bluuebunny/crossref_metadata_2025 huggingface dataset:
Immobilized Heparin Inhibits the Increase in Leukocyte Surface Expression of Adhesion Molecules
Authors: Garred Peter , Mollnes Tom Eirik
Published: July 2010

Abstract: The effect of heparin coating of artificial materials on the surface expression of leukocyte surface molecules was assessed in blood from 9 donors in an experimental model of extracorporeal circulation. The leukocyte surface molecules CD11b, complement receptor type 3 (CR3). and CD45. leukocyte common antigen (LCA), on granulo‐cytes and monocytes exposed to unmodified polyvinyl chloride tubes increased significantly compared with unmanipu‐lated controls (p < 0.001) whereas a very modest and nonsignificant increase was observed in blood circulated in heparin‐coated tubes. Accordingly, a highly significant reduction in expression of the 2 molecules was achieved by heparin coating (p < 0.001). The expression of CD11b and CD4.5 correlated with the degree of complement activation in plasma (rho = 0.6, p = 0.003). The expression of CD14 (endotoxin receptor) and CD16 (Fcy III receptor) was increased to the same extent in blood from unmodified and heparin‐coated tubes (p < 0.02), and no correlation to complement activation was seen (rho = ‐0.27.5, p = 0.17 and rho = ‐0.004, p = 1, respectively). In conclusion, heparin coating of artificial surfaces has a substantial effect, reducing the expression of molecules involved in cellular adhesion and activation (CD11b and CD45), and the increase of these molecules by unmodified surfaces is complement dependent. In contrast, up‐regulation of other surface molecules (CD14 and CD16) seems to be independent of heparin coating and complement activation and, thus, might be regulated by other mechanisms.
Study of the Effect of Atrial Contraction on Mitral Prosthetic Valve by High Speed Video Camera
Authors: Naemura K. , Sonderegger M. , Matsumoto H. , Dohi T. , Izumi K. , Fujimoto T. , Umezu M. , Ota Y.
Published: July 2010

Abstract: To clarify the effect of atrial contraction on the dynamic behavior of mitral prosthetic valves, a mechanical mock circulatory system has been developed. It is able to simulate the inflow characteristics during diastole. The disc motions of Björk‐Shiley Monostrut (BSM29) and Car‐boMedics (CM29) valves (both with an annulus diameter of 29 mm) were measured and compared with a high speed video camera. After contraction of the artificial atrium (100 ms), there was a delay of 75 ms before the onset of the ventricular contraction. Mitral flow similar to physiological conditions could be achieved. The BSM29 was tested in the anterior position (a) and the posterior position (p). Under the condition of active atrial contraction (AC), we confirmed that the closing motion was initiated and the period during closing motion (PDCM) was prolonged (BSM29[a]: 22.4 ± 3.4 ± 63 ± 3.2; BSM29[p]: 71.2 ± 38 ± 94.2 ± 11; and CM29:14 ± 0.0 ± 28.4 ± 2.3 [unit: ms]), the prolongation of the PDCM of the CM29 due to the AC being smaller than that of the BSM29. We also confirmed that the closing volume (CV) increased slightly (BSM29 [a]: 7.8 ± 0.4 ± 8.5 ± 0.8; BSM29[p]: 6.9 ± 0.6 ± 7.0 ± 0.5; and CM29: 3.6 ± 0.6 ± 4.1 ± 0.6 [unit: ml]). The CM29 had a shorter PDCM, less prolongation of the PDCM due to the AC, and less CV than the BSM29. Thus, we confirmed that the CM29 produced better response at valve closure than the BSM29.
Eccentric Inlet Port of the Pivot Bearing Supported Gyro Centrifugal Pump
Authors: Takami Yoshiyuki , Andrade Aron , Nakazawa Tadashi , Makinouchi Kenzo , Glueck Julie , Benkowski Robert , Nosé Yukihiko
Published: July 2010

Abstract: An eccentric inlet port is a unique feature of the pivot bearing supported Gyro Compact‐1 Eccentric Inlet Port Model 3 (ClE3) centrifugal pump, a completely seal‐less centrifugal pump. The latest C1E3 has an eccentric inlet port with a 30 degree vertical angle. To investigate the adequacy of this 30 degree angle, flow visualization studies and in vitro hemolysis tests were performed, comparing 4 pumps, each with a different angle of the eccentric inlet port (0, 30, 60, and 90 degrees). The flow visualization study utilizing a tracer method focused on the flow pattern just distal to the inlet port of each pump, and each pump was operated at 5 L/min against 100 mm Hg and 5 L/min against 350 mm Hg. In the pumps with angles of 90 and 60 degrees, the flow direction changed horizontally, causing a vortex formation. In the pump with the 30 degree angle, the inflow did not change its course, resulting in minimal space for vortex formation. In the pump with the 0 degree angle, the inflow collided with the pump housing, resulting in a small vortex formation along the housing surface. The in vitro hemolysis tests at 5 L/min against 350 mm Hg revealed that the pump with the 30 degree angle was the least hemolytic and the pump with the 90 degree angle was the most hemolytic among the 4 pumps. These results suggest that the angle of the eccentric inlet port of the Gyro C1E3 pump should be 30 degrees to have less vortex formation and less red blood cell trauma.
Vibration Assessment for Thrombus Formation in the Centrifugal Pump
Authors: Nakazawa Tadashi , Makinouchi Kenzo , Takami Yoshiyuki , Glueck Julie , Tayama Eiki , Nosé Yukihiko
Published: July 2010

Abstract: To clarify the correlation of vibration and thrombus formation inside a rotary blood pump, 40 preliminary vibration studies were performed on pivot bearing centrifugal pumps. No such studies were found in the literature. The primary data acquisition equipment included an accelerometer (Isotron PE accelerometer, ENDEVCO, San Juan Capistrano, CA, U.S.A.), digitizing oscilloscope (TDS 420, Tektronix Inc., Pittsfield, MA, U.S.A.), and pivot bearing centrifugal pumps. The pump impeller was coupled magnetically to the driver magnet. The accelerometer was mounted on the top of the pump casing to sense radial and axial accelerations. To simulate the 3 common areas of thrombus formation, a piece of silicone rubber was attached to each of the following 3 locations as described: a circular shape on the center bottom of the impeller (CI), an eccentric shape on the bottom of the impeller (EI), and a circular shape on the center bottom casing (CC). A fast Fourier transform (FFT) method at 5 L/min against 100 mm Hg, with a pump rotating speed of 1,600 rpm was used. The frequency response of the vibration sensors used spans of 40 Hz to 2 kHz. The frequency domain was already integrated into the oscilloscope, allowing for comparison of the vibration results. The area of frequency domain at a radial direction was 206 ± 12.7 mVHz in CI, 239.5 ± 12.1 mVHz in EI, 365 ± 12.9 mVHz in CC, and 163 ± 7.9 mVHz in the control (control vs. CI p = 0.07, control vs. EI p < 0.001, control vs. CC p < 0.001, EI vs. CC p < 0.001, CI vs. CC p < 0.001). Three types of imitation thrombus formations were roughly distinguishable. These results suggested the possibility of detecting thrombus formation using vibration signals, and these studies revealed the usefulness of vibration monitoring to detect thrombus formation in a centrifugal pump.
In Vivo Evaluation of Platelet Activation by Different Cellulosic Membranes
Authors: Cases Aleix , Reverter Joan Carles , Escolar Gines , Saw Cristina , Sorribes Josep , Ordinas Antoni
Published: July 2010

Abstract: This study was undertaken to evaluate platelet activation in vivo induced by different cellulosic membranes by measuring the expression of P‐selectin on the platelet surface during hemodialysis in 9 uremic patients. Hollow fiber dialyzers of similar surface with different cellulosic membranes (Cuprophan, cellulose acetate, cellulose triacetate, and Hemophan) were evaluated and compared to a synthetic membrane (polysulfone). Blood samples were obtained before hemodialysis and from the efferent and afferent limbs 5 min after the beginning of dialysis. P‐select in exposure was evaluated by flow cytometry (FACScan) using a monoclonal antibody (RUU 2.17). The percentage of platelets expressing P‐select in before hemodialysis and the percentage from the arterial line during hemodialysis were similar. All membranes evaluated induced platelet activation (estimated as the increase in percentage of platelets expressing P‐selectin in samples obtained from the venous line with respect to the arterial line). Cuprophan induced more platelet activation than any other membrane (p < 0.05). The activation induced by cellulose acetate and cellulose triacetate membranes was also higher than that observed with Hemophan (p < 0.05). Hemophan‐induced platelet activation was similar to that of polysulfone. These results indicate that all cellulosic membranes induce platelet activation during hemodialysis although there are quantitative differences among them. While Cuprophan induced the highest degree of platelet activation, Hemophan was the only cellulosic membrane that showed a degree of platelet activation similar to the biocompatible membrane polysulfone.
Improved Flow Straighteners Reduce Thrombus in the NASA/DeBakey Axial Flow Ventricular Assist Device
Authors: Kawahito Koji , Benkowski Robert , Ohtsubo Satoshi , Noon George P. , Nosé Yukihiko , DeBakey Michael E.
Published: July 2010

Abstract: A small axial flow ventricular assist device (VAD) measuring 3 inches long and 1 inch in diameter is in development. The pump consists of a spinning inducer/ impeller, a flow straightener (FLS), and a diffuser enclosed in a cylindrical flow tube. The impeller has rod‐shaped permanent magnets embedded within its 6 blades and is activated magnetically by the motor stator which is positioned outside the flow tube. At the completion of a previous study, the FLS was identified as a thrombogenic area. The aim of the present study was to evaluate the thrombogenicity of redesigned FLSs (swept‐back and bulbous types), compared with standard type (STD) FLS. A total of 15 pumps (STD, n = 7; swept‐back, n = 4; and bulbous, n = 4) were sequentially implanted into 4 calves paracorporeally in a short‐term ex vivo test. The STD and bulbous FLSs experienced thrombus formation, but the swept‐back FLS was thrombus free during a 48 h screening test.
Blood Cardioplegia Infusion Using a Recirculation Type Circuit Generates Bradykinin in Significant Amounts During Open Heart Surgery
Authors: Watanabe Takashi , Sakai Yoshimasa , Shimomura Tsuyoshi , Song Min‐Ho , Miyahara Ken , Takagi Yasushi , Oohara Yasutoshi , Kawaradani Yoshitaka , Usui Akihiko , Maseki Takashi , Yasuura Kenzo , Murase Mitsuya
Published: July 2010

Abstract: The single pass type (SP) of blood cardioplegia is commonly used in North America during open heart surgery. However the recirculation type (RC) of blood cardioplegia is still widely used in other areas including Japan. Infusion blood cardioplegia using the latter technique often decreases the perfusion pressure. To determine the cause for this, blood levels of bradykinin (BK) were measured in cardiopulmonary bypass (CPB) and the 2 types of blood cardioplegic circuits. As the BK levels in the RC cardioplegia (>3,000 pg/ml) rose, the perfusion pressure decreased abruptly with the increase of the BK levels in the CPB circuit. With SP cardioplegia, the BK level was not increased either during cardioplegia (p < 0.009) or CPB (p < 0.009), and the perfusion pressure was not decreased (p < 0.02). We concluded that the SP circuit is superior to the RC one because of the lesser production of BK and thus lesser fluctuation of perfusion pressure.
Phenotypic Alterations in Circulating Monocytes Induced by Open Heart Surgery Using Heparinized and Nonheparinized Cardiopulmonary Bypass Systems
Authors: Ljunghusen Olof , Cederholm Ingemar , Lundahl Joachim , Nilsson Bo , Olin Christian , Sjogren Florence , Stendahl Olle
Published: July 2010

Abstract: In this study of 31 patients with coronary bypass surgery, we used flow cytometry to compare heparin‐coated and noncoated cardiopulmonary bypass systems on leukocyte activation. We found significant differences between the groups during bypass, with activation of the complement system, measured as elevated levels of C3a desArg, upregulation of granulocyte β2 integrin (CD11b). and a loss of circulating monocytes when noncoated systems were used. In both groups an early increase in the monocyte cell surface CD62L expression was obvious while the percentage of human leukocyte antigen (HLA)‐DR positive monocytes did not alter. The morning after the operation, leukocytosis was present. together with a highly significant reduction in the monocyte expression of CDllb and HLA‐DR, indicating the recruitment to the peripheral blood of cells with altered phenotypes. This alteration in phenotype on potent inflammatory cells may be one part of the impaired function of the immunological system reported after major surgery.
The Effect of Respiration on the Performance of the Total Artificial Heart
Authors: Ohashi Yukio , Andrade Aron de , Mueller Juergen , Nosé Yukihiko
Published: July 2010

Abstract: An electromechanical driven pusher plate type total artificial heart (TAH) has been developed in the Department of Surgery at Baylor College of Medicine. The control of this TAH is based upon Frank‐Starling's law, and the output is likely to be affected by the respiration cycle. The necessity of an averaging system for the pumping to avoid this drifting of the output has been discussed in several papers. In this study, the effect of respiration on the performance of the TAH was evaluated in both in vitro and in vivo conditions. This TAH was driven without an averaging system in its control system. The results indicated that the mean output pressure was stable with minute changes in both the heart rate and outflow. This verifies that the electromechanical driven pusher plate type TAH, which is under development in our laboratory, compensated for the effect of respiration without an averaging system.
Anatomical Consideration for an Implantable Centrifugal Biventricular Assist System
Authors: Takami Yoshiyuki , Nakazawa Tadashi , Otsuka Goro , Tayama Eiki , Ohashi Yukio , Sueoka Akinori , Schima Heinrich , Schmallegger Helmut , Wolner Ernst , Nosé Yukihiko
Published: July 2010

Abstract: A miniaturized pivot bearing‐supported centrifugal blood pump (Gyro PI) has been developed as a long‐term biventricular assist system (BiVAS). In this study we determined the anatomical configuration of this system using a bovine model. Under general anesthesia, a left lateral thoracotomy was performed to open the chest. Two Gyro PI‐601 pumps for left and right assists were placed in the preperitoneal pocket by a subcostal abdominal incision. The left pump could be placed along the dome of the diaphragm just beneath the apex of the left ventricle. The right pump could be placed next to the left pump. The inlet and outlet ports of both pumps penetrated the diaphragm. The inlet port of the left pump, with a length of 55 mm, was inserted directly into the apex of the left ventricle. A woven Dacron graft (150 mm long, 11 mm inner diameter) was placed between the outlet port of the left pump and the descending aorta. As for the right pump. a 100 mm long and 120 degree angled inflow conduit was placed between the inlet port and the right ventricular infundibulum. The outlet port of the right pump was connected to the main trunk of the pulmonary artery using a 90 mm long, 11 mm inner diameter Dacron graft. We could perform biventricular assistance to confirm the anatomical feasibility of the Gyro implantable centrifugal BiVAS.
Implant Science of Artificial Organ: Design for Success
Authors: Imachi Kou
Published: July 2010

Abstract: Although many artificial organs have come to be used clinically, there still remain many problems such as thrombus formation, calcification, infection, malfunction, etc., that sometimes expose the patient to danger. One of the causes of these damages is that we do not know the true mechanisms of these phenomena. In other words, the design criteria of implant devices have not yet been established under scientific basis. It is very important that we artificial organ researchers and manufacturers establish the implant science of artificial organs. In this paper, mention is made of the kinds of factors we should consider for the design of artificial organs and how we should approach them scientifically. Also introduced is our approach method for an implantable total artificial heart.
Moral Aspects of Risk and Innovation
Authors: Sass Hans‐Martin
Published: July 2010

Abstract: In all areas of technological innovation and application, there are nontechnical (moral, cultural, religious, political, and regulatory) risk factors and uncertainties that have to be taken into account if research design and introduction of new devices and applications are to be successful. Products and methods will be beneficial to the patient if they meet personal and cultural expectations. Value assessment of individual patients and of cultural preferences and obstacles therefore has to be included in complex technology assessment. Successful recognition and management of moral and cultural risk factors may require changes in governmental regulation and research design and the development of risk recognition competence within professional organizations.
Estimation of the Minimum Pump Speed to Prevent Regurgitation in the Continuous Flow Left Ventricular Assist Device: Left Ventricular Drainage versus Left Atrial Drainage
Authors: Tayama Eiki , Ohashi Yukihiko , Niimi Yoshinari , Takami Yoshiyuki , Ohtsuka Goro , Benkowski Robert , Glueck Julia A. , Nosé Yukihiko
Published: July 2010

Abstract: Due to the fact that centrifugal and axial pumps do not require valves, there is a possibility of back flow when the pump speed is low. To estimate the minimum required pump speed to prevent this regurgitation, an in vitro simulation test was conducted. A pulsatile pump simulated the natural heart while a centrifugal pump simulated the continuous flow left ventricular assist device (LVAD). The LVAD flow was attained from the left atrial (LA) drainage or left ventricular (LV) drainage. The minimum or regurgitate flow was observed in the systolic phase with LA drainage and in the diastolic phase with LV drainage. LV drainage always provided higher flow than LA drainage at the same pump speed. These differences are due to the various total pressure heads of the LVAD. To prevent the regurgitation, the LVAD should maintain a certain pump speed which can create positive flow against the aortic systolic pressure with LA drainage and against the aortic diastolic pressure with LV drainage. These required pump speeds can be identified by the LVAD flow‐pressure curve.
Quantitative Approach to Control Spinning Stability of the Impeller in the Pivot Bearing‐Supported Centrifugal Pump
Authors: Takami Yoshiyuki , Makinouchi Kenzo , Otsuka Goro , Nosé Yukihiko
Published: July 2010

Abstract: The Gyro C1E3 pump has been developed as a completely sealless centrifugal pump driven by a magnetic coupling system for long‐term usage. The Gyro C1E3 pump is a pivot bearing‐supported pump in which the impeller is supported with the top and bottom pivot bearings. In the Gyro C1E3 pump, the impeller spinning is affected by the force balance between the floating force (Ff [N]) of the hydrodynamic effect and the magnetic thrust force (Tf [N]). The authors quantitatively investigated the floating force of the impeller in vitro to determine the magnetic coupling distance (MCD[mm]) that would result in stable impeller spinning. In vitro tests were performed using a loop filled with 37% glycerin solution to obtain the relationship between the MCD and floating speed (Rf, rotational speed when the impeller starts floating [rpm]) and the relationship between the MCD and Tf From the obtained relationships, we calculated Ff and determined the relationship between the Ff and the rotational speed (R). Furthermore, we determined the relationship between d (minimum required MCD [mm]) and R from the results of determining the relationship of the MCD and Tf and of the Ff and R. The following relationships were obtained: Rf= 6.24 104. MCD−135; Tf= 5.27.103.MCD‐2.29Ff= 4.71 . 10‐‐6RPM1.69; and d= 9.02 .RPM‐085 where RPM is the rotational speed. It was demonstrated that the floating force of the impeller is a function only of the rotational speed in the pivot bearing‐supported Gyro C1E3 pump. The floating force is estimated to be 10 N to 40 N at rotational speeds of 1,500 rpm to 3,000 rpm at which the Gyro pump may be used in most clinical situations. It would be possible to control the impeller position of the Gyro pump automatically at the stable spinning condition by controlling the adequate magnetic coupling distance based upon its relationship with the rotational speed which was obtained in this study.
Development of a Numerical Simulation Model of the Cardiovascular System
Authors: Geertsema Albert A. , Rakhorst Gerhard , Mihaylov Dimiter , Blanksma Paul K. , Verkerke Gijsbertus J.
Published: July 2010

Abstract: A numerical simulation model of the cardiovascular system has been developed. It consists of a model of the left atrium, the left ventricle, the coronary vascular system, the aorta, the arterial system, and the venous system. The input of the complete model is the elastance (pressure/Volume ratio) developed by the left ventricle. The shape of this elastance is constant in different circumstances. Left ventricular (LV) myocardial oxygen consumption and the amount of oxygen offered to the left ventricle can be calculated with the model. The model has been validated using data from a patient suffering from coronary artery disease. The measured clinical hemody‐namical waveforms could be fitted to those generated by the model. With the numerical simulation model, it is possible to predict the functioning of the left ventricle under different circumstances. This makes it possible to study in vitro various pathological clinical situations.
Pannus Resection Through the Tilting Disc Prosthesis: Successful Treatment Preserving the Prosthesis
Authors: Misawa Yoshio , Fuse Katsuo , Karo Morito
Published: July 2010

Abstract: A 59‐year‐old woman was admitted to our hospital because of heart failure. In 1988, she underwent aortic valve replacement with an Omnicarbon valve and mitral valve replacement with a bioprosthetic valve. She was doing well until July in 1996 when she developed heart failure. Echocardiography revealed massive mitral valve regurgitation, and cinefluoroscopy showed implanted Omnicarbon valve dysfunction with a leaflet opening angle of 35 degrees. At reoperation, it was revealed that pannus formation prevented the valve from functioning well. The pannus was resected through the major orifice, and the leaflet was rotated toward the right anterolateral orientation. The worn bioprosthetic valve was replaced with a mechanical one. Postoperative cinefluoroscopy of the rotated Ominicarbon valve showed the opening angle to be 61 degrees.
Development of a Direct Mechanical Left Ventricular Assist Device for Left Ventricular Failure
Authors: Hotei Hiroshi , Koura Yoshihiko , Orihashi Kazumasa , Sueda Taijiro , Fukunaga Sintaro , Matsuura Yuichiro
Published: July 2010

Abstract: We have developed a direct mechanical left ventricular assist device (DMLVAD) for severe left ventricular failure. The DMLVAD was attached to the left ventricle and compressed the heart by a pneumatic driving unit. In a mock circulation model with an extracted non‐beating heart, a cardiac output (CO) of 1.93 L/min was obtained at a driving pressure of 200 mm Hg. In a canine left ventricular failure model induced by injection of sodium hydroxide into the myocardium, the systolic arterial pressure, systolic left ventricular pressure, maximum LV dP/dt, peak flow, and CO increased by 21, 24, 58, 144, and 37%, respectively. The mean left atrial pressure also decreased by 15% when the DMLVAD was driven. These effects were most prominent when the mean left atrial pressure was over 15 mm Hg, and the driving pressure was over 100 mm Hg. Compression at late systole was more effective in obtaining greater CO. We suggest that the DMLVAD could be an optional circulatory assist device for patients with left ventricular failure awaiting heart transplantation.
Application of Argatroban, Direct Thrombin Inhibitor, in Heparin‐Intolerant Patients Requiring Extracorporeal Circulation
Authors: Matsuo Takefumi , Koide Masanohu , Kario Kazuomi
Published: July 2010

Abstract: This study describes the present knowledge regarding the clinical application of argatroban, a direct competitive thrombin inhibitor for heparin‐intolerant patients, including those with congenital and acquired antithrombin III deficiencies, those with heparin‐induced thrombocytopenia, and those with high levels of polymor‐phonuclear granulocyte elastase. These patients are often associated with intracircuit clot formation with heparin anticoagulation during extracorporeal circulation. Therefore. argatroban may be chosen as one of the alternate anticoagulants. Because the anticoagulant effect of argatroban is reflected in the prolongation of activated thromboplastin time, monitoring is easy, similar to that for heparin. Because argatroban has a fast acting anticoagulant effect without any cofactors such as antithrombin III, this drug is a favorable anticoagulant for heparin‐intolerant patients with antithrombin III deficiencies requiring extracorporeal circulation. In adverse reactions to heparin, heparin acts as an antigen after complexing with platelet factor 4, which leads to life‐threatening heparin‐induced thrombocytopenia. As argatroban prevents heparin‐induced platelet aggregation, it is effective for use as a therapeutic anticoagulant. In other clinical applications, heparin decreases antithrombin activity and causes intracircuit clot formation during extracorporeal circulation when the polymorpho‐nuclear granulocyte elastase level is very high. The antithrombin activity shows less decrease when argatroban is substituted for heparin. These findings indicate that argatroban is a useful alternative anticoagulant in these heparin‐intolerant patients.
Surface‐Treated Catheters with Ion Beam‐Based Process Evaluation in Rats
Authors: Barnbauer R. , Mestres P. , Schiel R. , Klinkrnann J. , Sioshansi P.
Published: July 2010

Abstract: Ion beam‐based processes such as ion implantation (silicone rubber) and ion beam‐assisted deposition (silver‐based coatings) affect the outer micron layers of catheter surfaces. These processes were used on the common catheter materials of silicone and polyurethane. In 56 rats, surface (Spi‐Silicone and Spi‐Argent I and II) catheter segments were implanted for 1, 3, and 6 weeks. After removal, these pieces were investigated for bacterial colonization and fixed for scanning electron microscopic evaluation. As controls, untreated catheter segments were implanted in 28 rats. Bacterial colonization was found in 2.4% in the surface treated catheter pieces versus 7.1% in the control group. The scanning electron microscope investigations showed low thrombogenicity in all of the treated catheters independent of the implantation times.
Inhaled Low‐Dose Nitric Oxide for Postoperative Care in Patients with Congenital Heart Defects
Authors: Shimpo Hideto , Mitani Yoshihide , Tanaka Jin , Mizumoto Toru , Onoda Kouji , Tani Kazuhiro , Yuasa Hiroshi , Yada Isao , Maruyama Kazuo
Published: July 2010

Abstract: Postoperative pulmonary hypertensive crisis is a major problem that may account for a substantial part of the postoperative mortality and morbidity. We, therefore, evaluated the effect of inhalation of low‐dose nitric oxide (NO) on postoperative care in pediatric patients with pulmonary hypertension. We studied 10 infants and children ages 1–108 months (median age, 11 months) with congenital heart disease associated with pulmonary hypertension. The NO and N, gas mixture was then mixed with varied quantities of air and oxygen and delivered into a respirator instead of an inspiratory tube. Patients were treated with inhaled NO for 38.6 ± 19.6 h (range 1–200 h). All patients were eventually weaned from high level sedation and respirator. The NO concentration ranged from 2 to 5 parts per million. During NO inhalation patients demonstrated a statistically significant reduction in systolic pulmonary arterial pressure by approximately 26%; from 55 ± 10 to 41 k 10 mm Hg. inhalation of NO resulted in a significant increase of Pao2 from 110 ± 16 to 149 ± 20 mm Hg. A‐aDo2 significantly decreased from 284 ± 27 to 247 ± 31 mm Hg. In conclusion, we have shown that a low‐dose NO inhalation acted as a pulmonary vasodilator in patients with preexisting pulmonary hypertension.
Effects of Inhaled Nitric Oxide on Postoperative Pulmonary Circulation in Patients with Congenital Heart Disease
Authors: Matsui Junki , Yahagi Naoki , Kumon Keiji , Hayashi Hideaki , Watanabe Yasuhiko , Haruna Masaki , Tanigami Hironobu , Yagihara Toshikatsu , Takamoto Shinichi , Kamiya Tetsuro
Published: July 2010

Abstract: We studied 22 patients with residual pulmonary hypertension or symptoms of postoperative pulmonary hypertensive crisis. They received low‐dose inhalation (10 ppin) of nitric oxide (NO). a selective pulmonary vasodilator, after total correction for ccingenital heart anomalies. Fifteen minutes of NO inhalation improved the pulmonary circulation and lessened the imbalance in the ventilation‐perfusion ratio in both groups. Thus, NO inhalation is effective in the treatment of pulmonary hypertension and in the prevention of pulmonary hypertensive crises after total correction for congenital heart anomalies. All patients continued to receive NO therapeuti‐cally. The duration of such therapeutic NO inhalation was well correlated with postoperative Qp/Qs (p = 0.014) and RpRs (p = 0.029).
Helium/Oxygen Breathing Improves Hypoxemia after Cardiac Surgery
Authors: Yahagi Naoki , Kumon Keiji , Haruna Masaki , Watanabe Yasuhiko , Matsui Junk , Hayashi Hideaki , Tanigami Hironobu , Takamoto Shinichi
Published: July 2010

Abstract: The effects of helium/oxygen (He/O2) on oxygen‐ation (respiratory index [Pao2,/Fio2] and inuapulmonary shunt [Qs/Qt]) and on lung parameters (dynamic compliance [Cdyn] and peak inspiratory pressure [PIP]) were studied in 12 patients. After cardiac surgery, they had impairment of oxygen‐ation without physiological findings and with normal chest radiographs despite having a positive end expiratory pressure of up to 10 cm H2O. After 90 min of inhalation of He/O2., oxy‐genation had improved significantly; that is, Pao2/Fio2, in creased significantly (from 113 to 174 mm Hg; mean values are given; p < 0.01), and there was a significant fall in Qs/Qt (from 29 to 19%; p < 0.01) together with an increase in Cdyn (from 60 ml/cm H2O to 64 mVcm H2O; p < 0.05). These results suggest that HeiO2 may have improved oxygenation by recruiting previously obstructed small airways and alveoli.
Trial of Electrolyzed Strong Acid Aqueous Solution Lavage in the Treatment of Peritonitis and Intraperitoneal Abscess
Authors: Inoue Yoshihiro , Endo Shigeatsu , Kondo Koryo , Ito Hironobu , Omori Hiroaki , Saito Kazuyoshi
Published: July 2010

Abstract: Electrolyzed strong acid aqueous solution is acidic water that contains active oxygen and active chlorine and possesses a redox potential. We performed peritoneal and abscess lavages with an electrolyzed strong acid aqueous solution to treat 7 patients with peritonitis and intraperitoneal abscesses, who were seen in our department between December 1994 and April 1995. The underlying disease was duodenal ulcer perforation in 4 of these 7 patients and gastric ulcer perforation, acute enteritis, and intraperitoneal perforation of pyometrium in 1 patient each. Irrigation was performed twice a day. Micro biological studies of the paracentesis fluid were negative in 3 cases, and the irrigation period was 2–4 days. Anaerobic bacteria were isolated in 3 of the 4 positive cases (Bacteroides in 2, Prevotella in l), and a fungus (Candida) was isolated in the remaining patient. The period of irrigation in these patients ranged from 9 to 12 days, but conversion to a microorganism negative state was observed in 3–7 days.
Successful Treatment of Mediastinitis after Cardiovascular Surgery Using Electrolyzed Strong Acid Aqueous Solution
Authors: Hayashi Hideaki , Kumon Keiji , Yahagi Naoki , Haruna Masaki , Watanabe Yasuhiko , Matsui Junki , Hattori Reiji
Published: July 2010

Abstract: Dilute povidone‐iodine solution has been widely used as an irrigant for the treatment of mediastinitis. However, its use is not without adverse effects and often cause? poor growth of pinulation tissues. To avoid the problems seen with the use of povidone‐iodine solution, we applied electrolyzed strong acid aqueous solution (ESAAS) to mediastinal irrigation in 4 patients (2 infants and 2 adults) who developed mediastinitis after cardiovascular surgery. According to the “open” method, the mediastinal wound was left open and irrigated with ESAAS 1 to 3 times a day until the infection was eradicated. Satisfactory growth of granulation tissues was observed in all patients treated with no evidence of adverse effects attributable to ESAAS. Delayed primary sternum closure was performed for 2 patients. and musculocutaneous transposition of rectus abdominis for 1. Our experience suggests that irrigation with ESAAS is a safe and effective method of therapy for mediastinitis. Keg Words: Electrolyzed strong acid aqueous solution—Mediastinitis—Median sternotomy—Povidone‐iodine— Cardiovascular surgery—Postoperative complication.
Mechanism and Computer Simulation of a New Robot Hand for Potential Use as an Artificial Hand
Authors: Lin Li‐Ren , Huang Han‐Pang
Published: July 2010

Abstract: A prosthetic hand is essential to provide rehabilitation for individuala who lose a hand. A prosthetic hand serves two purposes: cosinetic and functional. In this paper, a prototype of the artificial hand with an emphasis on the functionality purpose is presented. A new mechanism, the NTU‐Hand (NTU‐Hand. patent number 107115, Taiwan, R.O.C.), which has 5 fingers with 17 degrees of freedom, has been designed and fabricated in our laboratory. Due to the special design of the mechanism. the hand has an uncoupled configuration in which each finger and joint are all individually driven. The size of the hand is almost the same as a human hand. All actuators, mechanical parts, and sensors are on the hand. The compact design makes it feasible to adapt the hand to the injured wrist. A computer simulation with three‐dimensional graphics was also built to evaluate the manipulable range of the artificial hand. From the results of this simulation, the relationship between the hand and the grasped object in a specific viewpoint can be obtained.
Development of an Intravascular Pumping Oxygenator Using a New Silicone Membrane
Authors: Sueda Taijiro , Fukunaga Shintaro , Morita Satoru , Sueshiro Masafumi , Hirai Shinji , Okada Kenji , Orihashi Kazumasa , Matsuura Yuichiro
Published: July 2010

Abstract: A new intravascular pumping oxygenator (IVPO) was developed for intravascular gas exchange and circulatory assistance in critically ill patients with respiratory and circulatory failure. The IVPO utilizes new silicone hollow fibers (diameter. 1 mm: membrane width, 50 μm) and consists of two driving tubes for the oxygenation and pumping of circulating blood. The performance characteristics of the IVPO were studied using an experimental ex vivo model. With a mean hemoglobin concentration of 10.5 ± 2.3 g/dl, total oxygen transfer was 5.6 ± 1.5 ml/min at a blood flow of 200 ml/min and 6.3 ± 2.2 ml/min at a blood flow of 250 ml/min. Total CO2 transfer was 3.8 ± 1.4 ml/min at a blood flow of 200 ml/min and 4.2 ± 1.6 ml/min at a blood flow of 250 ml/min during IVPO pumping. This preliminary experiment demonstrated that the IVPO has the capacity to function both as a circulatory assist pump and as an intravascular hollow fiber oxygenator.
Polyurethane Catheters for Long‐Term Hemodialysis Access
Authors: Hirsch David J. , Bergen Patrick , Jindal Kailash K.
Published: July 2010

Abstract: Chronic hemodialysis patients with failed native fistulas and/or synthetic arteriovenous grafts are usually dialyzed via surgically placed silicone jugular catheters such as the PermCath (Quinton, Seattle, WA, U.S.A.). We report a successful experience with the use of double lumen polyurethane central venous catheters placed percutaneously. Catheters with poor flows were replaced over a guidewire at the bedside. Eleven long‐term hemodialysis patients failed arteriovenous access, 9 of them having had multiple attempts at fistulas and/or grafts. Seven of these patients had also failed peritoneal dialysis. They were dialyzed with polyurethane catheters for a mean of 681 ± 280 days (range 282–1150 days), requiring a mean of 3.4 ± 0.4 new venous punctures and 8.2 ± 1.5 catheter changes over a guidewire over that period of time. Actuarial patient survival was 50% at 2 years, and mean urea reduction during dialysis was 64.2 ± 1.7%. The septicemia rate was only 1.2 episodes per 1,000 catheter‐days, but about 20% of patients experienced central venous occlusion, attributable to the use of subclavian catheter placement in 82% of the sites. The success of this technique and its elimination of the need for urokinase, radiologic interventions, and surgical placement warrant its consideration as an acceptable form of long‐term vascular access, provided jugular placement allows reduced central venous occlusion rates.
Treatment of Homozygous Familial Hypercholesterolemia with Low Density Lipoprotein Apheresis: A 4 Year Follow‐Up Study
Authors: Fadul Jamal E. M. , Vess Bengt , Wikström Björn , Danielson Bo G.
Published: July 2010

Abstract: Hypercholesterolemia and elevated lipoprotein (a) (Lp[a]) levels are considered to be risk factors for the development and progression of premature atherosclerosis. The purpose of our report is to describe the effects of low density lipoprotein (LDL) apheresis (Liposorber system, Kanegafuchi Chemical Industrial Company LTD, Osaka, Japan) on serum lipoprotein concentrations and the clinical status in 2 male patients with homozygous familial hypercholesterolemia. Compared with pretreatment values, the posttreatment concentrations of total cholesterol, LDL cholesterol, and Lp(a) were significantly reduced by 50–60% (p < 0.0001). The concentration of high density lipoprotein (HDL) cholesterol was slightly affected. After one treatment session, LDL cholesterol and Lp(a) were decreased on average by 65% and then increased to reach about 70–75% of the pretreatment values before the next session. Prior to the treatment with LDL apheresis, each patient had suffered one myocardial infarction and had had 2 coronary angiographies. After treatment with LDL apheresis, neither cardiac complaints nor myocardial infarction were observed. The xanthomas were much decreased during the treatment or disappeared. We conclude that LDL apheresis can be continued safely and without major technical problems for several years. Apheresis effectively lowers the serum levels of total and LDL cholesterol. Furthermore, it reduces Lp(a), which is not influenced by lipid‐lowering drugs. The reduction of LDL cholesterol and Lp(a) may delay the progression of the atherosclerotic process, thereby helping to reduce the risk of new episodes of coronary heart disease and thus extending the life expectancy in these patients.
Use of Motor Current in Flow Rate Measurement for the Magnetically Suspended Centrifugal Blood Pump
Authors: Tsukiya Tomonori , Akamatsu Teruaki , Nishimura Kazunobu , Yamada Tomoyuki
Published: July 2010

Abstract: Indirect measurement of the flow rate of a centrifugal blood pump using the driving motor current was studied. The pump flow rate can be expressed as a function of the motor current under a given motor speed in the absence of energy loss resulting from uncertain mechanical contact friction. The magnetically suspended centrifugal blood pump (MSCP), developed by the collaboration of Kyoto University and NTN Inc., was suitable for the application of this measuring method because the impeller is suspended magnetically inside the pump housing without any mechanical contact. The effect of fluid viscosity on the pump performance was investigated in detail, and it was possible to estimate the pump flow rate and the pressure difference through the pump (from inlet port to outlet port) accurately by monitoring the motor current and speed when the kinematic viscosity of working fluids was known. The kinematic viscosity of working fluids can also be measured with the MSCP. The motor current and motor speed were monitored in a chronic animal experiment, and the estimated flow rate and pressure difference showed good correlation with directly measured data.
Local Glycoprotein IIb/IIIa Receptor Inhibitor Delivery From the Pump Surface Attenuates Platelet Adhesion in Continuous Flow Ventricular Assist Devices
Authors: Linneweber Joerg , Dohmen Pascal M. , Kertzscher Ullrich , Affeld Klaus , Konertz Wolfgang
Published: July 2010

Shear‐induced platelet activation (SIPA) has been identified to induce platelet adhesion and thrombus formation in continuous flow left ventricular assist devices (LVAD). Platelet glycoprotein (GP) IIb/IIIa receptor inhibitors are effective to prevent SIPA. However, systemic GP IIb/IIIa receptor inhibitor application is associated with severe bleeding complications. The aim of the study was to evaluate (i) the feasibility of absorption and elution of the GP IIb/IIIa receptor blocker TAK‐029 from the Ti6Al4V surface of the pump; and (ii) the effect of local GP IIb/IIIa receptor blocker delivery regarding platelet adhesion on the surface of a continuous flow VAD model.

Saturating concentrations of TAK‐029 were adsorbed on the surface of a centrifugal pump. Whole human blood was perfused in circulatory mock loops using untreated (control), albumin‐coated, or TAK‐029‐coated pumps. Peripheral resistance of the circulatory systems were adjusted accordingly to generate 5 L flow per min with impeller rotational speeds of 3500 (high‐shear group) and 1500 rpm (low‐shear group), respectively. Platelet adhesions on the respective impellers were quantified by ELISA and scanning electron microscopy (SEM). TAK‐029 elution and half‐life time were determined by ELISA.

Compared with control, albumin‐coated pumps showed 64 and 20% less platelet adhesions in the high‐ and low‐shear group, respectively. TAK‐029 coated pumps reduced platelet adhesion by additional 33 and 65%, respectively, compared with the albumin group. Elution of TAK 029 was initially very rapid and continued slowly.

The results show that it is possible to adsorb and elute a small molecular weight GP IIb/IIIa receptor blocker from the pump surface. This drug elution reduced platelet adhesion on the pump significantly. Further studies are necessary to find a suitable drug bonding that will prolong the antiplatelet effect and preclude any bleeding complication caused by this procedure.
Applied Neuromonitoring and Improving Central Nervous System Outcomes
Authors: Murkin John M.
Published: July 2010

This article will review the pathogenesis of perioperative neurological injury in patients undergoing coronary revascularization. The high percentage of such patients with diabetes or concomitant cerebrovascular disease renders this population particularly susceptible to injury as a consequence of both hypoperfusion and atheroemboli. The role of transesophageal echocardiography for assessment of ascending aortic atherosclerosis and the use of noninvasive cerebral oximetry to detect cerebral hypoperfusion are discussed with respect to their impact on patient outcomes.
Reducing Emboli in Cardiac Surgery: Does It Make a Difference?
Authors: Slaughter Mark S. , Sobieski Michael A. , Tatooles Antone J. , Pappas Patrokolos S.
Published: July 2010

Particulate embolization remains a serious complication of cardiac surgery. Adverse events associated with particulate embolization affect patient morbidity and long‐term survival, and increase the length of hospital stay and the cost of health care. Today, atherosclerosis plays a role in at least two‐thirds of all adverse events after coronary artery revascularization, and postoperative stroke is the second most common cause of operative mortality. Because many lower‐risk patients now undergo interventional revascularization, higher‐risk patients are now typically referred for surgical revascularization. These patients are older and sicker, and have multiple comorbidities, making them more susceptible to adverse events. For these high‐risk patients, surgeons should be proactive in attempting to reduce the possibility of emboli. Patients must be carefully assessed before surgery to determine their risk, and if the risk is high, surgeons should consider using newer, innovative devices, and techniques in their operative strategy that have proven to be effective in mitigating some of the potential embolic adverse events. A multifaceted, preventive strategy can make a difference, not only in reducing particulate emboli, but also in reducing morbidity and in lowering the economic burden on the health‐care system. This brief review will address three areas of focus that are important for the prevention of particulate embolization: (i) prevalence and morbidity of atherosclerotic disease; (ii) risk factors for adverse neurologic events; and (iii) prevention/mitigation of adverse events for patients undergoing cardiac surgery.
Plant Species Patterns and Restoration Perspectives in the Highly Disturbed Environment of the Carrara Marble Quarries (Apuan Alps, Italy)
Authors: Gentili Rodolfo , Sgorbati Sergio , Baroni Carlo
Published: July 2010

Quarrying activities result in vegetation destruction, soil denudation, and profound modification of the original landscape. This study was conducted in dump deposits (locally called ravaneti) of both abandoned and active Carrara marble quarries. The site is located close to a natural park rich in endemic species, making it a particularly interesting place to study environmental changes induced by quarrying activities. The goal of this study was to investigate the relationships between plant communities and four different types of ravaneti classified according to age and disturbance due to quarrying activities. We sampled 67 vegetation plots linked to site variables and Ellenberg indicator values in quarry sites. Species frequency on the most disturbed ravaneti allowed individuating five classes of species based on their tolerance to disturbance due to quarrying. The resulting species/environmental variables matrix was used to perform a canonical correspondence analysis (CCA). CCA primarily grouped species along soil reaction (R) and nutrient (N) availability gradients and on the basis of their response to excavation‐caused disturbance. Ravaneti created using modern excavation methods were colonized by ruderal and alien species at the expenses of endemic ones. On the basis of these findings, a set of native plant species have been identified for use in future restoration projects in abandoned quarries.