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H. FUKUMASU, T. BAN, S. YUASA
1986 Volume 15 Issue 2 Pages
463-468
Published: April 15, 1986
Released on J-STAGE: October 07, 2011
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The animal with a total artificial heart underwent acute studies for characteristics of peripheral vascular system. Treadmill exercise reduced significantly peripheral vascular system. Psychological stress did not changed vascular resistance (PVR). Effects of cardiac drugs was observed just same as the textbooks describe. Peripheral vascular resistance changed suddenly below the normal when the animal was pushed her head back for over 25 seconds. Blood pH below 6.9 dilated remarkably vascular bed.
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H. FURUKAWA, Y. NAKAGAWA, M. SHIBAIRI, M. MASUDA, K. YAMAMOTO, M. KITA ...
1986 Volume 15 Issue 2 Pages
469-472
Published: April 15, 1986
Released on J-STAGE: October 07, 2011
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A new left ventricular assist device using pulsatile bypass pump (PBP-LVAD) was developed. Experiments were performed on mock circulation. Results were as follows. 1) Maximum pumping flow was 4.3l/min with the single unit and 6.7l/min with the double unit. 2) Under optimal balloon driving pressures, and in the range of 40 to 140mmHg of of afterload, output of the single unit was 3.5 to 3.7l/min while the double unit achieved 3.9 to 4.9l/min of output. 3) Under the lower driving rate, the double unit could produce more stable output as compared to the single unit.
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H. FUKUMASU, A. YAMAZATO, Y. FUJIWARA, J. SONEDA, Y. OKAMOTO, T. BAN, ...
1986 Volume 15 Issue 2 Pages
473-477
Published: April 15, 1986
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Pulsatile ventricular assist devices have successfully been in clinical use according to the Pierce's criteria. However, there are many cases with more critical cardiac functions. Atrial withdrawal cannula can not eliminate blood flow into ventricle. So ventricular myocardium can be minimized volume load but can not be reduced pressure after-loads. Subendocardial infarction was found at autopsy following transatiral VAD in the animal heart criated more critical myocardial disfunction.
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Y. KATAHIRA, S. NITTA, T. YAMBE, M. TANAKA, Y. KAGAWA, T. HONGO, T. HO ...
1986 Volume 15 Issue 2 Pages
478-481
Published: April 15, 1986
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The flow behavior within an artificial heart (AR) in the various driving conditions were analyzed with a numerical method based on the quantitative flow visualization techniques. The velocity vector distribution, the streamline configuration and the vorticity distribution within the AH were obtained with this method. In this study, the flow velocity within the AR 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. Since this critical point was thought to be a minimum stroke volume, the driving condition should be avoided in this area to protect AH from thrombus formation.
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T. SHIROYAMA, T. AKAMATSU, H. FUKUMASU
1986 Volume 15 Issue 2 Pages
482-485
Published: April 15, 1986
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A nutation-type centrifugal blood pump (Tea-Spoon type B. P.) has been much improved in the configurations of impeller and annular passage, and the flexible diaphram-type shaft-seal. This pump proved to be of satisfactory performance in the non-pulsatile mode. Unblance by nutating motion of impeller and rod induces vibration, and it results in increase of friction energy-loss. Dynamic balance should be taken into account. Preliminary test showed that this pump had a good characteristic in the pulsatile mode.
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G. TAKEZAWA, S. FUKUNAGA, Y. HAMANAKA, J. MURASHITA
1986 Volume 15 Issue 2 Pages
486-489
Published: April 15, 1986
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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 their own driving tube, which can be driven separately. Thus three different bypass flow rate are obtained under the same drive-beating rate and the same driving condition. Using mock circulatory system, this device with a capacity of 60ml can assist 0.7-4.8L/min at beating rate of 40-100 BPM and another same type device with a capacity of 90ml can assist 0.75-6.7L/min (40-100 BPM). In dog experiment, induced heart failure, hemodynamic change was observed remarkably depend on the number of driving chamber. These experiment, showed satisfactory performance to control assisted flow rate with ease, made it clear that the variable output device was the most effective one during the weaning period from left ventricular assisted circulation.
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[in Japanese]
1986 Volume 15 Issue 2 Pages
490
Published: April 15, 1986
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Y. NAMIKI, A. YAMAZAKI, T. HASEGAWA, A. MIYAMOTO, M. SHIONO, K. OGASAW ...
1986 Volume 15 Issue 2 Pages
491-494
Published: April 15, 1986
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Hemodynamic changes, including coronary sinus flow, carotid and renal artery flow, were evaluated in the model of acute left ventricular failure complicated myocardial infarction in swine when pump flow rate was chaged from 10 to 60% of total cardiac output. The results showed that LVAD could improve hemodynamics at any flow rate. However, coronary sinus flow rate revealed maximum value at the assist rate of 40%, and carotid and renal artery flow rate showed plateau state when the pump flow rate was over 40%.
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K. SHIOTSU, T. KOMODA, A. SHIMIZU, Y. KIOKA, T. MURAKAMI, Y. SENO, S. ...
1986 Volume 15 Issue 2 Pages
495-499
Published: April 15, 1986
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Injection of 5NNaOH into the myocardium of the left ventricular free wall produced myocardial infarction and left heart failure model. Left heart bypass using left atrial-aortic perfusion with a pusher-plate pump while was operated with a non-synchronous 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.
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H. HATA, A. YAMAZAKI, T. HASEGAWA, A. MIYAMOTO, M. SHIONO, K. OGASAWAR ...
1986 Volume 15 Issue 2 Pages
500-503
Published: April 15, 1986
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Hemodynamic effectiveness of two different perfusion mode in LVAD was evaluated against acute left ventricular failure in swine. Renal blood flow was increased in descending aortic perfusion mode, but coronary sinus flow and endocardial viability ratio were increased more markedly in ascending aortic perfusion mode. These results suggested ascending mode appeared to be more promising method of assisting the failing heart complicated with acute myocardial infarction.
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H. TAKAGI, M. HAYAKAWA
1986 Volume 15 Issue 2 Pages
504-507
Published: April 15, 1986
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New system of our blood pump has been tested in 1-atrio femoral 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. 1) no heparin, 2) can be started by anyone, even untrained, by only turning the switch on, 3) maintained automatically, 4) bypass rate was 50 to 90% of normal cardiac output, 5) easier weaning, by only extracting the inflow duct without re=opening the chest, 6) extreemly lower cost, 7) easier transportation of the patient.
Thus, this simple methode may be more convenient and easier for use after cardiac surgery, as same as IABP.
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Y. KOH, S. KITAMURA, C. OYAMA, K. KAWACHI, H. KOBAYASHI, R. MORITA, T. ...
1986 Volume 15 Issue 2 Pages
508-511
Published: April 15, 1986
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The right and left artificial hearts (AH) were used and driven as the Pt's sick heart and were connected to a copy type of the Donovan mock circulatory system with 2 or 4 chambers. The VAD of 40ml 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, left heart failure model was produced as follows; mean arterial pressure (MAP) 43-73mmHg, total flow (TF) 1.8-2.6l/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 180mmHg and the rate of 100/min. The following hemodynamic changes were obtained; maximal flow assist of 1.5l/min, maximal MAP arise of 32mmHg, maximal mean PAP decrease of 11mmHg and maximal LAP decrease of 19mmHg. This new model of the circulatory system can be useful for the quantitative evaluation of VAD function.
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[in Japanese]
1986 Volume 15 Issue 2 Pages
512
Published: April 15, 1986
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M. KAWAUCHI, O. TANAKA, K., TANAKA, [in Japanese], K. WAKE, T. TAKAHA ...
1986 Volume 15 Issue 2 Pages
513-515
Published: April 15, 1986
Released on J-STAGE: October 07, 2011
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Since April 1981 to March 1985, Intra-aortic Balloon Assist was installed in 30 adult patients (Age 26-69 years old, mean 50.6 years old; =15:15). 16 patients (Age 26-69 years old, mean 51.3 years old; =7:9) died in the hospital. Ten patients died of insufficient support, two of too early weaning of IABP and four of other lethal reasons. There were two reasons for insufficient support, one was unsuccessful repair and the other was extemely low cardiac output. Necessity of more than 800ml/min/M
2 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, cardiac index in the early period of IABP assist.
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J. MIYA, H. MAETA, T. ASAKURA, M. HORI
1986 Volume 15 Issue 2 Pages
516-520
Published: April 15, 1986
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The efficacy of extra-pulmonary arterial balloon pumping (EPABP) as a circulatory assist for the failing right heart was evaluated experimentally using dogs with acute pulmonary hypertension (PH) caused from disseminated pulmonary emboli with polymethyl metacrylate beads. EPABP immediately improved hemodynamics 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 “extra-pulmonary arterial” application.: less arrhythmia induced and least thrombus formed. In chronic PH, e. g. in mitral valvular disease, EPABP of dilated main PA trunk will also bring a certain assisting effect.
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M. SHIONO, T. HASEGAWA, A. MIYAMOTO, S. KITAMURA, K. KAWANO, S. SHINDO ...
1986 Volume 15 Issue 2 Pages
521-524
Published: April 15, 1986
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Retrospective analysis was carried out in 15 dead cases of multiple organ failure which were applied clinically with mechanical circulatory assist device, such as intraaortic balloon pumping and left ventricular assist device. In conclusion it was suggested that low output syndrome and renal failure were the most popular causes of MOF and it might be possible to reduce its incidence by maintaining adequate systemic blood flow under heart lung machine and coronary flow with cold cardioplegic solution. Mechanical assist device had its limitations against multiple organ failure that was progressed preoperatively and intraoperatively.
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M. YAMADA, T. WATANABE, H. YOKOKAWA, K. INOUE, M. FUNAMI, N. YAMAMOTO, ...
1986 Volume 15 Issue 2 Pages
525-528
Published: April 15, 1986
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During recent four years, 47 patients was treated with 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 femoral artery. In six patients out of eight the balloon was surgically removed. Thrombus was found in two patients, leg ischemia because of the femoral artery compressed by the balloon catheter in one patient. Though 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 at the removal of IABP.
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M. OKADA, M. IIZUKA, T. SHIOZAWA, K. OKUNO, K. SHIO, S. MATSUDA, K. NA ...
1986 Volume 15 Issue 2 Pages
529-534
Published: April 15, 1986
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The major causes of death following acute myocardial infarction (AMI) are cardiogenic shock and arrhythmia. The number of rhythm death has been obviously decreased with the development of coronary care unit. To decrease the mortality rate of the patients with cardiogenic shock due to AMI, IABP has been widely, employed for thore severely ill patients. In this study, IABP was attempted in 94 mongrel dogs with cardiogenic shock due to AMI which was produced by multiple ligation of the coronary arteries. The effects of IABP on hemodynamics after AMI by using three types of balloon catheter (single, double, 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 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. Triple balloon is indicated for the patients in whom IABP must be utilized for long term period. In clinical cases, balloon volume of 20ml was convenient for the patient with body weight less than 50kg. 30ml for the patients more than 50kg. However, suitable size of balloon must be developed for the Japanese people in the near future.
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[in Japanese]
1986 Volume 15 Issue 2 Pages
535
Published: April 15, 1986
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T. TAKAHAMA, K. SUMA, Y. TAKEUCHI, K. INOUE, K. SHIROMA, Y. KOYAMA, H. ...
1986 Volume 15 Issue 2 Pages
536-540
Published: April 15, 1986
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24 hrs' LHB was performed experimentally using centrifugal pump or roller pump, administrating prostacyclin analogue as a sole anticoagulant instead of heparin. And coagulative study was performed.
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H. KANEKO, K. SUMA, Y. TAKEUCHI, K. INOUE, K. SHIROMA, Y. KOYAMA, J. N ...
1986 Volume 15 Issue 2 Pages
541-544
Published: April 15, 1986
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The effect of bio-pump and roller pump on hemolysis was compared by measuring free Hb concentration in the circulatory blood. In the experiments, bovine blood was circulated in the closed circuit by using each of the pumps. After 2 hour circulation, free Hb concentration was lower in the group of using bio-pump than that of roller pump. During 24 hour free Hb concentration was gradually increased in both groups, and after 24 hour circulation, there was no significant defference of free Hb concentration between the groups. The bio-pump was used in five patients undergoing open heart surgery. On the clinical use, there was no significant difference of free Hb concentration between the group of using bio-pump and roller pump. However, bio-pump was considered one of the efficient pumps applicable to the clinical use.
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K. KOJI, Y. KUNIYOSHI, F. IKEMURA, K. IHA, A. KUSABA, M. SHIMABUKURO, ...
1986 Volume 15 Issue 2 Pages
545-548
Published: April 15, 1986
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This study was done to determine the effect on blood components during extracorporeal circulation between Bio-Pump and Roller-pump. During six hours bypass plasma free hemoglobin increased a little in control group (1.88mg/dl/h) and Bio-Pump group (1.85mg/dl/h). It increased significantly in Roller-Pump group (12.60mg/dl/h). Lactate dehydrogenase value showed same change of free hemoglobin.
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S. NAWA, Y. KIOKA, T. KOMODA, A. SHIMIZU, Y. MIYACHI, K. EBARA, H. TSU ...
1986 Volume 15 Issue 2 Pages
549-553
Published: April 15, 1986
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In congenital heart diseases, almost all assisting ways were not effective, and the results were mainly depending on the operative indication, techniques and procedures. In acquired valvular heart diseases, prophil ctic use of IABP for postoperative low cardiac output syndrome would improve the operative outcome. By the cases, in that the bypass flow rate above 2.4l/min/m
2 and bypass time more than 100 minutes were needed, the prognosis was very poor. As for the combined use of IABP and V-A bypass or ECMO, the combination therapy was considered effective, and particularly early introduclion 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. Then, some other more effective and active assisting ways, such as the left ventricular or biventricular assist devices, and/or heart transplantation will be indicated when a high bypass flow rate is needed for many hours.
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Y. ORIME, A. YAMAZAKI, T. HASEGAWA, A. MIYAMOTO, M. SHIONO, K. OGASAWA ...
1986 Volume 15 Issue 2 Pages
554-557
Published: April 15, 1986
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This experimental study compared with IABP and LVAD, individually and in combination, for their hemodynamic effectiveness, in swine.
LVAD support resulted in significantly superior support than IABP, for the failing heart. Combination method with IABP (counterpulsation mode) and LVAD (counterpulsation mode) showed markedly improved the aortic pressure and endocardial viability ratio. However, in this combination method, renal artery flow was reduced, and this method was thought to have harmful influence on renal perfusion.
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K. OGASAWARA, T. HASEGAWA, A. MIYAMOTO, M. SHIONO, Y. ORIME, Y. NAMIKI ...
1986 Volume 15 Issue 2 Pages
558-561
Published: April 15, 1986
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An experimental study was planned for the purpous of demonstrating the optimal driving condition of LVAD and the effectiveness of combination of IABP and LVAD under acute left ventricular failure with left ventricular infraction in swine. The results showed that the recovery of left ventricular function were much more effective in counterpulsation. The combination method of IABP and LVAD was effective as same as individual LVAD (counterpulsation method) but renal artery flow was significantry reduced. But in a case of clinical application of LVAD, individual LVAD could not improve hemodynamicus and its combination of IABP could improve remarkably.
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[in Japanese]
1986 Volume 15 Issue 2 Pages
562
Published: April 15, 1986
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S. FUKUDA, H. TAKANO, T. NAKATANI, H. NODA, S. ADACHI, T. TANAKA, M. U ...
1986 Volume 15 Issue 2 Pages
563-566
Published: April 15, 1986
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Right ventricular (RV) function during LVAD pumping was studied in 5 dogs and 3 goats. No significant change was found in overall RV hemodynamic parameters at any bypass rate. But the RV stroke volume had a slight tendency to increase, while the max RVdp/dt to decrease with the increase in bypass rate. This finding indicates slight increase of RV contractility but decrease in its preload. However, since the normal RV had a good distensibility, the right atrial pressure and RV end-diastolic pressure remainded within normal range. This result suggests that the LVAD pumping will not affect the normal RV function in acute phase.
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K. NISHIGAKI, H. HIROSE, H. MATSUDA, S. NAKANO, T. SAKAKIBARA, M. OHTA ...
1986 Volume 15 Issue 2 Pages
567-570
Published: April 15, 1986
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We analysed the hemodynamic change and right ventricular pressure-dimension relationship during left heart bypass in dogs. 18 mongrel dogs (BW=11.8±1.9kg) were devided to following three groups. I: normal control, n=5. II: RV free wall ischemia, n=5. III: interventricular septum ischemia, n=8. During complete left heart bypass, right ventricular failure was detected only in group III. Right ventricular pressure-dimension curve did not change in group I. In group II the curve slightly removed to the right at 30 minutes after ischemia. In group III, the curve removed to right and upper side as time passed on after ischemia.
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S. TANAKA, S. YAMAMOTO, K. YAMAKOSHI, A. KAMIYA
1986 Volume 15 Issue 2 Pages
571-574
Published: April 15, 1986
Released on J-STAGE: October 07, 2011
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To analyse myocardial adaptive change in response to the prolonged left ventricular (LV) pressure reduction, RNA polymerase activity was measured in purified nuclear preparation from cannine heart muscle after 24hrs LV bypass using LV assist servosystem. The ratios of RNA polymerase activity of left to right ventricular muscle decreased as compared with those of control in both Mg
2+ and Mn
2+ activated reaction. This result suggests that the myocardial RNA synthesis would be reduced by prolonged afterload reduction and that the myocardial adaptation would progress an opposite way against cardiac hypertrophy process.
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-Evaluation of mechanical work of ischemic left ventricle-
T. NAKAMURA, K. HAYASHI, J. SEKI, T. NAKATANI, H. NODA, S. FUKUDA, H. ...
1986 Volume 15 Issue 2 Pages
575-578
Published: April 15, 1986
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Bulk and regional mechanical work of left ventricle during cardiac assist were studied by
in vivo acute experiments on mongrel dogs with ischemic hearts. Left vetricular 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 non-pumping. These results indicates that LVAD reduces the left ventricular work, developing no local forces nor expansion in the ischemic region of the ventricle.
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H. HATA, N. OHHASHI, Y. OKADA, S. NISHIUCHI, T. SHOHMURA
1986 Volume 15 Issue 2 Pages
579-582
Published: April 15, 1986
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Hemodynamic effectiveness, especially renal and hepatic flow, of the left ventricular assist device was evaluated in 19 mongrel dogs that were induced with left ventricular failure by coronary artery ligation. Nonoliguric renal failure was observed in dogs that were assisted 4 hours with the left ventricular assist device.
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T. NAKATANI, H. TAKANO, H. NODA, S. FUKYDA, S. ADACHI, T. NISHIMURA, Y ...
1986 Volume 15 Issue 2 Pages
583-586
Published: April 15, 1986
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The acute LVAD experiments (left atrium-descending aorta) were performed in five mongrel dogs to evaluate the heart assist effect on ischemic heart using NMR (Magnetom, super conductive type 1.5 Tesla). For enhancement of infarcted area, gadolinium-DTPA was injected. With LVAD on, enhanced area and signal intensity of infarcted area decreased. Also MR contrast (infarct image intensity minus normal myocardial image intensity devided by normal myocardial intensity) decreased with LVAD on. In conclusion, LVAD effectively decreased ischemic area and ischemic damage of myocardium.
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[in Japanese]
1986 Volume 15 Issue 2 Pages
587
Published: April 15, 1986
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T. NAKATANI, T. TAKANO, M. UMEZU, S. ADACHI, H. NODA, S. FUKUDA, T. TA ...
1986 Volume 15 Issue 2 Pages
588-591
Published: April 15, 1986
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We have evaluated the therapeutic effect of LVAD on PHF in experimental study (PHF induced by aortic-clamping under normothermia in goats) and clinical cases. In conclusion, LVAD can provide the failing heart with a sufficient recovery time to regain its function while maintaing the 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 following change of impaired muscle to connective tissue. The time required for LV assist depends upon the severity of myocardial damage.
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H. TAKANO, T. NAKATAIN, S. FUKUDA, M. UMEZU, H. NODA, S. ADACHI, T. MA ...
1986 Volume 15 Issue 2 Pages
592-595
Published: April 15, 1986
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Feasibility of prolonged circulatory maintenance with a SAH was studied in 10 goats. When pulmonary vascular resistance was in normal range (less than 15, 000 dynes. sec. cm
-5. Kg) and also right atrial pressure was kept at 10-18mmHg, circulation was well maintained. The flow fluctuated between 80-120ml/Kg/min and mean arterial pressure was kept above 80mmHg. Goats behaved quite normal but pleural and visceral effusion were noticed after 4 days. Maintenance of total protein level above 6.0g/dl could delay the appearance of effusion. The longest survival time to date is 32 days.
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C. M. WEI, M. IMURA, R. HATTORI, K. SAITO, M. FUKUYAMA, I. YADA, H. YU ...
1986 Volume 15 Issue 2 Pages
596-599
Published: April 15, 1986
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The left heart bypass (LHB) experiments (left atrium-aorta) were performed in failing hearts of fifteen mongrel dogs using a centrifugal pump. The LHB flow ratio (LHB flow×100/LHB flow+ascending aortic flow) vary in 50%, 75% and 100% (maximum flow). Coronary sinus blood flow (CSBF), myocardial oxygen consumption (MOC), myocardial blood flow (MBF) and right ventricular (RV) E max were studied before and during LHB. During maximum LHB flow, although significantly reduction of left ventricular (LV) movement were obtained, the contriction capability of RV notably decreased due to LV decompression. In conclusion a 75 percent LHB flow is appropriated for the balance of two ventricular functions.
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-Clinical and experimental study-
T. HONGO, Y. KAGAWA, N. SATO, N. UCHIDA, M. MIURA, Y. AKINO, S. NITTA, ...
1986 Volume 15 Issue 2 Pages
600-603
Published: April 15, 1986
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In most cases, partial artificial heart (PAH) was used for left heart and isolated use for right heart was very rare. Patient was a 59 year-old female with Ebstein's anomaly. TVR, plication of atrialized RV and closure of ASD were carried out and PAH was applied for profound right ventricular failure. Outflow canula was inserted via right ventricle. Patient weaned from PAH 7 days after surgery but died of acute renal failure in 18 postoperative day. Results of experimental study using goats to confirm safty and reliability of this canulation technique were reported.
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A. MIYAMOTO, T. HASEGAWA, S. KITAMURA, S. UMEDA, K. KAWANO, S. SHINDOU ...
1986 Volume 15 Issue 2 Pages
604-607
Published: April 15, 1986
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Three post operative cases with Low cardiac output syndrome were treated by Left ventricular assist device (LVAD). Two of them were weaned off from the LVAD but none of them could be survived. The indication of 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 on these cases.
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Y. MATSUYAMA, T. NITTA, A. HARADA, M. GOMIBUCHI, M. IKESHITA, S. TANAK ...
1986 Volume 15 Issue 2 Pages
608-611
Published: April 15, 1986
Released on J-STAGE: October 07, 2011
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RV failure has been recognized as a complication of LHB. The purpose of this study was to characterize RV functional change which occured during varying LV volume load. 8 dogs were subjected to roller pump LHB while RV pressure, it's first derivative (dp/dt) and contractile force (Strain gauge, SG) were evaluated. The venous return to the RA (CO) was maintained at 100ml/kg/min with 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 compaired before and after the ligation of the septal perforator (SP). Conclusion: 1) The more complete the LV decompression the more detrimental the effect on RV function. 2) Increased volume load to the LV produces an increase in RV dp/dt, but a decreased SG. 3) After ligation of the SP, RV dp/dt was unaffected despite the increased LV volume. 4) 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.
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[in Japanese]
1986 Volume 15 Issue 2 Pages
612
Published: April 15, 1986
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M. UMEZU, T. TANAKA, H. TAKANO, T. NAGATA, K. TSUCHIYA, T. AKUTSU
1986 Volume 15 Issue 2 Pages
613-616
Published: April 15, 1986
Released on J-STAGE: October 07, 2011
JOURNAL
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Hydrodynamic data, especially the water hammer (WH), for five valves (four disk and one polyurethane) were obtained to select appropriate valves for VAD pump. The results were as follows: 1) WHs by Björk-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 %-systole conditions. 2) When the disk material was changed from pyrolytic carbon to delrin, WH decreased. 3) WHs by Medtronic-Hall were slightly higher than those by BS. 4) Conduit type tri-leaflet polyurethane valves developed in our lab for VAD use, exhibited low WH as compared to disk valves.
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S. HASHIMOTO, Y. SUGIURA, T. SASADA
1986 Volume 15 Issue 2 Pages
617-620
Published: April 15, 1986
Released on J-STAGE: October 07, 2011
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The effect of the velocity gradient applying time on hemolysis was investigated quantitatively in vitro. Velocity gradients (max. 1500s
-1 (1) constant, (2) sinusoidal periodic) were applied to the heparinized canine blood contained in the concavo-convex type of testing machine for 0-120min 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 (1) and (2), and that the hemolysis ratio is bigger in the constant velocity gradient of 500s
-1 than in the sinusoidal periodic (period: 10s) variation (between 0 and 500s
-1) of the velocity gradient.
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T. MATUSDA, H. IWATA, H. TAKANO, T. NAKATANI, Y. TAENAKA, H. NODA, S. ...
1986 Volume 15 Issue 2 Pages
621-624
Published: April 15, 1986
Released on J-STAGE: October 07, 2011
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The short to long term antithrombogenic mechanisms of assist device inner-coated with segmented polyurethane were proposed in conjunction with controlled management of thrombog, enic potential especially focucing clinical cases with weaning process. The thrombogenic potential was controlled by bypass flow rate. The bypass flow rate dependency was gradually decreased as implantation period proceeds, which was rationalized by proposed multilayerd passivation mechanism.
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H. NISHIDA, T. ICHIHARA, R. SEINO, K. SOEJIMA, M. ENDO, H. KOYANAGI
1986 Volume 15 Issue 2 Pages
625-628
Published: April 15, 1986
Released on J-STAGE: October 07, 2011
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We developed new transatrialseptal cannula which can be inserted safely and quickly applicating Seldinger-like technique. This cannula has a stylet in which 0.038 inch gidewire is passable. In dog weighing 15-20kg, 100-120ml/kg/min flow was obtained using this 24Fr (ID=6mm) cannula. After 1 week insertion in left atrium, we pull back this cannula to right atrium. At that time no meaningful interatrial shunt was detected. Moreover interatrial hole was repaired and completely closed 2 week after decannulation.
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N. SATO, T. HONGO, Y. KAGAWA, N. UCHIDA, M. MIURA, Y. AKINO, T. HORIUC ...
1986 Volume 15 Issue 2 Pages
629-632
Published: April 15, 1986
Released on J-STAGE: October 07, 2011
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A VAD system for postoperative pediatric patients weighing 3-10kg is under development in our institute. Cannulae are designed on the basis of anatomical studies on 25 cases of congenital heart deseases within that body weight range. The fabricated outflow cannula has a EPTFE graft of 5mm φ on its end. The tip of inflow cannula has an inner diameter of 5mm. In vitro and in vivo evaluations of those cannulae were done in combination with a small pneumatic pump which has the stroke volume of 15ml. The system demonstrated output of more than 1.0L/min in a moc-circulation and up to 900ml/min in an acute animal experiment under the conventional driving conditions.
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[in Japanese]
1986 Volume 15 Issue 2 Pages
633
Published: April 15, 1986
Released on J-STAGE: October 07, 2011
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T. SHIMOOKA, Y. MITAMURA, E. OKAMOTO, T. MIKAMI
1986 Volume 15 Issue 2 Pages
634-637
Published: April 15, 1986
Released on J-STAGE: October 07, 2011
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The assist pump control system, using only indirectly measured arterial pressure and atrial pressure was developed. In the 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 drive rate.
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Y. AKINO, M. MIURA, N. UCHIDA, N. SATO, T. HONGO, Y. KAGAWA, T. HORIUC ...
1986 Volume 15 Issue 2 Pages
638-641
Published: April 15, 1986
Released on J-STAGE: October 07, 2011
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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 to extracorporeal circulation and 11 cases fall into severe LOS. In 12 cases, there were some doubts about complete surgical repair of complex cardiac anomalies or surgical indications. Assisted circulation were performed in 5 cases, but all in vain because of interstitial edema or bleeding problems. From this analysis, 7 cases seemed to be candidates for partial artificial heart.
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N. Takahiro, [in Japanese], [in Japanese], [in Japanese], [in Japanese ...
1986 Volume 15 Issue 2 Pages
642-645
Published: April 15, 1986
Released on J-STAGE: October 07, 2011
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On driving pulsatile pump, the water hammer phenomena occur at the vicinity of the valves. The water hammer causes valve fracture and hemolysis. We examined how to reduce the water hammer, which we evaluated as maximum pressure gradient across the valve, in in-vitro mock circulation system with four parameters; valve type, material and shape around valve, and pump diaphragm thickness. The results were as follows. 1) To employ polyurethane valve with thick leaflets. 2) To diminish Young's modulus of material around valve. 3) To place valsalva rasp behind valve, especially in case of employing polyurethane valve with thin leaflet.
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S. NITTA, Y. KATAHIRA, T. YAMBE, M. TANAKA, Y. KAGAWA, T. HONGO, T. HO ...
1986 Volume 15 Issue 2 Pages
646-649
Published: April 15, 1986
Released on J-STAGE: October 07, 2011
JOURNAL
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Piezorsistive pressure sensors and ISFET micro sensors (pH, Pco
2) for the use of the information from circulatory condition during a left ventricular assist device (LVAD) pumping have been developed and evaluated. These micro sensors were built in the inflow and outflow cannulae. Micro pressure 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.
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