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Straccia A, Chassagne F, Barbour MC, Beckman J, Li S, Mahr C, Aliseda A. A Computational Investigation of the Effects of Temporal Synchronization of Left Ventricular Assist Device Speed Modulation with the Cardiac Cycle on Intraventricular Hemodynamics. Ann Biomed Eng 2024; 52:1763-1778. [PMID: 38517620 DOI: 10.1007/s10439-024-03489-x] [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: 10/20/2023] [Accepted: 03/07/2024] [Indexed: 03/24/2024]
Abstract
Patients with advanced heart failure are implanted with a left ventricular assist device (LVAD) as a bridge-to-transplantation or destination therapy. Despite advances in pump design, the risk of stroke remains high. LVAD implantation significantly alters intraventricular hemodynamics, where regions of stagnation or elevated shear stresses promote thrombus formation. Third generation pumps incorporate a pulsatility mode that modulates rotational speed of the pump to enhance in-pump washout. We investigated how the timing of the pulsatility mode with the cardiac cycle affects intraventricular hemodynamic factors linked to thrombus formation. Computational fluid dynamics simulations with Lagrangian particle tracking to model platelet behavior in a patient-specific left ventricle captured altered intraventricular hemodynamics due to LVAD implantation. HeartMate 3 incorporates a pulsatility mode that modulates the speed of the pump every two seconds. Four different timings of this pulsatility mode with respect to the cardiac cycle were investigated. A strong jet formed between the mitral valve and inflow cannula. Blood stagnated in the left ventricular outflow tract beneath a closed aortic valve, in the near-wall regions off-axis of the jet, and in a large counterrotating vortex near the anterior wall. Computational results showed good agreement with particle image velocimetry results. Synchronization of the pulsatility mode with peak systole decreased stasis, reflected in the intraventricular washout of virtual contrast and Lagrangian particles over time. Temporal synchronization of HeartMate 3 pulsatility with the cardiac cycle reduces intraventricular stasis and could be beneficial for decreasing thrombogenicity.
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Affiliation(s)
- Angela Straccia
- Department of Mechanical Engineering, University of Washington, Seattle, WA, USA.
| | | | - Michael C Barbour
- Department of Mechanical Engineering, University of Washington, Seattle, WA, USA
| | - Jennifer Beckman
- Division of Cardiology, University of Washington, Seattle, WA, USA
| | - Song Li
- Institute for Advanced Cardiac Care, Medical City Healthcare, Dallas, TX, USA
| | - Claudius Mahr
- Institute for Advanced Cardiac Care, Medical City Healthcare, Dallas, TX, USA
| | - Alberto Aliseda
- Department of Mechanical Engineering, University of Washington, Seattle, WA, USA
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Tuna R, Yi W, Crespo Cruz E, Romero JP, Ren Y, Guan J, Li Y, Deng Y, Bluestein D, Liu ZL, Sheriff J. Platelet Biorheology and Mechanobiology in Thrombosis and Hemostasis: Perspectives from Multiscale Computation. Int J Mol Sci 2024; 25:4800. [PMID: 38732019 PMCID: PMC11083691 DOI: 10.3390/ijms25094800] [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: 02/11/2024] [Revised: 04/19/2024] [Accepted: 04/24/2024] [Indexed: 05/13/2024] Open
Abstract
Thrombosis is the pathological clot formation under abnormal hemodynamic conditions, which can result in vascular obstruction, causing ischemic strokes and myocardial infarction. Thrombus growth under moderate to low shear (<1000 s-1) relies on platelet activation and coagulation. Thrombosis at elevated high shear rates (>10,000 s-1) is predominantly driven by unactivated platelet binding and aggregating mediated by von Willebrand factor (VWF), while platelet activation and coagulation are secondary in supporting and reinforcing the thrombus. Given the molecular and cellular level information it can access, multiscale computational modeling informed by biology can provide new pathophysiological mechanisms that are otherwise not accessible experimentally, holding promise for novel first-principle-based therapeutics. In this review, we summarize the key aspects of platelet biorheology and mechanobiology, focusing on the molecular and cellular scale events and how they build up to thrombosis through platelet adhesion and aggregation in the presence or absence of platelet activation. In particular, we highlight recent advancements in multiscale modeling of platelet biorheology and mechanobiology and how they can lead to the better prediction and quantification of thrombus formation, exemplifying the exciting paradigm of digital medicine.
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Affiliation(s)
- Rukiye Tuna
- Department of Chemical & Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL 32310, USA; (R.T.); (E.C.C.); (Z.L.L.)
| | - Wenjuan Yi
- Department of Chemical & Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL 32310, USA; (R.T.); (E.C.C.); (Z.L.L.)
| | - Esmeralda Crespo Cruz
- Department of Chemical & Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL 32310, USA; (R.T.); (E.C.C.); (Z.L.L.)
| | - JP Romero
- Department of Chemical & Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL 32310, USA; (R.T.); (E.C.C.); (Z.L.L.)
| | - Yi Ren
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL 32304, USA
| | - Jingjiao Guan
- Department of Chemical & Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL 32310, USA; (R.T.); (E.C.C.); (Z.L.L.)
- Institute for Successful Longevity, Florida State University, Tallahassee, FL 32304, USA
| | - Yan Li
- Department of Chemical & Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL 32310, USA; (R.T.); (E.C.C.); (Z.L.L.)
- Institute for Successful Longevity, Florida State University, Tallahassee, FL 32304, USA
| | - Yuefan Deng
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY 11794, USA
| | - Danny Bluestein
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA;
| | - Zixiang Leonardo Liu
- Department of Chemical & Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL 32310, USA; (R.T.); (E.C.C.); (Z.L.L.)
- Institute for Successful Longevity, Florida State University, Tallahassee, FL 32304, USA
| | - Jawaad Sheriff
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA;
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Oks D, Reza S, Vázquez M, Houzeaux G, Kovarovic B, Samaniego C, Bluestein D. Effect of Sinotubular Junction Size on TAVR Leaflet Thrombosis: A Fluid-Structure Interaction Analysis. Ann Biomed Eng 2024; 52:719-733. [PMID: 38097896 DOI: 10.1007/s10439-023-03419-3] [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: 08/23/2023] [Accepted: 12/03/2023] [Indexed: 12/26/2023]
Abstract
TAVR has emerged as a standard approach for treating severe aortic stenosis patients. However, it is associated with several clinical complications, including subclinical leaflet thrombosis characterized by Hypoattenuated Leaflet Thickening (HALT). A rigorous analysis of TAVR device thrombogenicity considering anatomical variations is essential for estimating this risk. Clinicians use the Sinotubular Junction (STJ) diameter for TAVR sizing, but there is a paucity of research on its influence on TAVR devices thrombogenicity. A Medtronic Evolut® TAVR device was deployed in three patient models with varying STJ diameters (26, 30, and 34 mm) to evaluate its impact on post-deployment hemodynamics and thrombogenicity, employing a novel computational framework combining prosthesis deployment and fluid-structure interaction analysis. The 30 mm STJ patient case exhibited the best hemodynamic performance: 5.94 mmHg mean transvalvular pressure gradient (TPG), 2.64 cm2 mean geometric orifice area (GOA), and the lowest mean residence time (TR)-indicating a reduced thrombogenic risk; 26 mm STJ exhibited a 10 % reduction in GOA and a 35% increase in mean TPG compared to the 30 mm STJ; 34 mm STJ depicted hemodynamics comparable to the 30 mm STJ, but with a 6% increase in TR and elevated platelet stress accumulation. A smaller STJ size impairs adequate expansion of the TAVR stent, which may lead to suboptimal hemodynamic performance. Conversely, a larger STJ size marginally enhances the hemodynamic performance but increases the risk of TAVR leaflet thrombosis. Such analysis can aid pre-procedural planning and minimize the risk of TAVR leaflet thrombosis.
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Affiliation(s)
- David Oks
- Barcelona Supercomputing Center, Computer Applications in Science and Engineering, Barcelona, Spain
| | - Symon Reza
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, 11794-8084, USA
| | - Mariano Vázquez
- Barcelona Supercomputing Center, Computer Applications in Science and Engineering, Barcelona, Spain
- ELEM Biotech SL, Barcelona, Spain
| | - Guillaume Houzeaux
- Barcelona Supercomputing Center, Computer Applications in Science and Engineering, Barcelona, Spain
| | - Brandon Kovarovic
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, 11794-8084, USA
| | - Cristóbal Samaniego
- Barcelona Supercomputing Center, Computer Applications in Science and Engineering, Barcelona, Spain
| | - Danny Bluestein
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, 11794-8084, USA.
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Palomares DE, Tran PL, Jerman C, Momayez M, Deymier P, Sheriff J, Bluestein D, Parthasarathy S, Slepian MJ. Vibro-Acoustic Platelet Activation: An Additive Mechanism of Prothrombosis with Applicability to Snoring and Obstructive Sleep Apnea. Bioengineering (Basel) 2023; 10:1414. [PMID: 38136005 PMCID: PMC10741028 DOI: 10.3390/bioengineering10121414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 11/28/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023] Open
Abstract
Introduction: Obstructive sleep apnea (OSA) and loud snoring are conditions with increased cardiovascular risk and notably an association with stroke. Central in stroke are thrombosis and thromboembolism, all related to and initiaing with platelet activation. Platelet activation in OSA has been felt to be driven by biochemical and inflammatory means, including intermittent catecholamine exposure and transient hypoxia. We hypothesized that snore-associated acoustic vibration (SAAV) is an activator of platelets that synergizes with catecholamines and hypoxia to further amplify platelet activation. Methods: Gel-filtered human platelets were exposed to snoring utilizing a designed vibro-acoustic exposure device, varying the time and intensity of exposure and frequency content. Platelet activation was assessed via thrombin generation using the Platelet Activity State assay and scanning electron microscopy. Comparative activation induced by epinephrine and hypoxia were assessed individually as well as additively with SAAV, as well as the inhibitory effect of aspirin. Results: We demonstrate that snore-associated acoustic vibration is an independent activator of platelets, which is dependent upon the dose of exposure, i.e., intensity x time. In snoring, acoustic vibrations associated with low-frequency sound content (200 Hz) are more activating than those associated with high frequencies (900 Hz) (53.05% vs. 22.08%, p = 0.001). Furthermore, SAAV is additive to both catecholamines and hypoxia-mediated activation, inducing synergistic activation. Finally, aspirin, a known inhibitor of platelet activation, has no significant effect in limiting SAAV platelet activation. Conclusion: Snore-associated acoustic vibration is a mechanical means of platelet activation, which may drive prothrombosis and thrombotic risk clinically observed in loud snoring and OSA.
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Affiliation(s)
- Daniel E. Palomares
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ 85724, USA;
- Arizona Center for Accelerated Biomedical Innovation, University of Arizona, Tucson, AZ 85724, USA; (P.L.T.); (M.M.); (P.D.); (S.P.)
| | - Phat L. Tran
- Arizona Center for Accelerated Biomedical Innovation, University of Arizona, Tucson, AZ 85724, USA; (P.L.T.); (M.M.); (P.D.); (S.P.)
- Department of Medicine, University of Arizona, Tucson, AZ 85724, USA;
| | - Catherine Jerman
- Department of Medicine, University of Arizona, Tucson, AZ 85724, USA;
| | - Moe Momayez
- Arizona Center for Accelerated Biomedical Innovation, University of Arizona, Tucson, AZ 85724, USA; (P.L.T.); (M.M.); (P.D.); (S.P.)
- Department of Mining & Geological Engineering, University of Arizona, Tucson, AZ 85724, USA
| | - Pierre Deymier
- Arizona Center for Accelerated Biomedical Innovation, University of Arizona, Tucson, AZ 85724, USA; (P.L.T.); (M.M.); (P.D.); (S.P.)
- Department of Materials Science & Engineering, University of Arizona, Tucson, AZ 85724, USA
| | - Jawaad Sheriff
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA; (J.S.); (D.B.)
| | - Danny Bluestein
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA; (J.S.); (D.B.)
| | - Sairam Parthasarathy
- Arizona Center for Accelerated Biomedical Innovation, University of Arizona, Tucson, AZ 85724, USA; (P.L.T.); (M.M.); (P.D.); (S.P.)
- Department of Medicine, University of Arizona, Tucson, AZ 85724, USA;
- Health Sciences Center for Sleep and Circadian Sciences, University of Arizona, Tucson, AZ 85724, USA
| | - Marvin J. Slepian
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ 85724, USA;
- Arizona Center for Accelerated Biomedical Innovation, University of Arizona, Tucson, AZ 85724, USA; (P.L.T.); (M.M.); (P.D.); (S.P.)
- Department of Medicine, University of Arizona, Tucson, AZ 85724, USA;
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA; (J.S.); (D.B.)
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Oks D, Reza S, Vázquez M, Houzeaux G, Kovarovic B, Samaniego C, Bluestein D. Effect of Sinotubular Junction Size on TAVR Leaflet Thrombosis: A Fluid-structure Interaction Analysis. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.11.13.23298476. [PMID: 38014278 PMCID: PMC10680880 DOI: 10.1101/2023.11.13.23298476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Purpose TAVR has emerged as a standard approach for treating severe aortic stenosis patients. However, it is associated with several clinical complications, including subclinical leaflet thrombosis characterized by Hypoattenuated Leaflet Thickening (HALT). A rigorous analysis of TAVR device thrombogenicity considering anatomical variations is essential for estimating this risk. Clinicians use the Sinotubular Junction (STJ) diameter for TAVR sizing, but there is a paucity of research on its influence on TAVR devices thrombogenicity. Methods A Medtronic Evolut® TAVR device was deployed in three patient models with varying STJ diameters (26, 30, and 34mm) to evaluate its impact on post-deployment hemodynamics and thrombogenicity, employing a novel computational framework combining prosthesis deployment and fluid- structure interaction analysis. Results The 30 mm STJ patient case exhibited the best hemodynamic performance: 5.94 mmHg mean transvalvular pressure gradient (TPG), 2.64 cm 2 mean geometric orifice area (GOA), and the lowest mean residence time (T R ) - indicating a reduced thrombogenic risk; 26 mm STJ exhibited a 10 % reduction in GOA and a 35% increase in mean TPG compared to the 30 mm STJ; 34 mm STJ depicted hemodynamics comparable to the 30 mm STJ, but with a 6% increase in T R and elevated platelet stress accumulation. Conclusion A smaller STJ size impairs adequate expansion of the TAVR stent, which may lead to suboptimal hemodynamic performance. Conversely, a larger STJ size marginally enhances the hemodynamic performance but increases the risk of TAVR leaflet thrombosis. Such analysis can aid pre- procedural planning and minimize the risk of TAVR leaflet thrombosis.
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Vu V, Rossini L, del Alamo JC, Dembitsky W, Gray RA, May-Newman K. Benchtop Models of Patient-Specific Intraventricular Flow During Heart Failure and LVAD Support. J Biomech Eng 2023; 145:111010. [PMID: 37565996 PMCID: PMC10777504 DOI: 10.1115/1.4063147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 08/01/2023] [Accepted: 08/03/2023] [Indexed: 08/12/2023]
Abstract
The characterization of intraventricular flow is critical to evaluate the efficiency of fluid transport and potential thromboembolic risk but challenging to measure directly in advanced heart failure (HF) patients with left ventricular assist device (LVAD) support. The study aims to validate an in-house mock loop (ML) by simulating specific conditions of HF patients with normal and prosthetic mitral valves (MV) and LVAD patients with small and dilated left ventricle volumes, then comparing the flow-related indices result of vortex parameters, residence time (RT), and shear-activation potential (SAP). Patient-specific inputs for the ML studies included heart rate, end-diastolic and end-systolic volumes, ejection fraction, aortic pressure, E/A ratio, and LVAD speed. The ML effectively replicated vortex development and circulation patterns, as well as RT, particularly for HF patient cases. The LVAD velocity fields reflected altered flow paths, in which all or most incoming blood formed a dominant stream directing flow straight from the mitral valve to the apex. RT estimation of patient and ML compared well for all conditions, but SAP was substantially higher in the LVAD cases of the ML. The benchtop system generated comparable and reproducible hemodynamics and fluid dynamics for patient-specific conditions, validating its reliability and clinical relevance. This study demonstrated that ML is a suitable platform to investigate the fluid dynamics of HF and LVAD patients and can be utilized to investigate heart-implant interactions.
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Affiliation(s)
- Vi Vu
- Bioengineering Program, Department of Mechanical Engineering, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182;Division of Biomedical Physics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993
| | - Lorenzo Rossini
- Mechanical and Aerospace Engineering Department, University of California, San Diego 9500 Gilman Drive, La Jolla, CA 92093
| | - Juan C. del Alamo
- Center for Cardiovascular Biology & Mechanical Engineering Department, University of Washington, 1400 NE Campus Parkway, Seattle, WA 98195
| | - Walter Dembitsky
- Cardiothoracic Surgery, Mechanical Assist Program, Sharp Memorial Hospital, San Diego 7901 Frost Street, San Diego, CA 92123
| | - Richard A. Gray
- Division of Biomedical Physics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993
| | - Karen May-Newman
- Bioengineering Program, Department of Mechanical Engineering, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182
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Roka-Moiia Y, Ammann KR, Miller-Gutierrez S, Sheriff J, Bluestein D, Italiano JE, Flaumenhaft RC, Slepian MJ. Shear-Mediated Platelet Microparticles Demonstrate Phenotypic Heterogeneity as to Morphology, Receptor Distribution, and Hemostatic Function. Int J Mol Sci 2023; 24:7386. [PMID: 37108551 PMCID: PMC10138836 DOI: 10.3390/ijms24087386] [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: 03/07/2023] [Revised: 04/09/2023] [Accepted: 04/12/2023] [Indexed: 04/29/2023] Open
Abstract
Implantable Cardiovascular Therapeutic Devices (CTD), while lifesaving, impart supraphysiologic shear stress to platelets, resulting in thrombotic and bleeding coagulopathy. We previously demonstrated that shear-mediated platelet dysfunction is associated with downregulation of platelet GPIb-IX-V and αIIbβ3 receptors via generation of Platelet-Derived MicroParticles (PDMPs). Here, we test the hypothesis that sheared PDMPs manifest phenotypical heterogeneity of morphology and receptor surface expression and modulate platelet hemostatic function. Human gel-filtered platelets were exposed to continuous shear stress. Alterations of platelet morphology were visualized using transmission electron microscopy. Surface expression of platelet receptors and PDMP generation were quantified by flow cytometry. Thrombin generation was quantified spectrophotometrically, and platelet aggregation was measured by optical aggregometry. Shear stress promotes notable alterations in platelet morphology and ejection of distinctive types of PDMPs. Shear-mediated microvesiculation is associated with the remodeling of platelet receptors, with PDMPs expressing significantly higher levels of adhesion receptors (αIIbβ3, GPIX, PECAM-1, P-selectin, and PSGL-1) and agonist receptors (P2Y12 and PAR1). Sheared PDMPs promote thrombin generation and inhibit platelet aggregation induced by collagen and ADP. Sheared PDMPs demonstrate phenotypic heterogeneity as to morphology and defined patterns of surface receptors and impose a bidirectional effect on platelet hemostatic function. PDMP heterogeneity suggests that a range of mechanisms are operative in the microvesiculation process, contributing to CTD coagulopathy and posing opportunities for therapeutic manipulation.
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Affiliation(s)
- Yana Roka-Moiia
- Sarver Heart Center, Departments of Medicine and Biomedical Engineering, University of Arizona, 1501 N Campbell Ave, Building 201E, Room 6139, Tucson, AZ 85724, USA; (Y.R.-M.)
| | - Kaitlyn R. Ammann
- Sarver Heart Center, Departments of Medicine and Biomedical Engineering, University of Arizona, 1501 N Campbell Ave, Building 201E, Room 6139, Tucson, AZ 85724, USA; (Y.R.-M.)
| | - Samuel Miller-Gutierrez
- Sarver Heart Center, Departments of Medicine and Biomedical Engineering, University of Arizona, 1501 N Campbell Ave, Building 201E, Room 6139, Tucson, AZ 85724, USA; (Y.R.-M.)
| | - Jawaad Sheriff
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Danny Bluestein
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Joseph E. Italiano
- Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Robert C. Flaumenhaft
- Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
- Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
| | - Marvin J. Slepian
- Sarver Heart Center, Departments of Medicine and Biomedical Engineering, University of Arizona, 1501 N Campbell Ave, Building 201E, Room 6139, Tucson, AZ 85724, USA; (Y.R.-M.)
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Roka-Moiia Y, Ammann K, Miller-Gutierrez S, Sheriff J, Bluestein D, Italiano JE, Flaumenhaft RC, Slepian MJ. Shear-Mediated Platelet Microparticles Demonstrate Phenotypic Heterogeneity as to Morphology, Receptor Distribution, and Hemostatic Function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.08.527675. [PMID: 36798322 PMCID: PMC9934663 DOI: 10.1101/2023.02.08.527675] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Objective Implantable cardiovascular therapeutic devices (CTD) including stents, percutaneous heart valves and ventricular assist devices, while lifesaving, impart supraphysiologic shear stress to platelets resulting in thrombotic and bleeding device-related coagulopathy. We previously demonstrated that shear-mediated platelet dysfunction is associated with downregulation of platelet GPIb-IX-V and αIIbβ3 receptors via generation of platelet-derived microparticles (PDMPs). Here, we test the hypothesis that shear-generated PDMPs manifest phenotypical heterogeneity of their morphology and surface expression of platelet receptors, and modulate platelet hemostatic function. Approach and Results Human gel-filtered platelets were exposed to continuous shear stress and sonication. Alterations of platelet morphology were visualized using transmission electron microscopy. Surface expression of platelet receptors and PDMP generation were quantified by flow cytometry. Thrombin generation was quantified spectrophotometrically, and platelet aggregation in plasma was measured by optical aggregometry. We demonstrate that platelet exposure to shear stress promotes notable alterations in platelet morphology and ejection of several distinctive types of PDMPs. Shear-mediated microvesiculation is associated with the differential remodeling of platelet receptors with PDMPs expressing significantly higher levels of both adhesion (α IIb β 3 , GPIX, PECAM-1, P-selectin, and PSGL-1) and agonist-evoked receptors (P 2 Y 12 & PAR1). Shear-mediated PDMPs have a bidirectional effect on platelet hemostatic function, promoting thrombin generation and inhibiting platelet aggregation induced by collagen and ADP. Conclusions Shear-generated PDMPs demonstrate phenotypic heterogeneity as to morphologic features and defined patterns of surface receptor alteration, and impose a bidirectional effect on platelet hemostatic function. PDMP heterogeneity suggests that a range of mechanisms are operative in the microvesiculation process, contributing to CTD coagulopathy and posing opportunities for therapeutic manipulation.
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Kovarovic BJ, Rotman OM, Parikh PB, Slepian MJ, Bluestein D. Mild Paravalvular Leak May Pose an Increased Thrombogenic Risk in Transcatheter Aortic Valve Replacement (TAVR) Patients-Insights from Patient Specific In Vitro and In Silico Studies. Bioengineering (Basel) 2023; 10:bioengineering10020188. [PMID: 36829682 PMCID: PMC9952825 DOI: 10.3390/bioengineering10020188] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/27/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023] Open
Abstract
In recent years, the treatment of aortic stenosis with TAVR has rapidly expanded to younger and lower-risk patients. However, persistent thrombotic events such as stroke and valve thrombosis expose recipients to severe clinical complications that hamper TAVR's rapid advance. We presented a novel methodology for establishing a link between commonly acceptable mild paravalvular leak (PVL) levels through the device and increased thrombogenic risk. It utilizes in vitro patient-specific TAVR 3D-printed replicas evaluated for hydrodynamic performance. High-resolution µCT scans are used to reconstruct in silico FSI models of these replicas, in which multiple platelet trajectories are studied through the PVL channels to quantify thrombogenicity, showing that those are highly dependent on patient-specific flow conditions within the PVL channels. It demonstrates that platelets have the potential to enter the PVL channels multiple times over successive cardiac cycles, increasing the thrombogenic risk. This cannot be reliably approximated by standard hemodynamic parameters. It highlights the shortcomings of subjectively ranked PVL commonly used in clinical practice by indicating an increased thrombogenic risk in patient cases otherwise classified as mild PVL. It reiterates the need for more rigorous clinical evaluation for properly diagnosing thrombogenic risk in TAVR patients.
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Affiliation(s)
- Brandon J. Kovarovic
- Biofluids Research Group, Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Oren M. Rotman
- Biofluids Research Group, Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Puja B. Parikh
- Division of Cardiovascular Medicine, Department of Medicine, Stony Brook University, Stony Brook, NY 11794, USA
| | - Marvin J. Slepian
- Department of Medicine, Sarver Heart Center, University of Arizona, Tucson, AZ 85724, USA
- Department of Biomedical Engineering, College of Engineering, University of Arizona, Tucson, AZ 85721, USA
| | - Danny Bluestein
- Biofluids Research Group, Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
- Correspondence:
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Li Y, Yu J, Wang H, Xi Y, Deng X, Chen Z, Fan Y. Investigation of the influence of blade configuration on the hemodynamic performance and blood damage of the centrifugal blood pump. Artif Organs 2022; 46:1817-1832. [PMID: 35436361 DOI: 10.1111/aor.14265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 03/01/2022] [Accepted: 04/08/2022] [Indexed: 11/30/2022]
Abstract
PURPOSE The design and optimization of centrifugal blood pumps is crucial for improved extracorporeal membrane oxygenation system performances. Secondary flow passages are common in centrifugal blood pumps, allowing for a high volume of unstable flow. Traditional design theory offers minimal guidance on the design and optimization of centrifugal blood pumps, so it's critical to understand how design parameter variables affect hydraulic performances and hemocompatibility. METHODS Computational fluid dynamics (CFD) was employed to investigate the effects of blade number, blade wrap angle, blade thickness, and splitters on pressure head, hemolysis, and platelet activation state. Eulerian and Lagrangian features were used to analyze the flow fields and hemocompatibility metrics such as scalar shear stress, velocity distribution, and their correlation. RESULTS The equalization of frictional and flow losses allow impellers with more blades and smaller wrap angles to have higher pressure heads, whereas the trade-off between the volume of high scalar shear stress and exposure time allows impellers with fewer blades and larger blade wrap angles to have a lower HI; there are configurations that increase the possibility of platelet activation for both number of blades and wrap angles. The hydraulic performance and hemocompatibility of centrifugal blood pumps are not affected by blade thickness. Compared to the main blades, a splitters can improve the blood compatibility of a centrifugal blood pump with a small reduction in pressure head, but there is a trade-off between the length and location of the splitter that suppresses flow losses while reducing the velocity gradient. According to correlation analysis, pressure head, HI, and the volume of high shear stress were all substantially connected, and exposure time had a significant impact on HI. The platelet activation state was influenced by the average scalar shear stress and the volume of low velocity. CONCLUSION The findings reveal the impact of design variables on the performance of centrifugal blood pumps with secondary flow passages, as well as the relationship between hemocompatibility, hydraulic performance, and flow characteristics, and are useful for the design and optimization of this type of blood pump, as well as the prediction of clinical complications.
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Affiliation(s)
- Yuan Li
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China
| | - Jiachen Yu
- School of Sino-french Engineer, Beihang University, Beijing, 100083, China
| | - Hongyu Wang
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China
| | - Yifeng Xi
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China
| | - Xiaoyan Deng
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China
| | - Zengsheng Chen
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China
| | - Yubo Fan
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China
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11
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A new way to evaluate thrombotic risk in failure heart and ventricular assist devices. MEDICINE IN NOVEL TECHNOLOGY AND DEVICES 2022. [DOI: 10.1016/j.medntd.2022.100135] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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12
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Mencarini T, Bozzi S, Redaelli A. On-Chip Platelet Activation Assessment: Microfluidic Emulation of Shear Stress Profiles Induced by Mechanical Circulatory Support Devices. Methods Mol Biol 2022; 2373:201-212. [PMID: 34520014 DOI: 10.1007/978-1-0716-1693-2_12] [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] [Indexed: 06/13/2023]
Abstract
Mechanical circulatory support devices (MCSDs), although proved to be a pillar in the clinical setting of advanced heart failure, are afflicted by thromboembolic complications. Shear-mediated platelet activation has been recognized to drive thromboembolic events in patients implanted with MCSDs. Despite this, to date, a clinically reliable diagnostic test for assessing platelet response to stress stimuli is still missing. Here, we describe and apply the previously developed device thrombogenicity emulation methodology to the design of a microfluidic platform able to replicate shear stress profiles representative of MCSDs. The device-specific shear-mediated platelet activation is finally assessed by the platelet activity state assay, which measures real-time thrombin production, as a marker of platelet activation level. This technique can be employed to emulate the shear stress patterns of different MCSDs, such as mechanical heart valves, ventricular assist devices, and stents.
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Affiliation(s)
- Tatiana Mencarini
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Silvia Bozzi
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Alberto Redaelli
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy.
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13
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Assessment of Paravalvular Leak Severity and Thrombogenic Potential in Transcatheter Bicuspid Aortic Valve Replacements Using Patient-Specific Computational Modeling. J Cardiovasc Transl Res 2021; 15:834-844. [PMID: 34859367 PMCID: PMC9160219 DOI: 10.1007/s12265-021-10191-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 11/22/2021] [Indexed: 12/12/2022]
Abstract
Bicuspid aortic valve (BAV), the most common congenital valvular abnormality, generates asymmetric flow patterns and increased stresses on the leaflets that expedite valvular calcification and structural degeneration. Recently adapted for use in BAV patients, TAVR demonstrates promising performance, but post-TAVR complications tend to get exacerbated due to BAV anatomical complexities. Utilizing patient-specific computational modeling, we address some of these complications. The degree and location of post-TAVR PVL was assessed, and the risk of flow-induced thrombogenicity was analyzed in 3 BAV patients - using older generation TAVR devices that were implanted in these patients, and compared them to the performance of the newest generation TAVR devices using in silico patient models. Significant decrease in PVL and thrombogenic potential was observed after implantation of the newest generation device. The current work demonstrates the potential of using simulations in pre-procedural planning to assess post-TAVR complications, and compare the performance of different devices to achieve better clinical outcomes. Patient-specific computational framework to assess post-transcatheter bicuspid aortic valve replacement paravalvular leakage and flow-induced thrombogenic complications and compare device performances.
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14
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Sweedo A, Wise LM, Roka-Moiia Y, Arce FT, Saavedra SS, Sheriff J, Bluestein D, Slepian MJ, Purdy JG. Shear-Mediated Platelet Activation is Accompanied by Unique Alterations in Platelet Release of Lipids. Cell Mol Bioeng 2021; 14:597-612. [PMID: 34900013 PMCID: PMC8630256 DOI: 10.1007/s12195-021-00692-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 07/16/2021] [Indexed: 10/20/2022] Open
Abstract
INTRODUCTION Platelet activation by mechanical means such as shear stress exposure, is a vital driver of thrombotic risk in implantable blood-contacting devices used in the treatment of heart failure. Lipids are essential in platelets activation and have been studied following biochemical activation. However, little is known regarding lipid alterations occurring with mechanical shear-mediated platelet activation. METHODS Here, we determined if shear-activation of platelets induced lipidome changes that differ from those associated with biochemically-mediated platelet activation. We performed high-resolution lipidomic analysis on purified platelets from four healthy human donors. For each donor, we compared the lipidome of platelets that were non-activated or activated by shear, ADP, or thrombin treatment. RESULTS We found that shear activation altered cell-associated lipids and led to the release of lipids into the extracellular environment. Shear-activated platelets released 21 phospholipids and sphingomyelins at levels statistically higher than platelets activated by biochemical stimulation. CONCLUSIONS We conclude that shear-mediated activation of platelets alters the basal platelet lipidome. Further, these alterations differ and are unique in comparison to the lipidome of biochemically activated platelets. Many of the released phospholipids contained an arachidonic acid tail or were phosphatidylserine lipids, which have known procoagulant properties. Our findings suggest that lipids released by shear-activated platelets may contribute to altered thrombosis in patients with implanted cardiovascular therapeutic devices. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s12195-021-00692-x.
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Affiliation(s)
- Alice Sweedo
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ USA
| | - Lisa M. Wise
- Department of Immunobiology, University of Arizona, 1656 E. Mabel Street, PO Box 245221, Tucson, AZ 85724 USA
- BIO5 Institute, University of Arizona, Tucson, AZ USA
| | - Yana Roka-Moiia
- Department of Medicine, Sarver Heart Center, University of Arizona, Tucson, AZ USA
| | - Fernando Teran Arce
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ USA
- Department of Medicine, Sarver Heart Center, University of Arizona, Tucson, AZ USA
| | - S. Scott Saavedra
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ USA
- BIO5 Institute, University of Arizona, Tucson, AZ USA
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ USA
| | - Jawaad Sheriff
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY USA
| | - Danny Bluestein
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY USA
| | - Marvin J. Slepian
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ USA
- BIO5 Institute, University of Arizona, Tucson, AZ USA
- Department of Medicine, Sarver Heart Center, University of Arizona, Tucson, AZ USA
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY USA
- Department of Material Sciences and Engineering, University of Arizona, Tucson, AZ USA
| | - John G. Purdy
- Department of Immunobiology, University of Arizona, 1656 E. Mabel Street, PO Box 245221, Tucson, AZ 85724 USA
- BIO5 Institute, University of Arizona, Tucson, AZ USA
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15
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Neidlin M, Liao S, Li Z, Simpson B, Kaye DM, Steinseifer U, Gregory S. Understanding the influence of left ventricular assist device inflow cannula alignment and the risk of intraventricular thrombosis. Biomed Eng Online 2021; 20:47. [PMID: 33975591 PMCID: PMC8114696 DOI: 10.1186/s12938-021-00884-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 04/30/2021] [Indexed: 11/13/2022] Open
Abstract
Background Adverse neurological events associated with left ventricular assist devices (LVADs) have been suspected to be related to thrombosis. This study aimed to understand the risks of thrombosis with variations in the implanted device orientation. A severely dilated pulsatile patient-specific left ventricle, modelled with computational fluid dynamics, was utilised to identify the risk of thrombosis for five cannulation angles. With respect to the inflow cannula axis directed towards the mitral valve, the other angles were 25° and 20° towards the septum and 20° and 30° towards the free wall. Results Inflow cannula angulation towards the free wall resulted in longer blood residence time within the ventricle, slower ventricular washout and reduced pulsatility indices along the septal wall. Based on the model, the ideal inflow cannula alignment to reduce the risk of thrombosis was angulation towards the mitral valve and up to parallel to the septum, avoiding the premature clearance of incoming blood. Conclusions This study indicates the potential effects of inflow cannulation angles and may guide optimised implantation configurations; however, the ideal approach will be influenced by other patient factors and is suspected to change over the course of support. Supplementary Information The online version contains supplementary material available at 10.1186/s12938-021-00884-6.
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Affiliation(s)
- Michael Neidlin
- Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Pauwelsstraße 20, 52074, Aachen, Germany.
| | - Sam Liao
- Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Pauwelsstraße 20, 52074, Aachen, Germany.,Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC, 3800, Australia.,Cardio-Respiratory Engineering and Technology Laboratory (CREATElab), Baker Heart and Diabetes Institute, Melbourne, VIC, 3004, Australia.,Institute of Health and Biomedical Innovation (IHBI), Queensland University of Technology (QUT), Kelvin Grove, QLD, 4059, Australia
| | - Zhiyong Li
- Institute of Health and Biomedical Innovation (IHBI), Queensland University of Technology (QUT), Kelvin Grove, QLD, 4059, Australia
| | - Benjamin Simpson
- Department of Engineering, Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS, UK
| | - David M Kaye
- Cardio-Respiratory Engineering and Technology Laboratory (CREATElab), Baker Heart and Diabetes Institute, Melbourne, VIC, 3004, Australia
| | - Ulrich Steinseifer
- Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Pauwelsstraße 20, 52074, Aachen, Germany.,Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC, 3800, Australia
| | - Shaun Gregory
- Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC, 3800, Australia.,Cardio-Respiratory Engineering and Technology Laboratory (CREATElab), Baker Heart and Diabetes Institute, Melbourne, VIC, 3004, Australia
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16
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Slepian MJ, Italiano J, Bluestein D, Sheriff J, Roka-Moiia Y. Evolving perspectives on mechanical circulatory support biocompatibility and interfaces. Ann Cardiothorac Surg 2021; 10:396-398. [PMID: 34159123 DOI: 10.21037/acs-2020-cfmcs-247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Marvin J Slepian
- Deparment of Medicine and Biomedical Engineering, Sarver Heart Center, University of Arizona, Tucson, USA.,Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
| | - Joseph Italiano
- Brigham and Woman's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Danny Bluestein
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
| | - Jawaad Sheriff
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
| | - Yana Roka-Moiia
- Deparment of Medicine and Biomedical Engineering, Sarver Heart Center, University of Arizona, Tucson, USA
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17
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Roka-Moiia Y, Ammann KR, Miller-Gutierrez S, Sweedo A, Palomares D, Italiano J, Sheriff J, Bluestein D, Slepian MJ. Shear-mediated platelet activation in the free flow II: Evolving mechanobiological mechanisms reveal an identifiable signature of activation and a bi-directional platelet dyscrasia with thrombotic and bleeding features. J Biomech 2021; 123:110415. [PMID: 34052772 DOI: 10.1016/j.jbiomech.2021.110415] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 03/03/2021] [Indexed: 01/17/2023]
Abstract
Shear-mediated platelet activation (SMPA) in the "free flow" is the net result of a range of cell mechanobiological mechanisms. Previously, we outlined three main groups of mechanisms including: 1) mechano-destruction - i.e. additive platelet (membrane) damage; 2) mechano-activation - i.e. activation of shear-sensitive ion channels and pores; and 3) mechano-transduction - i.e. "outside-in" signaling via a range of transducers. Here, we report on recent advances since our original report which describes additional features of SMPA. A clear "signature" of SMPA has been defined, allowing differentiation from biochemically-mediated activation. Notably, SMPA is characterized by mitochondrial dysfunction, platelet membrane eversion, externalization of anionic phospholipids, and increased thrombin generation on the platelet surface. However, SMPA does not lead to integrin αIIbβ3 activation or P-selectin exposure due to platelet degranulation, as is commonly observed in biochemical activation. Rather, downregulation of GPIb, αIIbβ3, and P-selectin surface expression is evident. Furthermore, SMPA is accompanied by a decrease in overall platelet size coupled with a concomitant, progressive increase in microparticle generation. Shear-ejected microparticles are highly enriched in GPIb and αIIbβ3. These observations indicate the enhanced diffusion, migration, or otherwise dispersion of platelet adhesion receptors to membrane zones, which are ultimately shed as receptor-rich PDMPs. The pathophysiological consequence of this progressive shear accumulation phenomenon is an associated dyscrasia of remaining platelets - being both reduced in size and less activatable via biochemical means - a tendency to favor bleeding, while concomitantly shed microparticles are highly prothrombotic and increase the tendency for thrombosis in both local and systemic milieu. These mechanisms and observations offer direct clinical utility in allowing measurement and guidance of the net balance of platelet driven events in patients with implanted cardiovascular therapeutic devices.
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Affiliation(s)
- Yana Roka-Moiia
- Departments of Medicine and Biomedical Engineering, Sarver Heart Center, University of Arizona, Tucson, AZ 85721, United States; Arizona Center for Accelerated Biomedical Innovation, University of Arizona, Tucson, AZ 85721, United States
| | - Kaitlyn R Ammann
- Departments of Medicine and Biomedical Engineering, Sarver Heart Center, University of Arizona, Tucson, AZ 85721, United States; Arizona Center for Accelerated Biomedical Innovation, University of Arizona, Tucson, AZ 85721, United States
| | - Samuel Miller-Gutierrez
- Departments of Medicine and Biomedical Engineering, Sarver Heart Center, University of Arizona, Tucson, AZ 85721, United States; Arizona Center for Accelerated Biomedical Innovation, University of Arizona, Tucson, AZ 85721, United States
| | - Alice Sweedo
- Departments of Medicine and Biomedical Engineering, Sarver Heart Center, University of Arizona, Tucson, AZ 85721, United States; Arizona Center for Accelerated Biomedical Innovation, University of Arizona, Tucson, AZ 85721, United States
| | - Daniel Palomares
- Departments of Medicine and Biomedical Engineering, Sarver Heart Center, University of Arizona, Tucson, AZ 85721, United States; Arizona Center for Accelerated Biomedical Innovation, University of Arizona, Tucson, AZ 85721, United States
| | - Joseph Italiano
- Department of Medicine, Harvard Medical School, Boston, MA 02115, United States
| | - Jawaad Sheriff
- Department of Biomedical Engineering, Stony Brook University, NY 11794, United States
| | - Danny Bluestein
- Department of Biomedical Engineering, Stony Brook University, NY 11794, United States
| | - Marvin J Slepian
- Departments of Medicine and Biomedical Engineering, Sarver Heart Center, University of Arizona, Tucson, AZ 85721, United States; Department of Biomedical Engineering, Stony Brook University, NY 11794, United States; Arizona Center for Accelerated Biomedical Innovation, University of Arizona, Tucson, AZ 85721, United States.
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18
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Bozzi S, Roka-Moiia Y, Mencarini T, Vercellino F, Epifani I, Ammann KR, Consolo F, Slepian MJ, Redaelli A. Characterization of the competing role of surface-contact and shear stress on platelet activation in the setting of blood contacting devices. Int J Artif Organs 2021; 44:1013-1020. [PMID: 33845625 DOI: 10.1177/03913988211009909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Supraphysiological shear stress and surface-contact are recognized as driving mechanisms of platelet activation (PA) in blood contacting devices (BCDs). However, the competing role of these mechanisms in triggering thrombogenic events is poorly understood. Here, we characterized the dynamics of PA in response to the combined effect of shear stress and material exposure. Human platelets were stimulated with different levels of shear stress (500, 750, 1000 dynes/cm2) over a range of exposure times (10, 20, and 30 min) within capillary tubes made of various polymeric materials. Polyethylene (PE), polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), and polyether ether ketone (PEEK), used for BCDs fabrication, were investigated as compared to glass and thromboresistant Sigma™-coated glass. PA was quantified using the Platelet Activity State assay. Our results indicate that mechanical stimulation and polymer surface-contact both significantly contribute to PA. Notably, the contribution of the mechanical stimulus ranges between +36% and +43%, while that associated with polymer surface-contact ranges from +48% to +59%, depending on the exposure time. In more detail, our results indicate that: (i) PA increases with increasing shear stress magnitude; (ii) PA has a non-linear, time-dependent relationship to exposure time; (iii) PA is largely influenced by biomaterials, with PE and PEEK having respectively the lowest and highest prothrombotic potential; (iv) the effects of polymer surface-contact and shear stress are not correlated and can be studied separately. Our results suggest the importance of incorporating the evaluation of platelet activation driven by the combined effect of shear stress and polymer surface-contact for the comprehensive assessment, and eventually minimization, of BCDs thrombogenic potential.
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Affiliation(s)
- Silvia Bozzi
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - Yana Roka-Moiia
- Department of Medicine and Biomedical Engineering, Sarver Heart Center, University of Arizona, Tucson, AZ, USA
| | - Tatiana Mencarini
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - Federica Vercellino
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - Ilenia Epifani
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - Kaitlyn R Ammann
- Department of Medicine and Biomedical Engineering, Sarver Heart Center, University of Arizona, Tucson, AZ, USA
| | - Filippo Consolo
- Università Vita-Salute San Raffaele, Facoltà di Medicina e Chirurgia, Milano, Italy
| | - Marvin J Slepian
- Department of Medicine and Biomedical Engineering, Sarver Heart Center, University of Arizona, Tucson, AZ, USA
| | - Alberto Redaelli
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
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Fu M, Liu G, Wang W, Gao B, Ji B, Chang Y, Liu Y. Hemodynamic evaluation and in vitro hemolysis evaluation of a novel centrifugal pump for extracorporeal membrane oxygenation. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:679. [PMID: 33987377 PMCID: PMC8106046 DOI: 10.21037/atm-21-1135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Background The STM CP-24 I centrifugal pump is a newly developed centrifugal pump for extracorporeal membrane oxygenation equipment. This study aimed to combine hydraulic experiments, hemodynamic numerical simulations, and standard in vitro hemolysis experiments to investigate the comprehensive performance of this centrifugal pump. Methods In vitro experiments were first done to obtain the pressure-flow data of the centrifugal pump in its working range to evaluate its hydraulic performance. Next, the commonly used clinical working points were selected as boundary conditions, and a computational fluid dynamics method was applied to evaluate its hemodynamic performance. The blood pressure distribution, blood flow fields, and high-wall-shear-stress zones in the centrifugal pump were determined as indicators for hemodynamic evaluation. Finally, standard in vitro hemolysis experiments were performed to test the blood compatibility of this centrifugal pump (n=3 blood samples). In addition, its blood compatibility was evaluated in the form of the normalized index of hemolysis (NIH). Results The pressure-flow curve of the centrifugal pump showed that the head pressure and flow of the centrifugal pump showed a mostly linear relationship within the whole working range. When the rotation speed of the centrifugal pump was 5,500 rpm, it achieved a hydraulic performance of 550 mmHg head pressure and 8 L/min output flow, which could meet the clinical needs of extracorporeal membrane oxygenation. Analysis of computational fluid dynamics data indicated that the centrifugal pump had excellent hemodynamic performance: even distribution of blood pressure in the pump, no blood flow stagnation zone or dead zone in the overall flow field, and secondary flows in the gap between the rotor and the volute that significantly reduced the volume of the low-blood-flow zone close to the impeller. There was no obvious high-shear-stress zone on the surface of the volute or the impeller, which will effectively reduce the risk of thrombosis. In vitro hemolysis experiments indicated that the centrifugal pump had excellent blood biocompatibility, with a NIH =0.0125±0.0022 g/100 L. Conclusions The STM CP-24 I centrifugal pump has excellent hydraulic performance, a reasonable design of the hemodynamic structure of the blood pump, and excellent blood compatibility. Therefore, it can meet clinical needs.
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Affiliation(s)
- Minrui Fu
- Faculty of Environment and Life, Beijing University of Technology, Beijing, China
| | - Gang Liu
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Weining Wang
- Faculty of Environment and Life, Beijing University of Technology, Beijing, China.,Jiangsu STMed Technology Co. Ltd., Suzhou, China
| | - Bin Gao
- Faculty of Environment and Life, Beijing University of Technology, Beijing, China
| | - Bingyang Ji
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yu Chang
- National Clinical Research Center for Child Health, The Children's Hospital Zhejiang University School of Medicine, Hangzhou, China
| | - Youjun Liu
- Faculty of Environment and Life, Beijing University of Technology, Beijing, China
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Torner B, Konnigk L, Abroug N, Wurm H. Turbulence and turbulent flow structures in a ventricular assist device-A numerical study using the large-eddy simulation. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2021; 37:e3431. [PMID: 33336869 DOI: 10.1002/cnm.3431] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 12/14/2020] [Accepted: 12/14/2020] [Indexed: 06/12/2023]
Abstract
Numerical flow simulations that analyze the turbulent flow characteristics within a turbopump are important for optimizing the efficiency of such machines. In the case of ventricular assist devices (VADs), turbulent flow characteristics must be also examined in order to improve hemocompatibility. Turbulence increases the shear stresses in the VAD flow, which can lead to an increased damage to the transported blood components. Therefore, an understanding of the turbulent flow patterns and their significance for the numerical blood damage prediction is particularly important for flow optimizations in VADs in order to identify and thus minimize flow regions where blood could be damaged due to high turbulent stresses. Nevertheless, the turbulence occurring in VADs and the local turbulent structures that lead to increased turbulent stresses have not yet been analyzed in detail in these machines. Therefore, this study aims to investigate the turbulence in an axial VAD in a comprehensive and double tracked way. First, the flow in an axial VAD was computed using the large-eddy simulation method, and it was verified that the majority of the turbulence was directly resolved by the simulation. Then, the turbulent flow state of the VAD was quantified globally. For this purpose, a self-designed evaluation method, the power loss analysis, was used. Subsequently, local flow regions and flow structures were identified where significant turbulent stresses prevail. It will be shown that the identified regions are universal and will also occur in other axial blood pumps as well, for example, in the HeartMate II.
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Affiliation(s)
- Benjamin Torner
- Faculty of Mechanical Engineering and Marine Technology, Institute of Turbomachinery, University of Rostock, Rostock, Germany
| | - Lucas Konnigk
- Faculty of Mechanical Engineering and Marine Technology, Institute of Turbomachinery, University of Rostock, Rostock, Germany
| | - Nada Abroug
- Faculty of Mechanical Engineering and Marine Technology, Institute of Turbomachinery, University of Rostock, Rostock, Germany
| | - Hendrik Wurm
- Faculty of Mechanical Engineering and Marine Technology, Institute of Turbomachinery, University of Rostock, Rostock, Germany
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21
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Wang S, Griffith BP, Wu ZJ. Device-Induced Hemostatic Disorders in Mechanically Assisted Circulation. Clin Appl Thromb Hemost 2021; 27:1076029620982374. [PMID: 33571008 PMCID: PMC7883139 DOI: 10.1177/1076029620982374] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Mechanically assisted circulation (MAC) sustains the blood circulation in the body of a patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) or on ventricular assistance with a ventricular assist device (VAD) or on extracorporeal membrane oxygenation (ECMO) with a pump-oxygenator system. While MAC provides short-term (days to weeks) support and long-term (months to years) for the heart and/or lungs, the blood is inevitably exposed to non-physiological shear stress (NPSS) due to mechanical pumping action and in contact with artificial surfaces. NPSS is well known to cause blood damage and functional alterations of blood cells. In this review, we discussed shear-induced platelet adhesion, platelet aggregation, platelet receptor shedding, and platelet apoptosis, shear-induced acquired von Willebrand syndrome (AVWS), shear-induced hemolysis and microparticle formation during MAC. These alterations are associated with perioperative bleeding and thrombotic events, morbidity and mortality, and quality of life in MCS patients. Understanding the mechanism of shear-induce hemostatic disorders will help us develop low-shear-stress devices and select more effective treatments for better clinical outcomes.
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Affiliation(s)
- Shigang Wang
- Department of Surgery, 12264University of Maryland School of Medicine, Baltimore, MD, USA
| | - Bartley P Griffith
- Department of Surgery, 12264University of Maryland School of Medicine, Baltimore, MD, USA
| | - Zhongjun J Wu
- Department of Surgery, 12264University of Maryland School of Medicine, Baltimore, MD, USA.,Fischell Department of Bioengineering, A. James Clark School of Engineering, University of Maryland, College Park, MD, USA
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22
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Li M, Chen Y, Slepian MJ, Howard J, Thomas S, Barth EJ. Design, Modeling, and Experimental Characterization of A Valveless Pulsatile Flow Mechanical Circulatory Support Device. J Med Device 2021. [DOI: 10.1115/1.4049560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Abstract
Mechanical circulatory support (MCS) devices, i.e., ventricular assist devices (VADs) and total artificial hearts (TAHs), while effective and vital in restoring hemodynamics in patients with circulatory compromise in advanced heart failure, remain limited by significant adverse thrombotic, embolic and bleeding events. Many of these complications relate to chronic exposure, via these devices, to nonpulsatile flow and the high shear stress created by current methods of blood propulsion or use of prosthetic valves. Here we propose a novel noncompressing single sliding vane MCS device to: 1) dramatically reduce pump operating speed thus potentially lowering the shear stress imparted to blood; 2) eliminate utilization of prosthetic valves thus diminishing potential shear stress generations; 3) allow direct flow rate control to generate physically desired blood flow rate include pulsatile flow; and 4) achieve compactness to fit into the majority of patients. The fundamental working principle and governing design equations are introduced first with multiple design and performance objectives presented. A first prototype was fabricated and experimental tests were conducted to validate the model with a 93.10% match between theoretical and experimental flow rate results. After model validation, the proposed MCS was tested to illustrate the ability of pulsatile flow generation. Finally, it was compared with some representative MCS pumps to discuss its potential of improving current MCS design. The presented work offers a novel MCS design and paves the way for next steps in device hemocompatibility testing.
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Affiliation(s)
- Mengtang Li
- Department of Mechanical Engineering, Vanderbilt University, Nashville, TN 37235
| | - Ye Chen
- Department of Mechanical Engineering, Santa Clara University, Santa Clara, CA 95053
| | - Marvin J. Slepian
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ 85724; Department of Medicine, University of Arizona, Tucson, AZ 85724; Sarver Heart Center, University of Arizona, Tucson, AZ 85724
| | - Joseph Howard
- Department of Mechanical Engineering, Vanderbilt University, Nashville, TN 37235
| | - Seth Thomas
- Department of Mechanical Engineering, Vanderbilt University, Nashville, TN 37235
| | - Eric J. Barth
- Department of Mechanical Engineering, Vanderbilt University, Nashville, TN 37235
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23
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Sheriff J, Malone LE, Avila C, Zigomalas A, Bluestein D, Bahou WF. Shear-Induced Platelet Activation is Sensitive to Age and Calcium Availability: A Comparison of Adult and Cord Blood. Cell Mol Bioeng 2020; 13:575-590. [PMID: 33281988 PMCID: PMC7704822 DOI: 10.1007/s12195-020-00628-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 06/16/2020] [Indexed: 10/24/2022] Open
Abstract
INTRODUCTION Antiplatelet therapy for neonates and infants is often extrapolated from the adult experience, based on limited observation of agonist-induced neonatal platelet hypoactivity and poor understanding of flow shear-mediated platelet activation. Therefore, thrombotic events due to device-associated disturbed flow are inadequately mitigated in critically ill neonates with indwelling umbilical catheters and infants receiving cardiovascular implants. METHODS Whole blood (WB), platelet-rich plasma (PRP), and gel-filtered platelets (GFP) were prepared from umbilical cord and adult blood, and exposed to biochemical agonists or pathological shear stress of 70 dyne/cm2. We evaluated α-granule release, phosphatidylserine (PS) scrambling, and procoagulant response using P-selectin expression, Annexin V binding, and thrombin generation (PAS), respectively. Activation modulation due to depletion of intracellular and extracellular calcium, requisite second messengers, was also examined. RESULTS Similar P-selectin expression was observed for sheared adult and cord platelets, with concordant inhibition due to intracellular and extracellular calcium depletion. Sheared cord platelet Annexin V binding and PAS activity was similar to adult values in GFP, but lower in PRP and WB. Annexin V on sheared cord platelets was calcium-independent, with PAS slightly reduced by intracellular calcium depletion. CONCLUSIONS Increased PS activity on purified sheared cord platelets suggest that their intrinsic function under pathological flow conditions is suppressed by cell-cell or plasmatic components. Although secretory functions of adult and cord platelets retain comparable calcium-dependence, PS exposure in sheared cord platelets is uniquely calcium-independent and distinct from adults. Identification of calcium-regulated developmental disparities in shear-mediated platelet function may provide novel targets for age-specific antiplatelet therapy.
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Affiliation(s)
- Jawaad Sheriff
- Department of Biomedical Engineering, T08-50 Health Sciences Center, Stony Brook University, Stony Brook, NY 11794-8084 USA
| | - Lisa E. Malone
- Division of Hematology and Oncology, Department of Medicine, Stony Brook University, Stony Brook, NY 11794 USA
| | - Cecilia Avila
- Department of Obstetrics, Gynecology and Reproductive Medicine, Stony Brook University, Stony Brook, NY 11794 USA
| | - Amanda Zigomalas
- Department of Biomedical Engineering, T08-50 Health Sciences Center, Stony Brook University, Stony Brook, NY 11794-8084 USA
| | - Danny Bluestein
- Department of Biomedical Engineering, T08-50 Health Sciences Center, Stony Brook University, Stony Brook, NY 11794-8084 USA
| | - Wadie F. Bahou
- Division of Hematology and Oncology, Department of Medicine, Stony Brook University, Stony Brook, NY 11794 USA
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24
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Xu S, Piao J, Lee B, Lim C, Shin S. Platelet thrombus formation by upstream activation and downstream adhesion of platelets in a microfluidic system. Biosens Bioelectron 2020; 165:112395. [DOI: 10.1016/j.bios.2020.112395] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 06/14/2020] [Indexed: 01/30/2023]
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25
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In Vitro Durability and Stability Testing of a Novel Polymeric Transcatheter Aortic Valve. ASAIO J 2020; 66:190-198. [PMID: 30845067 DOI: 10.1097/mat.0000000000000980] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Transcatheter aortic valve replacement (TAVR) has emerged as an effective therapy for the unmet clinical need of inoperable patients with severe aortic stenosis (AS). Current clinically used tissue TAVR valves suffer from limited durability that hampers TAVR's rapid expansion to younger, lower risk patients. Polymeric TAVR valves optimized for hemodynamic performance, hemocompatibility, extended durability, and resistance to calcific degeneration offer a viable solution to this challenge. We present extensive in vitro durability and stability testing of a novel polymeric TAVR valve (PolyNova valve) using 1) accelerated wear testing (AWT, ISO 5840); 2) calcification susceptibility (in the AWT)-compared with clinically used tissue valves; and 3) extended crimping stability (valves crimped to 16 Fr for 8 days). Hydrodynamic testing was performed every 50M cycles. The valves were also evaluated visually for structural integrity and by scanning electron microscopy for evaluation of surface damage in the micro-scale. Calcium and phosphorus deposition was evaluated using micro-computed tomography (μCT) and inductive coupled plasma spectroscopy. The valves passed 400M cycles in the AWT without failure. The effective orifice area kept stable at 1.8 cm with a desired gradual decrease in transvalvular pressure gradient and regurgitation (10.4 mm Hg and 6.9%, respectively). Calcium and phosphorus deposition was significantly lower in the polymeric valve: down by a factor of 85 and 16, respectively-as compared to a tissue valve. Following the extended crimping testing, no tears nor surface damage were evident. The results of this study demonstrate the potential of a polymeric TAVR valve to be a viable alternative to tissue-based TAVR valves.
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26
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Wisniewski A, Medart D, Wurm FH, Torner B. Evaluation of clinically relevant operating conditions for left ventricular assist device investigations. Int J Artif Organs 2020; 44:92-100. [PMID: 32605416 DOI: 10.1177/0391398820932925] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Standardized boundary conditions for flow rate and pressure difference are currently not available for the development and certification process of ventricular assist devices. Thus, interdisciplinary studies lack comparability and quantitative assessment. Universally valid boundary conditions could be used for the application of numerical and experimental investigations and the approval procedure of ventricular assist devices. In order to define such boundaries, physiological data from INCOR® patients were evaluated. A total of 599 out of possible 627 ventricular assist device patients were analyzed regarding their cardiac demands of flow rate and pressure head. An analysis of long-term data was performed, in order to provide respective, static mean values for benchmark testing. Furthermore, the short-term data of 188 patients delivered field data-based dynamic flow and pressure curves. The results of the study revealed physiologically reasonable boundary conditions, which can be applied in numerical or experimental investigations of ventricular assist devices. For steady flow analysis, single values for flow rate (4.46 L/min) and pressure head (62 mmHg) are suggested. For the support of pulsatile and unsteady flow studies, seven typical patients and one representative dynamic curve for flow rate and pressure head are proposed.The standardized results provided in this article, can be used in favor of interdisciplinary comparability of future numerical computations or in vitro ventricular assist device tests in research, development, and approval.
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Affiliation(s)
- A Wisniewski
- Berlin Heart GmbH, Berlin, Germany.,Universität Rostock, Fakultät für Maschinenbau und Schiffstechnik, Rostock, Germany
| | - D Medart
- Berlin Heart GmbH, Berlin, Germany
| | - F-H Wurm
- Universität Rostock, Fakultät für Maschinenbau und Schiffstechnik, Rostock, Germany
| | - B Torner
- Universität Rostock, Fakultät für Maschinenbau und Schiffstechnik, Rostock, Germany
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27
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Li M, Walk R, Roka-Moiia Y, Sheriff J, Bluestein D, Barth EJ, Slepian MJ. Circulatory loop design and components introduce artifacts impacting in vitro evaluation of ventricular assist device thrombogenicity: A call for caution. Artif Organs 2019; 44:E226-E237. [PMID: 31876310 DOI: 10.1111/aor.13626] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 11/20/2019] [Accepted: 12/16/2019] [Indexed: 12/28/2022]
Abstract
Mechanical circulatory support (MCS) devices continue to be hampered by thrombotic adverse events (AEs), a consequence of device-imparted supraphysiologic shear stresses, leading to shear-mediated platelet activation (SMPA). In advancing MCS devices from design to clinical use, in vitro circulatory loops containing the device under development and testing are utilized as a means of assessing device thrombogenicity. Physical characteristics of these test circulatory loops may also contribute to inadvertent platelet activation through imparted shear stress, adding inadvertent error in evaluating MCS device thrombogenicity. While investigators normally control for the effect of a loop, inadvertent addition of what are considered innocuous connectors may impact test results. Here, we tested the effect of common, additive components of in vitro circulatory test loops, that is, connectors and loop geometry, as to their additive contribution to shear stress via both in silico and in vitro models. A series of test circulatory loops containing a ventricular assist device (VAD) with differing constituent components, were established in silico including: loops with 0~5 Luer connectors, a loop with a T-connector creating 90° angulation, and a loop with 90° angulation. Computational fluid dynamics (CFD) simulations were performed using a k - ω shear stress transport turbulence model to platelet activation index (PAI) based on a power law model. VAD-operated loops replicating in silico designs were assembled in vitro and gel-filtered human platelets were recirculated within (1 hour) and SMPA was determined. CFD simulations demonstrated high shear being introduced at non-smooth regions such as edge-connector boundaries, tubing, and at Luer holes. Noticeable peaks' shifts of scalar shear stress (sss) distributions toward high shear-region existed with increasing loop complexity. Platelet activation also increased with increasing shear exposure time, being statistically higher when platelets were exposed to connector-employed loop designs. The extent of platelet activation in vitro could be successfully predicted by CFD simulations. Loops employing additional components (non-physiological flow pattern connectors) resulted in higher PAI. Loops with more components (5-connector loop and 90° T-connector) showed 63% and 128% higher platelet activation levels, respectively, versus those with fewer (0-connector (P = .023) and a 90° heat-bend loop (P = .0041). Our results underscore the importance of careful consideration of all component elements, and suggest the need for standardization in designing in vitro circulatory loops for MCS device evaluation to avoid inadvertent additive SMPA during device evaluation, confounding overall results. Specifically, we caution on the use and inadvertent introduction of additional connectors, ports, and other shear-generating elements which introduce artifact, clouding primary device evaluation via introduction of additive SMPA.
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Affiliation(s)
- Mengtang Li
- Department of Mechanical Engineering, Vanderbilt University, Nashville, TN, USA
| | - Ryan Walk
- Department of Medicine, Sarver Heart Center, University of Arizona, Tucson, AZ, USA
| | - Yana Roka-Moiia
- Department of Medicine, Sarver Heart Center, University of Arizona, Tucson, AZ, USA
| | - Jawaad Sheriff
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Danny Bluestein
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Eric J Barth
- Department of Mechanical Engineering, Vanderbilt University, Nashville, TN, USA
| | - Marvin J Slepian
- Department of Medicine, Sarver Heart Center, University of Arizona, Tucson, AZ, USA.,Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA.,Department of Biomedical Engineering, University of Arizona, Tucson, AZ, USA
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Liu GM, Zhang Y, Chen HB, Hou JF, Jin DH, Gui XM, Hu SS. Platelet deposition estimation: A novel method for emulating the pump thrombosis potential of blood pumps. Artif Organs 2019; 44:465-472. [PMID: 31853998 DOI: 10.1111/aor.13620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 12/02/2019] [Accepted: 12/12/2019] [Indexed: 01/19/2023]
Abstract
Pump thrombosis potential exists in most blood pumps and limits their clinical use. To improve the pump thrombosis performance of blood pumps, a method for emulating the platelet deposition on the flow passage component surfaces inside blood pumps was presented and tested. The method emulates the blood platelet deposition, employing laser-induced fluorescence tracing technology. The blood pump was rotated in a mock circulation loop with deionized water filled with fluorescent particles. The component surfaces were then explored via laser. The fluorescent particles were induced by laser and imaged in a charge-coupled device (CCD) camera to show the distribution of fluorescent particles gathering on the blood pump component surfaces. The activated platelet deposition was emulated by fluorescent particle gathering. The experiment showed obvious particle gathering on the interface surfaces and cross-sectional surface (perpendicular to the flow). This platelet deposition estimation (PDE) method can be easily incorporated in the in vitro testing phase to analyze and decrease a pump's thrombosis potential before animal experimentation, thereby reducing the cost of blood pump development. This methodology of emulating blood platelet deposition indicates its potential for improving flow passage component structure and reducing device thrombosis of blood pumps.
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Affiliation(s)
- Guang-Mao Liu
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yan Zhang
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Hai-Bo Chen
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jian-Feng Hou
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Dong-Hai Jin
- School of Energy and Power Engineering, Beihang University, Beijing, China
| | - Xing-Min Gui
- School of Energy and Power Engineering, Beihang University, Beijing, China
| | - Sheng-Shou Hu
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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29
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Liu GM, Chen HB, Hou JF, Zhang Y, Hu SS. Platelet adhesion emulation: A novel method for estimating the device thrombosis potential of a ventricular assist device. Int J Artif Organs 2019; 43:252-257. [PMID: 31709882 DOI: 10.1177/0391398819885946] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Device thrombosis inside ventricular assist devices remains a limitation to their long-term clinical use. Thrombosis potential exists in almost all ventricular assist devices because the device-induced high shear stress and vortices can activate platelets, which then aggregate and adhere to the surfaces inside the ventricular assist device. To decrease the device thrombosis potential of long-term use of ventricular assist devices, a methodology entitled platelet adhesion emulation for predicting the thrombosis potential and thrombosis position inside the ventricular assist devices is developed. The platelet adhesion emulation methodology combines numerical simulations with in vitro experiments by correlating the structure of the flow passage components within the ventricular assist device with the platelet adhesion to estimate the thrombosis potential and location, with the goal of developing ventricular assist devices with optimized antithrombotic performance. Platelet adhesion emulation is aimed at decreasing the device thrombus potential of ventricular assist devices. The platelet adhesion emulation effectiveness is validated by simulating and testing an axial left ventricular assist device. The blood velocity relative to the surfaces of the flow passage components is calculated to estimate the platelet adhesion potential, indicating the probability of thrombus formation on the surfaces. Platelet adhesion emulation experiments conducted in a mock circulation loop with pump prototypes show the distribution of platelet adhesion on the surfaces. This methodology of emulating the device thrombosis distribution indicates the potential for improving the component structure and reducing the device thrombosis of ventricular assist devices.
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Affiliation(s)
- Guang-Mao Liu
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Hai-bo Chen
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jian-feng Hou
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yan Zhang
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Sheng-shou Hu
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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30
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Gupta P, Zhang P, Sheriff J, Bluestein D, Deng Y. A Multiscale Model for Recruitment Aggregation of Platelets by Correlating with In Vitro Results. Cell Mol Bioeng 2019; 12:327-343. [PMID: 31662802 DOI: 10.1007/s12195-019-00583-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Introduction We developed a multiscale model to simulate the dynamics of platelet aggregation by recruitment of unactivated platelets flowing in viscous shear flows by an activated platelet deposited onto a blood vessel wall. This model uses coarse grained molecular dynamics (CGMD) for platelets at the microscale and dissipative particle dynamics (DPD) for the shear flow at the macroscale. Under conditions of relatively low shear, aggregation is mediated by fibrinogen via αIIbβ3 receptors. Methods The binding of αIIbβ3 and fibrinogen is modeled by a molecular-level hybrid force field consisting of Morse potential and Hooke law for the nonbonded and bonded interactions, respectively. The force field, parametrized in two different interaction scales, is calculated by correlating with the platelet contact area measured in vitro and the detaching force between αIIbβ3 and fibrinogen. Results Using our model, we derived, the relationship between recruitment force and distance between the centers of mass of two platelets, by integrating the molecular-scale inter-platelet interactions during recruitment aggregation in shear flows. Our model indicates that assuming a rigid-platelet model, underestimates the contact area by 89% and the detaching force by 93% as compared to a model that takes into account the platelet deformability leading to a prediction of a significantly lower attachment during recruitment. Conclusions The molecular-level predictive capability of our model sheds a light on differences observed between transient and permanent platelet aggregation patterns. The model and simulation framework can be further adapted to simulate initial thrombus formation involving multiple flowing platelets as well as deposition and adhesion onto blood vessels.
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Affiliation(s)
- Prachi Gupta
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY 11794-3600 USA
| | - Peng Zhang
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794 USA
| | - Jawaad Sheriff
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794 USA
| | - Danny Bluestein
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794 USA
| | - Yuefan Deng
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY 11794-3600 USA
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31
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May‐Newman K, Montes R, Campos J, Marquez‐Maya N, Vu V, Zebrowski E, Motomura T, Benkowski R. Reducing regional flow stasis and improving intraventricular hemodynamics with a tipless inflow cannula design: An in vitro flow visualization study using the EVAHEART LVAD. Artif Organs 2019; 43:834-848. [DOI: 10.1111/aor.13477] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 04/11/2019] [Accepted: 04/23/2019] [Indexed: 12/13/2022]
Affiliation(s)
- Karen May‐Newman
- Bioengineering Program, Department of Mechanical Engineering San Diego State University San Diego California
| | - Ricardo Montes
- Bioengineering Program, Department of Mechanical Engineering San Diego State University San Diego California
| | - Josue Campos
- Bioengineering Program, Department of Mechanical Engineering San Diego State University San Diego California
| | - Nikolas Marquez‐Maya
- Bioengineering Program, Department of Mechanical Engineering San Diego State University San Diego California
| | - Vi Vu
- Bioengineering Program, Department of Mechanical Engineering San Diego State University San Diego California
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Device Thrombogenicity Emulation: An In Silico Predictor of In Vitro and In Vivo Ventricular Assist Device Thrombogenicity. Sci Rep 2019; 9:2946. [PMID: 30814674 PMCID: PMC6393420 DOI: 10.1038/s41598-019-39897-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 02/04/2019] [Indexed: 12/02/2022] Open
Abstract
Ventricular assist devices (VAD), a mainstay of therapy for advanced and end-stage heart failure, remain plagued by device thrombogenicity. Combining advanced in silico and in vitro methods, Device Thrombogenicity Emulation (DTE) is a device design approach for enhancing VAD thromboresistance. Here we tested DTE efficacy in experimental VAD designs. DTE incorporates iterative design modifications with advanced CFD to compute the propensity of large populations of platelets to activate by flow-induced stresses (statistically representing the VAD ‘Thrombogenic Footprint’). The DTE approach was applied to a VAD (MINDTE) design with a favorable thromboresistance profile and compared against a design (MAXDTE) that generated an intentionally poor thromboresistance profile. DTE predictions were confirmed by testing physical prototypes in vitro by measuring VAD thrombogenicity using the modified prothrombinase assay. Chronic in vivo studies in VAD implanted calves, revealed MINDTE calf surviving well with low platelet activation, whereas the MAXDTE animal sustained thromboembolic strokes. DTE predictions were confirmed, correlating with in vitro and in vivo thrombogenicity, supporting utility in guiding device development, potentially reducing the need for animal studies.
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Liu GM, Jin DH, Chen HB, Hou JF, Zhang Y, Sun HS, Zhou JY, Hu SS, Gui XM. Numerical investigation of the influence of a bearing/shaft structure in an axial blood pump on the potential for device thrombosis. Int J Artif Organs 2019; 42:182-189. [PMID: 30630379 DOI: 10.1177/0391398818823769] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Adverse events caused by flow-induced thrombus formation around the bearing/shaft of an axial blood pump remain a serious problem for axial blood pumps. Moreover, excessive anticoagulation with thrombosis around the bearing potentially increases the risk of postoperative gastrointestinal bleeding. The purpose of this study is to analyze the influence of the bearing structure on the thrombosis potential of an axial blood pump. The bearing/shaft structure was embedded into an axial blood pump numerical model. The numerical simulation and analysis are focused on the low wall shear stresses, recirculation, and residence time close to the bearing region to evaluate the potential for thrombosis around the bearing. Then, the flow field near the blood pump bearing was tested via in vitro particle image velocimetry experiments to verify the numerical results. The simulation results showed that after embedding the bearing/shaft structure a recirculation zone appeared in the outlet guide vane bearing/shaft region, the residence time increased 11-fold in comparison to the pump without the bearing/shaft structure, the scalar shear stress in the shaft surface was less than 7.8 Pa, and the stress accumulation was less than 0.10 Pa s. The numerical results showed that platelets that flow through the bearing region are exposed to significantly lower wall shear stress and a longer residence time, leading to activated platelet adhesion. The reduced stress accumulation and increased time in the bearing region lead to increased platelet activation.
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Affiliation(s)
- Guang-Mao Liu
- School of Energy and Power Engineering, Beihang University, Beijing, China
- State Key Laboratory of Cardiovascular Disease, National Center for Cardiovascular Diseases, Fu Wai Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Dong-Hai Jin
- School of Energy and Power Engineering, Beihang University, Beijing, China
| | - Hai-bo Chen
- State Key Laboratory of Cardiovascular Disease, National Center for Cardiovascular Diseases, Fu Wai Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Jian-feng Hou
- State Key Laboratory of Cardiovascular Disease, National Center for Cardiovascular Diseases, Fu Wai Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Yan Zhang
- State Key Laboratory of Cardiovascular Disease, National Center for Cardiovascular Diseases, Fu Wai Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Han-song Sun
- State Key Laboratory of Cardiovascular Disease, National Center for Cardiovascular Diseases, Fu Wai Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Jian-Ye Zhou
- State Key Laboratory of Cardiovascular Disease, National Center for Cardiovascular Diseases, Fu Wai Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Sheng-shou Hu
- State Key Laboratory of Cardiovascular Disease, National Center for Cardiovascular Diseases, Fu Wai Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Xing-Min Gui
- School of Energy and Power Engineering, Beihang University, Beijing, China
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34
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Patient-specific simulation of transcatheter aortic valve replacement: impact of deployment options on paravalvular leakage. Biomech Model Mechanobiol 2018; 18:435-451. [PMID: 30460623 DOI: 10.1007/s10237-018-1094-8] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 11/01/2018] [Indexed: 10/27/2022]
Abstract
Transcatheter aortic valve replacement (TAVR) has emerged as an effective alternative to conventional surgical valve replacement in high-risk patients afflicted by severe aortic stenosis. Despite newer-generation devices enhancements, post-procedural complications such as paravalvular leakage (PVL) and related thromboembolic events have been hindering TAVR expansion into lower-risk patients. Computational methods can be used to build and simulate patient-specific deployment of transcatheter aortic valves (TAVs) and help predict the occurrence and degree of PVL. In this study finite element analysis and computational fluid dynamics were used to investigate the influence of procedural parameters on post-deployment hemodynamics on three retrospective clinical cases affected by PVL. Specifically, TAV implantation depth and balloon inflation volume effects on stent anchorage, degree of paravalvular regurgitation and thrombogenic potential were analyzed for cases in which Edwards SAPIEN and Medtronic CoreValve were employed. CFD results were in good agreement with corresponding echocardiography data measured in patients in terms of the PVL jets locations and overall PVL degree. Furthermore, parametric analyses demonstrated that positioning and balloon over-expansion may have a direct impact on the post-deployment TAVR performance, achieving as high as 47% in PVL volume reduction. While the model predicted very well clinical data, further validation on a larger cohort of patients is needed to verify the level of the model's predictions in various patient-specific conditions. This study demonstrated that rigorous and realistic patient-specific numerical models could potentially serve as a valuable tool to assist physicians in pre-operative TAVR planning and TAV selection to ultimately reduce the risk of clinical complications.
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Rotman OM, Bianchi M, Ghosh RP, Kovarovic B, Bluestein D. Principles of TAVR valve design, modelling, and testing. Expert Rev Med Devices 2018; 15:771-791. [PMID: 30318937 DOI: 10.1080/17434440.2018.1536427] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
INTRODUCTION Transcatheter aortic valve replacement (TAVR) has emerged as an effective minimally-invasive alternative to surgical valve replacement in medium- to high-risk, elderly patients with calcific aortic valve disease and severe aortic stenosis. The rapid growth of the TAVR devices market has led to a high variety of designs, each aiming to address persistent complications associated with TAVR valves that may hamper the anticipated expansion of TAVR utility. AREAS COVERED Here we outline the challenges and the technical demands that TAVR devices need to address for achieving the desired expansion, and review design aspects of selected, latest generation, TAVR valves of both clinically-used and investigational devices. We further review in detail some of the up-to-date modeling and testing approaches for TAVR, both computationally and experimentally, and additionally discuss those as complementary approaches to the ISO 5840-3 standard. A comprehensive survey of the prior and up-to-date literature was conducted to cover the most pertaining issues and challenges that TAVR technology faces. EXPERT COMMENTARY The expansion of TAVR over SAVR and to new indications seems more promising than ever. With new challenges to come, new TAV design approaches, and materials used, are expected to emerge, and novel testing/modeling methods to be developed.
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Affiliation(s)
- Oren M Rotman
- a Department of Biomedical Engineering , Stony Brook University , Stony Brook , NY , USA
| | - Matteo Bianchi
- a Department of Biomedical Engineering , Stony Brook University , Stony Brook , NY , USA
| | - Ram P Ghosh
- a Department of Biomedical Engineering , Stony Brook University , Stony Brook , NY , USA
| | - Brandon Kovarovic
- a Department of Biomedical Engineering , Stony Brook University , Stony Brook , NY , USA
| | - Danny Bluestein
- a Department of Biomedical Engineering , Stony Brook University , Stony Brook , NY , USA
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Selmi M, Chiu WC, Chivukula VK, Melisurgo G, Beckman JA, Mahr C, Aliseda A, Votta E, Redaelli A, Slepian MJ, Bluestein D, Pappalardo F, Consolo F. Blood damage in Left Ventricular Assist Devices: Pump thrombosis or system thrombosis? Int J Artif Organs 2018; 42:113-124. [PMID: 30354870 DOI: 10.1177/0391398818806162] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Introduction: Despite significant technical advancements in the design and manufacture of Left Ventricular Assist Devices, post-implant thrombotic and thromboembolic complications continue to affect long-term outcomes. Previous efforts, aimed at optimizing pump design as a means of reducing supraphysiologic shear stresses generated within the pump and associated prothrombotic shear-mediated platelet injury, have only partially altered the device hemocompatibility. Methods: We examined hemodynamic mechanisms that synergize with hypershear within the pump to contribute to the thrombogenic potential of the overall Left Ventricular Assist Device system. Results: Numerical simulations of blood flow in differing regions of the Left Ventricular Assist Device system, that is the diseased native left ventricle, the pump inflow cannula, the impeller, the outflow graft and the anastomosed downstream aorta, reveal that prothrombotic hemodynamic conditions might occur at these specific sites. Furthermore, we show that beyond hypershear, additional hemodynamic abnormalities exist within the pump, which may elicit platelet activation, such as recirculation zones and stagnant platelet trajectories. We also provide evidences that particular Left Ventricular Assist Device implantation configurations and specific post-implant patient management strategies, such as those allowing aortic valve opening, are more hemodynamically favorable and reduce the thrombotic risk. Conclusion: We extend the perspective of pump thrombosis secondary to the supraphysiologic shear stress environment of the pump to one of Left Ventricular Assist Device system thrombosis, raising the importance of comprehensive characterization of the different prothrombotic risk factors of the total system as the target to achieve enhanced hemocompatibility and improved clinical outcomes.
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Affiliation(s)
- Matteo Selmi
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
- Department of Surgery, Division of Cardiac Surgery, Università di Verona, Verona, Italy
| | - Wei-Che Chiu
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | | | - Giulio Melisurgo
- Anesthesia and Cardiothoracic Intensive Care, San Raffaele Scientific Institute, Milano, Italy
| | | | - Claudius Mahr
- Division of Cardiology, University of Washington, Seattle, WA, USA
| | - Alberto Aliseda
- Department of Mechanical Engineering, University of Washington, Seattle, WA, USA
| | - Emiliano Votta
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - Alberto Redaelli
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - Marvin J Slepian
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
- Departments of Medicine and Biomedical Engineering, The University of Arizona, Tucson, AZ, USA
| | - Danny Bluestein
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Federico Pappalardo
- Anesthesia and Cardiothoracic Intensive Care, San Raffaele Scientific Institute, Milano, Italy
- Advanced Heart Failure and Mechanical Circulatory Support Program, San Raffaele Scientific Institute, Milano, Italy
- Università Vita-Salute San Raffaele, Milano, Italy
| | - Filippo Consolo
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
- Advanced Heart Failure and Mechanical Circulatory Support Program, San Raffaele Scientific Institute, Milano, Italy
- Università Vita-Salute San Raffaele, Milano, Italy
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Hazan O, Sternik L, Waiss D, Eldar M, Hoffer O, Goitein O, Kuperstein R, Konen E, Ovadia-Blechman Z. An innovative appendage invagination procedure to reduce thrombus formation – a numerical model. Comput Methods Biomech Biomed Engin 2018; 21:370-378. [DOI: 10.1080/10255842.2018.1466116] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Ori Hazan
- The Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel
- School of Medical Engineering, Afeka –Tel Aviv Academic College of Engineering, Tel-Aviv, Israel
| | - Leonid Sternik
- Leviev Heart Center, Chaim Sheba Medical Center, Tel Hashomer, Israel
| | - Dar Waiss
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Michael Eldar
- The Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel
- Leviev Heart Center, Chaim Sheba Medical Center, Tel Hashomer, Israel
| | - Oshrit Hoffer
- School of Electrical Engineering, Afeka –Tel Aviv Academic College of Engineering, Tel-Aviv, Israel
| | - Orly Goitein
- Imaging Department, Sheba Medical Center, Tel-HaShomer, Israel
| | - Rafael Kuperstein
- Leviev Heart Center, Chaim Sheba Medical Center, Tel Hashomer, Israel
| | - Eli Konen
- Imaging Department, Sheba Medical Center, Tel-HaShomer, Israel
| | - Zehava Ovadia-Blechman
- School of Medical Engineering, Afeka –Tel Aviv Academic College of Engineering, Tel-Aviv, Israel
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Abstract
Treatment of end-stage heart failure includes cardiac transplantation or ventricular assist device (VAD) therapy. Although increasingly prevalent, current VAD therapy has inherent complications, including thrombosis. Studies have demonstrated that VAD implantation alters intracardiac blood flow, creating areas of stagnation that predispose to thrombus formation. Two potential surgical configurations exist for VAD implantation: through the apical or diaphragmatic surfaces of the heart. We hypothesized that diaphragmatic implantation causes more stagnation than apical implantation. We also hypothesized that intermittent aortic valve (AV) opening reduces stagnation of blood inside the left ventricle (LV) when compared with a closed AV. To test these hypotheses, a human LV geometry was recreated in silico and a VAD inflow cannula was virtually implanted in each configuration. A computational indicator-dilution study was conducted where "virtually dyed blood" was washed out of the LV by injecting blood with no dye. Simulations demonstrated a substantial reduction in stagnation with intermittent AV opening. In addition, virtual dye was cleared slightly faster in the apical configuration. Simulations from our study demonstrate the clinical importance of VAD management to allow intermittent opening of the AV to prevent subvalvular stagnation, and also suggests that apical configuration might be more hemodynamically favorable.
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Buck AKW, Goebel SG, Goodin MS, Wright NJ, Groszek JJ, Moyer J, Singh S, Bluestein D, Fissell WH, Roy S. Original article submission: Platelet stress accumulation analysis to predict thrombogenicity of an artificial kidney. J Biomech 2018; 69:26-33. [PMID: 29395231 DOI: 10.1016/j.jbiomech.2018.01.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 12/27/2017] [Accepted: 01/08/2018] [Indexed: 02/01/2023]
Abstract
An implantable artificial kidney using a hemofilter constructed from an array of silicon membranes to provide ultrafiltration requires a suitable blood flow path to ensure stable operation in vivo. Two types of flow paths distributing blood to the array of membranes were evaluated: parallel and serpentine. Computational fluid dynamics (CFD) simulations were used to guide the development of the blood flow paths. Pressure data from animal tests were used to obtain pulsatile flow conditions imposed in the transient simulations. A key consideration for stable operation in vivo is limiting platelet stress accumulation to avoid platelet activation and thrombus formation. Platelet stress exposure was evaluated by CFD particle tracking methods through the devices to provide distributions of platelet stress accumulation. The distributions of stress accumulation over the duration of a platelet lifetime for each device revealed that stress accumulation for the serpentine flow path exceeded levels expected to cause platelet activation while the accumulated stress for the parallel flow path was below expected activation levels.
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Affiliation(s)
- Amanda K W Buck
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | | | | | - Nathan J Wright
- Department of Bioengineering & Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
| | - Joseph J Groszek
- Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jarrett Moyer
- Department of Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Sukhveer Singh
- Department of Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Danny Bluestein
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - William H Fissell
- Nephrology and Hypertension, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Shuvo Roy
- Department of Bioengineering & Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA.
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Ventricular Assist Device Implantation Configurations Impact Overall Mechanical Circulatory Support System Thrombogenic Potential. ASAIO J 2018; 63:285-292. [PMID: 27922885 DOI: 10.1097/mat.0000000000000488] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Ventricular assist devices (VADs) became in recent years the standard of care therapy for advanced heart failure with hemodynamic compromise. With the steadily growing population of device recipients, various postimplant complications have been reported, mostly associated with the hypershear generated by VADs that enhance their thrombogenicity by activating platelets. Although VAD design optimization can significantly improve its thromboresistance, the implanted VAD need to be evaluated as part of a system. Several clinical studies indicated that variability in implantation configurations may contribute to the overall system thrombogenicity. Numerical simulations were conducted in the HeartAssist 5 (HA5) and HeartMate II (HMII) VADs in the following implantation configurations: 1) inflow cannula angles: 115° and 140° (HA5); 2) three VAD circumferential orientations: 0°, 30°, and 60° (HA5 and HMII); and 3) 60° and 90° outflow graft anastomotic angles with respect to the ascending aorta (HA5). The stress accumulation of the platelets was calculated along flow trajectories and collapsed into a probability density function, representing the "thrombogenic footprint" of each configuration-a proxy to its thrombogenic potential (TP). The 140° HA5 cannula generated lower TP independent of the circumferential orientation of the VAD. Sixty-degree orientation generated the lowest TP for the HA5 versus 0° for the HMII. An anastomotic angle of 60° resulted in lower TP for HA5. These results demonstrate that optimizing the implantation configuration reduces the overall system TP. Thromboresistance can be enhanced by combining VAD design optimization with the surgical implantation configurations for achieving better clinical outcomes of implanted VADs.
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Left Ventricular Assist Devices - A State of the Art Review. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018. [PMID: 29532330 DOI: 10.1007/5584_2018_145] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Cardiovascular diseases are the leading cause of mortality rates throughout the world. Next to an insufficient number of healthy donors, this has led to increasing numbers of patients on heart transplant waiting lists with prolonged waiting times. Innovative technological advancements have led to the production of ventricular assist devices that play an increasingly important role in end stage heart failure therapy. This review is intended to provide an overview of current implantable left ventricular assist devices, different design concepts and implantation techniques. Challenges such as infections and thromboembolic events that may occur during LVAD implantations have also been discussed.
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Valerio L, Sheriff J, Tran PL, Brengle W, Redaelli A, Fiore GB, Pappalardo F, Bluestein D, Slepian MJ. Routine clinical anti-platelet agents have limited efficacy in modulating hypershear-mediated platelet activation associated with mechanical circulatory support. Thromb Res 2017; 163:162-171. [PMID: 29428715 DOI: 10.1016/j.thromres.2017.12.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 11/03/2017] [Accepted: 12/02/2017] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Continuous flow ventricular assist devices (cfVADs) continue to be limited by thrombotic complications associated with disruptive flow patterns and supraphysiologic shear stresses. Patients are prescribed complex antiplatelet therapies, which do not fully prevent recurrent thromboembolic events. This is partially due to limited data on antiplatelet efficacy under cfVAD-associated shear conditions. MATERIALS AND METHODS We investigated the efficacy of antiplatelet drugs directly acting on three pathways: (1) cyclooxygenase (aspirin), (2) phosphodiesterase (dipyridamole, pentoxifylline, cilostazol), and (3) glycoprotein IIb-IIIa (eptifibatide). Gel-filtered platelets treated with these drugs were exposed for 10min to either constant shear stresses (30dyne/cm2 and 70dyne/cm2) or dynamic shear stress profiles extracted from simulated platelet trajectories through a cfVAD (Micromed DeBakey). Platelet activation state (PAS) was measured using a modified prothrombinase-based assay, with drug efficacy quantified based on PAS reduction compared to untreated controls. RESULTS AND CONCLUSIONS Significant PAS reduction was observed for all drugs after exposure to 30dyne/cm2 constant shear stress, and all drugs but dipyridamole after exposure to the 30th percentile shear stress waveform of the cfVAD. However, only cilostazol was significantly effective after 70dyne/cm2 constant shear stress exposure, though no significant reduction was observed upon exposure to median shear stress conditions in the cfVAD. These results, coupled with the persistence of reported clinical thrombotic complication, suggest the need for the development of new classes of drugs that are especially designed to mitigate thrombosis in cfVAD patients, while reducing or eliminating the risk of bleeding.
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Affiliation(s)
- Lorenzo Valerio
- Department of Electronics, Information, and Bioengineering, Politecnico di Milano, Milan, Italy; Department of Cardiothoracic Anesthesia and Intensive Care, Istituto Scientifico San Raffaele, Milan, Italy
| | - Jawaad Sheriff
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Phat L Tran
- Department of Biomedical Engineering, Sarver Heart Center, University of Arizona, Tucson, AZ, USA
| | - William Brengle
- Department of Biomedical Engineering, Sarver Heart Center, University of Arizona, Tucson, AZ, USA
| | - Alberto Redaelli
- Department of Electronics, Information, and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Gianfranco B Fiore
- Department of Electronics, Information, and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Federico Pappalardo
- Department of Cardiothoracic Anesthesia and Intensive Care, Istituto Scientifico San Raffaele, Milan, Italy
| | - Danny Bluestein
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Marvin J Slepian
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA; Department of Biomedical Engineering, Sarver Heart Center, University of Arizona, Tucson, AZ, USA; Department of Medicine, Sarver Heart Center, University of Arizona, Tucson, AZ, USA.
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Dimasi A, Rasponi M, Consolo F, Fiore GB, Bluestein D, Slepian MJ, Redaelli A. Microfludic platforms for the evaluation of anti-platelet agent efficacy under hyper-shear conditions associated with ventricular assist devices. Med Eng Phys 2017; 48:31-38. [PMID: 28869117 PMCID: PMC5610105 DOI: 10.1016/j.medengphy.2017.08.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 07/31/2017] [Accepted: 08/09/2017] [Indexed: 01/06/2023]
Abstract
Thrombus formation is a major adverse event affecting patients implanted with ventricular assist devices (VADs). Despite anti-thrombotic drug administration, thrombotic events remain frequent within the first year post-implantation. Platelet activation (PA) is an essential process underling thrombotic adverse events in VAD systems. Indeed, abnormal shear forces, correlating with specific flow trajectories of VADs, are strong agonists mediating PA. To date, the ability to determine efficacy of anti-platelet (AP) agents under shear stress conditions is limited. Here, we present a novel microfluidic platform designed to replicate shear stress patterns of a clinical VAD, and use it to compare the efficacy of two AP agents in vitro. Gel-filtered platelets were incubated with i) acetylsalicylic acid (ASA) and ii) ticagrelor, at two different concentrations (ASA: 125 and 250 µM; ticagrelor: 250 and 500 nM) and were circulated in the VAD-emulating microfluidic platform using a peristaltic pump. GFP was collected after 4 and 52 repetitions of exposure to the VAD shear pattern and tested for shear-mediated PA. ASA significantly inhibited PA only at 2-fold higher concentration (250 µM) than therapeutic dose (125 µM). The effect of ticagrelor was not dependent on drug concentration, and did not show significant inhibition with respect to untreated control. This study demonstrates the potential use of microfluidic platforms as means of testing platelet responsiveness and AP drug efficacy under complex and realistic VAD-like shear stress conditions.
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Affiliation(s)
- Annalisa Dimasi
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Via Golgi 39, 20133, Milano, Italy.
| | - Marco Rasponi
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Via Golgi 39, 20133, Milano, Italy
| | - Filippo Consolo
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Via Golgi 39, 20133, Milano, Italy; Anesthesia and Cardiothoracic Intensive Care Unit. Università Vita Salute, San Raffaele Scientific Institute, Via Olgettina 58, 20132, Milano, Italy
| | - Gianfranco B Fiore
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Via Golgi 39, 20133, Milano, Italy
| | - Danny Bluestein
- Department of Biomedical Engineering, StonyBrook University, Stony Brook, NY, USA
| | - Marvin J Slepian
- Department of Biomedical Engineering, StonyBrook University, Stony Brook, NY, USA; Department of Medicine and Biomedical Engineering, Sarver Heart Center, University of Arizona, 1501 N Campbell Ave, 85724, Tucson, AZ, USA
| | - Alberto Redaelli
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Via Golgi 39, 20133, Milano, Italy
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The Effect of Inflow Cannula Length on the Intraventricular Flow Field: An In Vitro Flow Visualization Study Using the Evaheart Left Ventricular Assist Device. ASAIO J 2017; 63:592-603. [DOI: 10.1097/mat.0000000000000559] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
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Consolo F, Sheriff J, Gorla S, Magri N, Bluestein D, Pappalardo F, Slepian MJ, Fiore GB, Redaelli A. High Frequency Components of Hemodynamic Shear Stress Profiles are a Major Determinant of Shear-Mediated Platelet Activation in Therapeutic Blood Recirculating Devices. Sci Rep 2017; 7:4994. [PMID: 28694489 PMCID: PMC5503983 DOI: 10.1038/s41598-017-05130-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 05/25/2017] [Indexed: 11/25/2022] Open
Abstract
We systematically analyzed the relative contributions of frequency component elements of hemodynamic shear stress waveforms encountered in cardiovascular blood recirculating devices as to overall platelet activation over time. We demonstrated that high frequency oscillations are the major determinants for priming, triggering and yielding activated “prothrombotic behavior” for stimulated platelets, even if the imparted shear stress has low magnitude and brief exposure time. Conversely, the low frequency components of the stress signal, with limited oscillations over time, did not induce significant activation, despite being of high magnitude and/or exposure time. In vitro data were compared with numerical predictions computed according to a recently proposed numerical model of shear-mediated platelet activation. The numerical model effectively resolved the correlation between platelet activation and the various frequency components examined. However, numerical predictions exhibited a different activation trend compared to experimental results for different time points of a stress activation sequence. With this study we provide a more fundamental understanding for the mechanobiological responsiveness of circulating platelets to the hemodynamic environment of cardiovascular devices, and the importance of these environments in mediating life-threatening thromboembolic complications associated with shear-mediated platelet activation. Experimental data will guide further optimization of the thromboresistance of cardiovascular implantable therapeutic devices.
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Affiliation(s)
- Filippo Consolo
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy. .,Anesthesia and Cardiothoracic Intensive Care, IRCCS San Raffaele Scientific Institute, Vita Salute University, Milan, Italy.
| | - Jawaad Sheriff
- Department of Biomedical Engineering, Stony Brook University, New York, USA
| | - Silvia Gorla
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Nicolò Magri
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Danny Bluestein
- Department of Biomedical Engineering, Stony Brook University, New York, USA
| | - Federico Pappalardo
- Anesthesia and Cardiothoracic Intensive Care, IRCCS San Raffaele Scientific Institute, Vita Salute University, Milan, Italy
| | - Marvin J Slepian
- Department of Biomedical Engineering, Stony Brook University, New York, USA.,Department of Medicine and Biomedical Engineering, Sarver Heart Center, The University of Arizona, Arizona, USA
| | - Gianfranco B Fiore
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Alberto Redaelli
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
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46
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Bluestein D. Utilizing Computational Fluid Dynamics in Cardiovascular Engineering and Medicine-What You Need to Know. Its Translation to the Clinic/Bedside. Artif Organs 2017; 41:117-121. [PMID: 28181302 DOI: 10.1111/aor.12914] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Danny Bluestein
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, 11794-8181, USA
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47
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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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48
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Wu WT, Yang F, Wu J, Aubry N, Massoudi M, Antaki JF. High fidelity computational simulation of thrombus formation in Thoratec HeartMate II continuous flow ventricular assist device. Sci Rep 2016; 6:38025. [PMID: 27905492 PMCID: PMC5131309 DOI: 10.1038/srep38025] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 11/04/2016] [Indexed: 12/22/2022] Open
Abstract
Continuous flow ventricular assist devices (cfVADs) provide a life-saving therapy for severe heart failure. However, in recent years, the incidence of device-related thrombosis (resulting in stroke, device-exchange surgery or premature death) has been increasing dramatically, which has alarmed both the medical community and the FDA. The objective of this study was to gain improved understanding of the initiation and progression of thrombosis in one of the most commonly used cfVADs, the Thoratec HeartMate II. A computational fluid dynamics simulation (CFD) was performed using our recently updated mathematical model of thrombosis. The patterns of deposition predicted by simulation agreed well with clinical observations. Furthermore, thrombus accumulation was found to increase with decreased flow rate, and can be completely suppressed by the application of anticoagulants and/or improvement of surface chemistry. To our knowledge, this is the first simulation to explicitly model the processes of platelet deposition and thrombus growth in a continuous flow blood pump and thereby replicate patterns of deposition observed clinically. The use of this simulation tool over a range of hemodynamic, hematological, and anticoagulation conditions could assist physicians to personalize clinical management to mitigate the risk of thrombosis. It may also contribute to the design of future VADs that are less thrombogenic.
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Affiliation(s)
- Wei-Tao Wu
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | - Fang Yang
- Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, Jilin University, Changchun 130012, China
| | - Jingchun Wu
- Advanced Design Optimization, Irvine, CA, 92618, USA
| | - Nadine Aubry
- Department of Mechanical Engineering, Northeastern University, Boston, MA, 02115, USA
| | - Mehrdad Massoudi
- U. S. Department of Energy, National Energy Technology Laboratory (NETL), PA, 15236, USA
| | - James F. Antaki
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
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Modeling the Link between Left Ventricular Flow and Thromboembolic Risk Using Lagrangian Coherent Structures. FLUIDS 2016. [DOI: 10.3390/fluids1040038] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Slepian MJ, Sheriff J, Hutchinson M, Tran P, Bajaj N, Garcia JGN, Scott Saavedra S, Bluestein D. Shear-mediated platelet activation in the free flow: Perspectives on the emerging spectrum of cell mechanobiological mechanisms mediating cardiovascular implant thrombosis. J Biomech 2016; 50:20-25. [PMID: 27887727 DOI: 10.1016/j.jbiomech.2016.11.016] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 11/02/2016] [Indexed: 12/13/2022]
Abstract
Shear-mediated platelet activation (SMPA) is central in thrombosis of implantable cardiovascular therapeutic devices. Despite the morbidity and mortality associated with thrombosis of these devices, our understanding of mechanisms operative in SMPA, particularly in free flowing blood, remains limited. Herein we present and discuss a range of emerging mechanisms for consideration for "free flow" activation under supraphysiologic shear. Further definition and manipulation of these mechanisms will afford opportunities for novel pharmacologic and mechanical strategies to limit SMPA and enhance overall implant device safety.
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Affiliation(s)
- Marvin J Slepian
- Departments of Medicine and Biomedical Engineering, University of Arizona, Tucson, AZ 85721, United States; Department of Biomedical Engineering, Stony Brook University, NY 11794, United States.
| | - Jawaad Sheriff
- Department of Biomedical Engineering, Stony Brook University, NY 11794, United States
| | - Marcus Hutchinson
- Departments of Medicine and Biomedical Engineering, University of Arizona, Tucson, AZ 85721, United States
| | - Phat Tran
- Departments of Medicine and Biomedical Engineering, University of Arizona, Tucson, AZ 85721, United States
| | - Naing Bajaj
- Departments of Medicine and Biomedical Engineering, University of Arizona, Tucson, AZ 85721, United States
| | - Joe G N Garcia
- Departments of Medicine and Biomedical Engineering, University of Arizona, Tucson, AZ 85721, United States
| | - S Scott Saavedra
- Departments of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, United States
| | - Danny Bluestein
- Department of Biomedical Engineering, Stony Brook University, NY 11794, United States
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