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[in Japanese]
1991 Volume 20 Issue 3 Pages
661
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
JOURNAL
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H. TANAKA, M. FUNAMI, T. TAKABA, S.g. KOVACS, L.e. ONDROVIC, M. AIBA, ...
1991 Volume 20 Issue 3 Pages
663-665
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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A magnetically actuated left ventricular assist device which has small size and simple mechanism has been developed. This device consists of 4-main subassemblies. 1) actuator (size 32.5cm
3, weight 312g). 2) magnetic pusher-plate diaphragms. 3) pump-chamber with valve parts. 4) interface mount. Pumping force is generated by an electromagnetic actuator whose (magnetic flux) core is centered on the axis of the rare-earth permanent magnet, which in turn is centrally mounted on the pump pusher-plate diaphragm. This device's hydraulic power is 7.8- 11.2 watts. Using Mock loop model, this pump generates 3.2-5.8 1/min out put with 120mmHg afterload and 8-12mmHg preload when heart rate was changed from 80 to 120 bpm.
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S FUKUNAGA, Y HAMANAKA, T SUEDA, S HAYASHI, T ITOH, H ISHIHARA, Y MATS ...
1991 Volume 20 Issue 3 Pages
666-669
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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An artificial heart was made and modified toward a totally implantable use and tested on Donovan mock circulation. The artificial heart was assembled with a pendulum swing pusher and lenticular sacs of polyurethane rubber. A geared brushless do motor drived the link member followed by the pendulum swing motion of the pusher inside the artificial heart. The sacs were pushed alternately through the pendulum swing motion of the pusher. Percent systole of the driver was fixed at 50% for both sacs. The systole and diastole phase of left and right sacs was inverted each other. The pusher and each sac was tied by small tab to energize active filling function. The artificial heart derived 83% of the sac volume at preload of OmmHg against 100mmHg afterload. The artificial heart worked at driving rate of 110bpm with flow rate of 6.2L/min through mock test. Observed efficiency of the artificial heart was 24-32% at that time.
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T SONOBE, S NITTA, Y KATAHIRA, T YAMBE, S NAGANUMA, H AKIHO, H HAYASHI ...
1991 Volume 20 Issue 3 Pages
670-675
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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In order to develop a new totally implantable artificial herat using vibrating electroagnetic pump (VEMP) which generates flow with the frequency of 1-30 Hz, effects of VEMP drive on hemodynamic parameters were examined. Hemodynamic properties during VEMP drive were evaluated in the frequencys of 5, 10 and 20 Hz using adult goats in 10 acute experiments. This pump acted very well as a left ventricular assist device in any kinds of frequency in the satisfied physiological condition. These results suggest that the VEMP is useful for a totally implantable assist device or a total artificial heart.
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T TAKEUCHI, T BAN, Y OKAMOTO, H OKABAYASI, T AKAMATSU, T SHIROYAMA, K ...
1991 Volume 20 Issue 3 Pages
676-679
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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This study was performed to examine the efficacy and safety of “tea spoon pump” in vivo experiments as the bridge use for profound left ventricular failure. Six male sheep, weighing 48 to 80 kg were used in this study. Four sheep were used for totally assisted circulation. The entire circulation was easily maintained (>4L/min), and blood cell trauma was subtle in all cases. But some problems were observed; 1) When the ventricular fibrillation occured in the severe hypovolemic status, the drainage was found inadequate. 2) All sheep in totally assisted circulation could not keep the standing position postoperatively. (The values of serum GOT, GPT, and creatinine increased after assist circulation began.) Only the last case, in which tea spoon pump was used as the partially assisted circulation, could keep the standing position postoperatively. We suspected that we should reexamine the limit of non-pulsatile assist alone for the left ventricle assist device.
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E OKAMOTO, T MIKAMI, Y MITAMURA
1991 Volume 20 Issue 3 Pages
680-686
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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A totally implantable assist heart system has been developed and evaluated in vitro. The system consists of two subsystems; a DC brushless motor-driven assist heart and a transcutaneous energy transmission system. The motor-driven assist heart utilizes a ball-screw to convert highspeed rotary motion into low-speed rectilinear motion. The specially designed miniature ball-screw has been developed to reduce the volume of the pump. The volume of motor-driven pump is 312ml and that of a controller 330ml. The motor-driven artificial heart actuator can be used for both total hearts and an assist heart by changing attachments. The transcutaneous energy transmission system has transcutaneous optical information transmission system to transmit secondary output voltage signal and pump stroke signal. The totally implantable assist heart system was characterized in vitro. The transcutaneous energy transmission system transmitted power of 14W to the motor-driven assist heart system. Pump outflow of 4.6l/min was obtained against the afterload of 110mmHg at the drive rate of 80bpm with efficiency of 13.5%.
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S NITTA, S NAGANUMA, Y KATAHIRA, T YAMBE, T SONOBE, H AKIHO, M TANAKA, ...
1991 Volume 20 Issue 3 Pages
687-692
Published: June 15, 1991
Released on J-STAGE: December 02, 2011
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Newly developped total VAD, which is more practical and proper for farmass-production, have been evaluated. This new VAD system is parted into the sac and outer case, inflow and outflow cannulae, and their prosthetic valve built in connectors. Therefore, when we find the partial accident in VAD system, we can exchange only the accidental part. We developed 2 kinds of connector: one is Hjork-Shiley valve (BS v), and the other is our originary fabricated silicon ball valve. Durability test in the mock circulation and chronic animal experiments using adult goats were performed. The results shows that our VAD system has good property of hydrodynamics and antithrombogenecity and durability. We conclude that our VAD system can be useful for clinical application.
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H. HAYASHI, S. NITTA, Y. KATAHIRA, T. YAMBE, T. SONOBE, S. NAGANUMA, H ...
1991 Volume 20 Issue 3 Pages
693-698
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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Characteristics of a pressure microsensor for automatic control of ventricular assist device (VAD) have been evaluated. The sensor consists of a Pyrex glass cover and a silicon chip. This absolute pressure sensor has high stability because of the four resistors diffused into the diaphragm. The sensor is built in outflow cannula which is sustained with thin membrane of anti-thrombogenic material together with surface of cannula. After 60 days VAD drive in the moo circulatory loop, satisfactory stability and performance were shown. This result indicates the possibility of the clinical application of this pressure sensor in cannula for VAD.
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K. IMANISHI, K. IMACHI, Y. ABE, T. CHINZEI, K. MABUCHI, T. YONEZAWA, I ...
1991 Volume 20 Issue 3 Pages
699-704
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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As the second step in a project to develop a totally implanta-ble artificial heart at Tokyo Universitya modified type of pneumatically driven blood pump was designed for implantationinside the chest, The blood pump was consisted of two atrial cuffs, four newly designed Jellyfish valves and two sac type ventricles as one body. So quick connectors for attaching an atrial cuff and blood pump could be omitted, To implant this blood pump in a goat's chest cavity, we applied the surgical procedureof heart transplantation, The blood pumpwas easily implanted using this technique and it fitted well in the goat's chest cavity. The results promise-dapplicability in the clinical field.
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K. YAMAZAKI, M. KITAMURA, A. SHIIKAWA, K. EISHI, A. KAWAI, C. NOJIRI, ...
1991 Volume 20 Issue 3 Pages
705-710
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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We have recetly developed an intraventricular axial flow blood pump as an implantable left ventricular assist device. The system consists of a 14mm diameter, 10cm long outlet cannula, a motor rotor with a spindle impeller, an electric motor, and a drive cable. This pump is introduced through the LV apex, then passed antegrade across the aortic valve. Blood is withdrawn from LV through the inlet ports at the pump base, and discharged to the ascending aorta through the outlet cannula. The tip of the outlet cannula tapers off for ease of insertion. The motor is flanged to the pump base and placed at the LV apex and, therefore, fully implantable in the thoracic cavity. The pump flow of more than 2L/min at 4 volt output voltage against 100mmHg afterload was easily obtained in the mock circulatory system. The pump was tested in 10 dogs (11-20Kg) and showed an efficient circulatory assistance in an acute failing heart model. At autopsy there was no detectable injury to intracardiac structures including aortic and mitral valve leaflets. These results suggest that this simple and compact axial flow blood pump can be a potential LVAD with prompt accessibility and less invasive surgical procedure than existing large VADs.
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Katsuhisa ONOGUCHI, K. KAWADA, R. YOZU, [in Japanese], R. TAKAHASHI, H ...
1991 Volume 20 Issue 3 Pages
711-714
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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In the past 3 years, we have used a shunt tube procedure for the surgical treatment of 18 patients with thoracic aortic aneurysm. In this study we tried to determine the risk factors that affect cardiac function. Considering two hypotheses: 1) ST-T change on ECG during and after the shunt tube procedure, 2) Persistent cardiac index decrease (CI<2.01/min/m
2) during the shunt tube procedure, we found two statistically valuable risk factors. One was age over 65, and the other was coronary artery disease. Under this experiences, we employed another supportive measure using a Bio-pump for 17 patients, We could easily maintain hemodynamics by controlling the preload or the afterload. But we must take care about the heart failure when weaning from the left heat bypass procedure and the tendency of the decreasing diastolic pressure when using the aortic bypass performed between ascending aorta and femoral artery.
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K IKEUCHI, H KAZUI, M HOSAKA, M KONDO, T OHTA, H NOGAKI, Y NAGATA, R K ...
1991 Volume 20 Issue 3 Pages
715-720
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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Ten dogs were examined for descending aorta clamping with veno-arterial bypass using a centrifugal pump without an oxygenator. A bypass route was made between the SVC and the femoral artery. A control study by left heart bypass between the left atrium and the femoral artery was done in 5 dogs. Aorta clamping time was set at 2 hours. All dogs survived 1 to 2 weeks and were sacrificed for laboratory data. In the venoarterial bypass group, PaO
2 and O
2 saturation of perfusion blood were low compared with the left heart bypass group, but there were no complications, and postoperative laboratory data were not significantly different from those of the control group.
We experienced 2 clinical cases of descending aortic surgical procedure with simplified veno-arterial bypass during aorta clamping. There were no complications due to this assist circulation, and postoperative courses were uneventful.
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DEVELOPMENT AND EXPERIMENTAL STUDY OF FLOW
B OSHIYAMA, T KUROO, A NOGAWA, B FUKASAWA, K BORIUCHI, T KIJIMA, H SHI ...
1991 Volume 20 Issue 3 Pages
721-726
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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We evaluated the flow dynamics of our newly developed venous cannula designed for percutaneous V-A bypass. The cannula is made of 18 Fr. polyester elastomer. It is O. D. 6.0mm, I. O. 5.2mm, and 50-60cm long which is long enough to reach the right atrium through a femoral vein approach. It has side holes to assure low pressure drop. In vitro tests were performed to evaluate the flow rate and pressure drop of the venous cannula as well as the flow rate of each side hole. The results indicated that: a) possibility of side holes designed by the draining distribution, b) percutaneous intubation of the cannula was smooth and assured low pressure drop, and c) draining volume from the vena cava was sufficient.
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H. SATOH, T. KOBAYASHI, Y. FUDEMOTO
1991 Volume 20 Issue 3 Pages
727-731
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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Five patients with cardiogenic shock following coronary bypass surgery were treated with LVS. IABP was used combined with LVS in all patients. Three patients were weaned from LVS, and 2 patients are long-term servivors for 9 and 25 months. One hospital death occurred later (30 days) from low cardiac output and renal failure. LVS flow were maintained at 3-4 L/min. Pump flow capacity with various sizes of cannulae were evaluated using mock circulation for the development of the percutaneous LVS cannula. A sufficient flow (3-4 L/min) was obtained in the system with smaller cannulae. (ID 5-6 mm) and CFP. The percutaneous LVS system with CFP may be developed with use of these size of cannulae.
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Hidemiki SASAKI, Takeshi SHIMIZU, Shigeru SAKAMOTO, Yoshiyuki KANETO, ...
1991 Volume 20 Issue 3 Pages
732-735
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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To clarify the effectiveness of ventricular pressure-volume loops in determining indication, weaning, and setting of a proper drivin condition of Ventricular Assist Device (VAD) after cardiac surgery, we designed two experimental goat models of Left Ventricular Assist Device (LVAD) composed of a diaphragm type of blood pump and an electrohydraulic linear actuator. Using a Baan's Conductace Catheter, we obtained left ventricular pressure-volume (LVPV) loops in CRT monitor. Preload reserve and afterload matching of left ventricular performance were evaluated by LVPV loops during increase in afterload caused by aortic partial cross-clamping. Under various conditions of LVAD, pressure-volume loops of LVAD and LVPV loops of native heart were obtained simultaneously. By means of the multiple regression analysis, the stroke volume of LVAD which is the independent variable of the analysis was determined by the independent variables of driving rate, upper duty, lower duty and %systole of LVAD. The opening time of cardiac valves of native heart were revealed by ejection and dilatation periods of LVPV loop. From these results, it was suggested that LVPV loops of native heart obtained by Baan's Conductance Catheter is a reliable guide to determine indication, weaning, and setting of driving condition of LVAD.
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T MURAKAMI, K ISHINO, H NAKAYAMA, Y NAKAYAMA, K KINO, Y YAMAMOTO, Y SE ...
1991 Volume 20 Issue 3 Pages
736-740
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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Seven patients with postcardiotomy shock were supported with the ventricular assist device. Six patients required left ventricular support and one received biventricular assistance. Duration of support ranged from 4.5 to 9 days (mean length, 6.1 days). All patients were weaned from the deviceand 3 were discharged. Common complications were bleeding in 3 patients, septicemia in 3, renal failure in 3 and ileus in one. Factors affecting survival were renal failure and systemic infection.
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NEW LEFT VENTRICULAR ASSIST SYSTEM
Y SHIMOYAMA, R YOZU, S KAWADA
1991 Volume 20 Issue 3 Pages
741-745
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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A new, simple, left ventricular assist system has been developed and its use in animals evaluated This system allows for ventricular drainage via transaortic valve cannula introduced percutaneousely. The system utilizes a centrifugal pump and can achieve a flow rate about 1.0l/min/m
2for patients and maintains good cardiac support for dogs suffering from left ventricular failure. The most ramarkable effect of this system is its left ventricular decompression in such dogs. However, total circulatory assistance cannot be obtained for clinical applications. This new, simple system is considered to take a middle position between intraaortic balloon pumping and the device for total left ventricular assist.
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E SASAKI, T NAKATANI, H TAKANO, Y TAENAKA, E TATSUMI, H AKAGI, H SEKII ...
1991 Volume 20 Issue 3 Pages
746-751
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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We have built a new drive unit (VCT200) which can drive both IABP and LVAS in the same way as separate units. And we devised a new weaning method, Alternate Synchronous Driving (ASD), to wean from LVAS to IABP smoothly. ASD was installed in VCT200 to be applied easily and automatically. After IABP insertion in the final weaning stage, ASD drives LVAS and IABP alternately, with electrocardiogram synchronization. The pumping ratio of IABP increases while that of LVAS decreases according to the recovery of natural heart function. In vitro and in vivo studies, ASD was effective method to prevent hemodynamic deterioration during final weaning from LVAS and overlap in pump ejection and balloon inflation.
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To obtain maximal augmentation of cardiac function on cardiomyoplasty with latissimus dorsi in acute heart failure state
T TSUKUBE, M OKADA, T MUKAI, Y TSUJI, M YOSHIDA, M MORIMOTO, K NAKAMUR ...
1991 Volume 20 Issue 3 Pages
752-755
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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Experimental studies on latissimus dorsi cardiomyoplasty. To obtain maximal augmentation of cardiac function on cardiomyoplasty with latissimus dorsi in acute heart failure state, experimental studies were performed using 24 mongrel dogs. First of all, adequate stimulation mode were evaluated by ejection fraction on left ventriculogram and improvement of arterial pressure and cardiac out-put in acute heart failure, induced by multiple ligations of the branches of left coronary arteries. Subsequently, hemodynamic effects according to different wrapping directions of the latissimus dorsi muscle flap were evaluated. It was considered that burst synchronous pacing improved the left ventricular function. And optimal delay time of the stimulation was 100 msec and optimal pulse duration time was 100 msec. And clockwise direction of the total wrapping of the both ventricles was effective to improve the hemodynamics as compared with counter-clock-wise direction of the wrapping method.
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Blood flow is the major factor of the function of skeletal muscle graft
S. ISODA, J. KONDO, K. IMOTO, H. KAJIWARA, I. TAMURA., S. SUZUKI, I. Y ...
1991 Volume 20 Issue 3 Pages
756-760
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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Blood flow is the major factor of the function of skeletal muscle graft. For preparatin of grafts, the ligation of collateral vessels is necessary. This results in ischemia which con-tributes to the fatigue and lower performance of the graft. Tissue blood flow at acute stage after preperation was mesured applying a laser flowmeter. Tissue blood flow in the distal portion of latissimus dorsi muscle graft prepared was significant-ly low. Clinical application of the distalportion at acute stage seemed to be limited.
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Yoshihiro NARUSE, Haruo MAKU-UCHI, Kuniyoshi YAGYU, Hitoshi MATSUNAGA, ...
1991 Volume 20 Issue 3 Pages
761-766
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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In 9 mongrel dogs, we investigated hemodynamic changes caused by wrapp-ing of latissimus dorsi muscle around the heart and the efficacy of synchronous con-traction of the sutured muscle. After surgical wrapping procedure, left ventricular systolic pressure (LVSP) decreased from 109±21 to 93±16mmHg, max dp/dt from 761±211 to 642±234mmHg/sec, respectively (p<0.05) Left ventricular stroke volume (LVSV), maximum elastance of left ventricle (Emax) and peak flow of descending aorta (AOF) did not show any significant change. With synchronous contraction of latissimus dorsi muscle, LVSV increased clearly from 11.4±3.4 to 17.6±2.6ml (p<0.01), and AOF from 1.79±0.37 to 2.08±0.30l/min (p<0.05), respectively. Emax was also improved from 7.1±1.6 to 9.1±3.0mmHg/ml (p<0.05), while neither LVSP nor max dp/dt demon-strated any remarkable change. These studies suggest that: 1) synchronous con-traction of the sutured muscle is able to improve the cardiac function. 2) wrapping of the muscle may cause adverse hemodynamic effect to the native diseased heart.
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Y TAENAKA, T MASUZAWA, T NAKATANI, A YAGURA, E TATSUMI, H SEKII, E SAS ...
1991 Volume 20 Issue 3 Pages
767-771
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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An electro-hydraulic total artificial heart system consisted of a separately placed actuator and blood pumps was designed. In the actuator a brushless DC motor is sandwiched by 2 pusher-plate pumps connected with the blood pumps by flexible tubes. A roller-screw system is employed for alternative pumping and silicone oil is used to trans-mit the action. The pumps were implanted in 4 goats of 54-59 kg as a pneumatic sys-tem. The longest survivor could be maintained for 40 days. The system could yield around 6L/min in an in vitro evaluation.
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Y MATSUO, A YAGURA, Y TAENAKA, H TAKANO, T NAKATANI, E TATSUMI, H AKAG ...
1991 Volume 20 Issue 3 Pages
772-776
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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We estimated the EHVAS in 4 goats and examined the effect of the automatic negative pressure control (ANPC) mechanism to prevent atrial wall sucking. ANPC regulates the filling power of the actuator automatically by monitoring sillicone oil pressure. Our EHVAS could be operated for 21-42 days. When ANPC was not used, instantaneous left atrial pressure during filling phase was-40mmHg, however, it was-10mmHg by using ANPC. ANPC could prevent atrial wall sucking. Our EHVAS could become a portable VAS.
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N KABEI, H IIDA, R KANNO, Y SAKURAI, K TSUCHIYA
1991 Volume 20 Issue 3 Pages
777-782
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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We have developed a non-rotating-type centrifugal pump which has an oscillating disk in its blood chamber. The blood leakage through the gap between the driving shaft and the housing can be completely prevented by the membrane seal which is tightly fixed at one end to the shaft and at the other end to the housing. Under a motor rotational speed of 3000 rpm, the output flow rate of the pump designed for 25 degrees oscillation was 14L/min at a mean aortic pressure of 100mmHg.
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H. YAMADA, M. KARITA, Y. MITAMURA, T. AKUTSU
1991 Volume 20 Issue 3 Pages
783-788
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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The paper deals with the result of development on a linear pulse motor driven artificial heart with left and right blood pumps. The linear pulse motor(LPM-S90) has the static thrust of 107 newtons and kinetic thrust of 65 newtons. The volume of the artificial heart is 520 milliliters, the mass is 1.2 kilograms, and the stroke volume of each blood pump is 60 milliliters. Omnicarbon valves were used as artificial valves. The mean flow rate of the artificial heart using linear pulse motor was 5.3-5.7 liters/min at 100 beats/min and at the aortic pressure of 80mmHg in a mock circulatory test.
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K IMACHI, K MABUCHI, T CHINZEI, Y ABE, K IMANISHI, M SUZUKAWA, T YONEZ ...
1991 Volume 20 Issue 3 Pages
789-794
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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A practical model of jellyfish valve which can be incorpolated into an artificial heart blood pump without seam was designed and fabricated. In-vitro experiment revealed that the valve had superior performances to B-S valve at the points of flow resistance, regurgitation during the valve closure and leakage after the valve closure. Durability test was cleared over 8 months. Essentially, no thrombus was formed around the valve in in-vivo experiments without anticoagulant. The chronic implantation of this valve into the goats as a TAH, revealed an amazing improvement of oathophysiological abnormalities which were always observed in TAH animals.
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T KOMODA, C UYAMA, H MAETA
1991 Volume 20 Issue 3 Pages
795-801
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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Based on transverse(TRN) and LV long axis(LAX) MR images of two cadaver hearts, three-dimensional (3-D) computer models of the connecting interface between remaining heart and total artificial heart, i.e., mitral and tricuspid valvular annuli(MVA and TVA), ascending aorta (Ao) and pulmonary artery (PA), were reconstructed to compare the shape and the size of MVA and those of TVA, the distance between the center of MVA and TVA (D
G), the angle between the plane of MVA and that of TVA (R
T), and the angles of Ao and PA, respectively, to the plane of MVA (R
A, R
P), with those obtained in cast silicone models. It was found that based on LAX rather than TRN MR image, MVA and TVA might be more precisely reconstructed. The data obtained in 3-D images of MVA, TVA, An and PA based on silicone models of 32 hearts were as follows: D
G(cm): 4.17±0.43, R
T(degrees): 22.1±11.3, R
A(degrees): 54.9±15.3, R
p(degrees): 30.8±17.1
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Y YOSHIOKA, N TSUTSUI
1991 Volume 20 Issue 3 Pages
802-805
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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To decrease the incidence of thromboembolism of iliac artery and complication of lower extremity, we developed two types of sheath introducer for IABP. One is to utilize Implant Aid Lead Introducer (peel away type). This introduer can be removed from balloon catheter after insertion into iliac artery, and the catheter can be fixed in the artery by itself. Therefore the blood flow of artery is not obstructed by introducer. The other is to use the new sheath introducer which has thin tube on the lateral portion of it. The heparin can be injected into the femoral artery through the thin tube and introducer selectively to reduce thrombosis of lower extremity.
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M. GOTO, T. NAKATANI, Y. TAENAKA, E. TATSUMI, H. AKAGI, E. SASAKI, T. ...
1991 Volume 20 Issue 3 Pages
806-810
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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ABIOMED Bi-Ventricular Support (BVS) System 5000 was evaluated in mock circulation and acute animal experiments. The device consists of a disposable blood pump and electromechanical console. The blood pump is driven pneumatically without vacuum (with gravity-filled) and has an inflow chamber (artificial atrium: 100ml volume), an outflow chamber (pumping chamber: 100ml volume) and two polyurethane trileaf let valves. The priming volume of this system is 550ml. The console can operate two pumps independently and asynchronously with fill to empty mode. In mock circulation, maximum pump flow was 5.3L/min with ABIOMED console and was 5.8L/min with TOYOBO VCT30 console. In left heart failure model using mock circulation, BVS system 5000 showed ability to maintain circulation when the preload exceeds 10mmHg. In acute animal experiment using 57kg goat, maximum pump flow of left ventricular assist was 4.3L/min. In bi-ventricular assist using 60kg goat, maximum left pump flow was 5.0L/min and maximum right pump flow was 4.8L/min. ABIOMED BVS System 5000 has enough ability of circulatory support, however, the priming volume is large for Japanese. It is necessary for Japanese to modify the pump or cannula size.
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Yoichi SUGITA, Michihiko MATSUI, Kiyozo MORITA, Yoshihiko MOICHIZUKI, ...
1991 Volume 20 Issue 3 Pages
811-816
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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The concept of this Single Pump Artificial Heart is that both failed right and left natural ventricles are removed and the atrial septum is also removed totally. Both right and left atrium are anastomosed to create common atrium to maintain low pressure pumonary circulation, while single artificial pump which is connected between the main pulmonary artery and aorta carries the systemic circulation. In this method, pulmonary circulation is totally reversed. Preliminary studies indicate that the approach is feasible, and that some number of biventricular failure cases can be treated in this manner using only a single artifical heart.
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Y. ORIME, Y. HARADA, T. YAMAMOTO, K. KURIHARA, O. SUZUKI, S. TSUKAMOTO ...
1991 Volume 20 Issue 3 Pages
817-822
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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Hypoventilation and heart failure model of swines were treated by the bi-ventricular assist device incorporated menbrane oxygenator. Roller pump was used for right ventricular assist, pulsatile blood pump for left ventricular assist device and polypropylene hollow fiber for membrane oxygenator. Using this device, hemodynamics were improved, ie, right atrial pressure was dropped significantly and arterial pressure, total cardiac output were rised significantly. And the datas of blood gas analysis were also improved, using this device. This new assisted circuration device was able to treat cardiac failure, maintain systemic circulation and also improve hypoxia and hypercapnea, and it seems to be very effective for the cases that have heart failure associated respiratory failure.
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Y TAENAKA, E TATSUMI, M SAKAKI, E SASAKI, T NAKATANI, H AKAGI, H SEKII ...
1991 Volume 20 Issue 3 Pages
823-828
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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A pulsatile left ventricular assist device was quickly replaced by a centrifugal pump without anesthesia in 5 goats 2 weeks after surgery. A 100% bypass of nonpulsatile systemic flow was immediately obtained and the pump was controlled to maintain the same mean aortic pressure as before the switch. Central venous pressure, cardiac output, systemic vascular resistance, oxygen consumption, blood lactate, and plasma adrenalin, noradrenalin, renin activity, angiotensin II and aldosterone did not deviate from the control levels.
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T SHIMOOKA, T URASHIMA, T HONDA, Y MITAMURA, T YUHTA
1991 Volume 20 Issue 3 Pages
829-834
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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The predictor of mean aortic or left atrial pressure (mAoP or mLAP) when LVAD-off, which assists the decision of weaning time, was investigated by computer simulation. The relationship of mAoP or mLAP and mean bypass flow (mBF) was estimated with time-series model. Based on the estimated parameters mAoP and mLAP when LVAD-off can be predicted. The vacuum pressure was changed every 30 heart beats to change mBF and prediction was performed. Errors between the predicted pressures and true values when LVAD-off was investigated. Results of the simulation show that the smaller the left ventricular (LV) contractility becomes, the larger the prediction errors. Predicted mAoPs were smaller and predicted mLAPs were larger than true values. As for mAoP prediction the errors were reduced by compensating the increase of mLAP. Errors of the mLAP prediction were reduced when mBF was strictly controlled to the setpoints. The developed predictor of LVAD-off state pass the simulation test. We will adopt the predictor to data of animal experiments.
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H AKIHO, S NITTA, Y KATAHIRA, T YAMBE, T SONOBE, S NAGANUM, M TANAKA, ...
1991 Volume 20 Issue 3 Pages
835-840
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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In order to evaluate cardiac function of natural heart during left ventricular assistance, external work and pressure-volume area (PVA), which were calculated from left ventricular pressure-volume curve, were analysed by our hemodynamics analysing system and automatic control system. Our TH-7B pneumatically driven sac type Ventricular Assist device (VAD) was used in 6 adult goats in acute animal experiments. VAD were inserted between the left atrium and the descending aorta. Coductance catheter and catheter tip manometer were inserted into the left ventricle. External work decreased and PVA increased in co-pulsation mode (CoP) compared with counterpulsation mode (CP). External work calculated by our system changed in proportion to the positive and negative inotropic agents. These results indicate that cardiac function of natural heart under left ventricular assistance can be obtained with this newly developed system.
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M KATO, M OHTANI, N OHKUBO, H TAKANO, H YASUDA, K OHNISHI
1991 Volume 20 Issue 3 Pages
841-847
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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(USING CONDUCTANCE CATHETER) Comparative left ventricular end diastolic volume (EDV), end systolic tension (EST) and pressure volume area (PVA) were studied in 6 dogs undergoing left atrial bypass (LAB) or left ventricular bypass (LVB). Though LAB decreased EDV, EST did not decrease by increasing bypass flow rates. LVB decreased EDV and EST by increasing bypass flow rates. PVA, the index of myocardial oxygen consumption, remained at 60% from control value during 120ml/kg LAB. On the other hand, PVA was decreased at 41% from control value during 120ml kg LVB. These results suggest that LVB may be useful in myocardial support systems.
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M YOSHIZAWA, K KURAMOTO, H TAKEDA, W MIURA, T YAMBE, Y KATAHIRA, S NIT ...
1991 Volume 20 Issue 3 Pages
848-857
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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The estimation and monitoring system of the cardiovascular dynamics under ventricular assist device (LVAD) pumping has been developed on the basis of a time series model. This system has the functions which can identify the parameters of the cardiovascular dynamics such as peripheral vessel resistance and arterial compliance beat by beat and can estimate the instantaneous value of the cardiac output of the natural heart assisted by the LVAD. The required measurements are only the aortic pressure and the outflow rate from the LVAD measured with an electromagnetic flow meter outside the body. In this system, the parameter identification of the cardiovascular dynamics and the estimation of the flow rate wave form of the cardiac output can be realized in an on-line and real time fashion. Hence, the proposed system is useful for monitoring the hemodynamic behavior of the circulatory system supported by the LVAD and for developing an automatic control system in which the driving conditions are automatically changed on the basis of the estimated cardiac output.
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Y KATAHIRA, S NITTA, T YAMBE, T SONOBE, S NAGANUMA, H AKIHO, H HAYASHI ...
1991 Volume 20 Issue 3 Pages
858-864
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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In order to evaluate the autonomic response of conscious adult goats under the systemic ventricular assistance, the power spectrum of the heart rate variability was analyzed using the newly developed system. The power spectra were analyzed on the several different conditions; (1) asynchronous mode of different assist volumes and different driving frequencies, (2) synchronous mode of the constant assist volume and different time-delays from R-wave. In the asynchronous mode, the low-peak (Mayer wave) and the high-peak (respiratory arrhythmia) were clearly observed. On the contrary, in the synchronous mode with time-delays of 300, 400 and 500 ms, the low-peak was attenuated. Because this autonomic response under the synchronous assistance is different from that produced by administration of the β-blockade which attenuates the sympathetic activity, the synchronous assistance may influence the response of the sympathetic nervous system to physiological disturbances. In addition, power spectra were processed by means of the maximum entropy method for the automatic control system. Using this method, both the locations and the strengths of spectral peaks could be automatically calculated. It was concluded that the power spectral analysis of the heart rate could be useful as one of the information for the automatic control system of ventricular assist device.
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Tatsuhiko TAKAHAMA, Fukuei KANAI, Kiyoshi ONISHI, Mamoru HIRAISHI, Yos ...
1991 Volume 20 Issue 3 Pages
865-868
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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A new VAD pneumatic driver with servomatic control mechanism of left atrial pressure was developed for easy and safe contrl of assist circulation during the performance of left ventricular assist device. This new driver has variable delay and duration of driving pressure, and both mode of ECG triggered and variable internal rate. And as a servomatic mode, ngative driving pressure can be controled according to the LAP, to control the assist circulation flow.
This servomatic control system was revealed to be useful by both in-vitro and in-viva experiments.
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O. SUZUKI, M. SHIONO, Y. ORIME, T. YAMAMOTO, K. KURIHARA, S. TSUKAMOTO ...
1991 Volume 20 Issue 3 Pages
869-874
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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Effect of Urinastatin during Right Ventricular Assist Ventricular assist device(VAD) has become utilized widely for clinical application. Multiple organ failure (MOF) which occurs while VAD is using is in a high mortality, and it is essential to pursue the cause and be prepared with countermeasures. In the present study, we examined the histological change of the pulmonary tissues, measuring of granulocyte elastase activity and extravascular lung water ( EVLW) when RVAD were used in 16 pigs. Urinastatin, protease inhibiter, stabilizes the lysosomal membrane. It was administered to 8 animal during RVAD . After right ventricular failure, RVAD was started. RVAD was operated for 3 hours. The result might be well explained that hemodynamic conditions were well stabilized in RVAD. But it was suggested from measuring of granulocyte elastase that the ischemic changes at the cellular level were still being advanced, and administration of urinastatin can prevent the cellular destruction during R VAD, it is considered that RVAD may induce pulmonary dysfuntion due to advanced permeability in the system of pulmonary capillary vessel and edema in the inter-alveolar septum. It was suggested from the histologi-cal change of lung tissues and EVLW that the edema can be inhibited by urinastatin.
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T KOYAMA, A TAKASU, T ITOH, K TERANISHI, F MURAKAMI, Y IBMIDA, Y YAMAZ ...
1991 Volume 20 Issue 3 Pages
875-882
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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A 53-yr-old male and a 12-yr-old female were suffered from fulminant myocarditis. Because conventional therapy such as volume replacement, inotropic support, cardiac pacing and intraaortic balloon pumping (IABP) failed to improve their circulatory state, they received percutaneous cardiopulmonary support (POPS) for 107 hours and 227 hours, respectively. The both cases showed tremendous circulatory improvement as soon as PCPS started and successfully weaned. A 37-yr-old female was transferred to our hospital. Although ECG revealed multifocal VPC and short run, drug therapy failed to control them. Then she developed sudden ventricular fibrillation. Endotracheal intubation was performed and cardiac massage was started immediately. As drug therapy and cardioversions were ineffective, PCPS was started with a flow rate of 4L/min. The arrhythmias disappeared 15 hours later and PCPS could be discontinued after 39 hours. Traditional methods of cardiac bypass usually require surgical exposure of the great vessels, which can be time-consuming and moreover may lead to a serious loss of blood. We have developed a simple PCPS system using percutaneous cannula, a centrifugal pump and an artificial lung. The circuit of the system is set up beforehand and sterilized for emergency situation. PCPS appears to be beneficial in the treatment of circulatory collapse and resuscitation which are refractory to conventional therapy.
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M. TANJI, F. IWAYA, T. IGARI, T. ABE, K. HAGIWARA, H. SATOKAWA, M. WAT ...
1991 Volume 20 Issue 3 Pages
883-886
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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A LVAD was used for ten patients. Of these, three cases, who had ventricular septal perforation (VSP), and one case, who had left ventricular aneurysm (LVA), were able to be weaned from the LV AD and discharged. We have studied these four cases for an extended period of time. Two VSP patients and the LVA patient are now, after 24-41 months, well and are in NYHA class 1. The remaining VSP patient, 24 months after sur-gery had protracted mediastinitis and suffered false aortic aneurysm and aortic regurgitation and died. When a LVAD is employed, because there are many chances of infection and further, because severe illness can originate from slight infection, careful monitoring of the patients after surgery is necessary. Moreover, at the time of weaning from LVAD, when suturing the aorta, it is important, as far as possible, to remove all foreign bodies because of possible danger of infection. Finally, long term observation by CT-scan or echocardiography is considered essential.
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H TAKAGI, T TAKAGI
1991 Volume 20 Issue 3 Pages
887-892
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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This pump system consists of 4 mechanism as follows. (1) Double chambered alternate pumpimg. (2) Magnet-hall IC sensor was provided between each chamber and each housing. Each solenoid valve was opened by the trigger of presetting electrical voltage. However, both valve can not open at the same time, but wait untill first come pulse finishes its action. (3) Air pressure was adjusted to minimize this delay time, because it should be no delay when the output is equal to the input. (4) Trigger point was set to minimize the negative pressure which was generated inside the pump due to the resiliency of the chamber wall itself. Results obtained in mock circulation and in animal experiment indicated that our pump system worked automatically on the Starling's law of the heart.
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T YAMBE, S NITTA, Y KATAHIRA, T SONOBE, S NAGANUMA, H AKIHO, [in Japan ...
1991 Volume 20 Issue 3 Pages
893-898
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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In order to determine the effect of left ventricular assistance on cardiac related sympathetic activity, renal sympathetic nerve activity (RSNA) were analysed by the use of power spectrum and coherence function. Our TH-7H pneumatically driven sac type ventricular assist device ( VAD ) was used in 7 adult mongrel dogs. VADS were inserted between the left atrium and the descending aorta. After the left frank was opened, bipolar electrode was attached to the left renal sympathetic nerve via retroperitoneal approach to detect the RSNA. Values of the squared coherence between the arterial pressure waveform and RSNA were measured at the same frequency level of cardiac rhythm and VAD pumping rhythm. With the LVAD pumping, coherence spectra at the cardiac rhythm frequency was decreased, and the coherence at the pumping rhythm frequency was increased. These results indicate that arterial pulse wave which was made by the LVAD assistance contributed to the postganglionic sympathetic activity.
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M KOLA, H HARA, K ASO, K SETOJIMA, K YAMAHA, N AOYAGI, K KOSUGA, K. OH ...
1991 Volume 20 Issue 3 Pages
899-903
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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To determine whether severe hemodynamic and biochemical function of the left heart ventricle and the left ventricular mitochondoria is reversible or not by biventricular mechanical support, we subjected 15 caries of global ischemia. After 45 minutes of normothermic global ischemia with aortic cross clamp during CPB and further 20 minutes of reperfusion (G2), developed pressure. LV max dp/dt and LVSWI were significantly reduced compared to the normal control (G1) values of the left ventricular functions. The study of the left ventricular functions using BVAS for these failing hearts revealed that the reduced left ventricular functions was significantly recovered after three hours of BVAS support (G3). The quantitative assessment of mitochondoria score (grade 0-5) was utilized to evaluated the ischemic change of myocardial cell. Mean G1 score was significantly lower than mean G2 score (p<0.01). After three hours BVAS support, mean G3 score was significantly lower than mean G2 score (p<0.01). In biochemical aspects. RCI of mitochondoria showed the recovery tendency by BVAS of three hours. In conclusion, BVAS support to myocardial damage due to normothermic global ischemia make a contribution to the recovery of the failing heart.
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Y MIYAMOTO, H MATSUDA, Bp GRIFFITH
1991 Volume 20 Issue 3 Pages
904-908
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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The interrelationships between hemodynamic variables including right ventricular (RV) performance and filling/ejection dynamics of Novacor LVAD were investigated in 10 patients who received the LVAD as a bridge to heart transplant. Data were obtained intraoperatively, at periodic intervals, up to 48 hours post implant and at explant. During the period of LVAD support, pumping characteristics showed filling volume of 24-70ml, residual volume of 1-18ml, pump rate of 63-175/minute and pump output of 2.8-8.2 l/minute. Multiple regression analysis identified PVR, RVSWI and PCWP as the significant (p<0.001, R
2=0.6) parameters affecting LVAD filling volume. LVAD pump output was influenced mainly by RVSWI, PVR and SVR. (p<0.001, R
2=0.7) These results indicate that Novacor LVAD performance is highly dependent upon RV function and systemic/pulmonary vascular resistances.
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M ASADA, T NAKAMURA, K HAYASHI, [in Japanese], K SAKAI, T TANABE, H MA ...
1991 Volume 20 Issue 3 Pages
909-914
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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Six mongrel dogs were used for this study. Intraaortic balloon pump(IABP) was inserted through the femoral artery and positioned in the descending thoracic aorta. After 7-paired ultrasonic sonomicrometers(USM) were embedded inside the left ventricular wall, the left anterior descending coronary artery(LAD) was ligated. 3-paired USM5 were used for obtaining the left ventricular volume(LVV), and another 4-paired USMs were for the regional muscle areas(Am).The bulk mechanical work(BMW; mW/100gLVW), regional mechanical work in the ischemic area(RMWi; mw/cm
3) and in the normal area(RMWn) were calculated from LVV and Am, respectively. Effects of IABP on cardiac mechanics were compared with those of left ventricular assist device(LVAD). Results obtained were: (1) During IABP, BMWs were reduced by 7% from IABP-off results. (2) RMWi decreased by 35 to 52% by IABP, and RMWn increased by 10 to 23%. On the other hand, LVAD reduced RMWi and RMWn by 55 to 150%.
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Y. FUJITA, J. HAYASHI, H. MORO, A. SAITO, M. UENO, S. EGUCHI, J. HORI, ...
1991 Volume 20 Issue 3 Pages
915-918
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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The closing sound of the SJM cardiac valve prosthesis was analysed both in vitro and in vivo, using the technique of the fast Fourier transform. In vitro, the power-spectrum curve of the closing sound contains a peak at 0.6 KHz, and the power gradually decline to 7 KHz. It also has small peaks at about 1.2, 1.8, 2.4 and 3.6 KHz. In vivo, the spectra of the normally functioning SJM cardiac valve prostheses show the same curve as the curve in vitro. In the case of the cardiac valve prosthesis attached with fibrin glue on the housing, the power declined to between 0.6 and 3 KHz. The same curve was shown clinically in two cases of the thrombosed SJM cardiac valve prosthesis and thromboembolism. The decline of the power between 0.6 and 3 KHz suggests the throm-bus or pannus formation of the SJM cardiac valve prosthesis.
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A. GOMI, Y. TAKEUCHI, Y. OKAMURA, H. MORI, M. NAGASHIMA, J. HATTORI, Y ...
1991 Volume 20 Issue 3 Pages
919-923
Published: June 15, 1991
Released on J-STAGE: December 02, 2011
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To detect malfunction in prosthetic heart valves at an early stage, we have effectively analyzed prosthetic valve sounds (PVS) using trans-telephone PCG monitoring. To analyze more precisely, we attempted frequency analysis of PVS by digital transmission. [Method] We developed a new telephone line INS64, which combines with SB-ADPCM and its demodulator to transmit 0.05-7 kHz. Analog and digital trans-mission, and direct diagnosis were compared. [Results] (1) Frequency distribution of PVS by digital transmission was similar to direct monitoring, but analysis of analog transmission was impossible. (2)Transmission frequency of 4-7kHz is important because amplitude is often diminished during malfunction. [Conclusion] Frequency analysis of PVS by digital transmission is useful to detect valve malfunction at an early stage.
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T. SHIBATA, M MATSUI, S. MIYAZAWA, K SUSUKI, K KOYANAGI, T. ARAI
1991 Volume 20 Issue 3 Pages
924-927
Published: June 15, 1991
Released on J-STAGE: December 02, 2011
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Twenty-five patients with a Ionescu-Shiley valve replacement in the mitral position were included in this study. Those patients were divided into two groups as follows, group A; thickness of leaflets was less than 3mm, group B; greater than 3mm in the two dimensional cardiography. The ratio of II-OR/RR, expressed the length of a second heart sound to an opening sound divided by the ECG R-R interval, was 0.14±0.03 in the group A and 0.11±0.04 in the severity of the valvular thickness. Pressure half time (PHT), which was measured by the doppler and was known as a good indicator of the valve stenosis, prolonged in the severely thickened valves, the group A; 97±30, the group B; 192±82 msec, The ratio II-OS/RR had a correlation(r=-0.68) with PHT. We concluded that the ratio was rereplacement was to be considered.
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Y TANAKA, M OKUMORI, H MATSUMOTO, Y OOTA, T HORIUCHI, T DOHI, T HASEGA ...
1991 Volume 20 Issue 3 Pages
928-931
Published: June 15, 1991
Released on J-STAGE: October 07, 2011
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We developed a motion analyzing system for implanted tilting disk valves. The cinefilms of the 40 patients underwent cardiac valve replacement with Bjork-Shiley valve (20 cases of AVR and 20 cases of MVR) were analyzed using this system. The duration between the top of the R wave on ECG, and the time of valve closing and opening were particulary measured for the present evaluation. We found that this motion analyzing system was very useful for the detection of prosthetic valve failure, and the evaluation of cardiac function as well.
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