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Kuroda T, Miyagi C, Polakowski AR, Flick CR, Kuban BD, Fukamachi K, Karimov JH. Preservation of pulsatility with universal ventricular assist device: In vitro assessment for biventricular support. Artif Organs 2024; 48:182-190. [PMID: 37787082 DOI: 10.1111/aor.14656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 08/08/2023] [Accepted: 09/21/2023] [Indexed: 10/04/2023]
Abstract
BACKGROUND The objective of this study was to assess the pulsatility preservation capability of the universal ventricular assist device (UVAD) when used as a biventricular assist device (BVAD). This evaluation was conducted through an in vitro experiment, utilizing a pulsatile biventricular circulatory mock loop. METHODS Two UVAD pumps were tested in a dual setup (BVAD) in the circulatory model with the simulated conditions of left heart failure (HF), right HF, and moderate/severe biventricular HF (BHF). The total flow, aortic pulse pressure, the pulse augmentation factor (PAF), the energy-equivalent pressure (EEP), and the surplus hemodynamic energy (SHE) were observed at various pump speeds to evaluate the pulsatility. RESULTS The aortic pulse pressure increased from the baseline (without pump) in all simulated hemodynamic conditions. The PAF ranged from 17%-35% in healthy, left HF, right HF, and mild BHF conditions, with the highest PAF of 90% being observed in the severe BHF condition. The EEP correlated with LVAD flow in all groups (R2 = 0.87-0.97) and increased from the baseline in all cases. The SHE peaked at approximately 5-6 L/min of LVAD support and was likely to decrease at higher LVAD pump flow. The largest decrease in SHE from the baseline, 53%, was observed in the mild BHF conditions with the highest LVAD and RVAD support. CONCLUSIONS The UVAD successfully demonstrated the ability to preserve pulsatility in vitro, and to optimize the cardiac output, as an isolated circulatory support device option (RVAD or LVAD) and when used for BVAD support.
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Affiliation(s)
- Taiyo Kuroda
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Chihiro Miyagi
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Anthony R Polakowski
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Christine R Flick
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Barry D Kuban
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
- Department of Cardiovascular Medicine, Kaufman Center for Heart Failure Treatment and Recovery, Section of Heart Failure and Cardiac Transplant Medicine, Cleveland, Ohio, USA
| | - Kiyotaka Fukamachi
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
- Department of Cardiovascular Medicine, Kaufman Center for Heart Failure Treatment and Recovery, Section of Heart Failure and Cardiac Transplant Medicine, Cleveland, Ohio, USA
- Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio, USA
| | - Jamshid H Karimov
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
- Department of Cardiovascular Medicine, Kaufman Center for Heart Failure Treatment and Recovery, Section of Heart Failure and Cardiac Transplant Medicine, Cleveland, Ohio, USA
- Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio, USA
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2
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D'Souza GA, Rinaldi JE, Meki M, Crusan A, Richardson E, Shinnar M, Herbertson LH. Using a Mock Circulatory Loop as a Regulatory Science Tool to Simulate Different Heart Failure Conditions. J Biomech Eng 2024; 146:011004. [PMID: 37831143 DOI: 10.1115/1.4063746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 10/06/2023] [Indexed: 10/14/2023]
Abstract
Mechanical circulatory support (MCS) device therapy is one of the primary treatment options for end-stage heart failure (HF), whereby a mechanical pump is integrated with the failing heart to maintain adequate tissue perfusion. The ISO 14708-5:2020 standard prescribes generic guidelines for nonclinical device evaluation and system performance testing of MCS devices using a mock circulatory loop (MCL). However, the utility of MCLs in premarket regulatory submissions of MCS devices is ambiguous, and the specific disease states that the device is intended to treat are not usually simulated. Hence, we aim to outline the potential of MCLs as a valuable regulatory science tool for characterizing MCS device systems by adequately representing target clinical-use HF conditions on the bench. Target pathophysiologic hemodynamics of HF conditions (i.e., cardiogenic shock (CS), left ventricular (LV) hypertrophy secondary to hypertension, and coronary artery disease), along with a healthy adult at rest and a healthy adult during exercise are provided as recommended test conditions. The conditions are characterized based on LV, aorta, and left atrium pressures using recommended cardiac hemodynamic indices such as systolic, diastolic, and mean arterial pressure, mean cardiac output (CO), cardiac cycle time, and systemic vascular resistance. This study is a first step toward standardizing MCLs to generate well-defined target HF conditions used to evaluate MCS devices.
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Affiliation(s)
- Gavin A D'Souza
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993
| | - Jean E Rinaldi
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993
| | - Moustafa Meki
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993
| | - Annabelle Crusan
- Circulatory Support Devices Team, Office of Product Evaluation and Quality, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993
| | - Eric Richardson
- Circulatory Support Devices Team, Office of Product Evaluation and Quality, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993
| | - Meir Shinnar
- Circulatory Support Devices Team, Office of Product Evaluation and Quality, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993
| | - Luke H Herbertson
- Division of Applied Mechanics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993
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3
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(Physiology of Continuous-flow Left Ventricular Assist Device Therapy. Translation of the document prepared by the Czech Society of Cardiology). COR ET VASA 2022. [DOI: 10.33678/cor.2022.040] [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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4
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Rosenbaum AN, Antaki JF, Behfar A, Villavicencio MA, Stulak J, Kushwaha SS. Physiology of Continuous-Flow Left Ventricular Assist Device Therapy. Compr Physiol 2021; 12:2731-2767. [PMID: 34964115 DOI: 10.1002/cphy.c210016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The expanding use of continuous-flow left ventricular assist devices (CF-LVADs) for end-stage heart failure warrants familiarity with the physiologic interaction of the device with the native circulation. Contemporary devices utilize predominantly centrifugal flow and, to a lesser extent, axial flow rotors that vary with respect to their intrinsic flow characteristics. Flow can be manipulated with adjustments to preload and afterload as in the native heart, and ascertainment of the predicted effects is provided by differential pressure-flow (H-Q) curves or loops. Valvular heart disease, especially aortic regurgitation, may significantly affect adequacy of mechanical support. In contrast, atrioventricular and ventriculoventricular timing is of less certain significance. Although beneficial effects of device therapy are typically seen due to enhanced distal perfusion, unloading of the left ventricle and atrium, and amelioration of secondary pulmonary hypertension, negative effects of CF-LVAD therapy on right ventricular filling and function, through right-sided loading and septal interaction, can make optimization challenging. Additionally, a lack of pulsatile energy provided by CF-LVAD therapy has physiologic consequences for end-organ function and may be responsible for a series of adverse effects. Rheological effects of intravascular pumps, especially shear stress exposure, result in platelet activation and hemolysis, which may result in both thrombotic and hemorrhagic consequences. Development of novel solutions for untoward device-circulatory interactions will facilitate hemodynamic support while mitigating adverse events. © 2021 American Physiological Society. Compr Physiol 12:1-37, 2021.
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Affiliation(s)
- Andrew N Rosenbaum
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota, USA.,William J von Liebig Center for Transplantation and Clinical Regeneration, Mayo Clinic, Rochester, Minnesota, USA
| | - James F Antaki
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York, USA
| | - Atta Behfar
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota, USA.,William J von Liebig Center for Transplantation and Clinical Regeneration, Mayo Clinic, Rochester, Minnesota, USA.,VanCleve Cardiac Regenerative Medicine Program, Center for Regenerative Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | | | - John Stulak
- Department of Cardiovascular Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Sudhir S Kushwaha
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota, USA.,William J von Liebig Center for Transplantation and Clinical Regeneration, Mayo Clinic, Rochester, Minnesota, USA
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5
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Liu H, Liu S, Ma X. Varying speed modulation of continuous-flow left ventricular assist device based on cardiovascular coupling numerical model. Comput Methods Biomech Biomed Engin 2020; 24:956-972. [PMID: 33347766 DOI: 10.1080/10255842.2020.1861601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Continuous-flow left ventricular assist devices (CFLVADs) routinely operate at a constant speed for the support of a failing heart, which decreases the pulsatility in the arteries. Some late complications could be related to a long-term lack of pulsatility. Modulating the CFLVAD speed is a solution to enhance the pulsatility. The purpose of this study is to modulate multiple varying speed patterns and investigate their effects on the ventricle and vascular system. A cardiovascular coupling numerical model is developed to provide a simulation platform for testing the varying speed patterns. The varying speed patterns are modulated by combining the shape, amplitude, frequency, phase shift, and pulsatile duty cycle of the speed profile. The influence of varying speed support is examined by analyzing the indexes of pulsatility, indexes of ventricular unloading, and hemodynamic variables. The results show that the synchronous counterpulsation pattern can effectively reduce the ventricular unloading indexes, whereas the low-frequency asynchronous pattern can effectively increase the vascular pulsatility indexes. Also, the hemodynamics with synchronous varying speed support is more physiological than that with asynchronous varying speed support. This study provides valuable insight for further optimization of varying speed modulation by weighing vascular pulsatility, ventricular unloading, and hemodynamics.
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Affiliation(s)
- Hongtao Liu
- School of Electrical Engineering, Shandong University, Jinan, PR China
| | - Shuqin Liu
- School of Electrical Engineering, Shandong University, Jinan, PR China
| | - Xiaoxu Ma
- School of Electrical Engineering, Shandong University, Jinan, PR China
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6
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Ogawa D, Kobayashi S, Yamazaki K, Motomura T, Nishimura T, Shimamura J, Tsukiya T, Mizuno T, Takewa Y, Tatsumi E, Nishinaka T. Evaluation of cardiac beat synchronization control for a rotary blood pump on valvular regurgitation with a mathematical model. Artif Organs 2020; 45:124-134. [PMID: 32813920 DOI: 10.1111/aor.13795] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 07/10/2020] [Accepted: 08/05/2020] [Indexed: 01/17/2023]
Abstract
We have studied the cardiac beat synchronization (CBS) control for a rotary blood pump (RBP) and revealed that it can promote pulsatility and reduce cardiac load. Besides, patients with LVAD support sometimes suffer from aortic and mitral regurgitation (AR and MR). A control method for the RBP should be validated in wider range of conditions to clarify its benefits and pitfalls prior to clinical application. In this study, we evaluated pulsatility and cardiac load reduction obtained with the CBS control on valvular failure conditions with a mathematical model. Diastolic assist could reduce cardiac load on the left ventricle by decreasing external work of the ventricle even in MR cases while it was not so effective in AR cases. Systolic assist can still promote pulsatility in AR and MR cases; however, aortic valve function should be carefully confirmed since pulse pressure can be wider not due to systolic assist but to AR.
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Affiliation(s)
- Daisuke Ogawa
- Sun Medical Technology Research Corp., Nagano, Japan
| | | | | | | | - Takashi Nishimura
- Department of Cardiovascular and Thoracic Surgery, Graduate school of Medicine, Ehime University, Ehime, Japan
| | - Junichi Shimamura
- Department of Artificial Organs, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Tomonori Tsukiya
- Department of Artificial Organs, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Toshihide Mizuno
- Department of Artificial Organs, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Yoshiaki Takewa
- Advanced Medical Engineering Research Center, Asahikawa Medical University, Hokkaido, Japan
| | - Eisuke Tatsumi
- Department of Artificial Organs, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Tomohiro Nishinaka
- Department of Artificial Organs, National Cerebral and Cardiovascular Center, Osaka, Japan.,Department of Cardiovascular Surgery, Graduate School of Medicine, Osaka University, Osaka, Japan
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7
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Melo TR, Neto JS, Cestari IA, Lima AM. Feedback controller for restoring the basal hemodynamic condition with a rotary blood pump used as left ventricular assist device. Biomed Signal Process Control 2020. [DOI: 10.1016/j.bspc.2020.102136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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8
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Gharaie SH, Amir Moghadam AA, Al'Aref SJ, Caprio A, Alaie S, Zgaren M, Min JK, Dunham S, Mosadegh B. A Proof-of-Concept Demonstration for a Novel Soft Ventricular Assist Device. J Med Device 2019. [DOI: 10.1115/1.4043052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Patients treated by current ventricular assist devices (VADs) suffer from various post implantation complications including gastrointestinal bleeding and arteriovenous malformation. These issues are related to intrinsically mismatch of generated flow by VADs and the physiological flow. In addition, the common primary drawback of available VADs is excessive surgical dissection during implantation, which limits these devices to less morbid patients. We investigated an alternative soft VAD (SVAD) system that generates physiological flow, and designed to be implanted using minimally invasive surgery by leveraging soft materials. A soft VAD (which is an application of intraventricular balloon pump) is developed by utilizing a polyurethane balloon, which generates pulsatile flow by displacing volume within the left ventricle during its inflation and deflation phases. Our results show that the SVAD system generates an average ejection fraction of 50.18 ± 1.52% (n = 6 ± SD) in explanted porcine hearts. Since the SVAD is implanted via the apex of the heart, only a minithoracotomy should be required for implantation. Our results suggest that the SVAD system has the performance characteristics that could potentially make it useful for patients in acute and/or chronic heart failure, thus serving as a bridge-to-transplantation or bridge-to-recovery.
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Affiliation(s)
- Saleh H. Gharaie
- Dalio Institute of Cardiovascular Imaging, Department of Radiology, New York-Presbyterian Hospital and Weill Cornell Medicine, 413 E.69th street, Suite 108, New York, NY 10021 e-mail:
| | - Amir Ali Amir Moghadam
- Dalio Institute of Cardiovascular Imaging, Department of Radiology, New York-Presbyterian Hospital and Weill Cornell Medicine, 413 E.69th street, Suite 108, New York, NY 10021 e-mail:
| | - Subhi J. Al'Aref
- Dalio Institute of Cardiovascular Imaging, Department of Radiology, New York-Presbyterian Hospital and Weill Cornell Medicine, 413 E.69th street, Suite 108, New York, NY 10021 e-mail:
| | - Alexandre Caprio
- Dalio Institute of Cardiovascular Imaging, Department of Radiology, New York-Presbyterian Hospital and Weill Cornell Medicine, 413 E.69th street, Suite 108, New York, NY 10021 e-mail:
| | - Seyedhamidreza Alaie
- Dalio Institute of Cardiovascular Imaging, Department of Radiology, New York-Presbyterian Hospital and Weill Cornell Medicine, 413 E.69th street, Suite 108, New York, NY 10021 e-mail:
| | - Mohamed Zgaren
- Dalio Institute of Cardiovascular Imaging, Department of Radiology, New York-Presbyterian Hospital and Weill Cornell Medicine, 413 E.69th street, Suite 108, New York, NY 10021 e-mail:
| | - James K. Min
- Dalio Institute of Cardiovascular Imaging, Department of Radiology, New York-Presbyterian Hospital and Weill Cornell Medicine, 413 E.69th street, Suite 108, New York, NY 10021 e-mail:
| | - Simon Dunham
- Dalio Institute of Cardiovascular Imaging, Department of Radiology, New York-Presbyterian Hospital and Weill Cornell Medicine, 413 E.69th street, Suite 108, New York, NY 10021 e-mail:
| | - Bobak Mosadegh
- Dalio Institute of Cardiovascular Imaging, Department of Radiology, New York-Presbyterian Hospital and Weill Cornell Medicine, 413 E.69th street, Suite 108, New York, NY 10021 e-mail:
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9
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Good BC, Weiss WJ, Deutsch S, Manning KB. Asynchronous Pumping of a Pulsatile Ventricular Assist Device in a Pediatric Anastomosis Model. World J Pediatr Congenit Heart Surg 2017; 8:511-519. [PMID: 28696878 DOI: 10.1177/2150135117713697] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Both pulsatile and continuous flow ventricular assist devices are being developed for pediatric congenital heart defect patients. Pulsatile devices are often operated asynchronously with the heart in either an "automatic" or a fixed beat rate mode. However, most studies have only investigated synchronized ejection. METHODS A previously validated viscoelastic blood solver is used to investigate the parameters of pulsatility, power loss, and graft failure in a pediatric aortic anastomosis model. RESULTS Pulsatility was highest with synchronized flow and lowest at a 90° phase shift. Power loss decreased at 90° and 180° phase shifts but increased at a 270° phase shift. Similar regions of potential intimal hyperplasia and graft failure were seen in all cases but with phase-shifted ejection leading to higher wall shear stress on the anastomotic floor and oscillatory shear index on the anastomotic toe. CONCLUSION The ranges of pulsatility and hemodynamics that can result clinically using asynchronous pulsatile devices were investigated in a pediatric anastomosis model. These results, along with the different postoperative benefits of pump modulation, can be used to design an optimal weaning protocol.
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Affiliation(s)
- Bryan C Good
- 1 Department of Biomedical Engineering, Pennsylvania State University, University Park, PA, USA
| | - William J Weiss
- 1 Department of Biomedical Engineering, Pennsylvania State University, University Park, PA, USA.,2 Department of Surgery, Penn State Hershey Medical Center, Hershey, PA, USA
| | - Steven Deutsch
- 1 Department of Biomedical Engineering, Pennsylvania State University, University Park, PA, USA
| | - Keefe B Manning
- 1 Department of Biomedical Engineering, Pennsylvania State University, University Park, PA, USA.,2 Department of Surgery, Penn State Hershey Medical Center, Hershey, PA, USA
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10
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Fukamachi K, Karimov JH, Sunagawa G, Horvath DJ, Byram N, Kuban BD, Dessoffy R, Sale S, Golding LAR, Moazami N. Generating pulsatility by pump speed modulation with continuous-flow total artificial heart in awake calves. J Artif Organs 2017; 20:381-385. [PMID: 28391521 DOI: 10.1007/s10047-017-0958-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 03/27/2017] [Indexed: 11/27/2022]
Abstract
The purpose of this study was to evaluate the effects of sinusoidal pump speed modulation of the Cleveland Clinic continuous-flow total artificial heart (CFTAH) on hemodynamics and pump flow in an awake chronic calf model. The sinusoidal pump speed modulations, performed on the day of elective sacrifice, were set at ±15 and ± 25% of mean pump speed at 80 bpm in four awake calves with a CFTAH. The systemic and pulmonary arterial pulse pressures increased to 12.0 and 12.3 mmHg (±15% modulation) and to 15.9 and 15.7 mmHg (±25% modulation), respectively. The pulsatility index and surplus hemodynamic energy significantly increased, respectively, to 1.05 and 1346 ergs/cm at ±15% speed modulation and to 1.51 and 3381 ergs/cm at ±25% speed modulation. This study showed that it is feasible to generate pressure pulsatility with pump speed modulation; the platform is suitable for evaluating the physiologic impact of pulsatility and allows determination of the best speed modulations in terms of magnitude, frequency, and profiles.
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Affiliation(s)
- Kiyotaka Fukamachi
- Cardiovascular Dynamics Laboratory, Department of Biomedical Engineering/ND20, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA.
| | - Jamshid H Karimov
- Cardiovascular Dynamics Laboratory, Department of Biomedical Engineering/ND20, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA.
| | - Gengo Sunagawa
- Cardiovascular Dynamics Laboratory, Department of Biomedical Engineering/ND20, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
| | - David J Horvath
- Cardiovascular Dynamics Laboratory, Department of Biomedical Engineering/ND20, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
- R1 Engineering, Cleveland, OH, USA
| | - Nicole Byram
- Cardiovascular Dynamics Laboratory, Department of Biomedical Engineering/ND20, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
| | - Barry D Kuban
- Electronics Core, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Raymond Dessoffy
- Cardiovascular Dynamics Laboratory, Department of Biomedical Engineering/ND20, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
| | - Shiva Sale
- Department of Cardiothoracic Anesthesiology, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Leonard A R Golding
- Cardiovascular Dynamics Laboratory, Department of Biomedical Engineering/ND20, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
| | - Nader Moazami
- Cardiovascular Dynamics Laboratory, Department of Biomedical Engineering/ND20, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
- Department of Thoracic and Cardiovascular Surgery, Kaufman Center for Heart Failure, Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH, USA
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11
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Rüschen D, Prochazka F, Amacher R, Bergmann L, Leonhardt S, Walter M. Minimizing left ventricular stroke work with iterative learning flow profile control of rotary blood pumps. Biomed Signal Process Control 2017. [DOI: 10.1016/j.bspc.2016.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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12
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Sunagawa G, Koprivanac M, Karimov JH, Moazami N, Fukamachi K. Is a pulse absolutely necessary during cardiopulmonary bypass? Expert Rev Med Devices 2016; 14:27-35. [DOI: 10.1080/17434440.2017.1265445] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Gengo Sunagawa
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Marijan Koprivanac
- Department of Thoracic and Cardiovascular Surgery, Kaufman Center for Heart Failure, Cardiac Transplantation and Mechanical Circulatory Support, Miller Family Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Jamshid H. Karimov
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Nader Moazami
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
- Department of Thoracic and Cardiovascular Surgery, Kaufman Center for Heart Failure, Cardiac Transplantation and Mechanical Circulatory Support, Miller Family Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Kiyotaka Fukamachi
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
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13
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Capoccia M. Mechanical Circulatory Support for Advanced Heart Failure: Are We about to Witness a New "Gold Standard"? J Cardiovasc Dev Dis 2016; 3:E35. [PMID: 29367578 PMCID: PMC5715724 DOI: 10.3390/jcdd3040035] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Revised: 12/03/2016] [Accepted: 12/06/2016] [Indexed: 01/08/2023] Open
Abstract
The impact of left ventricular assist devices (LVADs) for the treatment of advanced heart failure has played a significant role as a bridge to transplant and more recently as a long-term solution for non-eligible candidates. Continuous flow left ventricular assist devices (CF-LVADs), based on axial and centrifugal design, are currently the most popular devices in view of their smaller size, increased reliability and higher durability compared to pulsatile flow left ventricular assist devices (PF-LVADs). The trend towards their use is increasing. Therefore, it has become mandatory to understand the physics and the mathematics behind their mode of operation for appropriate device selection and simulation set up. For this purpose, this review covers some of these aspects. Although very successful and technologically advanced, they have been associated with complications such as pump thrombosis, haemolysis, aortic regurgitation, gastro-intestinal bleeding and arterio-venous malformations. There is perception that the reduced arterial pulsatility may be responsible for these complications. A flow modulation control approach is currently being investigated in order to generate pulsatility in rotary blood pumps. Thrombus formation remains the most feared complication that can affect clinical outcome. The development of a preoperative strategy aimed at the reduction of complications and patient-device suitability may be appropriate. Patient-specific modelling based on 3D reconstruction from CT-scan combined with computational fluid dynamic studies is an attractive solution in order to identify potential areas of stagnation or challenging anatomy that could be addressed to achieve the desired outcome. The HeartMate II (axial) and the HeartWare HVAD (centrifugal) rotary blood pumps have been now used worldwide with proven outcome. The HeartMate III (centrifugal) is now emerging as the new promising device with encouraging preliminary results. There are now enough pumps on the market: it is time to focus on the complications in order to achieve the full potential and selling-point of this type of technology for the treatment of the increasing heart failure patient population.
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Affiliation(s)
- Massimo Capoccia
- Scottish National Advanced Heart Failure Service, Golden Jubilee National Hospital, Glasgow G81 4DY, UK.
- Biomedical Engineering, University of Strathclyde, Glasgow G4 0NW, UK.
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14
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Date K, Nishimura T, Arakawa M, Takewa Y, Kishimoto S, Umeki A, Ando M, Mizuno T, Tsukiya T, Ono M, Tatsumi E. Changing pulsatility by delaying the rotational speed phasing of a rotary left ventricular assist device. J Artif Organs 2016; 20:18-25. [DOI: 10.1007/s10047-016-0920-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 07/12/2016] [Indexed: 10/21/2022]
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15
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Ji B, Undar A. Review Article: Comparison of perfusion modes on microcirculation during acute and chronic cardiac support: is there a difference? Perfusion 2016; 22:115-9. [PMID: 17708160 DOI: 10.1177/0267659107080115] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Although heart-lung machines and cardiac assist devices have been used successfully for acute and chronic cardiac support for decades, controversies still remain concerning the benefits of pulsatile and non-pulsatile perfusion. The core of the debate is whether enough energy is generated by the artificial pulse to keep capillary beds open and cell metabolism stabilized during acute or chronic cardiac support. In other words, does artificial pulsatility exist in the microcirculation: small vessels of less than 100 μm in diameter? Many investigators have tried to use different tools and biomarkers to reflect directly or indirectly the state of the microcirculation when comparing the two different perfusion modes during acute and chronic cardiac support. However, the results are controversial. First, direct observation of the state of the microcirculation during acute and chronic cardiac support is limited; and reports concerning direct observation of the microcirculation with different perfusion modes in contemporary literature are rare. Secondly, different investigators have used their own criteria to define pulsatile flow. Therefore, it is necessary to develop more efficient methodologies, enabling direct observation of the microcirculation during acute and chronic cardiac support and also establish common criteria that will precisely quantify the pulsatile flow in terms of energy equivalent pressure (EEP) and surplus hemodynamic energy (SHE) levels. Using these critical parameters may explain how excess energy is created by pulsatile flow and maintains perfusion through the microcirculation by ensuring capillary patency. Perfusion (2007) 22, 115—119.
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Affiliation(s)
- Bingyang Ji
- Department of Pediatrics, Penn State Children's Hospital, Penn State College of Medicine, Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania 17033-0850, USA
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16
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Ganushchak YM, Simons AP, Weerwind PW. The hidden limitations in "advertising" a novel synchronized cardiac assist device. Artif Organs 2015; 39:451-2. [PMID: 25953235 DOI: 10.1111/aor.12503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yuri M Ganushchak
- Department of Cardiothoracic Surgery, Maastricht University Medical Center, Maastricht, The Netherlands.,Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Antoine P Simons
- Department of Cardiothoracic Surgery, Maastricht University Medical Center, Maastricht, The Netherlands. .,Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands.
| | - Patrick W Weerwind
- Department of Cardiothoracic Surgery, Maastricht University Medical Center, Maastricht, The Netherlands.,Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
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17
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Moazami N, Dembitsky WP, Adamson R, Steffen RJ, Soltesz EG, Starling RC, Fukamachi K. Does pulsatility matter in the era of continuous-flow blood pumps? J Heart Lung Transplant 2014; 34:999-1004. [PMID: 25447568 DOI: 10.1016/j.healun.2014.09.012] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 09/05/2014] [Accepted: 09/19/2014] [Indexed: 10/24/2022] Open
Abstract
Despite significant improved survival with continuous flow left ventricular assist devices (LVADs), complications related to aortic valve insufficiency, gastrointestinal bleeding, stroke, pump thrombosis, and hemolysis have dampened the long term success of these pumps. Evolution has favored a pulsatile heart pump to be able to deliver the maximum flow at different levels of systemic vascular resistance, confer kinetic energy to the flow of blood past areas of stenosis and generate low shear stress on blood elements. In this perspective, we suggest that lack of pulsatility may be one factor that has limited the success of continuous flow LVADs and suggest that research needs to focus on methods to generate pulsatility either by the native heart or by various speed modulation algorithms.
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Affiliation(s)
- Nader Moazami
- Department of Thoracic and Cardiovascular Surgery, Heart and Vascular Institute; Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio.
| | - Walter P Dembitsky
- Department of Cardiac Surgery, Sharp Memorial Hospital, San Diego, California
| | - Robert Adamson
- Department of Cardiac Surgery, Sharp Memorial Hospital, San Diego, California
| | - Robert J Steffen
- Department of Thoracic and Cardiovascular Surgery, Heart and Vascular Institute
| | - Edward G Soltesz
- Department of Thoracic and Cardiovascular Surgery, Heart and Vascular Institute
| | - Randall C Starling
- Department of Cardiovascular Medicine, Heart and Vascular Institute, Kaufman Center for Heart Failure, Cleveland Clinic, Cleveland, Ohio
| | - Kiyotaka Fukamachi
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
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18
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Ohuchi K, Takatani S. Currently available ventricular-assist devices: capabilities, limitations and future perspectives. Expert Rev Med Devices 2014; 3:195-205. [PMID: 16515386 DOI: 10.1586/17434440.3.2.195] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The continuous progress in ventricular-assist device (VAD) technology and the management of patients with VADs has broadened the treatment options for end-stage heart failure patients. The available line-up of clinical devices provides the current optimal therapies to meet the specific needs of each patient. The extended durability, safety, efficacy and improved quality of life of the patients provides sufficient proof for the VAD to be a likely alternative therapy to heart transplantation. The sequential progress from the first-, to the second- and to the third-generation VAD technology is expected to bring increasing benefits to clinical outcomes. This article reviews the current status, capabilities, limitations and future perspectives of currently available VADs by generally classifying them via support duration, alignment of pump devices and via pulsatile or nonpulsatile mode of perfusion. Furthermore, the future direction of research and development for next-generation VADs is presented based on the lessons learned from currently available VADs.
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Affiliation(s)
- Katsuhiro Ohuchi
- Institute of Biomaterials and Bioengineering, Department of Artificial Organs, Tokyo Medical and Dental University, Tokyo, Japan.
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19
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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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High Pulsatility Flow Induces Acute Endothelial Inflammation through Overpolarizing Cells to Activate NF-κB. Cardiovasc Eng Technol 2012; 4:26-38. [PMID: 23667401 DOI: 10.1007/s13239-012-0115-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Large artery stiffening and small artery inflammation are both well-known pathological features of pulmonary and systemic hypertension, but the relationship between them has been seldom explored. We previously demonstrated that stiffening-induced high pulsatility flow stimulated a pro-inflammatory response in distal pulmonary artery endothelial cells (PAEC). Herein, we hypothesized that high pulsatility flow activated PAEC pro-inflammatory responses are mediated through cell structural remodeling and cytoskeletal regulation of NF-κB translocation. To test this hypothesis, cells were exposed to low and high pulsatility flows with the same mean physiological flow shear stress. Results showed that unidirectional, high pulsatility flow led to continuous, high-level NF-κB activation, whereas low pulsatility flow induced only transient, minor NF-κB activation. Compared to cell shape under the static condition, low pulsatility flow induced cell elongation with a polarity index of 1.7, while high pulsatility flow further increased the cell polarity index to a value greater than 3. To explore the roles of cytoskeletal proteins in transducing high flow pulsatility into NF-κB activation, PAECs were treated with drugs that reduce the synthesis-breakdown dynamics of F-actin or microtubules (cytochalasin D, phalloidin, nocodazole, and taxol) prior to flow. Results showed that these pre-treatments suppressed NF-κB activation induced by high pulsatility flow, but drugs changing dynamics of F-actin enhanced NF-κB activation even under low pulsatility flow. Taxol was further circulated in the flow to examine its effect on cells. Results showed that circulating taxol (10nM) reduced PAEC polarity, NF-κB activation, gene expression of pro-inflammatory molecules (ICAM-1 and VCAM-1), and monocyte adhesion on the PAECs under high pulsatility flow. Therefore, taxol effectively reduced high pulsatility flow-induced PAEC overpolarization and pro-inflammatory responses via inhibiting cytoskeletal remodeling. This study suggests that stabilizing microtubule dynamics might bea potential therapeutic means of reducing endothelial inflammation caused by high pulsatility flow.
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Scott-Drechsel D, Su Z, Hunter K, Li M, Shandas R, Tan W. A new flow co-culture system for studying mechanobiology effects of pulse flow waves. Cytotechnology 2012; 64:649-66. [PMID: 22526489 DOI: 10.1007/s10616-012-9445-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Accepted: 02/21/2012] [Indexed: 11/29/2022] Open
Abstract
Artery stiffening is known as an important pathological change that precedes small vessel dysfunction, but underlying cellular mechanisms are still elusive. This paper reports the development of a flow co-culture system that imposes a range of arterial-like pulse flow waves, with similar mean flow rate but varied pulsatility controlled by upstream stiffness, onto a 3-D endothelial-smooth muscle cell co-culture. Computational fluid dynamics results identified a uniform flow area critical for cell mechanobiology studies. For validation, experimentally measured flow profiles were compared to computationally simulated flow profiles, which revealed percentage difference in the maximum flow to be <10, <5, or <1% for a high, medium, or low pulse flow wave, respectively. This comparison indicated that the computational model accurately demonstrated experimental conditions. The results from endothelial expression of proinflammatory genes and from determination of proliferating smooth muscle cell percentage both showed that cell activities did not vary within the identified uniform flow region, but were upregulated by high pulse flow compared to steady flow. The flow system developed and characterized here provides an important tool to enhance the understanding of vascular cell remodeling under flow environments regulated by stiffening.
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Affiliation(s)
- Devon Scott-Drechsel
- Department of Mechanical Engineering, University of Colorado at Boulder, Boulder, CO, 80309, USA
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22
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Lammers S, Scott D, Hunter K, Tan W, Shandas R, Stenmark KR. Mechanics and Function of the Pulmonary Vasculature: Implications for Pulmonary Vascular Disease and Right Ventricular Function. Compr Physiol 2012; 2:295-319. [PMID: 23487595 DOI: 10.1002/cphy.c100070] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The relationship between cardiac function and the afterload against which the heart muscle must work to circulate blood throughout the pulmonary circulation is defined by a complex interaction between many coupled system parameters. These parameters range broadly and incorporate system effects originating primarily from three distinct locations: input power from the heart, hydraulic impedance from the large conduit pulmonary arteries, and hydraulic resistance from the more distal microcirculation. These organ systems are not independent, but rather, form a coupled system in which a change to any individual parameter affects all other system parameters. The result is a highly nonlinear system which requires not only detailed study of each specific component and the effect of disease on their specific function, but also requires study of the interconnected relationship between the microcirculation, the conduit arteries, and the heart in response to age and disease. Here, we investigate systems-level changes associated with pulmonary hypertensive disease progression in an effort to better understand this coupled relationship.
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Affiliation(s)
- Steven Lammers
- Department of Cardiovascular Pulmonary Research, University of Colorado Denver, Aurora, Colorado ; Department of Bioengineering, University of Colorado Denver, Aurora, Colorado
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23
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Jung JS, Son KH, Ahn CB, Lee JJ, Son HS, Sun K. Analysis of pulsatile and nonpulsatile blood flow effects in different degrees of stenotic vasculature. Artif Organs 2011; 35:1118-23. [PMID: 22023148 DOI: 10.1111/j.1525-1594.2011.01361.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Vessel lumens that have been chronically narrowed by atherosclerosis should be increased in flow velocity and intrastenotic area pressure to maintain an equal flow. This might be followed by a decrease in hemodynamic energy, leading to a reduction of tissue perfusion. In this study, we compared hemodynamic energies according to degrees of stenotic vasculature between pulsatile flow and nonpulsatile flow. Cannuale with 25, 50, and 75% diameter stenosis (DS) were located at the outlet cannula. Using the Korea Hybrid ventricular assist device (KH-VAD) (pulsatile pump: group A) and Biopump (nonpulsatile pump: group B), constant flow of 2 L/min was maintained then real-time flow and velocity in the proximal and distal part of the stenotic cannula were measured. The hemodynamic energies of two groups were compared. At 75% DS, proximal energy equivalent pressure (EEP) delivered to the distal end was only 41.9% (group A) and 42.5% (group B). As the percent EEP fell below 10%, pulsatility disappeared from the 50% stenosis in group A. The surplus hemodynamic energy (SHE) of group B at all degrees of stenosis must have been 0, which was also the case of group A at 75% stenosis. This research evaluated the hemodynamic energy on various degrees of DS in both pulsatile and nonpulsatile flow with mock system. Using a pulsatile pump, pulsatility disappeared above 50% DS while hemodynamic energy was maintained. Therefore, our results suggest that pulsatile flow has a better effect than nonpulsatile flow in reserving hemodynamic energy after stenotic lesion.
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Affiliation(s)
- Jae Seung Jung
- Department of Thoracic and Cardiovascular Surgery, Anam Hospital, Korea University Medical Center, Seoul, Korea
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24
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Lim E, Alomari AHH, Savkin AV, Dokos S, Fraser JF, Timms DL, Mason DG, Lovell NH. A method for control of an implantable rotary blood pump for heart failure patients using noninvasive measurements. Artif Organs 2011; 35:E174-80. [PMID: 21843286 DOI: 10.1111/j.1525-1594.2011.01268.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We propose a deadbeat controller for the control of pulsatile pump flow (Q(p) ) in an implantable rotary blood pump (IRBP). Noninvasive measurements of pump speed and current are used as inputs to a dynamical model of Q(p) estimation, previously developed and verified in our laboratory. The controller was tested using a lumped parameter model of the cardiovascular system (CVS), in combination with the stable dynamical models of Q(p) and differential pressure (head) estimation for the IRBP. The control algorithm was tested with both constant and sinusoidal reference Q(p) as input to the CVS model. Results showed that the controller was able to track the reference input with minimal error in the presence of model uncertainty. Furthermore, Q(p) was shown to settle to the desired reference value within a finite number of sampling periods. Our results also indicated that counterpulsation yields the minimum left ventricular stroke work, left ventricular end diastolic volume, and aortic pulse pressure, without significantly affecting mean cardiac output and aortic pressure.
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Affiliation(s)
- Einly Lim
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia.
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25
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Ando M, Nishimura T, Takewa Y, Yamazaki K, Kyo S, Ono M, Tsukiya T, Mizuno T, Taenaka Y, Tatsumi E. Electrocardiogram-Synchronized Rotational Speed Change Mode in Rotary Pumps Could Improve Pulsatility. Artif Organs 2011; 35:941-7. [DOI: 10.1111/j.1525-1594.2011.01205.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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26
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Letsou GV, Pate TD, Gohean JR, Kurusz M, Longoria RG, Kaiser L, Smalling RW. Improved left ventricular unloading and circulatory support with synchronized pulsatile left ventricular assistance compared with continuous-flow left ventricular assistance in an acute porcine left ventricular failure model. J Thorac Cardiovasc Surg 2010; 140:1181-8. [DOI: 10.1016/j.jtcvs.2010.03.043] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2009] [Revised: 03/03/2010] [Accepted: 03/20/2010] [Indexed: 10/19/2022]
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Hemodynamic energy changes after ischemia-reperfusion injury in an aortic cross-clamped rabbit model. ASAIO J 2010; 56:296-300. [PMID: 20559137 DOI: 10.1097/mat.0b013e3181dd4efe] [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
Blood flow pulsatility can be quantified using the concept of hemodynamic energy. Because ischemia-reperfusion injury is known to affect microcirculation as well as vascular tone detrimentally, we hypothesized that vascular tone changes after ischemia-reperfusion injury would influence pulsatility of the blood vessels. We investigated the changes in pulsatility after ischemia-reperfusion injury using hemodynamic energy parameters-energy equivalent pressure (EEP) and surplus hemodynamic energy (SHE). Twenty-one New Zealand white male rabbits were divided into three groups. Ischemia group (I group, n = 7) underwent 3 hours of ischemia by clamping the abdominal aorta. Reperfusion group (I/R group, n = 7) underwent 2 hours of ischemia followed by 1 hour of reperfusion. Control group (C group, n = 7) underwent a sham procedure. Observed parameters were mean arterial pressure (MAP), mean blood flow (MBF), pulse pressure (PP), EEP, and SHE, measured at baseline, during ischemia (60 minutes after clamping), and reperfusion 5, 15, 30, and 60 minutes after clamp release. In I group, all parameters, except MBF, were higher during ischemia than at baseline. In I/R group, all except MBF were higher during ischemia. After reperfusion, MBF increased and the other parameters decreased. Interestingly, PP and EEP showed only minor changes during reperfusion (p = NS), whereas SHE decreased abruptly immediately after reperfusion and then gradually recovered to its baseline level. Surplus hemodynamic energy showed more significant changes than PP or EEP during reperfusion period (p < 0.05). In C group, no changes were noted throughout the observation period. Ischemia-reperfusion injury reduces vascular pulsatility. In this study, SHE was found to be a more sensitive hemodynamic energy parameter during ischemia-reperfusion injury than PP or EEP.
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Choi H, Lee H, Choi J, Lee JJ, Nam KW, Park JW, Park Y, Sun K, Lee HM. Optimal Moving Angle of Pusher Plate in Occlusive-Type Pulsatile Blood Pump. Artif Organs 2010; 34:554-60. [DOI: 10.1111/j.1525-1594.2010.01039.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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29
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Khalil HA, Kerr DT, Schusterman MA, Cohn WE, Frazier O, Radovancevic B. Induced pulsation of a continuous-flow total artificial heart in a mock circulatory system. J Heart Lung Transplant 2010; 29:568-73. [DOI: 10.1016/j.healun.2009.12.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2009] [Revised: 10/28/2009] [Accepted: 12/06/2009] [Indexed: 01/27/2023] Open
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Antaki JF, Ricci MR, Verkaik JE, Snyder ST, Maul TM, Kim J, Paden DB, Kameneva MV, Paden BE, Wearden PD, Borovetz HS. PediaFlow™ Maglev Ventricular Assist Device: A Prescriptive Design Approach. CARDIOVASCULAR ENGINEERING (DORDRECHT, NETHERLANDS) 2010; 1:104-121. [PMID: 20544002 PMCID: PMC2882700 DOI: 10.1007/s13239-010-0011-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
This report describes a multi-disciplinary program to develop a pediatric blood pump, motivated by the critical need to treat infants and young children with congenital and acquired heart diseases. The unique challenges of this patient population require a device with exceptional biocompatibility, miniaturized for implantation up to 6 months. This program implemented a collaborative, prescriptive design process, whereby mathematical models of the governing physics were coupled with numerical optimization to achieve a favorable compromise among several competing design objectives. Computational simulations of fluid dynamics, electromagnetics, and rotordynamics were performed in two stages: first using reduced-order formulations to permit rapid optimization of the key design parameters; followed by rigorous CFD and FEA simulations for calibration, validation, and detailed optimization. Over 20 design configurations were initially considered, leading to three pump topologies, judged on the basis of a multi-component analysis including criteria for anatomic fit, performance, biocompatibility, reliability, and manufacturability. This led to fabrication of a mixed-flow magnetically levitated pump, the PF3, having a displaced volume of 16.6 cc, approximating the size of a AA battery and producing a flow capacity of 0.3-1.5 L/min. Initial in vivo evaluation demonstrated excellent hemocompatibility after 72 days of implantation in an ovine. In summary, combination of prescriptive and heuristic design principles have proven effective in developing a miniature magnetically levitated blood pump with excellent performance and biocompatibility, suitable for integration into chronic circulatory support system for infants and young children; aiming for a clinical trial within 3 years.
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Affiliation(s)
- James F. Antaki
- Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
| | | | | | | | | | - Jeongho Kim
- Carnegie Mellon University, Pittsburgh, PA, USA
| | | | | | - Bradley E. Paden
- LaunchPoint Technologies, Inc., Goleta, CA, USA
- University of California, Santa Barbara, CA, USA
| | - Peter D. Wearden
- Section of Pediatric Cardiothoracic Surgery of the Heart Lung and Esophageal Institute, Children’s Hospital of Pittsburgh, Pittsburgh, PA, USA
| | - Harvey S. Borovetz
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
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Lim E, Dokos S, Cloherty S, Salamonsen R, Mason D, Reizes J, Lovell N. Parameter-Optimized Model of Cardiovascular–Rotary Blood Pump Interactions. IEEE Trans Biomed Eng 2010; 57:254-66. [DOI: 10.1109/tbme.2009.2031629] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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32
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Lim CH, Yang S, Choi JW, Sun K. Optimizing the Circuit of a Pulsatile Extracorporeal Life Support System in Terms of Energy Equivalent Pressure and Surplus Hemodynamic Energy. Artif Organs 2009; 33:1015-20. [DOI: 10.1111/j.1525-1594.2009.00887.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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33
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High pulsatility flow induces adhesion molecule and cytokine mRNA expression in distal pulmonary artery endothelial cells. Ann Biomed Eng 2009; 37:1082-92. [PMID: 19340571 DOI: 10.1007/s10439-009-9684-3] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2008] [Accepted: 03/25/2009] [Indexed: 10/20/2022]
Abstract
BACKGROUND Arterial stiffening or reduced compliance of proximal pulmonary vessels has been shown to be an important predictor of outcomes in patients with pulmonary hypertension. Though current evidence indicates that arterial stiffening modulates flow pulsatility in downstream vessels and is likely related to microvascular damage in organs without extensive distributing arteries, the cellular mechanisms underlying this relationship in the pulmonary circulation are unexplored. Thus, this study was designed to examine the responses of the microvascular pulmonary endothelium to changes in flow pulsatility. METHODS A flow system was developed to reproduce arterial-like pulse flow waves with the capability of modulating flow pulsatility through regulation of upstream compliance. Pulmonary microvascular endothelial cells (PMVECs) were exposed to steady flow and pulse flow waves of varied pulsatility with varied hemodynamic energy (low: pulsatility index or PI = 1.0; medium: PI = 1.7; high: PI = 2.6) at flow frequency of 1 or 2 Hz for different durations (1 and 6 h). The mean flow rates in all the conditions were kept the same with shear stress at 14 dynes/cm(2). Gene expression was evaluated by analyzing mRNA levels of adhesion molecules (ICAM-1, E-selectin), chemokine (MCP-1) and growth factor/receptor (VEGF, Flt-1) in PMVECs. Functional changes were observed with monocyte adhesion assay. RESULTS 1) Compared to either steady flow or low pulsatility flow, increased flow pulsatility for 1 h induced significant increases in mRNA levels of ICAM-1, E-selectin and MCP-1. 2) Sustained high pulsatility flow perfusion induced increases in ICAM, E-selectin, MCP-1, VEGF and its receptor Flt-1 expression. 3) Flow pulsatility effects on PMVECs were frequency-dependent with greater responses at 2 Hz and likely associated with the hemodynamic energy level. 4) Pulse flow waves with high flow pulsatility at 2 Hz induced leukocyte adhesion and recruitment to PMVECs. CONCLUSION Increased upstream pulmonary arterial stiffness increases flow pulsatility in distal arteries and induces inflammatory gene expression, leukocyte adhesion and cell proliferation in the downstream PMVECs.
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The Effects of Vasopressor and Vasodilator on Hemodynamic Energy in Terms of Surplus Hemodynamic Energy. ASAIO J 2008; 54:534-7. [DOI: 10.1097/mat.0b013e31818652fc] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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35
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The effects of dopamine, ephinephrine, and esmolol on the hemodynamic energy in terms of the energy equivalent pressure. ASAIO J 2008; 53:791-4. [PMID: 18043167 DOI: 10.1097/mat.0b013e318158e930] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
The generation of pulsatile flow depends on the hemodynamic energy gradient rather than the pressure gradient. We hypothesized that either positive or negative inotropic agents can affect the hemodynamic energy, which can be measured using the energy equivalent pressure (EEP) and surplus hemodynamic energy (SHE). This study examined the change in hemodynamic energy induced by dopamine, epinephrine, and esmolol infusion in terms of the EEP and SHE. Dopamine (5, 10 microg/kg/min), epinephrine (0.02, 0.1 microg/kg/min) and esmolol (after bolus 1 mg/kg, 0.1, 0.3 mg/kg/min) were infused into six anesthetized dogs. The hemodynamic parameters were collected in the descending thoracic aorta. The mean arterial pressure, blood flow, EEP, and SHE increased significantly with the dopamine infusion. The mean arterial pressure and EEP decreased significantly after the esmolol infusion, while it increased after the epinephrine infusion (p < 0.05 respectively). There was a correlation between the EEP and flow on the descending aorta during the dopamine, esmolol and epinephrine infusions (p < 0.05 respectively). In conclusion, the change in hemodynamic energy induced by dopamine, esmolol, and epinephrine may be expressed in terms of the EEP and SHE. In addition, there was a strong correlation between the EEP and flow.
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36
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Vasků J, Wotke J, Dobsák P, Baba A, Rejthar A, Kuchtícková S, Imachi K, Abe Y, Saito I, Isoyama T, Nitta SI, Yambe T. Acute and chronic consequences of non-pulsatile blood flow pattern in long-term total artificial heart experiment. PATHOPHYSIOLOGY 2007; 14:87-95. [PMID: 17689936 DOI: 10.1016/j.pathophys.2007.06.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Revised: 06/15/2007] [Accepted: 06/15/2007] [Indexed: 11/16/2022] Open
Abstract
Vessel pulsation is presumably a key physiological function for the optimal supply of peripheral tissues and vital organs by oxygen and nutrients. The absence of pulsatility might impair the peripheral perfusion stability and trigger microvascular dysfunction of vital organs. The main purpose of this study was to investigate the influence of non-pulsatile flow on the microcirculation in experimental goat with implanted undulation pump total artificial heart (UPTAH). A microscopic system (Keyence, Japan) for the direct observation of the microcirculation of bulbar conjunctiva was used. Following the acute flow pattern change (from pulsatile to non-pulsatile one), the number of perfused capillaries decreased significantly (from 34.7+/-6.3 to 19.7+/-4.1 number of capillaries/mm; P<0.05). The velocity of erythrocytes dropped (from 526+/-83 to 132+/-41mum/s; P<0.05). The velocity of erythrocytes and capillary density were only partly recovered, when the pulsatile flow mode was restored. Histopathological analysis after 33 days of pumping in non-pulsatile mode revealed the presence of chronic venostasis, tissue edema, hemorrhages, hypoxia and ischemic necroses in the tissue samples from liver, kidneys and lung. These findings could be regarded as a direct effect of the chronic non-pulsatile pumping mode and inadequate blood supply. We conclude that the presence of pulsatile flow should be considered as a vital condition for a successful long-term survival after total artificial heart implantation.
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Affiliation(s)
- Jaromír Vasků
- Tohoku University Biomedical Engineering Research Organization, Tohoku University of Sendai, Japan
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Colacino FM, Moscato F, Piedimonte F, Arabia M, Danieli GA. Left Ventricle Load Impedance Control by Apical VAD Can Help Heart Recovery and Patient Perfusion: A Numerical Study. ASAIO J 2007; 53:263-77. [PMID: 17515714 DOI: 10.1097/mat.0b013e31805b7e39] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
The aim of this work is to investigate the dependence between left ventricular load impedance control by an apical ventricular assist device (VAD) and the consequent benefits for pathological heart recovery. A pathological left ventricle with 34% contractility has been simulated in the assisted and nonassisted conditions. By means of an extended Kalman filter, left ventricular pressure-volume loops have been partially estimated and ventricular as well as circulatory quantities inferred. The heart operation mode, based on cardiac energetic criteria, is imposed by controlling the VAD filling phase. In the assisted condition, results show that the left ventricle end-diastolic volume, left atrial pressure, and wall stress all decrease; stroke volume, ejection fraction, ventricular efficiency, aortic pressure, and cardiac output all increase. Benefits are also evident for the right ventricle and systemic and pulmonary circulation. The strategy outlined in this work also shows that good results for heart recovery are achievable and a possible way to improve the functional properties of commercial pulsatile VADs.
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Kaebnick BW, Giridharan GA, Koenig SC. Quantification of Pulsatility as a Function of Vascular Input Impedance: An In Vitro Study. ASAIO J 2007; 53:115-21. [PMID: 17413547 DOI: 10.1097/01.mat.0000250265.69542.80] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
The physiological benefits of pulsatility generated by ventricular assist device (VAD) support continue to be heavily debated as application of VAD support has been expanded to include destination and recovery therapies. In this study, the relationship between input impedance (Zart) and vascular pulsatility during continuous flow (CF) or pulsatile flow (PF) VAD support was investigated. Hemodynamic waveforms were recorded at baseline failure and with 50%, 75%, and 100% CF or PF VAD support for nine different Zart test conditions (combination of three different resistance and compliance settings) in a mock circulatory system simulating left ventricular failure. High-fidelity hemodynamic pressure and flow waveforms were recorded to calculate mean arterial pressure (MAP), Zart, energy equivalent pressure (EEP), and surplus hemodynamic energy (SHE) as metrics for quantifying vascular pulsatility. MAP and EEP were elevated with increasing resistance whereas SHE was reduced with increasing compliance. Vascular pulsatility was restored with increasing PF VAD support, but diminished by up to 90% with increasing CF VAD support. The nonpulsatile energy component (MAP) of the pressure waveform is dependent on resistance whereas the pulsatile energy component (SHE) is dependent on compliance. The impact of Zart and vascular pulsatility on patient recovery with VAD support warrants further investigation.
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Affiliation(s)
- Brian W Kaebnick
- Cardiovascular Innovation Institute, Department of Bioengineering, University of Louisville, Louisville, Kentucky, USA
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Travis AR, Giridharan GA, Pantalos GM, Dowling RD, Prabhu SD, Slaughter MS, Sobieski M, Undar A, Farrar DJ, Koenig SC. Vascular pulsatility in patients with a pulsatile- or continuous-flow ventricular assist device. J Thorac Cardiovasc Surg 2007; 133:517-24. [PMID: 17258591 DOI: 10.1016/j.jtcvs.2006.09.057] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2006] [Revised: 07/07/2006] [Accepted: 09/25/2006] [Indexed: 11/21/2022]
Abstract
OBJECTIVE We sought to investigate differences in indices of pulsatility between patients with normal ventricular function and patients with heart failure studied at the time of implantation with continuous-flow or pulsatile-flow left ventricular assist devices. METHODS Eight patients with normal ventricular function and 22 patients with heart failure were studied. A high-fidelity aortic and left ventricular pressure catheter was inserted retrograde through the aortic valve into the left ventricle, and transit-time flow probes were placed on the aorta and device outflow graft. Hemodynamic waveforms were recorded at native heart rate before cardiopulmonary bypass and over a range of device flow rates controlled by adjusting beat rate or rpm. These data were used to calculate vascular input impedance and 2 indices of vascular pulsatility: energy-equivalent pressure and surplus hemodynamic energy. RESULTS At low support levels, pulsatile support restored surplus hemodynamic energy to within 2.5% of normal values, whereas continuous support diminished surplus energy by more than 93%. At high support levels, pulsatile support augmented surplus energy by 49% over normal values, whereas continuous support further diminished surplus energy by 97%. Pulsatile support diminished vascular impedance from baseline failure values, whereas continuous support increased impedance. Vascular impedances at baseline for patients undergoing pulsatile and continuous support and during pulsatile support revealed normal vascular compliance, whereas impedance during continuous support indicated a loss of compliance (or "stiffening") of the vasculature. CONCLUSION These results suggest that selection of device type and flow rate can influence vascular pulsatility and input impedance, which might affect clinical outcomes.
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Affiliation(s)
- Adam R Travis
- Cardiovascular Innovation Institute, University of Louisville, Louisville, Ky 40202, USA
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Bourque K, Dague C, Farrar D, Harms K, Tamez D, Cohn W, Tuzun E, Poirier V, Frazier OH. In Vivo Assessment of a Rotary Left Ventricular Assist Device-induced Artificial Pulse in the Proximal and Distal Aorta. Artif Organs 2006; 30:638-42. [PMID: 16911321 DOI: 10.1111/j.1525-1594.2006.00276.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The increasing clinical use of rotary left ventricular assist devices (LVADs) suggests that chronic attenuation of arterial pulse pressure has no clinically significant detrimental effects. However, it remains possible that modulating LVAD rotor speed to produce an artificial pulse may be of temporary or occasional benefit. We sought to evaluate a pulse produced by a continuous-flow, centrifugal pump in an ovine thoracic and abdominal aorta. Both ventricles of an adult sheep were resected to eliminate all native cardiac contributions to pulsatility, each replaced by a continuous-flow Thoratec HeartMate III blood pump (Burlington, MA, USA). An LVAD-induced pulsatile flow was achieved by sharply alternating the speed of the magnetically levitated rotor of the left pump between 1,500 rpm (artificial diastole) and 5,500 rpm (artificial systole) at a rate of 60 bpm at a "systolic" interval of 30%. A catheter was advanced from the ascending aorta to the iliac bifurcation via the ventricular assist device outflow graft for pressure measurement and data acquisition. The mean LVAD-induced pulse pressures were 34, 29, 27, and 26 mm Hg in the ascending, thoracic, and abdominal aorta, and the iliac bifurcation, respectively. The maximum rate of pressure rise (deltap/deltat) was between 189 and 238 mm Hg/s, approaching that of the native pulse, although the energy equivalent pressure did not exceed the mean arterial pressure. The HeartMate III's relatively stiff speed control, low rotor mass, and robust magnetic rotor suspension result in a responsive system, enabling very rapid speed changes that can be used to simulate physiologic pulse pressure and deltap/deltat.
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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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Lee JJ, Lim CH, Son HS, Kim HK, Hwang CM, Park YD, Moon KC, Kwak YT, Sun K. In Vitro Evaluation of the Performance of Korean Pulsatile ECLS (T-PLS) Using Precise Quantification of Pressure-Flow Waveforms. ASAIO J 2005; 51:604-8. [PMID: 16322725 DOI: 10.1097/01.mat.0000176240.78374.16] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
The Twin-Pulse Life Support System (T-PLS) is a novel pulsatile extracorporeal life support system developed in Korea. It has been reported that the T-PLS achieves higher levels of tissue perfusion of the kidney during short-term extracorporeal circulation and provides more blood flow to coronary artery than nonpulsatile blood pumps. However, these results lack pulsatility quantifications and thus make it hard to analyze the effects of pulsatility upon hemodynamic performance. We have adopted the concepts of hemodynamic energy, energy equivalent pressure (EEP), and surplus hemodynamic energy (SHE) to evaluate pulsatility performance in the different circuit configurations of the T-PLS and a membrane oxygenator (MO) in vitro. In a mock system, three different circuits were constructed depending on the location of an MO: pump-MO-pump (serial), MO-pumps (parallel A), and pumps-MO (parallel B). In parallel A, a low-resistance MO was used to preserve the pulsatility from the pump. All circuits showed good pulsatility in terms of EEP (serial: 13.2% +/- 3.2%, parallel A: 10.0% +/- 1.6%, parallel B: 7.00% +/- 1.1%; change from aortic pressure to EEP; p < 0.003). The SHE levels were 17,404 +/- 3750 ergs/cm3, 13,170 +/- 1486 ergs/cm3, and 9192 +/- 1122 ergs/cm3 in each circuit setup (p < 0.001). Although EEP levels were somewhat lower, both parallel types provided higher pump output compared with the serial type (serial: 1.87 +/- 0.29 l/min, parallel A: 3.09 +/- 0.74 l/min, parallel B: 3.06 +/- 0.56 l/min; p < 0.003 except parallel A vs. parallel B, p = 0.90). Conclusively, the precise quantifications of pressure flow waveforms, EEP, and SHE are valuable tools for evaluating pulsatility of the mechanical circulatory devices, and are expected to be used as additional performance indexes of a blood pump. The pulsatility performances are different according to circuit setups. However, the parallel A circuit could achieve higher pump output and generate adequate pulsatility level. Thus, the parallel A circuit is suggested as the optimal configuration in T-PLS applications.
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Affiliation(s)
- Jung Joo Lee
- Korea Artificial Organ Center, Korea University, Seoul, Korea
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Lim CH, Son HS, Lee JJ, Fang YH, Moon KC, Ahn CB, Kim KH, Lee HW, Sun K. Optimization of the Circuit Configuration of a Pulsatile ECLS: An In Vivo Experimental Study. ASAIO J 2005; 51:609-13. [PMID: 16322726 DOI: 10.1097/01.mat.0000177779.59381.95] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
An extracorporeal life support system (ECLS) with a conventional membrane oxygenator requires a driving force for the blood to pass through hollow fiber membranes. We hypothesized that if a gravity-flow hollow fiber membrane oxygenator is installed in the circuit, the twin blood sacs of a pulsatile ECLS (the Twin-Pulse Life Support, T-PLS) can be placed downstream of the membrane oxygenator. This would increase pump output by doubling pulse rate at a given pumpsetting rate while maintaining effective pulsatility. The purpose of this study was to determine the optimal circuit configuration for T-PLS with respect to energy and pump output. Animals were randomly assigned to 2 groups in a total cardiopulmonary bypass model. In the serial group, a conventional membrane oxygenator was located between the twin blood sacs of the T-PLS. In the parallel group, the twin blood sacs were placed downstream of the gravity-flow membrane oxygenator. Energy equivalent pressure (EEP), surplus hemodynamic energy (SHE) and pump output were collected at the different pump-setting rates of 30, 40, and 50 beats per minute (BPM). At a given pump-setting rate the pulse rate doubled in the parallel group. Percent changes of mean arterial pressure to EEP were 13.0 +/- 1.7, 12.0 +/- 1.9, and 7.6 +/- 0.9% in the parallel group, while 22.5 +/- 2.4, 23.2 +/- 1.9, and 21.8 +/- 1.4 in the serial group at 30, 40, and 50 BPM of pump-setting rates. SHE at each pump setting rate was 20,131 +/- 1408, 21,739 +/- 2470, and 15,048 +/- 2108 erg/ cm3 in the parallel group, while 33,968 +/- 3001, 38,232 +/- 3281, 37,964 +/- 2693 erg/cm3 in the serial group. Pump output was higher in the parallel circuit at 40, and 50 BPM pump-setting rates (3.1 +/- 0.2, 3.7 +/- 0.2 L/min vs. 2.2 +/- 0.1 and 2.5 +/- 0.1 L/min, respectively, p =0.01). Either parallel or serial circuit configuration of T-PLS generates effective pulsatility. As for the pump out, the parallel circuit configuration provides higher flow than the serial circuit configuration by doubling the pulse rate at a given pump-setting rate.
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Affiliation(s)
- Choon Hak Lim
- Department of Anesthesiology and Pain Medicine, Korea University, Seoul, Korea
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Weiss WJ, Lukic B, Undar A. Energy Equivalent Pressure and Total Hemodynamic Energy Associated with the Pressure-Flow Waveforms of a Pediatric Pulsatile Ventricular Assist Device. ASAIO J 2005; 51:614-7. [PMID: 16322727 DOI: 10.1097/01.mat.0000179341.95404.f8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
A pulsatile pediatric ventricular assist device (VAD) with a dynamic stroke volume of approximately 12 ml was tested to quantify the effect of flowrate and systolic duration on pulsatility as quantified by the energy equivalent pressure (EEP), defined as the hemodynamic energy per unit volume of fluid pumped. The VAD was tested on a mock circulatory loop, adjusted to maintain a systemic arterial pressure of approximately 90/60 mm Hg (systolic/diastolic) and a mean of 75 mm Hg. The EEP was calculated for each beat for 1 minute at both the proximal end of the pump outlet cannula and at the distal end (arterial EEP). Nominal mean flowrates were 0.50, 0.75, 1.00, and 1.25 l/min. Systolic duration was set at either 230 or 400 milliseconds. With a rapid systolic ejection (230 milliseconds), the arterial EEP ranged from 5.58% to 8.41% relative to the mean arterial pressure. The highest EEP occurred at the lowest flowrate. With a slower (400 milliseconds) systolic ejection, the arterial EEP ranged from 2.33% to 4.20%. Hemodynamic energy loss in the outlet cannula was also quantified by the differential EEP and shown to increase markedly as systolic duration was decreased, but was relatively insensitive to mean flowrate.
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Affiliation(s)
- William J Weiss
- Departments of Surgery and Bioengineering, The Pennsylvania State University, The Milton S. Hershey Medical Center, Hershey, PA 17033, USA.
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Undar A, Rosenberg G, Myers JL. Major Factors in the Controversy of Pulsatile Versus Nonpulsatile Flow During Acute and Chronic Cardiac Support. ASAIO J 2005; 51:173-5. [PMID: 15968944 DOI: 10.1097/01.mat.0000161944.20233.40] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Undar A, Rosenberg G, Myers JL. Part 1: Principles of Research on Pulsatile and Nonpulsatile Perfusion During Chronic Support. ASAIO J 2005; 51:303-4; author reply 305-8. [PMID: 15968964 DOI: 10.1097/01.mat.0000161943.74868.c5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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48
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Ündar A, Rosenberg G, Myers JL. Part 2: Principles of Research on Pulsatile and Nonpulsatile Perfusion. ASAIO J 2005. [DOI: 10.1097/01.mat.0000161941.85873.96] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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