDITION OF LEFT VENTRICULAR ASSIS-

THE EXTRACORPOREAL LUNG ASSIST FOR NEONATAL RESPIRATORY FAILURE. T. Ohtsu, H . Terasaki, K . Takase, H . Shimamura, and Y. Yamada. Jinkozoki 15(2):932-6, 1986.

We devised a new machine for extracorporeal lung assist (ECLA) with an artificial-membrane lung and prolonged venovenous bypass to support gas exchanges for neonatal respiratory failure. While water moves up and down under pressure in a rigid plastic box including a small silicone reservoir, blood intermit-

tently comes in and out the reservoir via a thin-wall single-lumen catheter of segmented polyurethane inserted into the vein. h e u - matic pinch valves that are electrically controlled close and open the extracorporeal circuit to circulate the blood through an artificial-membrane lung. In 18 pigs 14 days old, we tested the safety and efficacy of the apparatus. The blood-priming volume was less than 220 ml. The apparatus had bypass blood flow of 112 mllkg/min at maximum. By preventing hemorrhage from surgical wounds in the cervical region with careful hemostasis and control of the rate of heparin infusion, the prolonged venovenous bypass of 7 days was successfully accomplished. This system of extracorporeal lung assist may be clinically suitable for neonatal respiratory failure. Key Words: Artificial membrane lung- Extracorporeal lung assist-Venovenous bypass-Neonatal respiratory failure.

CLINICAL EXPERIENCE WITH S n E Y M-2000 MEMBRANE OXYGENATOR. H. Oka, Y . Kusumoto, 0. Katayam, T. Ni- shioka, and H . Shirotani. Jinkozoki 15(2):910-3, 1986.

The Shiley M-2000 membrane oxygenator contains heat exchange and 2.3 m2 of microporous polypropylene membrane in a parallel-plate design. This membrane uses two Cellgard mem- branes, pore size 0.2 x 0.02 pm and 0.4 x 0.04 pm, which are placed one crossed over the other. The element of Z-fold membrane are kept separated by the insertion of a latticed polypropylene spacer in each gas and blood fold and provide bilevel crossflow. In vitro, the gas transfer performance and oxygenator resistance of M-2000 were proved to be better than those of CML, but the heat exchange performance was lower than that of CML. Five clinical cases using M-2000 were compared with the other four membrane oxygenator groups. There is no significant difference among the four membrane oxygenators in the counts of platelets, white blood cells, microbubbles, and urine volume without plasma free hemoglobin, which is significantly low in CML. Key Words: M-2000 membrane oxygenator-Gas transfer performance-Oxygenator resistance-Heat exchange performance-Blood trauma.

CLINICAL COMPLICATIONS OF BIOPROSTHETIC VALVES AFTER LONG-TERM APPLICATION. M. Okabe, et al. Jinko- zoki 15(2):72&3, 1986.

Long-term evaluations of bioprosthetic valves in 31 cases operated on in our institute were carried out, in particular concerning the primary tissue failure. The follow-up period ranged from 0.5 to 8.5 years with an average of 4.8 years and a total of 170.5 patient-years (p.y.). Late postoperative complications of the 3 1 cases receiving the tissue valves were as follows: thromboembolism five cases (2.9% per p.y.), sepsis four cases (2.3% per p.y.), primary tissue failure including the two cases of valvular regurgitations (2.3% per p.y.), and one case of calcified valve stenosis (1.2% per p.y.). The clinical symptoms coming from the primary valve failure had begun to appear in the patients who had survived 4 years after the initial operations. Reoperations for the dysfunctional valves were performed in three cases, including the two cases with tom valve leaflets and one case of ste- nosed valve, successfully. It is concluded that bioprosthetic valves have several problems left to be solved, especially concerning their durability, and careful examinations are necessary in patients with the prostheses, especially 4 years after the operations in regard to primary tissue failure. Key Words: Biopros- thetic valves-Long-term follow-uHomplications.

AN ASSESSMENT OF INTRAAORTIC BALLOON PUMPING FOR PUMP FAILURE-ANALYSIS FROM SHAPES AND SIZES OF BALLOON. M. Okada, M . Zizuka, T. Shiozawa, K . Okuno, K . Shio, S. Maisuda, and K . Nakamura. Jinkozoki 15(2):529-34, 1986.


COMMUNICATIONS 303

The major causes of death after acute myocardial infarction (AMI) are cardiogenic shock and arrhythmia. The number of rhythm deaths has been obviously decreased with the development of the coronary care unit. To decrease the mortality rate of patients with cardiogenic shock due to AMI, the intraaortic balloon pump (IABP) has been widely employed for those severely ill patients. In this study, IABP was attempted in 94 mongrel dogs with cardiogenic shock due to AM1 that was produced by multiple ligation of the coronary arteries. The effects of IABP on hemodynamics after AM1 by using three types of balloon catheters (single! double, and triple balloon) were also studied. The effects of IABP on hemodynamics resulted in an increase in coronary blood flow, cardiac output, and diastolic pressure. A decrease in left ventricular pressure and end-diastolic pressure of the left ventricle was simultaneously observed as systolic unloading. A significant improvement was found in the proximal and distal portion of the balloon by using a single or triple balloon. On the other hand, a marked improvement in hemodynamics was seen in the proximal portion of the balloon by using a double balloon. A triple balloon is indicated for patients in whom IABP must he utilized for a long-term period. In clinical cases, a balloon volume of 20 ml was convenient for patients with a body weight less than 50 kg or 30 ml for patients more than 50 kg. However, a suitable size of balloon must be developed for the Japanese people in the near future. Key Words: Acute myocardial infarction-Cardiogenic shock-IABP-Balloon shape and size.

SIDE HOLE EFFECT OF CAVOATRIAL CANNULA ON AUG- MENTING DRAINAGE FLOW RATE. H . Okamoto, K . Ya- suura, et al. Jinkozoki 15(2):1126-8, 1986.

The influence of side holes of cavoatrial cannulae on augment- ing flow rate was studied using an in-vitro circuit. As a result, side holes must be made at a distance from the tip of the cannula, but too many holes do not contribute to increasing flow rate. We have developed a new venous cannula, 26F, 60 cm long, and having multiple holes in its tip, that permits drainage of blood from both the right atrium and the inferior vena cava. Key Words: Cavoatrial cannula-Side hole-Flow r a t e F - F bypass.

AUTOMATIC CONTROL SYSTEM OF CARDIAC HYPOTHER- MIA BY THE ARTIFICIAL HEART-LUNG MACHINE. Y. Oka- mum, T. Okada, A . Gomi, H . Masuda, and J . Hattori. Jinkozoki 15(2):1150-4, 1986.

We have developed an automatic control system for cardiac hypothermia by the artificial heart-lung machine with a topical cooling unit. It is a simple method because the operator only has to put the cooling pad in the pericardial cavity, and the perfu- sionist only has to set the upper and lower limit of the temperature. Compared with an ordinary method using much more ice slush or cold water, automatic control has the following merits: (a) to keep an adequate myocardial temperature easily, and (b) to avoid excessive hemodilution and postoperative phrenic nerve palsy. Key Words: Topical cooling-cardiac hypothermia- Myocardial protection-Extracorporeal circulation-Artificial heart-lung machine.

EXPERIMENTAL STUDY OF OPTIMAL DRIVING MODE, IN COMBINATION METHOD WITH LVAD AND IABP. Y. Orime, A . Yamazaki, T . Hasegawa, A . Miyamoto, M . Shiono, K . Oga- sawara, Y . Namiki, H . Hata, K . Kurihara, S . Yagi, T. Ya- mamoto, Y. Sezai, and T. Saitoh. Jinkozoki 15(2):554-7, 1986.

This experimental study compared the intraaortic balloon pump (IABP) and the left ventricular assist device (LVAD), in- dividually and in combination, for their hemodynamic effectiveness in swine. LVAD support resulted in significantly superior support to that of IABP for the failing heart. A combination

method with IABP (counterpulsation mode) and LVAD (counterpulsation mode) showed marked improvement in the aortic pressure and endocardial viability ratio. However, in this combination method, renal artery flow was reduced, and this method was thought to have a harmful influence on renal perfusion. Key Words: IABP-LVAD-Left ventricular failure-Renal artery flow.

CLINICAL. EVALUATION OF VARIOUS TYPES OF ARTIFI- CIAL OXYGENATOR. M . Otaki, A . Yamaguchi, M . Sasou, H . Tamura, M . Atobe, and N . Kitamura. Jinkozoki 15(2):87543, 1986.

In our department, we made use of 11 types of oxygenators; 6 were the bubble type, and the others were the membrane type. Evaluation of oxygenators was as follows. (a) efficiency of gas transfer were shown to changes .of P,o,, P,co, with V/Q being changed, 0, transfer and Qp/Qt; (b) efficiency of heat exchange; (c) platelet retension; and (d) hemolysis. As for platelet retension and hemolysis, membrane oxygenators were superior to bubble types. Key Words: Bubble oxygenator-Membrane oxygenator-Efficiency of gas exchange-Platelet retention- Hemolysis.

CLINICAL EVALUATION OF OXYGENATORS BY CONTIN- UOUS BLOOD OXYGEN SATURATION MONITOR (OXY- SAT). K . Ozawa, S. Sugimura, T . Iriyama, Y . Hattori, K . Wa- tanabe, K . Negi , H . Nakamura, and M . Matsuda. Jinkozoki 15(2):888-91, 1986.

Five oxygenators (A: Travenol LPM 50, 3: Shiley M-2000, C : Bentley BOS CM 40, D: Bentley BOS lOS, E: William Harvey H-1700) were evaluated in 54 patients. Continuous blood oxygen saturation (by Bentley Oxysat), P,co2, and gas to blood flow ratio (V/Q) were compared in each group after the temporary low-flow state. Subnormal blood gas data were obtained in each group as follows: A: 70%, B: 60%, C: 44%, D: 33%, and E: 30%. V/Q in C was significantly low but SvO, below 70% was never recorded. BOS CM 40 seemed to be the choice for our current cardiopulmonary bypass. Oxysat was found to be a useful and reliable device to maintain safe conduct of cardiopulmonary bypass. Key Words: Oxygenator-Continuous blood oxygen saturation monitor.

DEEP HYPOTHERMIA AND PULSATILE FLOW. H . Saigusa, M . Kawamura, M . Murase, M . Tanaka, E . Takeuchi, Y . Suenaga, M . Hibi, K . Ogawa, and T . Abe . Jinkozoki 15(2):1017- 20, 1986.

The effect of pulsatile flow during cardiopulmonary bypass with deep hypothermia on the hormonal stress response was studied. There were 19 patients with moderate hypothermia and 26 patients with deep hypothermia. The plasma epinephrine levels decreased in the deep hypothermia group (DH) relative to the moderate hypothennia group (MH), but significantly increased with pulsation (DH: 0.210 +. 0.181 ng/ml, MH: 0.391 2 0.232 ngiml, DH with pulsation: 0.388 2 0.275 ngiml). The same response was noted in the norepinephrine levels (DH: 0.313 & 0.194 ng/ml, MH: 0.673 2 0.511 ng/ml). However, there was no signifcant increase of norepinephrine with the addition of pulsatile flow. There was no significant difference in thromboxane B, (TXB2)/6-keto prostaglandin E,, (PGE,,) between both groups, but the increase of TXB2/6-keto PGF,, in the ischemic heart disease group was noted as comparable with that of the nonischemic heart disease group. These data suggest that pulsatile flow may improve maldistribution of the blood flow of the adrenomedullary gland.

EXPERIMENTAL CARDIOPULMONARY BYPASS WITH USE OF DBcAMP. T. Sakairi, M. Takahira, Y . Ishibashi, R . Ya- mazaki , H . Takeda, K . Sakai , and T . Tanabe. Jinkozoki 1 512): 989-92, 1986.



Ten mongrel dogs were divided into two groups and cardiopulmonary bypass was done. Five dogs were a control group with use of heparin (group H) and 5 dogs were a DBcAMP group (group D). DBcAMP was administered by drip infusion at a rate of 0.01 mg/kg/min just after the start of cardiopulmonary bypass. The hemodynamic parameters, BGA, pyruvate, and lactate showed no significant changes, but the significant decrease of whole blood aggregation and thromboxane Bz of group D suggests that DBcAMP may preserve platelet function. Key Words: DBcAMP-Cardiopulmonary bypass-Platelet preservation.

ASSESSMENT OF THE OPENING ANGLE OF BJ6RK-SHILEY MONOSTRUT VALVE BY BKPLANE CINERADIOGRAPHY. S. Sakaki, H . Hirose, S . Nakano, H . Mastuda, S . Nakata, T. Sakakibara, T. Hiranaka, K . Taniaguchi, T. Kawamoto, H . Imagawa, T. Miura, and Y. Kawashima. Jinkozoki 15(2):777-80, 1986.

By biplane cineradiography, a new method was developed to measure the opening angle of an implanted Bjork-Shiley monostrut valve and phantom valve. In the measurement of the phantom valve, there were no differences between the measured angle and the real opening angle. The maximum opening angles of the implanted valve were 70 +- 1.8" at rest and 69.9 k 1.7" at 150 pacing rate per minute. Measurement of the opening angle by using biplane cineradiography was considered to be useful, reliable, and accurate. Key Words: Biplane cineradiography- Opening angle-Bjork-Shiley monostrut valve.

DEVELOPMENT AND IN-VITRO EVALUATION OF AN OUT- SIDE-FLOW-TYPE ARTIFICIAL LUNG WITH PLASTIC HEAT EXCHANGER. I. Santo, J . Kamo, H . Takahashi, H . Yoshida, and T. Yoshihara. Jinkozoki 15(2):107&9, 1986.

A novel artificial lung (AL) with heat exchanger using plastic tubes has been developed and evaluated in vitro. In this AL, blood flows outside and across the bundles of microporous polypropylene hollow fibers and plastic tubes. This AL showed high performance for oxygenation and heat exchange: the oxygen saturation was approximately 95% at the blood flow rate of 3 Ymin . m2 and the heat-exchange performance was equal to or higher than those using the stainless tubes. Moreover, the values of pressure drop were sufficient for gravity venous drainage. Key Words: Microporous hollow-fiber membrane-Plastic heat exchanger-Membrane oxygenator.

'

CLINICAL STUDY OF TWO KINDS OF BLOOD CONCEN- TRATOR USED AFTER CARDIOPULMONARY BYPASS. T. Sasaki, H . Furukawa, S . Horikoshi, S . Suzuki, T. Kozukue, K . Mashiko, K . Suzuki, A . Mizuno, T. Arai, H . Kamata, Y. Ta- kenaka, and H. Fukumi. Jinkozoki 15(2): 11014, 1986.

Postbypass hemoconcentration was achieved in group I with the hemofdter PAN-140 or a new device, ASA-800, for short- extracorporeal circulation (ECC) time patients, and in group I1 with blood-concentrator ASA-1200 for long-ECC-time patients. Changes of blood components before and after hemoconcentration were analyzed. Hematocrit and platelets were significantly increased in both groups, and serum protein and free hemoglobin were not concentrated in group 11. The blood transfusion volume in these groups was significantly less than in the control group. ASA-800 and ASA-1200 were recognized to be effective devices for hemoconcentration after cardiopulmonary bypass. Key Words: Postbypass hemoconcentration-Blood concentrator- Plasma separator-Hemofilter.

DEVELOPMENT OF CANNULAE OF VENTRICULAR ASSIST DEVICES WAD) FOR PEDIATRIC USE. N . Sato, T. Hongo, Y. Kagawa, N . Uchida, M. Miura, Y. Akino. T. Horiuchi, S. Nitta, Y. Katahira, and R . Yoda. Jinkozoki 15(2):629-32, 1986.

A VAD system for postoperative pediatric patients weighting 3-10 kg is under development in our institute. Cannulae are designed on the basis of anatomical studies on 25 cases of congenital heart diseases within that body-weight range. The fabricated outflow cannula has an EPTFE graft of 5 mm fi on its end. The tip of the inflow cannula has an inner diameter of 5 mm. In-vitro and in-vivo evaluations of those cannulae were done in combination with a small pneumatic pump that has a stroke volume of 15 ml. The system demonstrated output of more than 1.0 Wmin in a mock circulation and up to 900 mumin in an acute animal experiment under the conventional driving conditions. Key Words: Ventricular assist device-Pediatric postoperative LOS-Cannula-Anatomical study.

CLINICAL STUDY OF CARDIOPULMONARY BYPASS (CPB) IN INFANTS LESS THAN 3 MONTHS OLD. Y. Sawa, Y. Shi- mazaki, H . Hirose, H . Matsuda, H . Kishimoto, K . Kadoba, K . Nishigaki, S . Ohtake, F. Nomura, and Y. Kawashima. Jinkozoki

Twenty-three patients less than 3 months old were analyzed in terms of CPB. The results indicate that prolonged CPB, preoperative heart failure, and complexity of the lesions affect the outcome. As the perfusion rate, 150 ml/kg/min seemed adequate for the patients in this age group. Key Words: Cardiopulmonary bypass-Infants less than 3 months old-Postoperative compli- cation-Urine output during CPB-Perfusion index.

15(2):867-70, 1986.

EXPERIMENTAL STUDIES ON EXTRACORPOREAL MEM- BRANE OXYGENATION (ECMO) FOR APPLICATION OF IN-

OF VENOVENOUS BYPASS WITH INTERMITTENT PERFU- FANTS WITH SEVERE RESPIRATORY FAILURE: A STUDY

SION FLOW. T. Sawamura, K . Hisano, T . lenaga, C . Kusu- moto, K . Shio, S. Tachibana, M. Okada, K . Nakamura, S . Mat- suda, H . Sirae, and T. Nishimura. Jinkozoki 15(2):937-40, 1986.

This study was performed by using dogs (2-9 kg weight) to investigate the venovenous bypass for respiratory support. Three types of methods of ECMO consisted of venoarterial (V- A) bypass and venovenous (V-V) bypass (continuous flow and intermittent flow). After completion of the ECMO perfusion, oxygenation and hemodynamics were studied. The intermittent flow was obtained by inflation or deflation of the flexible chamber in which pump and reservoir were combined in each. A flow rate of 30% of the cardiac output was maintained in this study. The difference of oxygenation and pressure of the femoral artery was not seen between V-A bypass and V-V bypass. Intermittent flow by V-V bypass slightly increased the pressure of the pulmonary artery and right ventricle. This was caused by drainage and perfusion of the venous blood. Key Words: Respiratory failure-ECMO-V-A and V-V bypass-Intermittent flow- Flexible chamber.

FLUID-MECHANICAL ANALYSIS OF PULSATILE FLOW BE- HIND POLYURETHANE THREE-LEAFLET VALVE USING LASER-DOPPLER ANEMOMETER. J. Seki, T. Nakamura, M . Umezu, and K . Hayashi. Jinkozoki 15(2):7414, 1986.

Fluid-mechanical characteristics of a newly developed con- duit-type polyurethane three-leaflet valve was analyzed in vitro under pulsatile flow condition by a laser-Doppler anemometer. Central flow with high velocity was observed in the maximum- velocity phase at a distance of 2 diameters from the valve, although the average velocity distribution approached uniform with the distance from the valve. The velocity was low behind the commissure of the valve leaflets. Turbulence intensity was high around the central flow in the maximum velocity phase and the deceleration phase. Reynolds stress was >400 dydcm' in the high-shear region. Key Words: Polyurethane heart valve- Laser-Doppler anemometer-Average velocity profile- Turbulence intensity-Reynolds stress.



CLINICAL EXPERIENCE OF NEWLY DEVELOPED MEM- BRANE OXYGENATOR. A . Sekiguchi, K . Sudo, K . Asano, A . Mizuno, M . Kawauchi, K . Tanaka, 0. Tanaka, and G. Shindo. Jinkozoki 15(2): 1088-93, 1986.

A newly developed microporous polypropylene membrane oxygenator (CML) with a single-pump system was clinically evaluated in 15 adult cases undergoing open-heart surgery, and the hollow-fiber membrane oxygenator (Capoix 11) in 10 adult cases was the control. There were no statistically significant differences between the two oxygenators in point of hemolysis and platelet depletion during perfusion, but there was a tendency toward higher levels of V/Q ratio to maintain the suitable P,co, in CML than in Capiox 11. Key Words: Membrane oxygenator- Carbon dioxide transfer-Platelet depletion-Hemolysis- Clinical cases.

IN-VITRO COMPARISON OF PROSTHETIC HEART VALVE IN DEVELOPED PULSE DUPLICATOR WITH TILTING HEAD. R . Shimada, T. Hasegawa, A . Miyamoto, S . Kitamura, K . Kawano, S . Umeda, S . Shindo, H . Rikukawa, M . Shiono, and Y. Sezai. Jinkozoki 15(2):7814, 1986.

In heart valve replacement, a prosthetic valve is deflection angle between valve axis and flow axis, so we developed a tilting head that could be changed 0 to 2-30". The hydrodynamic performance of four prosthetic heart valves-St. Jude medical (SJM), Starr-Edwards ball (S-E), monostrut Bjork-Shiley (mB- S), Ultracor (UC)-has been assessed. The pressure gradient, output, and calculated valve areas for these valves were measured at each angle and heart rate. The mMVG mm Hg of the mB-S and UC valves at -15" were less than at other angles. The MVA cm2 at -15" were greater than at other angles. The mMVG mm Hg and MVA cm2 of the S-E and SJM valves were not significantly change at any angle. Key Words: Prosthetic heart valve-Pulse duplicator-Tilting head-Heart valve replacement-Pressure gradient.

DEVELOPMENT OF A NEW MODEL OF ACUTE RESPIRA- TORY INSUFFICIENCY (ARI) AND EXPERIMENTAL EVAL- UATION OF VENOVENOUS ECMO. A . Shimizu, K . Shiotsu, Y. Kioka, T . Nakao, S. Nawa, Y. Senoo, and S. Teramoto. Jinko- zoki 15(2):928-31, 1986.

We have originally developed a new model of ARI by injecting seawater endotracheally. This method was proved to establish a stable state of ARI without depressing cardiac function signif- cantly. Using a dog model, venovenous bypass for extracorporeal membrane oxygenator (ECMO) (V-V ECMO) was carried out by changing the ventilation-perfusion ratio (V/Q ratio) to 1 .O , 2.0, and 3.0 at each bypass flow rate of 40, 60, and 80% of preperfusion cardiac output. Changes in blood gas and hemodynamics were evaluated at each condition to reveal the effects of V-V ECMO. Although little evaluation of P,co, was observed, significant reduction of P,co2 could be obtained even at a low bypass flow rate. It was considered that P,co, could be controlled not only by changing the bypass flow rate but also by alternating the V/Q ratio. Because the circulatory derangement would scarcely occur by V-V ECMO, this method of ECMO was considered clinically useful, particularly for CO, removal. Key Words: Acute respiratory insufficiency (AR1)-New ARI model-Venovenous ECMO-Extracorporeal CO, removal (ECCO, R).

DEVELOPMENT OF THE ASSIST PUMP CONTROL SYSTEM BASED ON INDIRECT PRESSURE MEASUREMENT. T . Shi- mooka, Y . Mitamura, E . Okamoto, and T . Mikami. Jinkozoki 15(2):63&7, 1986.

The assist pump control system, using only indirectly measured arterial pressure and atrial pressure, was developed. In

experiments on dogs, between the indirectly measured and the directly measured values, we had good linear relations; r = ,959 for arterial pressure, r = .982 for atrial pressure. Arterial pressure control experiments were performed on dogs, and the system could maintain circulation by regulating the drive rate. Key Words: Assist pump control system-Indirect pressure measurement-Arterial pressure control.

THE CARBON-TIP ELECTRODE-A CLINICAL LONG-TERM STUDY. G . Shindo, F . Miyawaki, M . Nakata. K . Tanaka, 0. Tanaka, A . Sekiguchi. A . Furuse, A . Mizuno, and K . Asano. Jinkozoki 1x2): 837-9, 1986.

Activated carbon-tip electrodes have been implanted in a group of 23 patients for up to 5 years. (a) The initial stimulation threshold of the carbon-tip electrode was reasonably low. More- over, the chronic stimulation threshold of the unipolar carbon-tip electrode has been maintained in sigruficantly lower value than that of metal-tip electrodes. (b) The carbon-tip electrodes also showed less frequent dislodgement and less frequent sensing failure compared with the metal-tip one. These results will promise to elongate pacemaker longevity. (c) However, the bipolar carbon-tip electrode showed a significantly high chronic stimulation threshold compared with the unipolar one, although the initial stimulation threshold was reasonably low. This group will need further investigation to resolve it. Key Words: Activated vitreous carbon-tip e lectrode4hronic stimulation threshold-Lead dislodgement-Sensing failure-Pacemaker longevity.

EFFECT OF ECMO ON LUNG IN RESPIRATORY FAILURE ANIMAL MODEL. H . Shinohara, K . Ohmori, Y . Zshii, H . Na- tori, 0. Nishimura, M . Ohata, Y . Rikukawa, Y . Sezai, K . Ku- wana, and H. Nakanishi.

We tried the extracorporeal membrane oxygenator (ECMO) in 10 dogs that were divided into two groups with two types of respiratory failure. Group 1 had circulatory and respiratory failure, and group I1 had only respiratory failure. Two or three small parts of the lung were removed every 3 h until the 9th h during ECMO, and were observed by electron microscopy. In group I several maximal changes were recognized in the blood-air barrier, but in group I1 the changes were minimal. Lung biopsy is advisable when it is decided to start ECMO. Key Words: Extra- corporeal membrane oxygenator-Acute respiratory failure- Electron microscopy of the lung-Blood-air barrier.

COMPARATIVE STUDIES ON MEMBRANE OXYGENATORS

(SHILEY 100 A). K . Shio, T . Zenaga, T. Sawamura, C . Kusu- moto, S . Tachibana, M . Okada, K . Nakamura, and S. Matsuda. Jinkozoki 15(2):914-8, 1986.

This clinical study was designed to compare the Shiley M-2000 membrane oxygenator, the Capiox I1 membrane oxygenator, and the Shiley 100 A bubble oxygenator as to blood gas, platelet counts, p-TG changes, and plasma free hemoglobin levels during and after cardiopulmonary bypass (CPB). The following results were obtained. (a) The 0, transfer rate was higher in the membrane oxygenator than in the Shiley 100 A bubble oxygenator, but other blood gas data such as P,co, and pH did not show any significant dif€erence in the three groups. (b) The change of platelet counts before and during CPB was not significantly different among these groups; however, platelet counts increased on the 1st postoperative day in the cases with membrane oxygenators. (c) There were no significant differences in P-TG value and plasma free hemoglobin levels among these three groups. These findings suggested that membrane oxygenators were superior to bubble oxygenator concerning platelet counts, but thereafter, precise differences in hemolysis and p-TG could not be obtained

(SHILEY M-2000, CAPIOX II) AND BUBBLE OXYGENATOR

Art$ Organs, Vol. 14, No. 4, 1990

306 COMMUNICATIONS

in the clinical cases. Key Words: Membrane oxygenator-Bubble oxygenator-cardiopulmonary bypass-Platelet count-Plasma free hemoglobin.

RETROSPECTIVE ANALYSIS OF MULTIPLE ORGAN FAIL- URE CASES; EFFECTIVENESS AND LIMITATIONS OF ME- CHANICAL CIRCULATORY ASSISTANCE. M . Shiono, T. Ha- segawa, A . Miyarnoio, S . Kitamura, K . Kawano, s. Shindo, H . Rikukawa, Y . Orime, Y. Namiki, Y . Sezai, K . Atsumi, I. Fuji- masa, and H . Imachi. Jinkozoki 15(2):5214, 1986.

Retrospective analysis was carried out in IS dead cases of multiple organ failure (MOF) in which the mechanical circulatory assist device was clinically applied, such as with intraaortic balloon pumping and the left ventricular assist device. In conclusion, it was suggested that low-output syndrome and renal failure were the most common causes of MOF and that it might be possible to reduce their incidence by maintaining adequate systemic blood flow by using the heart-lung machine and coronary flow with cold cardioplegic solution. The mechanical assist device had its limitations against MOF that had progressed preop- eratively and intraoperatively . Key Words: Multiple organ failure-Low cardiac output syndrome-Intraaortic balloon pumping-Left ventricular assist device-Mechanical circulatory assistance.

AN EXPERIMENTAL STUDY OF LEFT-HEART BYPASS US- ING LER-HEART-FAILURE MODEL. K . Shiotsu. T . Komoda, A . Shimizu, Y. Kioka, T. Murakami, Y. Senn, S . Teramoio, and S . Takatani. Jinkozoki 15(2):495-9, 1986.

Injection of 5NNaOH into the myocardium of the left ventricular free wall produced myocardial infarction and a left- side-of-the-heart failure model. Bypass of the left side of the heart using left atrial-aortic perfusion with a pusher-plate pump that was operated with a nonsynchronous variable rate was studied using goats. This method was not effective in terms of left ventricular decompression but was effective in terms of total circulatory assistance. Key Words: Left-heart bypass- Pusher-plate pump-Variable rate-Left-heart failure.

LONG-TERM RESULTS IN PATIENTS WITH PACEMAKER IMPLANTATION, ESPECIALLY AS TO MORTALITY. H . Shirakawa, T. Shimizu, H . Aida, J . Matubara, H . Iwanami, S . Sakamoto, Y . Anzai, K . Yuasa, Y. Kaneio, M . Nagasue, H . Hosaka, K . Nariia, T . Toyoda, H . Tikuta, and M . Douniwa. Jinkozoki 15(2):834-6, 1986.

Long-term survival was analyzed in 21 1 cases who underwent pacemaker implantation in our clinic by May 1985. The actual survival rate of all patients was 85% in 5-year follow-up and 79% in 10-year follow-up. The mortality rate in the follow-up period was 16.1% (34 cases). The number of deaths due to cerebral vascular disease was nine (26.5%). The mortality rate with physiological pacing was 7.6% and with ventricular pacing was 22.5%. The mortality rate in the old-age group (older than 70 years of age) was not high compared with that in the younger-age group (younger than 70 years of age). Therefore, pacemaker implantation should be recommended even in the old-age group. Key Words: Long-term survival-Mortality-Pacemaker.

ON IMPROVEMENT OF CHARACTERISTICS OF TEASPOON- TYPE BLOOD PUMP. T. Shiroyama, T. Akamarsu, and H . Fu- kumasu. Jinkozoki 15(2):482-5, 1986.

A nutation-type centrifugal blood pump (teaspoon type blood pump) has been much improved in the configurations of the impeller and annular passage, and the flexible diaphragm-type shaft seal. This pump proved to be of satisfactory performance in the

nonpulsatile mode. Unbalance by nutating motion of the impeller and rod induces vibration, and it results in increase of friction energy-loss. Dynamic balance should be taken into account. Pre- liminary tests showed that this pump had good characteristics in the pulsatile mode. Key Words: Nutation-type blood pump- Centrifugal blood pump-Pulsatile flow by centrifugal pump.

OPEN-HEART OPERATION FOR CASES WITH MULTI- ORGAN FAILURE. K . Soejima, M . Endo, Y . Takanashi, H . Koyanagi, and S . Suzuki. Jinkozoki 15(2):1133-6, 1986.

Open-heart operation in 10 cases with multiorgan failure (MOF) or other organ failure (OF) were performed with a centrifugal pump and LPMSO. OF consisted of renal dysfunction in eight cases, respiratory dysfunction in six cases, blood disorders in four cases, and other causes in three cases. Major postoperative complications were low-output syndrome in 10 cases, renal failure in 4 cases (in which 3 had had renal failure before operation), fatal intracranial bleeding in 2 cases, liver dysfunction in 2 cases, and other causes in 3 cases. Mean duration of tracheal intubation in six cases for preoperative respiratory dysfunction was 5.8 t 5.5 (in all 5.9 * 5.6) days. An average duration of hemoglobinuria in the intensive care unit in all but one with hematuria was 7.1 t 7.8 h. Postoperative values of glutamic oxalic-acetic transaminase, glutamic pyruvic transaminase, lactate dehydrogenase, creatinine, blood urea nitrogen, and platelet count remained almost the same as in preoperative studies, or slightly decreased. These data suggested that extracorporeal circulation using this method could prevent deterioration of OF. Key Words: Cardiopulmonary bypass-Centrifugal pump- Membrane oxygenator-MOF-Open-heart operation.

STUDY OF IMPLANTATION IN GOATS AND MOCK CIRCU- LATION TESTS OF TOTAL ARTIFICIAL HEART (TAH). J . Sono, H . Ogino, M . Hashihira, K . Tatemichi, H . Fukumasu, M . Aota, Y. Tanaka, and S . Yuasa. Jinkozoki 15(2):677-80, 1986.

Seventeen TAHs (Tohmasu heart) were implanted in goats. The longest survival was 8 days (two cases). Fibrin glue was effective in controlling bleeding at atrial suture lines. Cardiac Output of the left side of the heart (LH) was 7.85 L/min by Donnovan’s mock circulation (preload: 10 mm Hg; afterload: 100 mm Hg; percent systole: 30%; heart rate: 120imin). The stroke volume of the right side of the heart (RH) (55 ml) was 85% of that- of LH (65 ml). Thus, our TAH has a good balance between the RH and LH. Key Words: Total artificial heart (TAH)- Donnovan’s mock circulation4oat-Fibrin glue-Balance of two ventricles.

COMPARISON OF HOLLOW-FIBER OXYGENATOR (HFO) AND BUBBLE OXYGENATOR (BO): AN EXPERIMENTAL STUDY OF THE EFFECT OF MICROBUBBLES ON TISSUES. K . Sudoh, H . Makuuchi, Y . Koisuka, T . Takahama, K . Wake, M . Kawauchi, H . Ide, Y. Yokoi, H . Saitoh, A . Sekiguchi, K . Tanaka, K . Asano, and J . Shiga. Jinkozoki 15(2):879-83, 1986.

Currently the hollow-fiber membrane oxygenator (Capiox 11) is being used for -70% of our open-heart operations. No mi- crobubble was detected in the arterial line of this oxygenator by ultrasonic detector, whereas many microbubbles were recorded with the bubble oxygenator. We compared the HFO with the BO as to the effects on blood and tissue microcirculation. Fifteen mongrel dogs were divided into an HFO group and a BO group using a BOS-5 oxygenator. After cessation of perfusion for 2 h, they were observed for further 2 h under artificial respiration. Blood gas, hemogram, plasma free hemoglobin, and AT-I11 were measured for 60 and 120 min during perfusion and for 60 and 120 min after cessation of perfusion. Specimens of lung, heart, kidney, etc. were removed for microscopy to evaluate the effect of microbubbles on tissue microcirculation. Blood gas data did not



differ significantly between groups after perfusion. The platelet count was significantly higher (p < 0.01) in the HFO group at 120 min after the establishment of extracorporeal circulation. Peri- vascular bleeding and edema in the specimen of lung and kidney were found in both groups, but spotty coagulation necrosis in heart muscle was found more often in the BO group. Key Words: Hollow-fiber membrane oxygenator-Bubble oxygenator- Spotty coagulation necrosis of heart.

CLINICAL EVALUATION OF POLYPROPYLENE MICRO- POROUS HOLLOW-FIBER HEMOCONCENTRATOR DURING AND AFTER CARDIOPULMONARY BYPASS (CPB). S. TO- chibana, S. Matsuda, T . Ienaga, T . Sawamura, O . Kusumoro, K . Shio, M . Okada, K . Nakamura, T. Asada, S . Yamamoto, M . Nakao, H. Tsuruta, K . Ogawa, S . Matsumoto, T . Goro, and S . Kurisu. Jinkozoki 15(2): 1047-51, 1986.

The polypropylene microporous hollow-fiber hemoconcentrator (HC-100M) was employed as ECUM to concentrate the circulating blood during CPB (group A) and the blood remaining in the circuit after CPB (group B). Hemoconcentration was effective in two groups, as shown by the elevation of hematocrit value from 23 to 28% in group A and from 26 to 43% in group B. Total protein value, albumin value, and platelet count were also elevated, but the degrees of concentration of these elements were lower than the degree of concentration of hematocrit value, especially in group B. On the other hand, blood urea nitrogen, creatinine, and electrolytes were not concentrated, indicating free passage of these factors through the pores of membrane, but free hemoglobin was thought to be less filterable. These results indicated that this hemoconcentrator was useful for maintaining water balance during CPB and saving the blood in the circuit after CPB. Key Words: Polypropylene microporous hollow-fiber hemoconcentrator-Cardiopulmonary bypass-Cell saver- Dialyzer.

EFFECT OF PLATELET TRANSFUSION IN OPEN-HEART SURGERY ON POSTOPERATIVE BLEEDING. M. Takagi, T . Kugimiya, E. Kusaba, M . Kuroiwa, N . Miyagawa, H. Yamau- chi, and R . Shibata. Jinkozoki 15(2):996-8, 1986.

We have applied blood-component transfusion since 1979 in patients undergoing open-heart surgery for preventing excessive postoperative bleeding. In addition to the use of platelet-rich plasma and cryoprecipitate, we have recently introduced platelet transfusion using the technique of platelet pheresis. The total volume of platelets corresponding to 3,500 ml blood of the adult male, which were obtained from a single donor, was harvested 24 h before the operation and transfused to the patient after cardiopulmonary bypass. By the use of platelet transfusion, the volume of postoperative blood loss and the volume of blood transfusion were significantly reduced. However, an incidence of posttransfusion hepatitis (non-A, non-B type) was not reduced to the level of statistical significance. Key Words: Platelet pheresis- Blood-component transfusion-Cardiopulmonary bypass- Postoperative bleeding-Platelet-rich plasma.

S W L E L ATRIOFEMORAL BYPASS UNDER AUTOMATIC CONTROL. H. Takagi, and M . Hayakawa. Jinkozoki 15(2):504 7 , 1986.

A new blood pump system has been tested in I-atriofemoral bypass in 11 dogs. Their pumping was controlled automatically by changing the pumping rate and the stroke volume according to the preload and the afterload. Results obtained were as follows. (a) no heparin; (b) can be started by anyone, even those un- trained, only by turning the switch on; (c) maintained automatically; (d) bypass rate was 50-90% of normal cardiac output; (e) easier weaning, by simply extracting the inflow duct without reopening the chest; (fj extremely lower cost: (g) easier trans-

portation of the patient. Thus, this simple method may be more convenient and easier for use after cardiac surgery, as same as the intraaortic balloon pump. Key Words: Left-heart bypass- Left-heart assist device.

STUDY ON LONG-TERM NONHEPARINIZED LER-HEART BYPASS (LHB): CENTRIFUGAL PUMP OR ROLLER PUMP. T. Takahama, K . Suma, Y. Takeuchi, K . Inoue, K . Shiroma, Y . Koyama, H. Kaneko, Y. Kohri, and K . Asano. Jinkozoki 15(2): 53640, 1986.

Twenty-four hour LHB was performed experimentally using a centrifugal pump or roller pump, with administration of a prostacyclin analog as a sole anticoagulant instead of heparin. Coag- ulative study was performed. Key Words: Left-heart bypass- Prostacyclin-Centrifugal pump-Roller pump.

AN EXPERIMENTAL STUDY OF CONSTITUTION OF HE- MODILUTED SOLUTIONS FOR CARDIOPULMONARY BY- PASS. M . Takahira, T . Sakairi, Y . Ishibashi, R . Yamazaki, H . Takeda, K . Sakai, and T . Tanabe. Jinkozoki 15(2):977-80, 1986.

We compared three priming solutions: saline, lactated Ring- er’s solution (LR), and acetated Ringer’s solution (AR), in regard to hemodynamics and metabolism in hemodilution for 2-h cardiopulmonary bypass in 18 mongrel dogs. Results were as follows: (a) Hemodynamics: no significant difference between the three groups. (b) Acid-base balance: no significant difference between the LR group and the AR group. (c) Metabolism of lactate: no significant difference between the LR group and the AR group. (d) Percent NEFA: decrease of NEFA release was observed in the AR group (P < 0.05). Key Words: Hemodiluted solution-Cardiopulmonary bypass-Lactated Ringer’s solution-Acetated Ringer’s solution.

ELUCIDATION OF WATER HAMMER PHENOMENON AND ITS REDUCTION IN PULSATILE PUMP. N . Takahiro et al . Jinkozoki 15(2):642-5, 1986.

On the driving pulsatile pump, the water hammer phenomenon occurs in the vicinity of the valves. The water hammer causes valve fracture and hernolysis. We examined how to reduce the water hammer, which we evaluated as maximum pressure gradient across the valve, in an in-vitro mock circulation system with four parameters; valve type, material and shape around the valve, and pump diaphragm thickness. The results were as follows: (a) to employ a polyurethane valve with thick leaflets; (b) to diminish Young’s modulus of material around the valve; (c) to place a Valsalva casp behind the valve, especially in case of employing a polyurethane valve with a thin leaflet. Key words: Water hammer phenomenon-Maximum pressure gradient- Pulsatile pump-Young’s modulus-Valsalva casp.

PROLONGED CIRCULATORY MAINTENANCE WITH A SIN- GLE ARTIFICIAL HEART (SAH). H . Takano, T. Nakatani, S . Fukuda, M . Umezu, H . Noda, S. Adachi, T . Matsuda, H . Iwata, Y. Taenaka, T . Tanaka, S . Takarani, K . Hayashi, T . Nakamura, J . Seki, T. Akutsu, and H. Manabe. Jinkozoki 15(2):592-5, 1986.

Feasibility of prolonged circulatory maintenance with a SAH was studied in 10 goats. When pulmonary vascular resistance was in the normal range (less than 15,000 dyn/s/cm-’/kg) and also right atrial pressure was kept at 10-18 mm Hg, circulation was well maintained. The flow fluctuated between 80 and 120 ml/kg/min and mean arterial pressure was kept above 80 mm Hg. Goats behaved normally but pleural and visceral effusion were noticed after 4 days. Maintenance of the total protein level above 6.0 gidl could delay the appearance of effusion. The longest survival time to date is 32 days. Key Words: Single artificial heart- Circulatory maintenance-cardiac arrest-Pulmonary vascular resistance.

Artif Organs, Vol. 14, No. 4. 1990

308 COMMUNICATIONS

PROBLEMS AND PROGRESS OF TAH STUDY WITH GOATS AND CALVES. S. Takatani, T . Nakatani, H . Takano, T. Tanaka, M . Umezu, S . Adachi, H . Noda, S . Fukuda, T . Mat- suda, H . Iwata, T . Nakamura, and T . Akutsu. Jinkozoki 15(2): 654-9, 1986.

Since 1984, a feasibility study of circulatory maintenance with a pair of pneumatically operated pusher-plate type total artificial heart (TAH) was camed out in 16 goats and 6 calves. Although both goats and calves could stand up by themselves after the pump implantation, the longest survival time was 48 h. The major problems common to both goats and calves include poor lung function, acidosis, volume loss, and peripheral circulatory failure. The blood lactate data revealed that acidosis could be caused either by inadequate pump flow or obstruction of blood flow in the capillary level by white blood cells or microemboli. Key Words: Pusher-plate TAH-Blood lactate-Acidosis- Peripheral circulatory failure.

EXPERIMENTAL STUDY OF VARIABLE-OUTPUT LEFT VENTRICULAR ASSIST DEVICE. G. Takezawa, S. Fukunaga, Y . Hamanaka, and J . Murashita. Jinkozoki 15(2):4869, 1986.

A variable-output device for left-ventricular-assisted circulation has been developed to control bypass flow rate with ease. This bladder-type device has three driving chambers, connected to their own driving tube, which can be driven separately. Thus, three different bypass flow rates are obtained under the same drive-beating rate and the same driving condition. Using a mock circulatory system, this device, with a capacity of 60 ml, can assist 0 . 7 4 8 Wmin at a beating rate of 40-100 beats/min, and another same type of device with a capacity of 90 ml can assist 0.75-6.7 Wmin (40-100 beatdmin). In dog experiments with induced heart failure, hemodynamic change was observed to de- pend greatly on the number of driving chambers. These experiments showed a satisfactory performance in controlling assisted flow rate with ease, making it clear that the variable-output device was the most effective one during the weaning period from left-ventricular-assisted circulation. Key Words: Left ventricular assist device-Variable-output device-Three air-driving chambers-Bladder-type device.

INFLUENCE OF CARDIOPULMONARY BYPASS FLOW ON INTRINSIC PROSTANOIDS. H . Takeda, R. Yamataki, Y. Ishi- bashi, M . Takahira, K . Sakairi, and T. Tanabe. Jinkozoki 15(2):10034, 1986.

Twelve mongrel dogs were divided into two groups: six dogs perfused with 110 ml/kg/min (Gl) arid six dogs perfused with 52 ml/kg/min (G2). They were studied for aspects of circulatory conditions and prostanoids. These conclusions were obtained: (a) There was no significant difference between GI and G2 in either the carotid artery or renal artery flows, but in the femoral artery flow was significantly less in G2 than in G I . (b) Thromboxane, increased significantly in both the carotid and renal arteries in G1 compared with that of G2. These results suggested that less cardiopulmonary bypass flow might bring more favorable conditions for vasoactive prostanoids. Key Words: Cardiopulmonary bypass flow-Intrinsic vasoactive prostanoids.

COMPARATIVE STUDY OF MITRAL VALVE FUNCTION BE- FORE AND AFTER MANOUGUIAN’S AORTIC ANNULUS ENLARGEMENT. K. Tanaka. Jinkozoki 15(2):7124, 1986.

Among 14 cases of AS, 6 had Manouguian’s aortic annulus enlargement performed, and the other 8 had simple aortic valve replacement without annulus enlargement. Echocardiographic

evaluation of mitral valve function using computer analysis showed that there was no significant difference between pre- and postoperative mitral valve function after Manouguian’s operation. Moreover, no significant difference exists between simple AVR and Manouguian’s operation. As for materials, mitral valve function seems to improve with pericardial patches, although that with Gore-Tex patches seems to vary. This may be due to the increased size of the anterior mitral leaflet, and remains to be resolved in the future. Key Words: Mitral valve function- Manouguian’s aortic annulus enlargement.

EFFECT OF m E R L O A D REDUCTION ON MYOCARDIAL RNA SYNTHESIS UNDER LEFT VENTRICULAR BYPASS. S. Tanaka, S . Yamamoto, K . Yamakoshi, and A . Kamiya. Jinko- zoki 15(2):571-4, 1986.

To analyze myocardial adaptive change in response to prolonged left ventricular (LV) pressure reduction, RNA polymerase activity was measured in a purified nuclear preparation from canine heart muscle after 24 h LV bypass using a LV assist servosystem. The ratios of RNA polymerase activity of left to right ventricular muscle decreased as compared with those of control in both Mgz+ and Mn’+-activated reaction. This result suggests that myocardial RNA synthesis would be reduced by prolonged afterload reduction and that myocardial adaptation would progress in an opposite way against the cardiac hypertro- phy process. Key Words: Myocardial adaptive change-RNA polymerase activity-Nucleic acid metabolism-Left ventricular bypass-Afterload reduction.

SPECTROPHOTOMETRY: NONINVASIVE ANALYSIS OF MYOCARDIAL AND BRAIN OXYGEN METABOLISM. M . Tamura, H . Tachibana, S . Takeuchi, Y . Kubo, N . Samejima, and M . Tamura. Jinkozoki 15(2):1142-5, 1986.

Change of myoglobin oxygenation and of oxidation-reduction of cytochrome aa3 in cardiac tissue can be measured by the spectrophotometric method and can be used as optical indicators of both tissue oxygen concentration and energy state. With Lan- gendorff perfusion, the rat cardiac tissue became severely hyp- oxic at a perfusion pressure below 30 cm H,O. In the perfused failed heart, left ventricular unloading caused an increase in intracellular oxygen concentration, and thus improved myocardial metabolism. The degree of hemoglobin (Hb) oxygenation, oxidation-reduction of cyt. oxidase and change in blood volume were noninvasively measured in the rat brain by near-infrared transmission spectroscopy. Oxygenation of Hb in the brain increased almost linearly with increasing 0, in the inspired gas. Above 30% 0, in the inspired.gas, more than 85% of cyt. oxidase was oxidized and below 20% 0,. the oxidase started to reduce sharply. Temporary occlusion of the carotid artery caused a rapid deoxygenation of brain Hb, a large reduction of cyt. oxidase, and a decrease of blood volume in the brain. Key Words: Spectrophotornetry-Intracellular oxygen concentration-Mb oxygenation-Redox state of cyt. oxidase (aa,)-Hb oxygenation in the brain.

EVALUATION OF RESPONSE CHARACTERISTIC OF RATE- RESPONSIVE PACEMAKER BY PHYSICAL ACTIVITY RATE. T. Toyoshima, T . Togawa, T . Tsuji, and K . Suma. Jinko- zoki 15(2):814-7, 1986.

To evaluate rate-responsive pacemakers, heart rate simula- tions of healthy subjects were proposed. The heart rate was simulated from the physical activity rate defined from vertical ac- celeration of the body trunk, and posture was discriminated by mercury angular switches attached at midsternum and thigh. These data and electrocardiography were recorded by a minia-

Artif Organs, Vol. 14. No. 4, 1990


ture data recorder from an unconstrained subject for 24 h. Then the heart rate was simulated by the reproduced data. Key Words: Rate-responsive pacemaker-Physical activity rate-Posture- Heart rate simulation-Unconstrained record.

DEVELOPMENT OF LIQUID OXYGENATOR USING EVA CAPILLARY HOLLOW FIBER FOR ECMO. T . Tsuji. T . To- gawa, M . Okamoto, A . Sueoka, and H . Akasu. Jinkozoki 15(2):95%2, 1986.

Gas exchange across the EVA capillary hollow fiber (CHF) was studied using a heparinless dialyzer (KFlOl, Kuraray) in animal experiments. The extracapillary space was perfused by oxygen-saturated saline solution and CHFs were perfused by venous blood drained from an anesthetized dog. When the pressure difference between intra (Pi)- and extra (Pe)-hollow fiber was kept negative (Pi-Pe < 0) , standard venous blood at the flow rate of 50 mVmin through this dialyzer could be very oxygenated (500 torr) and CO, was removed (10 torr). This EVA liquid oxygenator can be cheaply used for extracorporeal membrane oxygenation without plasma leakage. Key Words: EVAL dialyzer-Heparinless dialyzer-ECMO-Liquid oxygenator.

EXPERlMENTAL STUDIES ON MICROCIRCULATION DUR- ING PULSATILE EXTRACORPOREAL CIRCULATION. H . Tsujiguchi, M . Kawasuji, T . Misaki, T. Magara, F. Kawajiri, E . Ishiguro, and T . Iwa. Jinkozoki 15(2):10214, 1986.

Experimental studies were camed out on the effects of arterial pressure curve, pulsatile or not, on tissue flood flow volume and hemodynamics during and after prolonged perfusion of >3 h. Results were as follows: (a) The arterial blood pressure in septa1 phase during extracorporeal circulation for 3 h with pulsatile flow is maintained >80 mm Hg. However, when non pulsatilic flow is used, it is impossible to maintain the blood pressure >80 mm Hg for longer perfusion than 1 h. (b) The tissue blood flow volume is maintained in very good condition by pulsatile flow for 3 h, but by nonpulsatile flow it decreases gradually with perfusion longer than 60 min. Key Words: Extracorporeal circulation-Pulsatile flow-Nonpulsatile flow-Tissue blood flow volume.

A STUDY ON THE PATHOGENESIS OF LIVER DAMAGE WITH THE ARTIFICIAL HEART ( T A H j T H E EFFECT OF ARTERIAL SIDE. S . Tsukagoshi, H . Sugimura, K . Imachi, M . Nakajima, K . Mabuchi, T . Chinzei, Y. Abe, I . Fujimasa, and K . Atsumi. Jinkozoki 15(2):695-8, 1986.

To examine the effects of the arterial side, such as unphysiological pressure waves, left ventricular bypass (LVB) and TAH were compared regarding the pathological findings of liver. Eigh- teen samples of LVBs were examined and the liver index was significantly smaller than that with TAH, and dilatation of the sinusoid, lipoid degeneration of liver cells around central veins, and fibrin thrombi in interlobular portal veins and central veins were found, but centrilobular necrosis was not found. From these observations, liver damage with the TAH, such as centrilobular necrosis, is not attributable to abnormal hemodynamics of the arterial side. Key Words: Left ventricular bypass-Total artificial heart-Hemodynamics of arterial side-centrilobular necrosis of liver.

RIGHT ATRIAL AND RIGHT VENTRICULAR PERMANENT PACING THROUGH A PERSISTENT LEFT SUPERIOR VENA CAVA. H . Turuta, et al. Jinkozoki 15(2):840-3, 1986.

Pacemaker insertion in a patient with a persistent left superior vena cava (PLSVC) presents many problems, such as dislodge-

ment of the catheter tip, pacing and sensing failure, and thrombosis of the coronary sinus other than difficulty in the insertion of catheter tip. We had two patients with PLSVC who could not be diagnosed as having PLSVC before operation. The anomalous position of the catheter tip made us suspect the presence of PLSVC and it was confirmed by intraoperative angiography . Left subclavian puncture more lateral than usual made catheter insertion easier. Both right atrial and right ventricular pacing were successful with a 60-cm catheter that was inserted via PLSVC. For atrial pacing, a J-shaped wire is not suitable because of difficulty in fixation. Both of the two patients are doing well without any complications. Key Words: Persistent left superior vena cava-Transvenous pacemaker-VVI-DDD.

HYDRODYNAMIC CHARACTERISTICS OF 35 PROSTHETIC HEART VALVES INCLUDING 5 NEWLY DEVELOPED VALVES. M . Umezu, T . Tanaka, N . Fujii, T. Fujita, and H . Mana be. Jinkozoki 15( 2):732-5, 1986.

The in vitro characteristics of newly developed valves were obtained using our ordinary evaluation system to compare them with the previously obtained data. Among the porcine aortic valves, Wessex and Kanton composite valves belonged to the large effective orifice area (EOA) group, whereas INTACT valve ranked next. The configuration of the Xenomedica pericardial valve was different from that of the trileaflet type; dome-shaped bovine pericardium was sandwiched with thin pillars. For the pulse rate of 60-100 beatslmin, this had the biggest EOA among all the valves tested; however, its EOA decreased significantly in tachycardia. We also obtained the water hammer (WH) at the vicinity of valves. WH by the Bjork-Shiley monostrut valve was larger than that by the spherical disk one. As for the biological valves, WHs produced by porcine valves were lower than those by bovine valves. Key Words: Water hammer-Valves-In-vitro performance test-Effective orifice area.

SELECTION OF THE ARTIFICIAL VALVES FOR VENTRIC- ULAR ASSIST DEVICE (VAD) FROM THE VIEWPOINT OF HYDRODYNAMIC BEHAVIORS OF THE VALVES. M . Umezu, T . Tanaka, H . Takano, T . Nagata, K . Tsuchiya, a n d T . A kutsu. Jinkozoki 15(2):6 1 3-6, 1986.

Hydrodynamic data, especially water hammer (WH), for five valves (four disk and one polyurethane) were obtained to select appropriate valves for the VAD pump. The results were as follows: (a) WHs by Bjork-Shiley monostrut [BS(MS)] were higher than those by BS. When BS(MS) was used as an inlet valve, irregular behavior of the disk was observed at low percent- systole conditions. (b) When the disk material was changed from pyrolytic carbon to delrin, W H decreased. ( c ) WHs by Medtronic-Hall were slightly higher than those by BS. (d) Con- duit type trileaflet polyurethane valves developed in our laboratory for VAD use exhibited low WH as compared with disk valves. Key Words: Water hammer-Polyurethane valve- Ventricular assist device-Valve.

GAS TRANSFER PERFORMANCE IN THE SERPENTINE- TUBE MEMBRANE OXYGENATOR. A . Watabe, M . Ujihira, K . Nakano, and K . Tanishita. Jinkozoki 15(2):955-8, 1986.

The secondary flow induced in the serpentine-tube membrane oxygenator with steady and pulsatile blood flow allows augmen- tation of gas-transfer performance as have been seen in our pre- vious studies. However, there is still some uncertainty regarding the effect of geometrical conditions on gas transfer performance in the serpentine tube. In this study, oxygen transfer performance with steady and pulsatile blood flow was investigated in



the serpentine tube with well-defined geometrical conditions such as coiling ratio and circular angle for the curved portion. The results of gas transfer evaluation indicate that the augmen- tation of oxygen transfer can be achieved in fairly wide conditions of nature of blood flow and tubing configurations. Key Words: Blood oxygenator-Serpentine tube-Pulsatile flow.

THE EFFECTS OF LEFT-HEART BYPASS ON CANME MYO- CARDIAL HEMODYNAMICS AND METABOLISM. C . M . Wei, M . Imura, R . Hattori, K . Saito, M . Fukuyama, Z . Yada, H . Yuasa, and M . Kusagawa. Jinkozoki 15(2):596-9, 1986.

Bypass experiments in the left side of the heart (LHB) (left atrium-aorta) were performed in failing hearts of 15 mongrel dogs with use of a centrifugal pump. The LHB flow ratio (LHB flow x 100/LHB flow + ascending aortic flow) vary by 50, 75, and 100% (maximum flow). Coronary sinus blood flow, myocardial oxygen consumption, myocardial blood flow, and right ventricular (RV) Em, were studied before and during LHB. During maximum LHB flow, although significant reduction of left ventricular (LV) movement was obtained, the constriction capability of RV notably decreased because of LV decompression. In conclusion, a 75% LHB flow is appropriate for the balance of two ventricular functions. Key Words: Left ventricular assist device-Coronary sinus blood flow-Myocardial blood flow- Myocardial oxygen consumption-Right ventricular E,,,.

FACTORS INFLUENCING ASSISTED CIRCULATION TIME. M . Yamada, T . Mushiaki, S . Nomoio, K . Znoue, M . Funami, T. Takaba, and J . Ishii. Jinkozoki 15(2):1129-32, 1986.

This study was aimed at examining the factors that prevented patients from being weaned from extracorporeal circulation (ECC). Between January 1982 and May 1985, we performed cardiac operations on 67 patients with valvular disease and on 40 patients with ischemic heart disease. These patients were divided into two groups. Group I was able to be weaned from ECC within 60 min after spontaneous beating. Group I1 was unable to be weaned from ECC within 60 min after spontaneous beating. Preoperative severe heart failure, prosthetic valve malfunction, pulmonary edema, and penoperative myocardial infarction were regarded as the factors preventing patients from being weaned from ECC within 60 min. In conclusion, to be weaned from ECC, a more suitable assist device, accurate surgical procedure, and myocardial protection are necessary. Key Words: Weaning from extracorporeal circulation-Assist device-Perioperative myocardial infarction.

COMPLICATIONS OF PERCUTANEOUS INSERTION OF IABP. M . Yamada, T. Watanabe, H . Yokokawa, K . Znoue, M . Funami, N . Yamamoto, T . Takaba, J . Zshii, and H . Gotoh. Jinkozoki 15(2):525-8, 1986.

For the past 4 years, 47 patients were treated with the intraaortic balloon pump (IABP). In 39 patients the balloon was inserted through the femoral artery surgically (using open cannulation). Another eight had insertion of a percutaneous IABP (Kontrol 12F double-lumen balloon catheter) in the femoral artery. In six of eight patients the balloon was surgically removed. Thrombus was found in two patients, and leg ischemia because the femoral artery was compressed by the balloon catheter was found in one patient. Although insertion of a percutaneous IABP is an effective method in case of emergency, it is better to reinsert surgically or at least inspect the femoral artery with a Fogarty catheter on removal of the IABP. Key Words: Percutaneous insertion of IABP-Leg ischemia-Anticoagulant therapy-Fogarty catheter.

CINEFLUOROSCOPIC EVALUATION OF AVR WITH THE OMNISCIENCE VALVE. 0. Yamada, T . Kazui, N . Watanabe, T . Tanaka, T. Sasaki. and S . Komatsu. Jinkozoki 15(2):72131, 1986.

Cinefluoroscopic evaluation and hemodynamics of 48 patients who underwent aortic valve replacement with the Omniscience valve was reported. With a tangential view of the Omniscience valve in the opened position, the maximum opening angle of the occuluder was measured. The maximum opening angle of the Omniscience valve of 80” was obtained in 56.3% of cases. In 16.7% of the cases, an opening angle of 30-45” was obtained and these tended to be high in the incidence of thromboembolism. In our series, no obvious correlation could be noted between the maximum opening angle and atrial fibrillation or hemodynamics. Key Words: Cinefluoroscopy-Omniscience-Maximum opening angle-TEA.

AN APPLICATION OF UNIPOLAR DUAL-CHAMBER PACE- MAKER TO SINGLE-CHAMBER PACING. S. Yamagata. Jinkozoki 15(2):85742, 1986.

Recent published studies have reported on the clinical disad- vantages of unipolar versus bipolar pacemaker configuration with regard to susceptibility to skeletal myopotentials, muscle twitching, flexibility, redundancy, etc. However, in Europacing- 85, we have presented a unique, unipolar, single-chamber pacing system with dual mode that automatically changes to VVI or VVT according to the level of the input signals and that could overcome the proposed superiority of the bipolar VVI pacing system. Key Words: Dual-chamber pacemaker-Multipro- grammability-Oversensing-Skeletal myopotential.

CLINICAL EXPERIENCE WITH A NEW MODULAR BUBBLE OXYGENATOR (HI-FLEX D700). M . Yamagishi, K . Soejima, S. Fukuchi, M . Kitamura, H . Tokunaga, M . Endo, A . Hashimoto, H . Koyanagi, S. Suzuki, S . Kazama, and A . Sasaki. Jinkozoki 15(2):106&71, 1986.

A new modular bubble oxygenator (HI-FLEX D700) consists of a heat exchanger, arterial blood reservoir, and five blood/gas mixing chambers (modules), which allows individual adjustment to the actual blood flow rate and can limit the prime volume according to a patient’s body weight. In-vitro experiments to measure its efficacy of gas exchange and heat-exchanger performance were carried out with favorable results. Clinically, this oxygenator was used in 37 adult cases of open-heart surgery. It provided adequate 0, and CO, transfer with four or five modules open. Compared with the BOS-IOS oxygenator in blood trauma, there was no significant difference between the two groups. These results were satisfactory for clinical use, especially for clear-priming cardiopulmonary bypass for low-body-weight adult cases. Key Words: Modular bubble oxygenator- Cardiopulmonary b y p a s s x l e a r priming-Blood trauma.

CLINICAL EVALUATION OF EXTRACORPOREAL CIRCU- LATION WITH AND WITHOUT DONOR BLOOD PRIMING. A. Yamaguchi, M . Saso, M . Otaki, C . Nojiri, T . Minoji, H . Tamura, M . Atobe, and N . Kitamura. Jinkozoki 15(2):9814, 1986.

Extracorporeal circulation (ECC) without blood priming in open-heart surgery was studied to evaluate preoperative hematocrit, body weight, ECC time, amount of blood transfusion, shift of hematocrit during ECC, and post-BTF hepatitis. The following results were obtained: (a) There were no signifcant differences between the three groups as to preoperative hematocrit and body weight. (b) ECC time is the most important factor for possibility of non-blood-priming ECC. (c) Non-blood-priming

Art$ Organs, Vol. 14, No. 4, 1990

COMMUNICATIONS 311

ECC made it possible to decrease the BTF volume and the oc- currence of post-BTF hepatitis. Key Words: Non blood priming-Blood priming-Post-BTF hepatitis-Preoperative hematocrit-Preoperative body weight.

USEFULNESS OF REUSING CONCENTRATED PRIMING BLOOD BY ULTRAFILTRATION IN CARDIAC SURGICAL PATIENTS. T. Yamakawa, K . Nishimura, H . Goto, and Y. Miyauchi. Jinkozoki 15(2): 1043-6, 1986.

Effects of the hollow-fiber hemoconcentrator on conserving blood and removing excess body water during cardiopulmonary bypass were studied. Among 108 patients, hemofiltration was used in 30 patients (HF group) during cardiopulmonary bypass. In the remaining 78 patients, hemofiltration was not used (non- H F group). In the HF group, the amount of intraoperative blood transfusion, postoperative weight gain, and incidence of posttransfusion hepatitis were less than those in the non-HF group. These results suggest that hemofiltration may be of value for preventing posttransfusion hepatitis and accumulation of excess body water in cardiac surgical patients. Key Words: Hemofiltra- t i o n x a r d i a c surgery-Cardiopulmonary bypass.

COMPARATIVE STUDY BETWEEN A BUBBLE TRAP AND ARTERIAL FILTER IN THE MEMBRANE OXYGENATOR SYSTEM. S. Yamamoto, T . Asada, M . Nakao, H . Tsuruta, and K . Ogawa. Jinkozoki 15(2):1122-5, 1986.

To prevent embolism during cardiopulmonary bypass with a membrane oxygenator, a bubble trap or an arterial fdter is used. In this study we compared a bubble trap with a filter in the arterial line from the points of view of blood injury and micro- embolism. In group 1 (15 cases), the system consisted of an arterial filter (40 pm) and a membrane oxygenator. In group 2 (22 cases), the system consisted of an arterial bubble trap, a membrane oxygenator, and a filter (40 pm) in the suction circuit. During and after bypass, hematologically, histologically, and clinically no significant difference was found between the two groups. However, the system in group 2 is recommendable because it is much easier to prepare. Key Words: Microemboli- Extracorporeal perfusion-Membrane oxygenator system- Arterial filler-Bubble trap.

LONG-TERM EVALUATION OF VALVE REPLACEMENT IN THE AORTIC POSITION WITH SMALL PROSTHESIS. N . Ya- masaki, M . Kimura, K . Shikano, M . Okabe, T . Mizutani, I . Yada, H . Yuasa, and M . Kusagawa. Jinkozoki 15(2):715-8, 1986.

Late results and hemodynamic function with the aortic valve less than 21 mm long was evaluated in 18 patients (valve no. 19: B-S2, no. 21: B-S9, 0 3 5 , SJM2). The late death of two patients with no. 19 valves was valve dysfunction and congestive heart failure. The cardiac output and the simultaneous transvalvular gradient were recorded at rest and during exercise. A SJM prosthesis had a low pressure gradient and a wide effective orifice area. The valve less than 21 mm had a high systolic gradient during exercise. The aortic replacement of a 21-mm valve should have a body surface area no greater than 1.5 m2. An aortic valve 23 mm or longer should be considered for long-term use. Key Words: Aortic valve replacementSmal1 prosthesis-Small aortic annulus-AVG-AVA.

CLINICAL RESULTS WITH THE ST. JUDE MEDICAL VALVE PROSTHESIS: A 5-YEAR EXPERIENCE. M . Yamashita, H . Saigenji, H. Ohzono, S . Shimokawa, T . Yuda, H . Toyohira, K . Arikawa, Y. Morishita, M . Maruko. and A . Taira. Jinkozoki 15(2):802-5, 1986.

Two hundred eighteen patients underwent valve replacement with the St. Jude Medical prosthesis. Early mortality was 10.6%, and the actuarial survival rate at 5 years was 79.2%. Valve- related complications occurred in 4.8% per patient-year, thromboembolism occured in 2.6%. and prosthetic valve endocarditis occurred in 0.7%. There were no instances of primary mechanical failure, but a thrombosed valve occurred in one patient, paravalvular leakage occurred in another, and hemolysis occurred in five. Although the hemodynamic performance and durability was satisfactory, intensive follow-up seemed to be necessary for preventing valve-related complications. Key Words: SJM valve-Thromboembolism-Prosthetic valve endocarditis-Hemolysis.

A BASIC STUDY ON CARDIOPULMONARY BYPASS, WITH

TIES ANALYZED BY TRANSITION OF COMPLEMENT LEVEL. M . Yamazaki et al. Jinkozoki 15(2):972-6, 1986.

Transition of the serum complement level was determined in 20 cardiac patients undergoing cardiopulmonary bypass, for better understanding of unphysiological entities in this artificial perfusion. No significant difference was noted in C3, C4, C5, or CH50 level between the membrane and bubble oxygenator groups. The C3a level in the bubble oxygenator group tended to be higher than that in the membrane group. The higher level in the former group was more prolonged than in the latter. Eleva- tion of the C5a level and neutropenia induced during cardiopulmonary bypass with the membrane oxygenator was more dom- inant than that induced with the bubble oxygenator. In conclusion, the following would be suggested: (a) C3a level is more intensively affected by the blood-xygen interface than the blood-material interaction, and (b) C5a level and neutropenia are more strongly affected by the blood-material interaction than the blood-xygen interface. Key Words: Cardiopulmonary bypass- Complement activation-Blood-oxygen interface-Blood- material interaction.

SPECIAL REFERENCE TO THE UNPHYSIOLOGICAL ENTI-

COMPARISON BETWEEN SILICONE AND POLYPROPYL- ENE HOLLOW-FIBER OXYGENATOR-EXPERIMENTAL AND CLINICAL STUDIES. R . Yamazaki, Y . Ishibashi, T. Sa- kairi, M . Takahira, H . Takeda, K . Sakai, and T. Tanabe. Jinko- zoki 15(2):108&7, 1986.

The silicone hollow-fiber oxygenators (group M) were used in elective cardiopulmonary bypass experimentally and clinically. They were compared with polypropylene hollow-fiber oxygenators (group C) regarding aspects of circulatory conditions, blood gas analysis, and blood components. These conclusions were obtained: (a) There were no significant differences between group M and group C in circulatory conditions and blood gas analysis. (b) Free hemoglobin increased significantly in group C, compared with that of group M. (c) Morphological changes of platelets observed by the scanning electron microscope in group M showed intermediate-type platelets in active stage. Key Words: Cardiopulmonary bypass-Silicone hollow-fiber oxygenator-Polypropylene hollow-fiber oxygenator.

HEMODYNAMIC EVALUATION OF VARIOUS PROSTHETIC

SOUND. H . Yanagi, M . Shigenobu, T. Murakami, S . Nawa, Y. Senoo, and S. Teramoto. Jinkozoki 15(2):80&9, 1986.

There were some patients who showed extremely less left ventricular (LV) end-diastolic volume during exercise than that at rest in patients who had impaired LV function. Some patients who had signifcant pressure gradient across the prosthesis at rest tended to show impaired L V function during exercise. It

VALVES IN MITRAL POSITION USING DOPPLER ULTRA-



could be considered that prosthetic stenosis resulted in impaired LV function during exercise. Key Words: Mitral valve replacement-Valve function-Doppler ultrasound-LV function- Prosthetic stenosis.

PUMP OXYGENATOR FOR INFANTS. T . Yokosawa, H. Ohzeki, H . Okazaki, M . Nakagomi, H . Moro, and S . Eguchi. Jinkozoki 15(2): 863-6, 1986.

The experimental study of a small-size pump oxygenator newly designed for infants was performed. Capiox I1 08 was used as a oxygenator, and PKS-Kidney was employed as a roller pump. Mongrel dogs, weighed &5 kg, were subjected to cardiopulmonary bypass using this pump oxygenator for 3 h. The priming volume was 300 mi, and 140 ml of blood as we11 as 60 ml of additive drugs had to be given to the lines during 3-h cardiopulmonary bypass. One hundred milliliters of uncollected cardioplegic solution was included in the circulating volume. This small- size pump oxygenator especially designed for cardiac surgery in neonates and small infants is sufficient for 3 h of cardiopulmonary bypass with 300 ml of priming volume, but in clinical use it is safe to add some extra volume to the prime. Key Words: Pump oxygenator-Infant-Priming volume-Cardiopulmonary bypass.

CLINICAL STUDY OF EXTRACAPILLARY BLOOD FLOW

ATOR. H . Yokoyama, A . Sasaki, S . Kikuchi, N . Inoue, T . Ka- zui, and S. Komatsu. Jinkozoki 15(2):897-901, 1986.

This new type of hollow fiber oxygenator, in which blood flows outside of capillaries, has the characteristics of lesser num- bers and large bore size of microporous polypropylene fibers. Not only a low prime volume (480 ml) but also a wide blood flow range (1-7 L/min) provide suitability for a large patient population. In a clinical study of 30 patients, this lung provided adequate 0, and CO, transfer without time-dependent deterioration in performance. No deleterious hematologic consequences were observed because of low surface membrane area that might decrease blood-material interaction. The platelet index (platelet countshematocrit) was not significantly decreased during bypass, and the plasma-free hemoglobin increasing rate was 0.33 & 0.22 mg/dl/min, which was low enough to maintain a stable serum haptoglobin value. The roller-pump pulsatile flow is an effective alternative of the pulsatile assist device because of a low transmembrane blood phase pressure gradient. An experimental pumpless arterial-venous shunt extracorporeal membrane oxygenator (ECMO) disclosed stable oxygenation capability during 13 h. The present study indicates that the new type of membrane oxygenator would be suitable for clinical application. Key Words: Maxima microporous hollow-fiber membrane oxygenator- Extracapillary blood flow type-Transmembrane pressure gradient-Pumpless A-V shunt ECMO-Membrane surface area.

TYPE ‘‘MAXIMA” HOLLOW-FIBER MEMBRANE OXYGEN-

FUNDAMENTAL STUDY ON STRESS IN THE MECHANICAL VALVE. T. Yuhta, S. Igarashi. and Y. Mitamura. Jinkozoki 15(2):773-6, 1986.

To obtain fundamental data for design of an ideal valve, stress of circular plates under blood pressure was analyzed and was calculated numerically for two cases: (a) outer edge is fmed, and (b) outer edge is simply supported. Results are as follows: The maximum radial and tangential stress for simply supported cases are larger than that for fixed cases. The maximum value of the annular plate is approximately three times as large as that of solid circular plates. Maximum tangential stress for annular plate appears at the inner edge, and the maximum value is dependent on the ratio of the diameters of the hole and of the plate. Key Words: Mechanical valve-Maximum tensile stress-Disk valve- Brittle material-Fracture.

CLINICAL EXPERIENCE WITH THE NEW MEMBRANE OX- YGENATOR “SHILEY M-2000.” K. Yukio, K . Kageharu, I . Fu- gio, I . Kiyoshi, U. Tadaoki, A . Mituru, S . Hiroshi, K . Akira, S . Masaaki, and K . Takashi. Jinkozoki 15(2):90&9, 1986.

A new parallel-plate oxygenator “Shiley M-2000,” was used on 10 patients, and was compared with the bubble oxygenator (William Harvey H-1700) as to (a) blood gas exchange (0, transfer rate, CO, transfer rate), and (b) protective effects against blood injuries, hemolysis. Our clinical study shows the superiority of the “Shiley M-2000” over the William Harvey H-1700 bubble oxygenator, especially of the CO, transfer rate (171.0 mumin) and the plasma-free-hemoglobin-producing rate (0.84 mg/dl/min). Our data show that the Shiley M-2000 oxygenator is one of the artificial lungs with the most satisfactory results in present use. Key Words: Parallel-plate oxygenator-Bubble oxygenator-Blood gas exchange-Plasma-free-hemoglobin- producing rate-Hemolysis.

Society News

New Board of Trustees Members

Brunner, Gorig, M.D. Dr. Brunner was born in Kassel, Germany in 1939. He studied medicine in Erlangen, Oxford, and Hamburg. He was a post- doctoral fellow of the Deutsche Forschungsgemein- schaft at the Institute of Physiological Chemistry, University of Munich under Prof. Th. Bucher; sci- entific assistant at the Department of Medicine, University of Gottingen under Prof. Dr. W . Creutzfeldt; Habilitation for internal medicine at the University of Gottingen; research visitor to the Department of Biochemistry at the University of Michigan; Associate Professor at the Department of Medicine, Division of Gastroenterology and Hepa- tology , and University Medical School, Hannover. Dr. Brunner became a full professor of internal medicine and the head of the Artificial Liver Re- search Unit in 1980. He has 154 international pub- lications in gastroenterology and hepatology to his credit.

Chang, Thomas Ming Swi, M.D. , Ph.D. In addition to being the director of Artificial Cells and Or- gans Research Centre at McGill University, Mont- real, Dr. Chang is also professor of physiology, fac- ulty of medicine; professor of medicine, Royal Victoria Hospital; career investigator, Medical Re- search Council of Canada; associate, Department of Chemical Engineering, and Associate, Department of Chemistry, at McGill University. Dr. Chang was the inventor of artificial cells, and his research in- terests include laboratory research and clinical tri- als in artificial cells, artificial kidney, artificial liver, detoxification, enzyme therapy, microencapsula- tion, biotechnology, immobilized enzymes and co- factors, animal model for fulminant hepatic failure, uremic toxins, hepatic toxins, blood-compatible

Artif Organs. Vol. 14, No. 4, 1990

abstracts from the japanese journal of artificial organs (jinkozoki) published by the japanese...

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