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[in Japanese]
1998 Volume 27 Issue 1 Pages
1
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
JOURNAL
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[in Japanese]
1998 Volume 27 Issue 1 Pages
2
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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Seiko ENDO, Toru MASUZAWA, Eisuke TATSUMI, Yoshiyuki TAENAKA, Takeshi ...
1998 Volume 27 Issue 1 Pages
3-7
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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We evaluated the heat transfer characteristics of an electrohydraulic total artificial heart (EH-TAH) that have been developed at our institute. In two in vitro experiments, the heat dissipation way of the TAH was investigated. First, we simulated heat transfer of the calf circulation by using a heat exchanger. The amount of heat dissipating directly from the TAH surface and that to the blood chamber were estimated to be almost the same. Second, the temperature of the actuator examined with thermography was found to be almost uniform, and no prominent high temperature area was observed. In an to vivo study, the TAH was implanted in a calf weighing 62kg for 10 days. The input power to the device was 18±2 W, the temperature of the actuator-tissue contacting surface was 39-41°C. This slight temperature elevation was thought to be attributable to the heat dissipation to the blood. Upon histological study of the chest wall and the lung in contact with the actuator, vascularized connective tissue envelopes were observed and unfavorable side effects such as tissue necrosis were not observed. These results suggest that the thermal effect of this system is acceptable at this input power
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Yumiko HORI, Takeshi NAKATANI, Yoshikado SASAKO
1998 Volume 27 Issue 1 Pages
8-12
Published: February 15, 1998
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Rehabilitation for the patients with Ventricular Assist System. It is obviously crucial for patients with ventricular assist system(VAS) to nomal physical activity by rehabilitation. We have proposed a systematic program for rehabilitation during and after support by V A S.Since 1994, 5 patients underwent ventricular assist using a device of the National Cardiovascular Center type. In patients on VAS, rehabilitation was carried out by 4-grade method; that is, exercise load tests on bed, in upright position, on 100m walking, and by cycling. When tolerance became satisfactory in a grade, the next stage of exercise load was attempted. In patients coming off V A S, we chose 7-graded exercise loads, which were on bed, in upright position in the room, on 50m, 200m, and 500m walking, by Master half, and by Master single. This programmed rehabilitation proved to be efficient. Early introduction of rehabilitation did not cause major problems, but condition of patients befor VAS were related to that after application of VAS. Gradual up grade of rehabilitation was likely important after coming off VAS, particularly within its former 3 stage, and in crease of heart rates as well as clinical symptoms of cardiac failure should be carefully noticed if present
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Yuka NISHIHARA, Chiemi MIZUKAMI
1998 Volume 27 Issue 1 Pages
13-16
Published: February 15, 1998
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It has been reported that ventricular assisting device (VAS) can work efficiently, in terms of physical aspect, in patients with severely impaired cardiac function. In contrast, however, treatments for psychological depression in the candidates to be submitted to this kind of circulatory support have yet to be established. Psychological status and mental depression were evaluated in 2 patients undergoing bridge use of VAS to heart transplantation. Mental status was investigated using the egogram method proposed by the group the University of Tokyo, and anxiety of the patients was digitised by STAI technique. In addition, SDS was used for objectivelynoting a change in depression, which can be an indicator of mental health. It proved that each anxiety in these patients was treated within themselves by taking a pattern of behaviour character-istically seen in a certain mental tatus against the anxiety potentially present. It is recommended, therefore, that mental status is to be investigated in candidates for VAS, and that the hidden anxiety should be objectively noted so as to establish the optimal psychological treatment after initiation of VAS for circulatory support
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E. UEZINO, Y. YAMAGUCHI, C. MIZUKAMI
1998 Volume 27 Issue 1 Pages
17-19
Published: February 15, 1998
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In patients having a progressively deteriorated general condition and wating for cardiac transplantation, ventoricular assisting device (VAS) is undoubtedly effective so as to improvetheir physical circumstances. Their quality of life, however, is not necessarily ideal. At our institution, 5 patients have undergone circulatoly support using VAS. In one of these, coming off VAS could be successfully achieved because of fortunate recoveryof ventoricular function.Quality of life was evaluated in this paticular patient in terms of physical and phychosocialaspects digitised by Sickness ImpactProfile (SIP), as well as degree of depression by Self rating Depression Scale(SDS) which can be an indicator of mental health. Physically, an impact score was increased by initiation of VAS, and extention of ADL decreased the impact. It was decreased still further with stable course after coming off VAS. As for phychosocial aspect, although change in score was similar to that seenin the physical aspect until ADL was considerably extended, it proved that prolonged use of VAS was a deleterious factor, increasing again the impact in this patient. SDS demonstrated no influence of initiation and termination of VAS on mental depression in this case
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Masaya KITAMURA, Kazuhiko UWABE, Fumitaka YAMAKI, Hideaki NAKANO, Akih ...
1998 Volume 27 Issue 1 Pages
20-24
Published: February 15, 1998
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We evaluated drive-modes and parameters of Zeon and Novacor left ventricular assist systems (LVAS) for appropriate drive-control in the short-term and long-term after operation. In control of the Zeon LVAS, pump ejection in the early diastole of the native heart with an intra-aortic balloon support in the late diastole was effective for cardiac recovery from postcardiotomy heart failure. Of 5 patients with the Zeon LVAS, 3 were weaned from the LVAS and 2 were discharged from the hospital. In the drive-control of the Novacor LVAS, specific setting of of the fill rate trigger mode as a counter-ejection was most appropriate for reduction of cardiac pre-and after-load and stable cardiac output. During 6 months after the Novacor implantation, gradual recovery of the native left ventricle was confirmed by means of echocardiography. However, the ventricular recovery did not reached the level of weaning from the Novacor LVAS. The patient underwent orthotopic heart transplantation after 7 months of the Novacor LVAS bridge, and he has survived with excellent general condition for over 1 year
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M. NAKAMURA, E. TATSUMI, T. MASUZAWA, Y. TAENAKA, T. NAKATANI, Y. SOHN ...
1998 Volume 27 Issue 1 Pages
25-30
Published: February 15, 1998
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The early changes in circulating blood volume (CBV) after implantation of total artificial heart (TAR) were investigated in conjunction with the changes in volume regulating humoral factors (VHFs). CBV and VHFs were periodically evaluated in three calves implanted with an Electrohydraulic or pneumatic TAH and a control calf. The CBV significantly increased in all of the TAH implanted calves, (to 111-155% of the preoperative levels) from early postoperative stage. No consistent decrease in ANP level or consistent increase in ADH level was not observed in the TAH animals, indicating neither ANP nor ADH directly caused the increase of CBV. Renin-angiotensin system were activated in two out of three TAR-implanted animals, suggesting that the implantation of TAR did not always activate the resin-angiotensin system, although there is possible interaction between the CBV and this system. In summary, the CBV increased in the early stage after TAH implantation, and the accompanying changes in VHFs seemed to be not a primary cause of but a secondary response to the increase of CBV
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T. TATSUMI, M NAKAMURA, T. MASUZAWA, Y. TAENAKA, Y. SOHN, M NAKATA, T. ...
1998 Volume 27 Issue 1 Pages
31-36
Published: February 15, 1998
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We evaluated the basic performance of an interatrial shunt (IAS), which was made by punching a hole in the atrial septum, in accommodating the left-right imbalance in our electrohydraulic total artificial heart (EHTAH) system. In an in vitro study conducted in a closed mock circuit connected with the EHTAH, the interatrial pressure gradient changed in proportion to the amount of bronchial flow and the size of the IAS. The IAS of 4.4mm in diameter or larger maintained the interatrial pressure gradient within physiologically permissible limits when the amount of bronchial flow was 5% of cardiac output or less. A left-to-right one-way valve made of a piece of pericardium, a possible option in our IAS method, successfully prevented right-to-left reverse shunt flow through the IAS. In a chronic in vivo study using a calf implanted with the EHTAH for 10 days, a 4.5mm IAS without the one-way valve demonstrated satisfactory dynamic left-right balancing capacity with a stable interatrial pressure gradient of 4±1mmHg over a wide range of atrial pressures. No thrombus was found in or around the IAS at autopsy. We conclude that the IAS is a simple and promising means of left-right balancing in the EHTAH system
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T. IIJIMA, T. INAMOTO, E. HATOH, A. UIHKI, M. NOGAWA, T. MINOWA, M. MI ...
1998 Volume 27 Issue 1 Pages
37-40
Published: February 15, 1998
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As the implantable ventricular assist devices, continuous flow devices have advantages over the pulsatile pumps. However, the RPM control of the continuous flow pumps will require special attention, because too high a RPM will result in a suction effect in the ventricle. In this study, we have evaluated the centrifugal pump in the mock loop that simulated the left ventricular apex to aorta bypass. This simulation revealed that the bypass flow waveform of the pump correlated well with the pump motor current waveform in the low frequency range. The frequency analysis of the motor current with and without the suction effect indicated that the ratio of the fundamental to the higher order frequency components of the motor current power spectral density decreased with occurrence of the suction effect. This result was verified in vivo study using adult goats. The optimum bypass flow can be obtained by setting the RPM that is just below the suction causing RPM. Furthermore, in the BVAD simulation, we demonstrate the usefulness of the above method in estimating the changes in the left atrial pressure, controlling the RPM of the right VAD and thus minimizing the suction effect by the left centrifugal VAD
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T INAMOTO, T. IIJIMA, N. HOMDA, H MLTACH, M NOGAWA, T LLTINOWA, M MLUR ...
1998 Volume 27 Issue 1 Pages
41-45
Published: February 15, 1998
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The objectives of this study were 1) to design completely implantable total artificial heart (TAH) and ventricular assist device (VAD) intended for 60Kg adults, and 2) to investigate the reliable, effective and physiologic control methods. The TAH is one-piece design with a miniature DC brush-less motor and planetary roller screw being sandwiched between the left and right pusher-plate type blood pumps. The TAH is operated lathe altemate ejection mode. The stroke volume is 60cc and nominal pump output is 4-5L/min with the maximum flow of 8l/min The blood contacting surfaces including pump housing, flexible diaphragm and inflow and outflow valves are made from polyurethane. The pump dimension is 90mm in diameter and 73mm in thickness. The pump volume is 440cc with weight bang 500g. The VAD is made using same components of the TAH and its volume and weight are 370cc and 560g, respectively. As the control methods, we investigated 1) Hall effect sensor based control, 2) invasive physiologic control and 3) noninvasive physiologic control. The TAN and VAD can run effectively and reliably with the Hall effect sensor based fill/empty operation. However, during exercise when oxygen consumption rapidly increases, the secondary control method may be necessary. The mixed venous oxygen saturation measured using reflectance optical sensor comes well with the oxygen oonsumption, allowing control of pump output. Thirdly, we looked into applications of noninvasive physiologic measurements such as ECG and blood pressure (BP) waveform to obtain status of the autonomic nervous systems (ANS). The results indicated that ANS status can be evaluated through noninvasive BP waveform analysis, which can be possibly used to control pump output of the completely implantable TAN and VAD
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E. OKAMOTO, M. SHIMANAKA, Y. MITAMURA
1998 Volume 27 Issue 1 Pages
46-51
Published: February 15, 1998
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We have studied aremote monitoring system of artiticial heart-implanted patientusing a personal handy phone system (PHS). Information on motor rotational angle (data:7bits+flag:1bit) and motor current (data:7bits+flag:1bit) of an implantable motor-driven assist pump was fed into a mobile computer for the transmission control outside the body from an implantable controller(16 bit one-chip microcomputer) according to 32 bits command codes from a host computer in a hospital. Each of three pairs of motor current data and motorrotational angle data from inside body were framed to gether with a control code (frame number and parity), and sent through the PH S connected to the mobile computer. The transmitted signals could be fed into a host computer for patient monitoring via a modem in a poor electric wave environment. The host computer calculated pump stroke and pump outflow and motor current based on the information, and showed real time waveforms on a computer display. When the host computer found error frames, the host computer sent the mobile computer a resend message with the broken frame number. This communication protocol contributed to reduce error-data transmission through the PHS.The developed system is useful for monitoring artificial heart-implanted patients
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—FROM THE SECOND GENERATION DEVICE TO THE FOURTH GENERATION DEVICE—
T. Sueda, M. Sueshiro, K. Orihashi, [in Japanese], Y. Matsuura
1998 Volume 27 Issue 1 Pages
52-55
Published: February 15, 1998
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Technical and instrumental advance of various AICDs is discussed. The second generation device (CPI, Ventak P1600) can work as a cardioverter device, but has not the ability for back-up pacing or antitachypacing. The third generation devices (Medtronic, PCD and CPI, Ventak PRXII) has both abilities for pacing and cardioversion. But these devices have large bodies (weight 197-235g) and their defi-brillating efficiencies are not sufficient. These devices should be implanted into abdominal subcutaneous space, in addition to supplemental implantation of subcutaneous patch leadinto the chest wall. The fourth generation device (Medtronic, Jewel Plus PCD and CPI, Ventak mini) can be implanted into the chest subcutaneous space and the subcutaneous patch lead is not required because defibrillating efficiency is improved by using biphasic shock pulse.
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Tadashi OMOTO, Ryohei YOZU, Hankei SHIN, Toru MATAYOSHI, Atsuhiro MITS ...
1998 Volume 27 Issue 1 Pages
56-58
Published: February 15, 1998
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Minimally invasive cardiac surgery in patients older than 65 years old. We analized our experience of minimally invasive cardiac surgery for patients older than 65 years old (n=5) The operative procedures were mitral valve replacement (n=2), mitral valve plasty (n=1), excision of left atrial myxoma (n=1) and aortic valve replacement (n=1). All patients underwent autologous blood donation preoperatively. For safety and efficiency, some technical or mechanical supports were needed such as sternum spreader for MICS, cardiopulmonary bypass circuit system for MICS, extracorponeal defibrillator, and transesopha eal echocardiography. Length of chest skin incision of was 7-10cm. Ischemic time was 127±29 mmn and total perfusion time was 240±49 min. 2 patients (40%) had homologous transfusion erioperatively. No major complication was noted and average hospital stay after operation was 20±7 days. Although MICS may decrease wound pain, shorten hospitalization and reduce cost, long term follow up is required to decide its applicaion.
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Anai H, Hadama T, Araki K, Oshikawa M, Mori Y, Shigemitsu O, Miyamoto ...
1998 Volume 27 Issue 1 Pages
59-62
Published: February 15, 1998
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Comprehensive hemolytic characteristics in centrifugal(CP), mixed-flow(MFP) and axial-flow blood pump(AFP), that had same size impellers(20mm in diameter), were investigated. Hemolytic tests were performed at several driving points. In CP, hemoglobin isolation dose per hour(Δf-Hb) was correlated with pump output power(OP). In MFP, Δf-Hb increased according to increase of OP when OP was lower than 1 watt, and decreased according to increase of OP when OP was higher than 1 watt. In AFP, Δf-Hb correlated with OP in two groups. Δf-Hb tended to correlate with pump speed in the CP and AFP. Relationship between Δf-Hb and pump efficiency was not observed clearly in any pump. We believe that MFP had a peculiar hemolytic characteristics because flow pattern change in the impeller due to driving point was complicated much more than other pumps.
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Yukio OHASHI, Eiki TAYAMA, Don B. OLSEN, Robert BENKOWSKI, Deborah MOR ...
1998 Volume 27 Issue 1 Pages
63-67
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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An axial flow ventricular assist device, DeBakey VAD, will be used for bridge to transplantation in the near future. At Baylor College of Medicine, basic studies of pump design and short term ex-vivo implantations have taken place. These studies successfully evaluated histocompatibility and long-term reliability. Six in vivo implantation were performed in bovine weighing around 100kg. The inflow cannula was inserted into the left ventricle through the apex and outflow was anastomosed to the descending aorta. The pump was placed into the chest cavity and controlled outside of the body. The bovine reached post-operative days 26 to 72 with the exception of one surgical failure model. The pump outflow was excellent in the last five cases where an L-shaped inflow cannula was employed. Plasma free hemoglobin was maintained less than 5 mg/dl in each case. No thromboembolic event was detected, even though a small ring thrombus was on the pump bearing in one case. Electrical problems derived from the driving line were observed in three cases, however, minor modifications will solve this problem. The results of this study demonstrates that the DeBakey VAD is promising as a long-term implantable cardiac assist device.
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H. Sakurai, M. Maeda, M. Nakayama, H. Takemura, M. Hayakawa, T Sugiura ...
1998 Volume 27 Issue 1 Pages
68-71
Published: February 15, 1998
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In the present study we investigated the changes in contact factors in cardiopulmonary bypass (CPB) using hemofiltration (HF) for priming blood. Red cell concentrates containing MAP (RC-MAP) and albumin solution were used for the pnming. Blood samples were collected from RC-MAP, priming solution before and after HF, hemofiltrate and patient before CPB, and 60 minutes after CPB and at the end of CPB. In 10 cases, high molecular weight kininogen (HMWK), prekallikrein (PK), factor XII (F XII) and bradykinin (BK) levels were examined in each sample. Through hemodilution and contact with the CPB circuit, HMWK, PK and F XII were consumed and a large quantity of BK was generated, but BK was hemofiltrated well. At the beginning of CPB, HMWK, PK and F XII were significantly decreased, since then they were not significantly changed. BK was not significantly changed during CPB. Because BK increases vasodilatation and capillary permeability, HF is useful to prevent a drop in blood pressure at the beginning of CPB and for the reduction of postoperative edema, especially in neonates and infants.
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D. Kikugawa, T. Murakami, K. Endoh, A. Ishida, A. Tabuchi, I. Morita, ...
1998 Volume 27 Issue 1 Pages
72-75
Published: February 15, 1998
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ECMO is effective in supporting the patients who have cardiopulmonary failure after pneumonectomy. Over the last 5 years, 20 patients received ECMO. There were 15 male and 5 female patients ranging in age from 10 to 75 years (average age 62.5). Operative procedures were coronary artery bypass grafting (CABG) in 9 patients 4 for valve replacement, 3 for graft replacement of aortic aneurysm, 1 for supported PTCA, 1 for acute myocardial infarction, and two for post. pneumonectomy. Two CABG patients were weaned (22.2%), 1 patient with valve replacement was weaned (25.0%), 1 patient with graft replacement of aortic aneurysm was weaned (33.3%), 1 patient with pneumonectomy were weaned (100%). Regarding to the supporting time, there was no significant difference between the patient group who were weaned from the ECMO and who were not weaned. ECMO was effective in supporting cardiopulmonary failure, especially for the patients who had righr heart failure following pneumonectomy.
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A Kobayashi, S Shirrokawa, T Ushijima, T Kinjo, H Masuda, K Hisatani, ...
1998 Volume 27 Issue 1 Pages
76-80
Published: February 15, 1998
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The factors influencing systemic vascular resistance(SVR) during cardiopulrrnnary bypass (CPB) were evaluated in 39 patients who underwent cardiac surgery(CAB:15, valve surgery: 19). There was no change in SVR during CPB between CABG and valve surgery. In the patients having CABG, additional evaluation was performed. The increased SVR was related to an older age and concomitant diabetes mellitus. Isoflurane strongly decreased SVR. Immediately after separation from CPB, low hematocrit value, which resulted fran the delay of timing of hemoconcentration, became one of the causes of decreased SVR.In the patients having CABG with isoflurane anesthesia, and also with low hematocrit value after weaning off CPB, an adequate use of vasoconstrictor is required.
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A. FUNAKUBO, Y. Fukui, I. Sakuma, T. HIGAMI, T. KAWAMURA
1998 Volume 27 Issue 1 Pages
81-86
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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Gas transfer performance of a membrane oxygenator is under the influence of the behavior of the blood flow patterns. Thus, to optimize design of a membrane oxygenator, it is very important to examine the flow patterns in detail. In an effort to improve the design of membrane oxygenators, a flow measurement system and visualization system have been developed and implemented. The flow measurement was conducted on in-vitro experiments using two types of fluids which have different conductions. In the experiments, four types of membrane oxygenators with different design were evaluated with flow measurement. The membrane oxygenators have 48 electrodes among hollow fibers inside of the housing to measure the change of the electric resistance between each electrodes.The flow visualization utilizing a computer was applied to visualize flow patterns in the membrane oxygenators. We could see the flow patterns, for example, channelling and stagnation, in 3D animation with this system. The findings from the flow visualization were that the fluids flowing depend heavily on the housing shape and winding patterns of the hollow fibers. In conclusion, the proposed flow visualization method was very effective in evaluating the flow patterns to examine of the housing design and winding pattern of hollow fibers.
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T. YAMAZAKI, H. OOSHIMA, A. Usui, M. Murase
1998 Volume 27 Issue 1 Pages
87-91
Published: February 15, 1998
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ONO-5046 is a specific inhibitor of neutrophil elastase (PMN-E). The purpose of this study is to evaluate the protective effectof ONO-5046 to lung injury that has resulted from cardiopulmonary bypass (CPB). Without thoracotomy, partial CPB (mean flow: 800ml/min) was performed for 1 hour in 12 mongrel dogs. After weaned from CPB, dogs were regulated to maintain hemodynamics and were made observation for five hours. Dogs were divided into two groups: group ONO (n=6); ONO-5046 was administered continuously (15mg/kg/h) during study; group CONTROL (n=6); no drugs were used. Using respiratory index, Aa-DO2, pulmonary wet gain and microscopical findings of lung, post-CPB pulmonary function were assessed. And plasma level of PMN-E and IL-6 were measured before, during, and after CPB respectively. Respiratory index, Aa-DO2, pulmonary wet gain of group CONTROL were higher than those of group ONO. Histlogic examination revealed interstitial and intraalveolar edema in group CONTROL, but virtually normal lung architecture in group ONO. However there were no significant differences in neutrophil accumulation on lung between both groups. ONO-5046 inhibited not only PMN-E but also IL-6 activity. These results suggested that ONO-5046 has influence on network of inflammation and has protective effect to CPB-associated pulmonary damage.
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Y Tomizawa, M Kitamura, H Koyanagi
1998 Volume 27 Issue 1 Pages
92-96
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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Variety of long-term implantable medical devices have been developed and accumulated date is desired to improve the long-term result and to get to know the cause of failure. For those purpose, planning a registry system on long-term implantable medical device is important. The purpose, choice of the device to start with, the location of registry center, space, man power and funding are major factors that we had to talk about. United Kingdom has nation wide medical device registry systems including in heart valve, breast implant, pace maker, cephalic shunt tube and implantable pump. And also it has one regional joint registry system. There are two explant analysis studies in heart valve and knee joint. Three national and one regional registry centers, and two explant systems were visited and studied. The importance and possibility of the systems in Japan were discussed. It is possible to start registry of medical device, however, we have to know it is strongly desired in Japan and Japanese government is willing to give funding
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H. MIYAKE
1998 Volume 27 Issue 1 Pages
97-102
Published: February 15, 1998
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To realize medical and welfare robots, which are able to move like a human arm and hand, a pronation robot arm system (155g in weight and 300mm in length) was developed. This system had a goal of rotation a knob of the door in the daily life of patients and was composed of the Shape Memory Alloy, which performs as a human muscle. From the results of the system evaluation, the aimed goal was accomplished in the mechanical pronation properties of movement angle, of torque, and of angular velocity.
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N. KABEI, R. TASHIRO, K. TSUCHIYA, F. TSUBOI, Y. ISHIGAKI, K. KATAYAMA
1998 Volume 27 Issue 1 Pages
103-108
Published: February 15, 1998
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A variable-capacitance-type electrostatic microgenrator harnessed motion of the living body was proposed and examined its performance. Three honeycomb-types variable capacitance that were the dominant part of electrostatic generator were made. Capacitance of type A model changed from 3.0 to 9.3 nF. That of type B model changed from 3.5 to 10.8 nF. That of type C model changed from 75 to 240 nF. There was big difference in layering method of the electrodes between type A model and type B or type C model. Output energy could not measure in type A model. Type B model generated 8 μJ in one cycle. Type C model generated 70 pJ in one cycle when initial supply voltage was 6 V. This means that type C microgenerator can supply enough power to operate a cardiac pacemaker if it can be vibrate over 1 Hz.
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M TANAKA, A KAWAMURA, T TAMAKI, Y KONOEDA, M TAKAHASHI, K KUKITA, J ME ...
1998 Volume 27 Issue 1 Pages
109-112
Published: February 15, 1998
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An extracorporeal circulation system in rats model has been performed mainly by direct insertion of optimal catheters into femoral artery and vein. Although this method is simple and convenient, it has been difficult to utilize for long-term repeated perfusion. In the present study, we tried extra-corporeal perfusion with the external arterio-venous (AV) fistula using a silastic tube interconnected from the carotid artery to the external jugular vein through the dorsal neck. The mean flow rate of cervical AV fistula was approximately 15ml/min. Initial perfusion was undertaken using the cut-ends of silastic tube at the flow rate of 4ml/min just before 500 U/kg of heparin was administered. Following extracorporeal perfusion, a polypropylene mini-fitting connector was telescoped into both cut-ends of silastic tube. Using cervical AV fistula, an extracorporeal perfusion was repeated three times for up to 10 days. Artificial graft and connector should be ameliorated as well as optimal dose of heparin in order to keep the patency for a long-term period.
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A MURAKAMI, M AIBA, N MURATA, M YAMADA, T MICHIHATA, K INOUE, T TAKABA
1998 Volume 27 Issue 1 Pages
113-117
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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To assess the biocompatibility of heparin-coated cardopulmonary circuits using Capiox SX, filters and tubing sets (TERUMO. CO.), we had measured as follows in group H (using heparin-coated circuits, n=9) and in group C (using ordinary circuits, control group, n=9). Compliments (C3a, C4a), granurocyte elastase (GEL), cytokines (Interleukin 6 & 8), Tumor Necrosis factor (TNF), thrombin-antithrombin III complex (TAT), fibrinopeptide A (FPA), fibrinogen, antithrombin-III (AT-III ), D-dimer, a 2-PI, renal function, liver function were measured before, during and immediately after cardio-pulmonary bypass (CPB), 24 hours after CPB (24H), and on the third operative day (3D), No statistically significant changes were found in all factors between the two groups. But peak levels of IL-6, C3a and GEL at AF in group H were lower than in group C. Furthermore, D-dimer reached its maximum value at AF in group C, but at 24H in group H. This study demonstrates the tendancy that the use of heparin-coated circuits reduce the release of IL-6, C3a, GEL and D- dimer, but the method of evaluation of organ damages should be reconsidered.
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N. HANDA, T. YASUDA, A. FUNAKUBO, Y. FUKUI
1998 Volume 27 Issue 1 Pages
118-123
Published: February 15, 1998
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During extracorporeal circulation, it has been thought that the hemolysis is caused by chemical and physical actions. There occur various forms of flow inside of the blood circuit and artificial organs. We think that the main factors which cause the hemolysis are physical factors, for example surface roughness, velocity gradient, pressure and temperature. Then, we investigated about the effects of physical factors and the complex effects of physical factors on hemolysis. In the experiments, bovine blood has been used with anticoagulant. As the result of that, we had a small amount of hemolysis about the factors of surface roughness, velocity gradient, pressure, temperature. On the other hand, we have confirmed that the complex effect has an influence on hemolysis. Especially, when the velocity gradient and pressure factor or temperature factor are addedto the blood at the same time, there occurs a higher amount of hemolysis than the single effect of a physical factor. However, it is thought that a collision stream causes hemolysis. In conclusion, we considered that it is possible to reduce the hemolysis when we could know the size of physical factors inside of the blood circuit in various conditions.
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T DAIMON, K FUJIWARA, N TANAKA, T ABE
1998 Volume 27 Issue 1 Pages
124-128
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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For two years and nine months from November 1994 untilAugust1997, Electrolysed Hyperacidity Water(EHW) was used as an agent to clean and disinfect hemodialysis equipment and tubing. lts effectivenss was examined and the results compared with the use of sodium hypochlorite and Electrolysed Hypoacidity Water (EOW). In the evaluation the long term effects of EHW use in the cleaning and disihfecting of dialysisequiprnent and tubing were assessed. During two years and nine months period of use, equipment cleaned in EHW showed excellent sterilization results in comparison with equipment cleaned using other me-thods. In the EHW soaking test, we saw small a very small degreeof.ionelution of SUS316 metal parts. However the degree of corrosion was less than 0.01mm/year, an insignificant amount. We also saw a small amount of deterioratin in resin products. Again, this presented no problems with regards to safety. From.the point of view of ster-ilization and inactivation of endotoxins, and more over from its usage characteristics, EHW has shownitself to be a highly effective and safe, with regard to the human body and the environment, agent for thecleaning and disinfecting ofhemodialysis equipment.
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—A clinical study in the elective coronary artery bypass grafting.—
Y HAMADA, K KAWACHI, T NAKATA, T YAMAMOTO, Y KASHU, M KADOTA
1998 Volume 27 Issue 1 Pages
129-134
Published: February 15, 1998
Released on J-STAGE: December 02, 2011
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We studied the clinical usefulness of heparin-coated cardiopulmonary bypass circuits (Duraflo II, H group) compared with non-coated circuit (N group) in patients with CABG. Alveolar-arterial oxygen pressure gradients (A-aDO2), respiratory index (RI) and intrapulmonary shunt (Qs/Qt) were compared. There was no significant difference in the A-aDO2 or RI. However, immediately after operation, the Qs/Qt in the N group increased significantly more than that in the H group (p<0.05). Six hours after operation, the difference between both groups in the Qs/Qt disappeared in the intensive care unit. There was no difference in the cardiac performance, liver function, renal function or the time of intubation and ICU stay between these groups. These results indicate that the heparin-coated circuits may be beneficial for these patients with preoperative lung dysfunction.
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Yukio ICHIKAWA, Hirokazu KAJIWARA, Toshiyuki HAMADA, Ichiya YAMAZAKI, ...
1998 Volume 27 Issue 1 Pages
135-139
Published: February 15, 1998
Released on J-STAGE: December 02, 2011
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In the present study of one hundred patients undergoing coronary bypass, heparin-coated circuits were evaluated compared with non coated circuits. In 50 patients, heparin-coated circuits were used with initial dose of heparin 1 mg/kg (ACT>300 seconds) (group H), and 50 served as control patients with initial dose of heparin 3mg/kg (ACT>400 seconds) (group N). In the group H, the heparin and the protamine dose were reduced to a third compared with those in the group N. There was a significant decrease of platelets in the group N (p=0.001). Blood loss through chest tube drainage in the first postoperative day (360±144 for low versus 506±329 ml for full) (p=0.005) and blood transfusions (466±765 for low versus 969±1417 ml for full) (p=0.03) were significantly decreased, and the chest tubes were pulled out significantly earlier (4.0±1.1 for low versus 4.4±1.1 days for full) in the group H. The total operation time (366±64 for low versus 421±103 min for full) (p=0.002) and the operation time after the pump was stopped (125±29 for low versus 147±54 min for full) (p=0.01) were also significantly decreased in the group H. The time required for the arrest of bleeding in the group H was considered to be shortened than that in the group N.
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S. MURATA, T. INO, H. ADACHI, A. YAMAGUCHI, H. KAMIO
1998 Volume 27 Issue 1 Pages
140-143
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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We evaluated seven patients (group L) introduced heparin coated percutaneous cardiopulmonary support (PCPS) systems maintained over 7 days. The causes of introduction were postcardiotomy shock in 2, acute fluminant myocarditis in 4, acute massive pulmonary embolism in 1. The average age (45.0±17.8) was younger than that (64.0±10.6) of the 55 patients (group S) supported by PCPS within a week. Six patients of group L weaned from the support and five discharged from the hospital, but there was no statistical difference between group S in the weaning and survival rate. Massive hemolysis was observed in three of the group L after 4 or 5 days. The newly developed heparin coated PCPS system may have a feasibility to use over a week. However it seems important to prevent infections and to care attentively for prolonged cardiopulmonary support.
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H. FURUKAWA, M. HACHIDA, M. KITAMURA, A. KAWAI, S. AOMI, H. NISHIDA, M ...
1998 Volume 27 Issue 1 Pages
144-146
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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Circulatory assist using a percutaneous cardiopulmonary support system (PCPS) was performed in 5 patients with non-surgical cardiogenic shock over the past 6 years. Their diagnoses were 3 cases of dilated cardiomyopathy (DCM), 1 acute myocardial infarction (AMI), and 1 acute myocarditis. The causes of circulatory assist were 4 cases of severe arrythmia, such as ventricular tachycardia (VT) and ventricular fibrillation (Vf). Survival rate was 20% (1/5); the cause of death in 4 cases was multiple organ failure (MOF). Parameters of renal and liver function during circulatory assist using PCPS were elevated from 3 days after starting circulatory assist. Platelet count was also decreased from 3 days after starting circulatory assist. Therefore, we think that the use of a ventricular support system as a mechanical bridge for cardiac transplantation should be considered at the stage when signs of MOF are absent while the patient is receiving temporary veno-arterial bypass (VAB).
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A. IWAKURA, Ch PARK, A. YAMAZATO
1998 Volume 27 Issue 1 Pages
147-149
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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Percutaneous cardiopulmonary support (PCPS) was instituted in 25 patients with acute circulatory failure. There were 16 male and 9 female patients ranging in age from 47 to 82 years. The causes of bypass initiation were acute myocardial infarction (12), post-infarction left ventricular rupture (4), Low output syndrome after coronary artery bypass grafting (4), ruptured thoracic aortic aneurysm (2), myocarditis (1), left ventricular rupture after mitral valve replacement (1), and iatrogenic right ventricular rupture (1). 14 of 25 patients underwent therapeutic interventions. The duration of support ranged from 0.25 to 64 (mean 22.3) hours. 16 patients weaned from PCPS and 11 were survived. In patients assisted within 24 hours, therapeutic interventions improved the survival rate. And some of patients assisted over 24 hours died of cardiac failure after weaned from PCPS. In conclusion, the use of PCPS for patients with acute circulatory failure achieved significant survival. To improve clinical results we should undergo therapeutic interventions as soon as possible during PCPS, and for patients assisted over 24 hours probably left heart bypass will be more effective.
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M. OSHIKAWA, K. ARAKI, K. NAKAMURA, T. ONITSUKA, H. ANAI
1998 Volume 27 Issue 1 Pages
150-153
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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We developed three types of percutaneous right ventricular assist systems (PRVAS) for severe acute cardiac failure during LVAD supporting. Type 1 PRVAS consists of inflow and outflow cannula and a extracorporeal centrifugal pump. Each cannula is placed at the right atrium and the pulmonary trunk via femoral and jugular vein, respectively. Type 2 PRVAS consists of double lumen cannula and a extracorporeal centrifugal pump. The smaller outflow cannula is set through the larger inflow cannula. Type 3 PRVAS is intra-ventricular axial flow pump which is driven by a extracorporeal apparatus of motor and flexible driving shaft with purge system. In vitro hemolytic test was performed using heparinized fresh bovine blood The flow rate 2L/min and pressure head 40mmHg were maintaned, when the pump speed of 2790, 3510 and 21100rpm were necessary in type 1, 2 and 3, respectively. The normalized index of hemolysis was 0.5, 2.9 and 0.84g/100L in type 1, 2 and 3, respectively, and unacceptable hemolysis was observed in type 2 system. In vivo evaluation using 19 mongrel dogs in type 1 (n=11) and 3 (n=8) revealed similar sufficient in assistant effect. We conclude that an axial flow pump system is simple and effective for PRVAS, comparing with a centrifugal pump system.
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H EMOTO, S HORIKOSHI, Y UNO, H SUZUKI, M UNO, H TAGUCHI
1998 Volume 27 Issue 1 Pages
154-157
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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Normothermic (36.5°C) cardiopulmonary bypass (CPB) and mild hypothermic (32°C) CPB were compared and studied. There is no significant difference in CPB time and aortic clamp time between two groups, but reperfusion time is significantly shorter in the normothermic group. Systemic vascular resistance (SVR) during CPB is significantly lower in the normothermic group. We see no significant difference in the urinary output during CPB between the both groups. There is the tendency that blood loss as long as 24 hours since the end of the operation is smaller in the normothermic group. There is no significant difference between the both groups at the time when serum levels of creatinine, GOT, GPT and platelet counts are compared on the preoperative day and on the first, second postoperative day. As the above results, normothermic CPB is surely acknowledged as a safe and effective approach.
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Tetsuo FUJIMOTO, Yasutaka MAKI, Yasuyuki SHIRAISHI, Mitsuo UMEZU, Kiyo ...
1998 Volume 27 Issue 1 Pages
158-163
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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We have been studying the opening action of a monoleaflet tilting disc valve, (Björk-Shiley Monostrut;sewing ring diameter: 23mm, BSM), and reported last year that the valve opening motion depended on the early period flow rate pattern from 0 to 20msec. This time, the Björk-Shiley Spherical and the St. Vincent's valve were tested. All three valves are monoleaflet tilting disc valves with the same disc diameter but with disc shapes that are different from each other. Each valve was incorporated in a mitral position of a mock circulatory system driven by pneumatic pressure. Changes in valvular disc angle were measured at 500 frames per second using a high speed videocamera. We found that the opening motion of the two valves depended on the early period flow rate pattern (from 0 to 20 msec;the same as the BSM valve). Using the moment of force values obtained, drag and lift coefficients (C
D and C
L) of each valve were calculated. Results showed that the C
D and the C
L were enlarged up to 3.0x10
4 at the early opening period. This result was speculated to be a cause of the influence of the flow pattern on the valve action at the same period.
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[in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
1998 Volume 27 Issue 1 Pages
164-167
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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Between 1990 and 1996 25 patients with a narrow aortic annulus who underwent aortic valve replacement with mechanical prosthetic valves, sized under 21mm were studied. There were 10 of 19mm Omnicarbon, 10 of 20mm Medtronic Hall and 5 of 19mm St. Jude Medical valves. There were 4 males and 21 females with a mean age of 61±9 years. Their mean body surface area (BSA) was 1.39±0.12m
2 There was no operative death or hospital death. Peak pressure gradient across the prosthetic valve (PG) evaluated by post operative (one year or more) doppler echocardiography was 33.3±16.8mmHg. There was no significant difference between the FG and the BSA. However, 6 out of 7 patients with over 4CmmHg of FG had a BSA of over 1.4m
2. The LVDd/Ds and LVmass index were significantly lower in the late postoperative period as compared with that of before surgery (50.7/32.6→44.1/25.6mm, 256.1±92→l71.5±54.8g/m
2). Best operative NYHA was I in 21 and II in 4 patients. NYHA improved in all patients at the end of the follow up period. In conclusion, less than 21mm aortic prosthetic valve provided satisfactory performance and acceptable in the size for elder patients with a BSA of less than 1.4m
2.
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H. S. LEE, T. SHIMOOKA, Y. MITAMURA, K. YAMAMOTO, T. YUHTA
1998 Volume 27 Issue 1 Pages
168-173
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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There are various reports on the fracture of mechanical heart valves implanted in human or animals, and they are pointed out that problems are induced by an erosion of disk surface, due to a cavitation effect. We have been investigating this mechanism using our original accelerated fatigue tester, and it was found that erosion was enhanced by a compliance effect in the test circuit. In this study, effects of compliance value and location on erosion were discussed, while disk closing velocity was measured by a high speed video camera. It was clarified that faster closing velocity was resulting in a enhancement of erosion on the disk surface.
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Y. TAKAHARA, Y. SUDOU, T. SUNAZAWA, T. SATOU, T. NAKAMURA
1998 Volume 27 Issue 1 Pages
174-177
Published: February 15, 1998
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From April 1985 to March 1994, 32 bioprostheses were implanted in the aortic position and 48 bio-prostheses were implanted in the mitral position. Actuarial freedom from overall valve-related complication at 12 years was 85% in the aortic position and 44% in the mitral position. Actuarial freedom from struatural deterioration at 12 years was 94% in the aortic position and 52% in the mitral position. However, in the patients over the age of sixty, actuarial freedom from struatural deterioration at 12 years was 100% in the aortic position and 82% in the mitral position. We conclude that the Carpentier-Edwards pericardial bio-prosthesis is good choice of the aortic and the mitral positions for the patients over the age of seventy.
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Yoshiro MATSUI, Yukio SUTOH, Jan DUDRA, Norihiko SHIIYA, Toshihumi MUR ...
1998 Volume 27 Issue 1 Pages
178-182
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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Surgical countermeasures for predictable regurgitation through an aortic stentless prosthesis, especially when the freehand method is employed, were investigated experimentally. Regurgitant flow at 100mmHg was measured under certain conditions using a porcine ascending aorta which included the valve. When one aortic cusp was injured, aortic regurgitation occured (160±18mL/min). Cusp enlargement and decreasing the size of the sinotubular junction (STJ) worsened the regurgitation. However annuloplasty eliminated the regurgitation when annular size was decreased by 30.7±6.9%. When the STJ was enlarged with three patches until it reached a size of 35.9±2.2mm (annular size;21.7±0.7mm), central regurgitation occured (54±18mL/min). When the STJ size was decreased by 22.0±6.0%, no regurgitation was observed. From this experiment, we concluded that annuloplasty and correction of the STJ size are effective countermeasures to decrease slight regurgitation through a soft aortic stentless prosthesis.
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K. NAKANO, J. KOBAYASHI, Y. SASAKO, F. YAMAMOTO, Y. KOSAKAI
1998 Volume 27 Issue 1 Pages
183-186
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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We reviewed 162 cases of valve replacement (Aortic: mechanical (M) 61, bi-oprosthesis (B) 43, Mitral: M 54, B 18) in patients more than 70 years old and 6 cases of AVR with stentless porcine valve (SPV). At 12 yeras, neither the actuari-al survival rate nor the event free rate of valve related complication were differ-ent between M and B in the aortic and in the mitral position. In the current stra-tegies, for the patient more than 70 years old, an alternative M and B are select-ed in the aortic position after informed consent and M is selected in the mitral position. The indication of the SPV is considered in the patient more than 65 years old.
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Masaya KITAMURA, Shigeyuki AOMI, Hideaki NAKANO, Fumitaka YAMAKI, Kazu ...
1998 Volume 27 Issue 1 Pages
187-190
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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Long-term results of mechanical valve replacement in 50 elderly patients (more than 70 years old) were compared with those in 403 younger patients (60-69 years old). Operative mortality was similar between two groups (elderly 6.0%, younger 3.0%). Actuarial survival (including all deaths) was relatively lower in the elderly group than that in the younger group (6-year survival 79.5%, 82.2%, respectively). Freedom from thromboembolism and reoperation free proportion was similar between elderly and younger groups. Freedom from all valve-related events after operation was relatively lower in elderly patients than that in younger patients (6-year freedom 75.3%, 79.9%, respectively). Incidence of bleeding event was higher in the elderly group than that in the younger group (2.13, 0.55%/patient-year, respectively). The above results suggest that medium-term results of mechanical valve replacement in elderly patients might be acceptable if precise anticoagulant therapy was well maintained.
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N. MIZUTANI, L. KATO, T. KOBAYASHI
1998 Volume 27 Issue 1 Pages
191-196
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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The clinical evaluation of the AIDA algorithm loaded into a dual chamber pacemaker. The importance of controlling arrhythmias following pacemaker implantation is well known. However, 24hr Holter ECGs and ambulatory ECGs often fail to detect paroxysmal arrhythmias. In this study, we prospectively evaluated the clinical usefulness of the AIDA (Automatic Interpretation for Diagnosis Assistance) loaded into a dual chamber pacemaker. Patients and Method: Fourteen patients, 9 AV Block and 5 SSS, were enrolled. Three of them showed documented paroxysmal atrial fibrillation before operation. The study was divided into two periods as D
1 and D
28During the D
1follow-up the pacemaker data recorded with the AIDA program over 24 hours was compared with that of a simultaneous surface Holter recording. The prevalence of atrial arrhythmias at D
28was calculated from the data recorded over the previous 28 days and automatically analyzed by the AIDA program. Result: Eighteen atrial arrhythmias were successfully recorded in 8 patients by the AIDA program and coincided with simultaneous surface Holter ECGs at D
1.A large incidence of asymptomatic arrhythmia was demonstrated by using the AIDA program in patients without prior history of atrial arrhythmia at D
28 Conclusion: The AIDA study demonstrated that the AIDA program of a pacemaker is useful to evaluate the prevalence of arrhythmias, especially the detection of asymptomatic anythmias. In addition, drug therapy maybe better assessed using this AIDAprogram.
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H. NAKANO, K. HIRATA, A. SHIIKAWA, K. HAYASHI, T. AKIMOTO, H. KOYANAGI
1998 Volume 27 Issue 1 Pages
197-201
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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Twenty-one 4th generation ICDs were implanted in our institute from April, 1995 to April, 1997. Two electrodes system in the 4th generation ICD often used the metallic housing of the ICD, so-called “Can” RV configulation. Two cases were required the change of the configulation of 2 electrodes (RV “Can”). In one of them, SVC lead was used together. In other 2 cases who had been removed of the 3rd generation ICDs with infection, new ICDs were implanted on the right chest wall. Induced VTs/vfs for DFT tests after implantation at the right side could be terminated by two-electrode system with low DFTs and impedances. The change of direction of shock delivery and the right chest wall implantation of the 4th generated ICD did not influence the impedance at defibrillation. The 4th generated ICD might be efficacious for treating life threating arrhythmias in the place of the 3rd generation ICD requiring the subcutaneous patch electrode and inclease the flexibility of site of implantation.
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K. KUKITA, M. OSANAI, M. YASUHARA, M. NAITOH, Y. TAKAHASHI, M. TANAKA, ...
1998 Volume 27 Issue 1 Pages
202-205
Published: February 15, 1998
Released on J-STAGE: December 02, 2011
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One of the troubles after setting dual lumen catheter into veins is so called “Attachment phenomenon”. It occurs by attachment of arterial side holes to the venous wall when extracorporeal circulation is done. In order to avoid “Attachment phenomenon”, a dual lumen catheter with a balloon between arterial and veneous holes (B-DLC) is developed. The balloon is blown up with 2ml saline on hemodialysis (HD) procedure. Fifteen HD patients received the catheter and the tips were positioned in the superior vena cava or common iliac vein. The balloon was blown up in only the HD procedure in 12 cases. In the remaining 3 cases, HD was performed without balloon inflation like a usual catheter. The catheter was retrieved at 10 to 28 days. In the former cases, one case had redness of the inserted portion. Two cases had thrombus episodes. In the latter cases, one was observed the “Attachment phenomenon”, so the balloon inflation was useful to get sufficient blood flow. The remaining cases had no trouble. Although some troubles such as thrombus and infection are still need to be resolved, B-DLC is useful to prevent “Attachment phenomenon” on HD procedures.
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M. MINESHIMA, I. KANEKO, T. SANAKA, T. AGISHI
1998 Volume 27 Issue 1 Pages
206-211
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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In order to establish a simple and precise in vitro evaluation for hemofilter performance, dextran testing method(DTM) was introduced in high ultrafiltration therapies such as hemofiltration(HF) and hemodiafiltration(HDF). Three types of experiments were carried out: hemodiaysis(HD), HDF and HF experiments. Value for a filtration flow rate(QF) was changed from 7.5 to 193 ml/min in HDF and HF experiments. Dextran concentration was determined by a GPC method. From these results, a relationship between clearance(CL) and molecular wegiht (MW) of dextran and a relationship between apparent sieving coefficient(SC) and MW were easily obtained by the method. And these relationships strongly depended on QF value due to concentration polarization near the membrane and solute condensation along the filter. DTM is an useful method for performance evaluation of hemofilter because widely and densely ranged dextrans can be utilized.
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M. FUKUDA, M. MIYAZAKI, T. HIYOSHI
1998 Volume 27 Issue 1 Pages
212-216
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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((BIOREX AM-BC-F)) is the new cellulosic membrane of which the inner surface is smoother than that of conventional cellulosic membrane, and alkyl ether carboxylic acid(polyethylene glycol) chain is grafted onto the inner surface of the membrane. ((AM-BC-F)) is produced by the new spinning method ((FIS(Fine Inner Surface) Technology)). It can be expected that it reduces hydrodynamic resistance between blood and the membrane. And it reduces complement activation in vivo, because rapid movement of the flexible PEG chain, ((Diffusive Layer)), leads to less interaction between blood and membrane.
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H. KAWANISHI, K. YAMANAKA, S. TSUCHIYA
1998 Volume 27 Issue 1 Pages
217-221
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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On-line preparation of substitution fluid by bicarbonate buffered dialysate permits virtually unlimited fluid volume exchange during continuous hemodiafiltration (CHDF) to intensive care. In on-line hemodiafiltration (HDF), endot-oxin free dialysate obtained using pyrogen cut filters is infused into the blood circuit, and HDF is automati-cally performed using the close-loop balancing system of the dialysis machine. On-line CHDF is another application of on-line HDF to continuous renal replacement therapy in the intensive care field. The pyrogen cut filter was inserted before the dialysis machine for removal of endotoxin in reverse osmosis water line (pre-filter). The first filter was placed at the outlet of the dialysis machine, and filtrate of dead end filtra-tion was used as dialysate. Part of this dialysate was passed through the secondary filter by cross filtration and used as substitution fluid. The first and secondary filters were exchanged in each patient. Endotoxin concentration in the filtrate of pyrogen cut filter was measured daily during therapy. Total treatment time with on-line CHDF in 31 patients 2, 570 hours during a 9-month period, during which period, neither me-chanical abnormalities nor dialysate contamination due to the failure of the system occurred. We conclude that on-line CHDF system is safe and effective in treating organ dysfunction patients.
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K. NAKAZAWA, H. IJIMA, M. KANEKO, T. ITO, T. MATSUSHITA, T. GION, K. S ...
1998 Volume 27 Issue 1 Pages
222-226
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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In this study, we determined optimum culture condition of primary porcine hepatocytes for development of hybrid artificial liver using polyurethane foam (PUF) / spheroid culture. Optimum components of culture medium were investigated in stationary culture using PUF plate (25×25 × 1mm). Immobilized cell density and intracapillary medium velocity in multi-capillary (MC) PUF packed-bed module (volume: 18.8 cm
3) were estimated in perfusion culture. As a result, porcine hepatocytes formed spheroid spontaneously and maintained ammonia metabolic activity in Williams'E medium supplemented with 10 to 20% PBS. And high activities of ammonia metabolism and albumin secretion were performed at the immobilized cell density of 1.0 × 10
7 cells/cm
3-module and at the intracapillary medium velocity in a range of 60 to 80 cm/min. This study provided optimum culture condition for hybrid artificial liver module using PUF/porcine hepatocyte spheroid culture.
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M. HOSHINO, Y. HARAAGUCHI, M. SAKAI, H. SAEGUSA, K. HAYASHI, H. OHSAWA
1998 Volume 27 Issue 1 Pages
227-232
Published: February 15, 1998
Released on J-STAGE: October 07, 2011
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We studied the accuracy of blood glucose mesurement by artificial pancreas (STG-22 and STG-11A, made by NIKKISOH corporation in Japan). The factors which made the error of measured blood glucose level(BG
AP) were investigted in terms of 1)patient condition, 2)blood sampling catheter, 3)connecting tube between the catheter and artificial pancreas, and 4)artif icial pancreas itself. Blood sampling catheter was inserted into superior vena cava(SVC). We also performed experimal study related to 3) and 4). [Results] 1)Factors which increased BG
AP were, increased SVC pressure, elevation of position of the sampling tube that made blood dilution ratio at the catheter tip increased, vicinity of the sampling catheter tip and IVH line catheter tip, and electric artifact. 2)Factors which decreased BG
AP were, occlusion of the catheter tip by blood clot or by SVC wall, blood clot adherence to the blood glucose measuring electrode, and narrowing of the sampling tube. [conclusion] It is important to understand factors which influence BG
AP for effective use of artificial pancreas, which should be excluded immediately.
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