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Tan Z, Huo M, Qin K, El-Baz AS, Sethu P, Wang Y, Giridharan GA. A sensorless, physiologic feedback control strategy to increase vascular pulsatility for rotary blood pumps. Biomed Signal Process Control 2023; 83:104640. [PMID: 36936779 PMCID: PMC10019090 DOI: 10.1016/j.bspc.2023.104640] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Continuous flow rotary blood pumps (RBP) operating clinically at constant rotational speeds cannot match cardiac demand during varying physical activities, are susceptible to suction, diminish vascular pulsatility, and have an increased risk of adverse events. A sensorless, physiologic feedback control strategy for RBP was developed to mitigate these limitations. The proposed algorithm used intrinsic pump speed to obtain differential pump speed (ΔRPM). The proposed gain-scheduled proportional-integral controller, switching of setpoints between a higher pump speed differential setpoint (ΔRPM Hr ) and a lower pump speed differential setpoint (ΔRPM Lr ), generated pulsatility and physiologic perfusion, while avoiding suction. The switching between ΔRPM Hr and ΔRPM Lr setpoints occurred when the measured ΔRPM reached the pump differential reference setpoint. In-silico tests were implemented to assess the proposed algorithm during rest, exercise, a rapid 3-fold pulmonary vascular resistance increase, rapid change from exercise to rest, and compared with maintaining a constant pump speed setpoint. The proposed control algorithm augmented aortic pressure pulsatility to over 35 mmHg during rest and around 30 mmHg during exercise. Significantly, ventricular suction was avoided, and adequate cardiac output was maintained under all simulated conditions. The performance of the sensorless algorithm using estimation was similar to the performance of sensor-based method. This study demonstrated that augmentation of vascular pulsatility was feasible while avoiding ventricular suction and providing physiological pump outflows. Augmentation of vascular pulsatility can minimize adverse events that have been associated with diminished pulsatility. Mock circulation and animal studies would be conducted to validate these results.
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Affiliation(s)
- Zhehuan Tan
- School of Biomedical Engineering, Dalian University of Technology, Dalian, China
| | - Mingming Huo
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, China
| | - Kairong Qin
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, China
| | - Ayman S El-Baz
- Department of Bioengineering, University of Louisville, Louisville, KY, USA
| | - Palaniappan Sethu
- Department of Biomedical Engineering, School of Engineering, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Yu Wang
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, China
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Designing an Active Valvulated Outflow Conduit for a Continuous-Flow Left Ventricular Assist Device to Increase Pulsatility: A Simulation Study. ASAIO J 2021; 67:529-535. [PMID: 33902101 DOI: 10.1097/mat.0000000000001255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The purpose of this work was to investigate, using a lumped parameter model, the feasibility of increasing the pulsatility of a continuous-flow ventricular assist device (VAD) by implanting an active valvulated outflow cannula. A lumped parameter model was adopted for this study. VAD was modeled, starting from its pressure-flow characteristics. The valvulated outflow conduit was modeled as an active resistance described by a square function. Starting from pathologic condition, the following simulations were performed: VAD, VAD and valvulated outflow conduit in copulsation and counterpulsation with different ratios between the VAD valve opening rate and the heart rate, and asynchrony work with the heart with different VAD valve opening intervals. The copulsation 1:1 configuration and the asynchrony 0.3s-close-0.7s-open configurations permit to maximize the hemodynamic benefits provided by the presence of the active VAD outflow valvulated conduit providing an increase of arterial pulsatility from 1.86% to 14.98% without the presence of left ventricular output. The presence of the active VAD valve in the outflow conduit causes a decrement of the left ventricular unloading and of VAD flow and, that can be counteracted by increasing the VAD speed without affecting arterial pulsatility. The valvulated outflow tube provides an increase in arterial pulsatility; it can be driven in different working modality and can be potentially applicable to all types of VADs. However, the valvulated outflow conduit causes a decrement of left ventricular unloading and of the VAD flow that can be counteracted, increasing the VAD speed.
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Di Molfetta A, Cusimano V, Ferrari G. Increasing the pulsatility of continuos flow VAD: comparison between a valvulated outflow cannula and speed modulation by simulation. J Artif Organs 2021; 24:146-156. [PMID: 33512579 DOI: 10.1007/s10047-020-01235-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 12/03/2020] [Indexed: 10/22/2022]
Abstract
To investigate by a lumped parameter model the feasibility of increasing the pulsatility of a continuous flow VAD, implanting an active valvulated outflow cannula and to compare the results with the haemodynamic outcome given by speed modulation methods. The concomitant presence of speed modulation and the active valvulated outflow conduit is also simulated. A lumped parameter model was adopted. VAD was modeled starting from its pressure flow characteristics with a second order polynomial equation. The valvulated outflow conduit was modeled as an active resistance described by a square function. Starting from pathological condition we simulated: VAD; VAD and valvulated outflow conduit in copulsation, counterpulsation and asynchrony work with the heart; VAD and active valvulated outflow tube and speed modulation. Copulsation 1:1 and asynchrony 0.3 s valve close-0.7 s valve open configurations maximised the haemodynamic benefits with the highest increment in pulsatility. The valvulated outflow conduit causes a decrement of the left ventricular unloading and of VAD flow that can be counteracted by increasing the VAD speed without affecting pulsatility. The concomitant use of the speed modulation and the active valvulated outflow conduit can further increase the pulsatility without altering left ventricular unloading and VAD flow. The valvulated outflow tube provide similar increase in pulsatility to speed modulation method but causes a decrement of left ventricular unloading and VAD flow that can be counteracted increasing the VAD speed or allowing a partial support. A valvulated outflow tube can be potentially applied to all continuous flow VADs.
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Affiliation(s)
- Arianna Di Molfetta
- Department of Cardiac Surgery, Policlinico Gemelli Hospital, Largo Agostino Gemelli, 8, 00100, Rome, Italy.
| | - Valerio Cusimano
- CNR-IASI BioMatLab, Italian National Research Council, Institute of Analysis, Systems and Computer Science, Biomathematics Laboratory, Rome, Italy
| | - Gianfranco Ferrari
- Institute of Biocybernetics and Biomedical Engineer, Polish Academy of Science, Warsaw, Poland
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Bozkurt S, van de Vosse FN, Rutten MCM. Enhancement of Arterial Pressure Pulsatility by Controlling Continuous-Flow Left Ventricular Assist Device Flow Rate in Mock Circulatory System. J Med Biol Eng 2016; 36:308-315. [PMID: 27441034 PMCID: PMC4935750 DOI: 10.1007/s40846-016-0140-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 10/14/2015] [Indexed: 01/09/2023]
Abstract
Continuous-flow left ventricular assist devices (CF-LVADs) generally operate at a constant speed, which reduces pulsatility in the arteries and may lead to complications such as functional changes in the vascular system, gastrointestinal bleeding, or both. The purpose of this study is to increase the arterial pulse pressure and pulsatility by controlling the CF-LVAD flow rate. A MicroMed DeBakey pump was used as the CF-LVAD. A model simulating the flow rate through the aortic valve was used as a reference model to drive the pump. A mock circulation containing two synchronized servomotor-operated piston pumps acting as left and right ventricles was used as a circulatory system. Proportional-integral control was used as the control method. First, the CF-LVAD was operated at a constant speed. With pulsatile-speed CF-LVAD assistance, the pump was driven such that the same mean pump output was generated. Continuous and pulsatile-speed CF-LVAD assistance provided the same mean arterial pressure and flow rate, while the index of pulsatility increased significantly for both arterial pressure and pump flow rate signals under pulsatile speed pump support. This study shows the possibility of improving the pulsatility of CF-LVAD support by regulating pump speed over a cardiac cycle without reducing the overall level of support.
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Affiliation(s)
- Selim Bozkurt
- Department of Biomedical Engineering, Eindhoven University of Technology, PO Box 513, GEM-Z 4.18, 5600 MB Eindhoven, The Netherlands
| | - Frans N. van de Vosse
- Department of Biomedical Engineering, Eindhoven University of Technology, PO Box 513, GEM-Z 4.18, 5600 MB Eindhoven, The Netherlands
| | - Marcel C. M. Rutten
- Department of Biomedical Engineering, Eindhoven University of Technology, PO Box 513, GEM-Z 4.18, 5600 MB Eindhoven, The Netherlands
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Bozkurt S, van de Vosse FN, Rutten MCM. Aortic Valve Function Under Support of a Left Ventricular Assist Device: Continuous vs. Dynamic Speed Support. Ann Biomed Eng 2014; 43:1727-37. [PMID: 25480480 DOI: 10.1007/s10439-014-1204-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 11/26/2014] [Indexed: 11/25/2022]
Abstract
Continuous flow left ventricular devices (CF-LVADs) support the failing heart at a constant speed and alters the loads on the aortic valve. This may cause insufficiency in the aortic valve under long-term CF-LVAD support. The aim of this study is to assess the aortic valve function under varying speed CF-LVAD support. A Medtronic freestyle valve and a Micromed DeBakey CF-LVAD were tested in a mock circulatory system. First, the CF-LVAD was operated at constant speeds between 7500 and 11,500 rpm with 1000 rpm intervals. The mean pump outputs obtained from these tests were applied in varying speed CF-LVAD support mode using a reference model for the pump flow. The peak of the instantaneous pump flow was applied at peak systole and mid-diastole, respectively. Ejection durations and in the aortic valve were the longest when the peak pump flow was applied at mid-diastole among the CF-LVAD operating modes. Furthermore, mean aortic valve area over a cardiac cycle was highest when the peak pump flow was applied at mid-diastole. The results show that changing phase of the reference flow rate signal may reduce the effects of the CF-LVADs on altered aortic valve closing behavior, without compromising the overall pump support level.
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Affiliation(s)
- Selim Bozkurt
- Department of Biomedical Engineering, Eindhoven University of Technology, Den Dolech 2, 5612 AZ, Eindhoven, The Netherlands,
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Bozkurt S, van Tuijl S, Schampaert S, van de Vosse FN, Rutten MC. Arterial pulsatility improvement in a feedback-controlled continuous flow left ventricular assist device: An ex-vivo experimental study. Med Eng Phys 2014; 36:1288-95. [DOI: 10.1016/j.medengphy.2014.07.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 05/31/2014] [Accepted: 07/02/2014] [Indexed: 10/25/2022]
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Improving Arterial Pulsatility by Feedback Control of a Continuous Flow Left Ventricular Assist Device via in Silico Modeling. Int J Artif Organs 2014; 37:773-85. [DOI: 10.5301/ijao.5000328] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/24/2014] [Indexed: 11/20/2022]
Abstract
Purpose Continuous flow left ventricular assist devices (CF-LVADs) generally operate at a constant speed, which causes a decrease in pulse pressure and pulsatility in the arteries and allegedly may lead to late complications such as aortic insufficiency and gastrointestinal bleeding. The purpose of this study is to increase the arterial pulse pressure and pulsatility while obtaining more physiological hemodynamic signals, by controlling the CF-LVAD flow rate. Methods A lumped parameter model was used to simulate the cardiovascular system including the heart chambers, heart valves, systemic and pulmonary arteries and veins. A baroreflex model was used to regulate the heart rate and a model of the Micromed DeBakey CF-LVAD (Micromed Technology, Houston, TX, USA) to simulate the pump dynamics at different operating speeds. A model simulating the flow rate through the aortic valve served as reference model. CF-LVAD operating speed was regulated by applying proportional-integral (PI) control to the pump flow rate. For comparison, the CF-LVAD was also operated at a constant speed, equaling the mean CF-LVAD speed as applied in pulsatile mode. Results In different operating modes, at the same mean operating speeds, mean pump output, mean arterial pressure, end-systolic and end-diastolic volume and heart rate were the same over the cardiac cycle. However, the arterial pulse pressure and index of pulsatility increased by 50% in the pulsatile CF-LVAD support mode with respect to constant speed pump support. Conclusions This study shows the possibility of obtaining more physiological pulsatile hemodynamics in the arteries by applying output-driven varying speed control to a CF-LVAD.
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Soucy KG, Koenig SC, Giridharan GA, Sobieski MA, Slaughter MS. Defining pulsatility during continuous-flow ventricular assist device support. J Heart Lung Transplant 2013; 32:581-7. [DOI: 10.1016/j.healun.2013.02.010] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 01/18/2013] [Accepted: 02/26/2013] [Indexed: 10/27/2022] Open
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De Buysscher P, Moerman A, Bové T, De Pauw M, Wouters P, De Hert S. Value of cerebral oxygen saturation monitoring during cardiopulmonary bypass in an adult patient with moyamoya disease. J Cardiothorac Vasc Anesth 2011; 27:740-3. [PMID: 22209176 DOI: 10.1053/j.jvca.2011.11.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2011] [Indexed: 11/11/2022]
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Ündar A, Palanzo D, Qiu F, Alkan-Bozkaya T, Akcevin A, Talor J, Baer L, Woitas K, Wise R, McCoach R, Guan Y, Haines N, Wang S, Clark JB, Myers JL. Benefits of pulsatile flow in pediatric cardiopulmonary bypass procedures: from conception to conduction. Perfusion 2011; 26 Suppl 1:35-9. [DOI: 10.1177/0267659111404468] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This review on the benefits of pulsatile flow includes not only experimental and clinical data, but also attempts to further illuminate the major factors as to why this debate has continued during the past 55 years. Every single component of the cardiopulmonary bypass (CPB) circuitry is equally important for generating adequate quality of pulsatility, not only the pump. Therefore, translational research is a necessity to select the best components for the circuit. Generation of pulsatile flow depends on an energy gradient; precise quantification in terms of hemodynamic energy levels is, therefore, a necessity, not an option. Comparisons between perfusion modes should be done after these basic steps have been taken. We have also included experimental and clinical data for direct comparisons between the perfusion modes. In addition, we included several suggestions for future clinical trials for other interested investigators.
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Affiliation(s)
| | | | - F Qiu
- Penn State Hershey Pediatric Cardiovascular Research Center, Departments of Pediatrics, Surgery, Bioengineering, Public Health Sciences, and Comparative Medicine, Penn State Hershey College of Medicine, Penn State Hershey Children’s Hospital, Hershey, Pennsylvania, USA
| | - T Alkan-Bozkaya
- Dept. of Cardiovascular Surgery, American Hospital, Istanbul, Turkey
| | - A Akcevin
- Dept. of Cardiovascular Surgery, American Hospital, Istanbul, Turkey
| | - J Talor
- Penn State Hershey Pediatric Cardiovascular Research Center, Departments of Pediatrics, Surgery, Bioengineering, Public Health Sciences, and Comparative Medicine, Penn State Hershey College of Medicine, Penn State Hershey Children’s Hospital, Hershey, Pennsylvania, USA
| | - L Baer
- Penn State Hershey Pediatric Cardiovascular Research Center, Departments of Pediatrics, Surgery, Bioengineering, Public Health Sciences, and Comparative Medicine, Penn State Hershey College of Medicine, Penn State Hershey Children’s Hospital, Hershey, Pennsylvania, USA
| | - K Woitas
- Penn State Hershey Pediatric Cardiovascular Research Center, Departments of Pediatrics, Surgery, Bioengineering, Public Health Sciences, and Comparative Medicine, Penn State Hershey College of Medicine, Penn State Hershey Children’s Hospital, Hershey, Pennsylvania, USA
| | - R Wise
- Penn State Hershey Pediatric Cardiovascular Research Center, Departments of Pediatrics, Surgery, Bioengineering, Public Health Sciences, and Comparative Medicine, Penn State Hershey College of Medicine, Penn State Hershey Children’s Hospital, Hershey, Pennsylvania, USA
| | - R McCoach
- Penn State Hershey Pediatric Cardiovascular Research Center, Departments of Pediatrics, Surgery, Bioengineering, Public Health Sciences, and Comparative Medicine, Penn State Hershey College of Medicine, Penn State Hershey Children’s Hospital, Hershey, Pennsylvania, USA
| | - Y Guan
- Dept. of Cardiopulmonary Bypass, The Fuwai Hospital, Beijing, China
| | - N Haines
- Penn State Hershey Pediatric Cardiovascular Research Center, Departments of Pediatrics, Surgery, Bioengineering, Public Health Sciences, and Comparative Medicine, Penn State Hershey College of Medicine, Penn State Hershey Children’s Hospital, Hershey, Pennsylvania, USA
| | - S Wang
- Dept. of Cardiopulmonary Bypass, The Fuwai Hospital, Beijing, China
| | - J B Clark
- Penn State Hershey Pediatric Cardiovascular Research Center, Departments of Pediatrics, Surgery, Bioengineering, Public Health Sciences, and Comparative Medicine, Penn State Hershey College of Medicine, Penn State Hershey Children’s Hospital, Hershey, Pennsylvania, USA
| | - J L Myers
- Penn State Hershey Pediatric Cardiovascular Research Center, Departments of Pediatrics, Surgery, Bioengineering, Public Health Sciences, and Comparative Medicine, Penn State Hershey College of Medicine, Penn State Hershey Children’s Hospital, Hershey, Pennsylvania, USA
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Gu YJ, van Oeveren W, Mungroop HE, Epema AH, den Hamer IJ, Keizer JJ, Leuvenink RP, Mariani MA, Rakhorst G. Clinical effectiveness of centrifugal pump to produce pulsatile flow during cardiopulmonary bypass in patients undergoing cardiac surgery. Artif Organs 2011; 35:E18-26. [PMID: 21314839 DOI: 10.1111/j.1525-1594.2010.01152.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Although the centrifugal pump has been widely used as a nonpulsatile pump for cardiopulmonary bypass (CPB), little is known about its performance as a pulsatile pump for CPB, especially on its efficacy in producing hemodynamic energy and its clinical effectiveness. We performed a study to evaluate whether the Rotaflow centrifugal pump produces effective pulsatile flow during CPB and whether the pulsatile flow in this setting is clinically effective in adult patients undergoing cardiac surgery. Thirty-two patients undergoing CPB for elective coronary artery bypass grafting were randomly allocated to a pulsatile perfusion group (n = 16) or a nonpulsatile perfusion group (n = 16). All patients were perfused with the Rotaflow centrifugal pump. In the pulsatile group, the centrifugal pump was adjusted to the pulsatile mode (60 cycles/min) during aortic cross-clamping, whereas in the nonpulsatile group, the pump was kept in its nonpulsatile mode during the same period of time. Compared with the nonpulsatile group, the pulsatile group had a higher pulse pressure (P < 0.01) and a fraction higher energy equivalent pressure (EEP, P = 0.058). The net gain of pulsatile flow, represented by the surplus hemodynamic energy (SHE), was found much higher in the CPB circuit than in patients (P < 0.01). Clinically, there was no difference between the pulsatile and nonpulsatile groups with regard to postoperative acute kidney injury, endothelial activation, or inflammatory response. Postoperative organ function and the duration of hospital stay were similar in the two patient groups. In conclusion, pulsatile CPB with the Rotaflow centrifugal pump is associated with a small gain of EEP and SHE, which does not seem to be clinically effective in adult cardiac surgical patients.
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Affiliation(s)
- Y John Gu
- Department of Biomedical Engineering, University Medical Center Groningen, University of Groningen, The Netherlands.
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Abstract
The control of force production in vascular smooth muscle is critical to the normal regulation of blood flow and pressure, and altered regulation is common to diseases such as hypertension, heart failure, and ischemia. A great deal has been learned about imbalances in vasoconstrictor and vasodilator signals, e.g., angiotensin, endothelin, norepinephrine, and nitric oxide, that regulate vascular tone in normal and disease contexts. In contrast there has been limited study of how the phenotypic state of the vascular smooth muscle cell may influence the contractile response to these signaling pathways dependent upon the developmental, tissue-specific (vascular bed) or disease context. Smooth, skeletal, and cardiac muscle lineages are traditionally classified into fast or slow sublineages based on rates of contraction and relaxation, recognizing that this simple dichotomy vastly underrepresents muscle phenotypic diversity. A great deal has been learned about developmental specification of the striated muscle sublineages and their phenotypic interconversions in the mature animal under the control of mechanical load, neural input, and hormones. In contrast there has been relatively limited study of smooth muscle contractile phenotypic diversity. This is surprising given the number of diseases in which smooth muscle contractile dysfunction plays a key role. This review focuses on smooth muscle contractile phenotypic diversity in the vascular system, how it is generated, and how it may determine vascular function in developmental and disease contexts.
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Affiliation(s)
- Steven A Fisher
- Department of Medicine, and Cardiovascular Research Institute, Case Western Reserve University, Cleveland, Ohio 44106-7290, USA.
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Guan Y, Karkhanis T, Wang S, Rider A, Koenig SC, Slaughter MS, El Banayosy A, Ündar A. Physiologic Benefits of Pulsatile Perfusion During Mechanical Circulatory Support for the Treatment of Acute and Chronic Heart Failure in Adults. Artif Organs 2010; 34:529-36. [DOI: 10.1111/j.1525-1594.2010.00996.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Baufreton C. Role of surgical factors in strokes after cardiac surgery. Arch Cardiovasc Dis 2010; 103:326-32. [PMID: 20619243 DOI: 10.1016/j.acvd.2009.12.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Accepted: 12/28/2009] [Indexed: 11/18/2022]
Abstract
Deficient neurological disorders after heart surgery are destructive and affect vital prognosis. They concern between 3% to 9% of patients and are related mainly to embolic episodes or brain perfusion defects. The causes of these mechanisms are numerous, but surgical procedures and cardiopulmonary bypass optimization reduce their occurrence significantly.
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Affiliation(s)
- Christophe Baufreton
- Department of Cardiac Surgery, CHU Angers, Medical University of Angers, Angers University, France.
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Undar A, Pauliks L, Clark JB, Zahn J, Rosenberg G, Kunselman AR, Sun Q, Pekkan K, Saliba K, Carney E, Thomas N, Freeman W, Vrana K, El-Banayosy A, Ural SH, Wilson R, Umstead TM, Floros J, Phelps DS, Weiss W, Snyder A, Yang S, Kimatian S, Cyran SE, Chinchilli VM, Guan Y, Rider A, Haines N, Rogerson A, Alkan-Bozkaya T, Akcevin A, Sun K, Wang S, Cun L, Myers JL. Penn State Hershey--center for pediatric cardiovascular research. Artif Organs 2009; 33:883-7. [PMID: 20021467 PMCID: PMC2797544 DOI: 10.1111/j.1525-1594.2009.00889.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Différences microcirculatoires entre CEC pulsée et non pulsée. Ing Rech Biomed 2007. [DOI: 10.1016/s1297-9562(07)78716-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Ji B, Undar A. An Evaluation of the Benefits of Pulsatile versus Nonpulsatile Perfusion during Cardiopulmonary Bypass Procedures in Pediatric and Adult Cardiac Patients. ASAIO J 2006; 52:357-61. [PMID: 16883112 DOI: 10.1097/01.mat.0000225266.80021.9b] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
The controversy over the benefits of pulsatile and nonpulsatile flow during cardiopulmonary bypass procedures continues. The objective of this investigation was to review the literature in order to clarify the truths and dispel the myths regarding the mode of perfusion used during open-heart surgery in pediatric and adult patients. The Google and Medline databases were used to search all of the literature on pulsatile vs. nonpulsatile perfusion published between 1952 and 2006. We found 194 articles related to this topic in the literature. Based on our literature search, we determined that pulsatile flow significantly improved blood flow of the vital organs including brain, heart, liver, and pancreas; reduced the systemic inflammatory response syndrome; and decreased the incidence of postoperative deaths in pediatric and adult patients. We also found evidence that pulsatile flow significantly improved vital organ recovery in several types of animal models when compared with nonpulsatile perfusion. Several investigators have also shown that pulsatile flow generates more hemodynamic energy, which maintains better microcirculation compared with nonpulsatile flow. These results clearly suggest that pulsatile flow is superior to nonpulsatile flow during and after open-heart surgery in pediatric and adult patients.
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Undar A. Pulsatile Versus Nonpulsatile Cardiopulmonary Bypass Procedures in Neonates and Infants: From Bench to Clinical Practice. ASAIO J 2005; 51:vi-x. [PMID: 16322700 DOI: 10.1097/01.mat.0000178215.34588.98] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Undar A, Eichstaedt HC, Masai T, Bigley JE, Kunselman AR. Precise Quantification of Pulsatility is a Necessity for Direct Comparisons of Six Different Pediatric Heart-Lung Machines in a Neonatal CPB Model. ASAIO J 2005; 51:600-3. [PMID: 16322724 DOI: 10.1097/01.mat.0000177780.39577.d2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Generation of pulsatile flow depends on an energy gradient. Surplus hemodynamic energy (SHE) is the extra hemodynamic energy generated by a pulsatile device when the adequate pulsatility is achieved. The objective of this study was to precisely quantify and compare pressure-flow waveforms in terms of surplus hemodynamic energy levels of six different pediatric heart-lung machines in a neonatal piglet model during cardiopulmonary bypass (CPB) procedures with deep hypothermic circulatory arrest (DHCA). Thirty-nine piglets (average weight, 3 kg) were subjected to CPB with a hydraulically driven physiologic pulsatile pump (PPP; n=7), Jostra-HL 20 pulsatile roller pump (Jostra-PR; n=6), Stockert Sill pulsatile roller pump (SIII-PR; n=6), Stockert Sill mast-mounted pulsatile roller pump with a miniature roller head (Mast-PR; n=7), Stockert Sill mast-mounted nonpulsatile roller pump (Mast-NP; n=7), or Stockert CAPS nonpulsatile roller pump (CAPS-NP, n=7). Once CPB was begun, each animal underwent 20 minutes of hypothermia, 60 minutes of DHCA, 10 minutes of cold reperfusion, and 40 minutes of rewarming. The pump flow rate was maintained at 150 ml x kg(-1) x min(-1) and the mean arterial pressure (MAP) at 45 mm Hg. In the pulsatile experiments, the pump rate was kept at 150 bpm and the stroke volume at 1 ml/kg. The SHE (ergs/cm3) = 1,332 ([(integral fpdt) / (integral fdt)] - MAP) was calculated at each experimental stage. During normothermic CPB (15 minutes on pump), the physiologic pulsatile pump generated the highest surplus hemodynamic energy (8563 +/- 1918 ergs/cm3, p < 0.001) compared with all other pumps. The Jostra HL-20 and Stockert Sill pulsatile roller pumps also produced adequate surplus hemodynamic energy. Nonpulsatile roller pumps and the Stockert Sill mast-mounted pulsatile roller pump did not generate any extra hemodynamic energy. During hypothermic CPB and after DHCA and rewarming, the results were extremely similar to those seen during normothermic CPB. The surplus hemodynamic energy formula is a novel method to precisely quantify different levels of pulsatility and nonpulsatility for direct and meaningful comparisons. The PPP produced the greatest surplus hemodynamic energy. Most of the pediatric pulsatile pumps (except Mast-PR) generated significant surplus hemodynamic energy. None of the nonpulsatile roller pumps generated adequate surplus hemodynamic energy.
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Affiliation(s)
- Akif Undar
- Department of Pediatrics, Penn State Children's Hospital, Penn State College of Medicine, Penn State Milton S. Hershey Medical Center, Hershey, PA 17033-0850, USA
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