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Lopez-Santana G, De Rosis A, Grant S, Venkateswaran R, Keshmiri A. Enhancing the implantation of mechanical circulatory support devices using computational simulations. Front Bioeng Biotechnol 2024; 12:1279268. [PMID: 38737533 PMCID: PMC11084291 DOI: 10.3389/fbioe.2024.1279268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 04/08/2024] [Indexed: 05/14/2024] Open
Abstract
Introduction: Patients with end-stage heart failure (HF) may need mechanical circulatory support such as a left ventricular assist device (LVAD). However, there are a range of complications associated with LVAD including aortic regurgitation (AR) and thrombus formation. This study assesses whether the risk of developing aortic conditions can be minimised by optimising LVAD implantation technique. Methods: In this work, we evaluate the aortic flow patterns produced under different geometrical parameters for the anastomosis of the outflow graft (OG) to the aorta using computational fluid dynamics (CFD). A three-dimensional aortic model is created and the HeartMate III OG positioning is simulated by modifying (i) the distance from the anatomic ventriculo-arterial junction (AVJ) to the OG, (ii) the cardinal position around the aorta, and (iii) the angle between the aorta and the OG. The continuous LVAD flow and the remnant native cardiac cycle are used as inlet boundaries and the three-element Windkessel model is applied at the pressure outlets. Results: The analysis quantifies the impact of OG positioning on different haemodynamic parameters, including velocity, wall shear stress (WSS), pressure, vorticity and turbulent kinetic energy (TKE). We find that WSS on the aortic root (AoR) is around two times lower when the OG is attached to the coronal side of the aorta using an angle of 45° ± 10° at a distance of 55 mm. Discussion: The results show that the OG placement may significantly influence the haemodynamic patterns, demonstrating the potential application of CFD for optimising OG positioning to minimise the risk of cardiovascular complications after LVAD implantation.
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Affiliation(s)
- Gabriela Lopez-Santana
- School of Engineering, The University of Manchester, Manchester, United Kingdom
- Department of Cardiothoracic Transplantation and Mechanical Circulatory Support, Wythenshawe Hospital, Manchester, United Kingdom
| | - Alessandro De Rosis
- School of Engineering, The University of Manchester, Manchester, United Kingdom
| | - Stuart Grant
- Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Rajamiyer Venkateswaran
- Department of Cardiothoracic Transplantation and Mechanical Circulatory Support, Wythenshawe Hospital, Manchester, United Kingdom
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Amir Keshmiri
- School of Engineering, The University of Manchester, Manchester, United Kingdom
- Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom
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Tadokoro N, Tonai K, Kainuma S, Kawamoto N, Suzuki K, Hirayama M, Fukushima S. Management of aortic valve insufficiency in patients with continuous-flow left ventricular assist device: a republication of the review published in Japanese Journal of Artificial Organs. J Artif Organs 2024:10.1007/s10047-024-01439-x. [PMID: 38594483 DOI: 10.1007/s10047-024-01439-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 02/21/2024] [Indexed: 04/11/2024]
Abstract
Since 2011, implantable ventricular assist devices have been a standard treatment for severe heart failure alongside heart transplantation in Japan. However, the limited availability of donors has led to a prolonged wait for transplants, now averaging 1719 days, intensifying the issue of aortic insufficiency in patients with continuous flow ventricular assist devices. These devices limit the opening of the aortic valve, leading to sustained closure and increased shear stress, which accelerates valve degradation. Risk factors for aortic insufficiency include having a smaller body surface area, being of advanced age, and the presence of mild aortic insufficiency prior to device implantation. In patients presenting with mild or moderate aortic regurgitation at the time of ventricular assist device implantation, interventions such as aortic valve repair or bioprosthetic valve replacement are performed with the aim of halting its progression. The choice of surgical procedure should be tailored to each patient's individual condition. The management of de novo aortic insufficiency in patients with continuous flow ventricular assist devices remains challenging, with no clear consensus on when to intervene. Interventions for significant aortic insufficiency typically consider the patient's symptoms and aortic insufficiency severity. De novo aortic insufficiency progression in continuous flow ventricular assist devices patients necessitates careful monitoring and intervention based on individual patient assessments and valve condition. This review was created based on a translation of the Japanese review written in the Japanese Journal of Artificial Organs in 2023 (Vol. 52, No. 1, pp. 77-80), with some modifications.
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Affiliation(s)
- Naoki Tadokoro
- Department of Cardiovascular Surgery, National Cerebral and Cardiovascular Center, 6-7 Kishibeshinmachi, Suita, Osaka, 564-8565, Japan.
| | - Kohei Tonai
- Department of Cardiovascular Surgery, National Cerebral and Cardiovascular Center, 6-7 Kishibeshinmachi, Suita, Osaka, 564-8565, Japan
| | - Satoshi Kainuma
- Department of Cardiovascular Surgery, National Cerebral and Cardiovascular Center, 6-7 Kishibeshinmachi, Suita, Osaka, 564-8565, Japan
| | - Naonori Kawamoto
- Department of Cardiovascular Surgery, National Cerebral and Cardiovascular Center, 6-7 Kishibeshinmachi, Suita, Osaka, 564-8565, Japan
| | - Kota Suzuki
- Department of Cardiovascular Surgery, National Cerebral and Cardiovascular Center, 6-7 Kishibeshinmachi, Suita, Osaka, 564-8565, Japan
| | - Masaya Hirayama
- Department of Cardiovascular Surgery, National Cerebral and Cardiovascular Center, 6-7 Kishibeshinmachi, Suita, Osaka, 564-8565, Japan
| | - Satsuki Fukushima
- Department of Cardiovascular Surgery, National Cerebral and Cardiovascular Center, 6-7 Kishibeshinmachi, Suita, Osaka, 564-8565, Japan.
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3
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Dual SA, Cowger J, Roche E, Nayak A. The Future of Durable Mechanical Circulatory Support: Emerging Technological Innovations and Considerations to Enable Evolution of the Field. J Card Fail 2024; 30:596-609. [PMID: 38431185 DOI: 10.1016/j.cardfail.2024.01.011] [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: 12/22/2023] [Revised: 01/25/2024] [Accepted: 01/26/2024] [Indexed: 03/05/2024]
Abstract
The field of durable mechanical circulatory support (MCS) has undergone an incredible evolution over the past few decades, resulting in significant improvements in longevity and quality of life for patients with advanced heart failure. Despite these successes, substantial opportunities for further improvements remain, including in pump design and ancillary technology, perioperative and postoperative management, and the overall patient experience. Ideally, durable MCS devices would be fully implantable, automatically controlled, and minimize the need for anticoagulation. Reliable and long-term total artificial hearts for biventricular support would be available; and surgical, perioperative, and postoperative management would be informed by the individual patient phenotype along with computational simulations. In this review, we summarize emerging technological innovations in these areas, focusing primarily on innovations in late preclinical or early clinical phases of study. We highlight important considerations that the MCS community of clinicians, engineers, industry partners, and venture capital investors should consider to sustain the evolution of the field.
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Affiliation(s)
- Seraina A Dual
- KTH Royal Institute of Technology, Department of Biomedical Engineering and Health Systems, Stockholm, Sweden
| | | | - Ellen Roche
- Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Aditi Nayak
- Baylor University Medical Center, Dallas, Texas.
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Zambrano BA, Wilson SI, Zook S, Vekaria B, Moreno MR, Kassi M. Computational investigation of outflow graft variation impact on hemocompatibility profile in LVADs. Artif Organs 2024; 48:375-385. [PMID: 37962282 DOI: 10.1111/aor.14679] [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: 04/24/2023] [Revised: 10/17/2023] [Accepted: 10/29/2023] [Indexed: 11/15/2023]
Abstract
BACKGROUND Hemocompatibility-related adverse events (HRAE) occur commonly in patients with left ventricular assist devices (LVADs) and add to morbidity and mortality. It is unclear whether the outflow graft orientation can impact flow conditions leading to HRAE. This study presents a simulation-based approach using exact patient anatomy from medical images to investigate the influence of outflow cannula orientation in modulating flow conditions leading to HRAEs. METHODS A 3D model of a proximal aorta and outflow graft was reconstructed from a computed tomography (CT) scan of an LVAD patient and virtually modified to model multiple cannula orientations (n = 10) by varying polar (cranio-caudal) (n = 5) and off-set (anterior-posterior) (n = 2) angles. Time-dependent computational flow simulations were then performed for each anatomical orientation. Qualitative and quantitative hemodynamics metrics of thrombogenicity including time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), endothelial cell platelet activation potential (ECAP), particle residence time (PRT), and platelet activation potential (PLAP) were analyzed. RESULTS Within the simulations performed, endothelial cell activation potential (ECAP) and particle residence time (PRT) were found to be lowest with a polar angle of 85°, regardless of offset angle. However, polar angles that produced parameters at levels least associated with thrombosis varied when the offset angle was changed from 0° to 12°. For offset angles of 0° and 12° respectively, flow shear was lowest at 65° and 75°, time averaged wall shear stress (TAWSS) was highest at 85° and 35°, and platelet activation potential (PLAP) was lowest at 65° and 45°. CONCLUSION This study suggests that computational fluid dynamic modeling based on patient-specific anatomy can be a powerful analytical tool when identifying optimal positioning of an LVAD. Contrary to previous work, our findings suggest that there may be an "ideal" outflow cannula for each individual patient based on a CFD-based hemocompatibility profile.
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Affiliation(s)
- Byron A Zambrano
- J. Mike Walker '66 Department of Mechanical Engineering, Texas A&M University, College Station, Texas, USA
| | - Shannon I Wilson
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas, USA
| | - Salma Zook
- Houston Methodist, Department of Cardiology, Houston Methodist Research Hospital, Houston, Texas, USA
| | - Bansi Vekaria
- Houston Methodist, Department of Cardiology, Houston Methodist Research Hospital, Houston, Texas, USA
| | - Michael R Moreno
- J. Mike Walker '66 Department of Mechanical Engineering, Texas A&M University, College Station, Texas, USA
| | - Mahwash Kassi
- Houston Methodist, Department of Cardiology, Houston Methodist Research Hospital, Houston, Texas, USA
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Wang X, Lu Y, Liu Z, Rubino AS, Perek B, Wendt D, Pisano C, Goudot G, Deutsch O, Liu X. Transcatheter aortic valve replacement in the management of aortic insufficiency secondary to left ventricular assist device implantation: a case report. J Thorac Dis 2023; 15:7130-7139. [PMID: 38249889 PMCID: PMC10797376 DOI: 10.21037/jtd-23-1642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 12/08/2023] [Indexed: 01/23/2024]
Abstract
Background Left ventricular assist device (LVAD) is considered either a destination therapy for patients with end-stage heart failure or heart transplantation bridging. LVAD implantation often causes aortic insufficiency (AI), which requires aortic valve repair. However, severe acute AI does not respond well to medication, and re-operation means higher risk to the patients; the most effective therapeutic strategies for LVAD-induced AI still need further exploration. In this report, we present the first described case of new-onset, severe LVAD-induced AI in China with a patient who underwent transcatheter aortic valve replacement (TAVR) and achieved significant improvement in functional capacity and symptoms with lower operation risk. Case Description A 55-year-old male patient was diagnosed with dilated cardiomyopathy for 14 years. The effect of the medication gradually deteriorated, LVAD (HeartCon®) was implanted one year earlier. The patient complained of intermittent chest tightness for one week, which had been aggravated for two days before hospitalization. Echocardiographic findings revealed new-onset, severe LVAD-induced AI. TAVR was performed with a self-expandable stent-valve (TAV30, Vitaflow Liberty). Within minutes, the patient recovered with rapid disappearance of chest tightness and stable vital signs. Before discharge, the position of the artificial valve was fixed without incomplete closure nor thrombus attachment, yielding a left ventricular ejection fraction (LVEF) of 35%. The patient was hospitalized for 38 days, and followed up with outpatient treatment, the condition was stable until 19 June 2023. Conclusions TAVR could be an effective, safe, and less invasive means of restoring ejection fraction for patients with a LVAD who develop severe AI.
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Affiliation(s)
- Xiaodong Wang
- Cardiovascular Department, TEDA International Cardiovascular Hospital, Tianjin, China
| | - Yujie Lu
- Cardiovascular Department, TEDA International Cardiovascular Hospital, Tianjin, China
| | - Zhigang Liu
- Cardiac Surgery, TEDA International Cardiovascular Hospital, Tianjin, China
| | - Antonino S. Rubino
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, AORN dei Colli, Cardiac Surgery, Vincenzo Monaldi Hospital, Naples, Italy
| | - Bartlomiej Perek
- Department of Cardiac Surgery and Transplantology, Poznan University of Medical Sciences, Poznan, Poland
| | - Daniel Wendt
- Department of Thoracic and Cardiovascular Surgery, Westgerman Heart and Vascular Center, Essen, Germany
| | - Calogera Pisano
- Cardiac Surgery Unit, Department of Surgical Science, Tor Vergata University Hospital, Rome, Italy
| | - Guillaume Goudot
- Vascular Medicine Department, Hôpital Européen Georges Pompidou, AP-HP, Université Paris Cité, INSERM U970 PARCC, Paris, France
| | - Oliver Deutsch
- Department of Cardiovascular Surgery, German Heart Centre Munich, Munich, Germany
| | - Xiaocheng Liu
- Cardiac Surgery, TEDA International Cardiovascular Hospital, Tianjin, China
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Gu Z, Ong CW, Mi Y, Seetharaman A, Ling RR, Ramanathan K, Leo HL. The Impact of Left Ventricular Assist Device Outflow Graft Positioning on Aortic Hemodynamics: Improving Flow Dynamics to Mitigate Aortic Insufficiency. Biomimetics (Basel) 2023; 8:465. [PMID: 37887596 PMCID: PMC10604423 DOI: 10.3390/biomimetics8060465] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 08/27/2023] [Accepted: 09/20/2023] [Indexed: 10/28/2023] Open
Abstract
Heart failure is a global health concern with significant implications for healthcare systems. Left ventricular assist devices (LVADs) provide mechanical support for patients with severe heart failure. However, the placement of the LVAD outflow graft within the aorta has substantial implications for hemodynamics and can lead to aortic insufficiency during long-term support. This study employs computational fluid dynamics (CFD) simulations to investigate the impact of different LVAD outflow graft locations on aortic hemodynamics. The introduction of valve morphology within the aorta geometry allows for a more detailed analysis of hemodynamics at the aortic root. The results demonstrate that the formation of vortex rings and subsequent vortices during the high-velocity jet flow from the graft interacted with the aortic wall. Time-averaged wall shear stress (TAWSS) and oscillatory shear index (OSI) indicate that modification of the outflow graft location changes mechanical states within the aortic wall and aortic valve. Among the studied geometric factors, both the height and inclination angle of the LVAD outflow graft are important in controlling retrograde flow to the aortic root, while the azimuthal angle primarily determines the rotational direction of blood flow in the aortic arch. Thus, precise positioning of the LVAD outflow graft emerges as a critical factor in optimizing patient outcomes by improving the hemodynamic environment.
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Affiliation(s)
- Zhuohan Gu
- Department of Biomedical Engineering, National University of Singapore, Singapore 119077, Singapore; (Z.G.); (A.S.)
| | - Chi Wei Ong
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 639798, Singapore
| | - Yongzhen Mi
- Institute of High Performance Computing (IHPC), Agency for Science, Technology and Research (A*STAR), Singapore 138632, Singapore;
| | - Ashwin Seetharaman
- Department of Biomedical Engineering, National University of Singapore, Singapore 119077, Singapore; (Z.G.); (A.S.)
| | - Ryan Ruiyang Ling
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore (K.R.)
| | - Kollengode Ramanathan
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore (K.R.)
- Cardiothoracic Intensive Care Unit, National University Heart Centre Singapore, National Univeristy Health System, Singapore 119228, Singapore
| | - Hwa Liang Leo
- Department of Biomedical Engineering, National University of Singapore, Singapore 119077, Singapore; (Z.G.); (A.S.)
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Wilson SI, Ingram KE, Oh A, Moreno MR, Kassi M. The role of innovative modeling and imaging techniques in improving outcomes in patients with LVAD. Front Cardiovasc Med 2023; 10:1248300. [PMID: 37692033 PMCID: PMC10484111 DOI: 10.3389/fcvm.2023.1248300] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 08/10/2023] [Indexed: 09/12/2023] Open
Abstract
Heart failure remains a significant cause of mortality in the United States and around the world. While organ transplantation is acknowledged as the gold standard treatment for end stage heart failure, supply is limited, and many patients are treated with left ventricular assist devices (LVADs). LVADs extend and improve patients' lives, but they are not without their own complications, particularly the hemocompatibility related adverse events (HRAE) including stroke, bleeding and pump thrombosis. Mainstream imaging techniques currently in use to assess appropriate device function and troubleshoot complications, such as echocardiography and cardiac computed tomography, provide some insight but do not provide a holistic understanding of pump induced flow alterations that leads to HRAEs. In contrast, there are technologies restricted to the benchtop-such as computational fluid dynamics and mock circulatory loops paired with methods like particle image velocimetry-that can assess flow metrics but have not been optimized for clinical care. In this review, we outline the potential role and current limitations of converging available technologies to produce novel imaging techniques, and the potential utility in evaluating hemodynamic flow to determine whether LVAD patients may be at higher risk of HRAEs. This addition to diagnostic and monitoring capabilities could improve prevention and treatment of LVAD-induced complications in heart failure patients.
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Affiliation(s)
- Shannon I. Wilson
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, United States
| | - Katelyn E. Ingram
- DeBakey Heart and Vascular- Heart Center Research, Houston Methodist Research Institute, Houston, TX, United States
| | - Albert Oh
- School of Engineering Medicine, Texas A&M University, Houston, TX, United States
| | - Michael R. Moreno
- J. Mike Walker ‘66 Department of Mechanical Engineering, Texas A&M University, College Station, TX, United States
| | - Mahwash Kassi
- Cardiology, DeBakey Heart and Vascular, Houston Methodist Hospital, Houston, TX, United States
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Grinstein J, Belkin MN, Kalantari S, Bourque K, Salerno C, Pinney S. Adverse Hemodynamic Consequences of Continuous Left Ventricular Mechanical Support: JACC Review Topic of the Week. J Am Coll Cardiol 2023; 82:70-81. [PMID: 37380306 DOI: 10.1016/j.jacc.2023.04.045] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 04/11/2023] [Accepted: 04/14/2023] [Indexed: 06/30/2023]
Abstract
Left ventricular assist devices (LVADs) provide lifesaving therapy for patients with advanced heart failure. The recognition of pump thrombosis, stroke, and nonsurgical bleeding as hemocompatibility-related adverse events (HRAEs) led to pump design improvements and reduced adverse event rates. However, continuous flow can predispose patients to right-sided heart failure (RHF) and aortic insufficiency (AI), especially as patients live longer with their device. Given the hemodynamic contributions to AI and RHF, these comorbidities can be classified as hemodynamic-related events (HDREs). Hemodynamic-driven events are time dependent and often manifest later than HRAEs. This review examines the emerging strategies to mitigate HDREs, with a focus on defining best practices for AI and RHF. As we head into the next generation of LVAD technology, it is important to differentiate HDREs from HRAEs so that we can continue to advance the field and improve the true durability of the pump-patient continuum.
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Affiliation(s)
- Jonathan Grinstein
- Section of Cardiology, Department of Medicine, University of Chicago, Chicago, Illinois, USA.
| | - Mark N Belkin
- Section of Cardiology, Department of Medicine, University of Chicago, Chicago, Illinois, USA
| | - Sara Kalantari
- Section of Cardiology, Department of Medicine, University of Chicago, Chicago, Illinois, USA
| | - Kevin Bourque
- Heart Failure Division, Abbott, Burlington, Massachusetts, USA
| | - Christopher Salerno
- Section of Cardiac Surgery, Department of Surgery, University of Chicago, Chicago, Illinois, USA
| | - Sean Pinney
- Section of Cardiology, Department of Medicine, University of Chicago, Chicago, Illinois, USA
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Pham J, Wyetzner S, Pfaller MR, Parker DW, James DL, Marsden AL. svMorph: Interactive Geometry-Editing Tools for Virtual Patient-Specific Vascular Anatomies. J Biomech Eng 2023; 145:031001. [PMID: 36282508 PMCID: PMC9791670 DOI: 10.1115/1.4056055] [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: 05/06/2022] [Revised: 08/07/2022] [Indexed: 12/30/2022]
Abstract
We propose svMorph, a framework for interactive virtual sculpting of patient-specific vascular anatomic models. Our framework includes three tools for the creation of tortuosity, aneurysms, and stenoses in tubular vascular geometries. These shape edits are performed via geometric operations on the surface mesh and vessel centerline curves of the input model. The tortuosity tool also uses the physics-based Oriented Particles method, coupled with linear blend skinning, to achieve smooth, elastic-like deformations. Our tools can be applied separately or in combination to produce simulation-suitable morphed models. They are also compatible with popular vascular modeling software, such as simvascular. To illustrate our tools, we morph several image-based, patient-specific models to create a range of shape changes and simulate the resulting hemodynamics via three-dimensional, computational fluid dynamics. We also demonstrate the ability to quickly estimate the hemodynamic effects of the shape changes via the automated generation of associated zero-dimensional lumped-parameter models.
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Affiliation(s)
- Jonathan Pham
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305
| | - Sofia Wyetzner
- Department of Computer Science, Stanford University, Stanford, CA 94305
| | - Martin R Pfaller
- Department of Pediatrics, Stanford University, Stanford, CA 94305
| | - David W Parker
- Stanford Research Computing Center, Stanford University, Stanford, CA 94305
| | - Doug L James
- Department of Computer Science, Stanford University, Stanford, CA 94305
| | - Alison L Marsden
- Department of Bioengineering, Department of Pediatrics, Stanford University, Stanford, CA 94305
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Acharya D, Kazui T, Al Rameni D, Acharya T, Betterton E, Juneman E, Loyaga-Rendon R, Lotun K, Shetty R, Chatterjee A. Aortic valve disorders and left ventricular assist devices. Front Cardiovasc Med 2023; 10:1098348. [PMID: 36910539 PMCID: PMC9996073 DOI: 10.3389/fcvm.2023.1098348] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 02/02/2023] [Indexed: 02/25/2023] Open
Abstract
Aortic valve disorders are important considerations in advanced heart failure patients being evaluated for left ventricular assist devices (LVAD) and those on LVAD support. Aortic insufficiency (AI) can be present prior to LVAD implantation or develop de novo during LVAD support. It is usually a progressive disorder and can lead to impaired LVAD effectiveness and heart failure symptoms. Severe AI is associated with worsening hemodynamics, increased hospitalizations, and decreased survival in LVAD patients. Diagnosis is made with echocardiographic, device assessment, and/or catheterization studies. Standard echocardiographic criteria for AI are insufficient for accurate diagnosis of AI severity. Management of pre-existing AI includes aortic repair or replacement at the time of LVAD implant. Management of de novo AI on LVAD support is challenging with increased risks of repeat surgical intervention, and percutaneous techniques including transcatheter aortic valve replacement are assuming greater importance. In this manuscript, we provide a comprehensive approach to contemporary diagnosis and management of aortic valve disorders in the setting of LVAD therapy.
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Affiliation(s)
- Deepak Acharya
- Division of Cardiovascular Diseases, University of Arizona, Tucson, AZ, United States
| | - Toshinobu Kazui
- Division of Cardiovascular Surgery, University of Arizona, Tucson, AZ, United States
| | - Dina Al Rameni
- Division of Cardiovascular Surgery, University of Arizona, Tucson, AZ, United States
| | - Tushar Acharya
- Division of Cardiovascular Diseases, University of Arizona, Tucson, AZ, United States
| | - Edward Betterton
- Artificial Heart Program, University of Arizona, Tucson, AZ, United States
| | - Elizabeth Juneman
- Division of Cardiovascular Diseases, University of Arizona, Tucson, AZ, United States
| | | | - Kapildeo Lotun
- Division of Cardiology, Carondelet Medical Center, Tucson, AZ, United States
| | - Ranjith Shetty
- Division of Cardiology, Carondelet Medical Center, Tucson, AZ, United States
| | - Arka Chatterjee
- Division of Cardiovascular Diseases, University of Arizona, Tucson, AZ, United States
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García-Galindo A, Agujetas R, López-Mínguez JR, Ferrera C. Assessment of valve implantation in the descending aorta as an alternative for aortic regurgitation patients not treatable with conventional procedures. Biomech Model Mechanobiol 2022; 22:575-591. [PMID: 36550245 PMCID: PMC10097802 DOI: 10.1007/s10237-022-01665-3] [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: 09/15/2022] [Accepted: 12/02/2022] [Indexed: 12/24/2022]
Abstract
BACKGROUND Aortic Regurgitation (AR) produces the entrance of an abnormal amount of blood in the left ventricle. This disease is responsible for high morbidity and mortality worldwide and may be caused by an aortic valve dysfunction. Surgical and transcatheter aortic valve replacement (TAVR) are the current options for treating AR. They have replaced older procedures such as Hufnagel's one. However, some physicians have reconsidered this procedure as a less aggressive alternative for patients not eligible for surgical or TAVR. Although Hufnagel suggested a 75% regurgitation reduction when a valve is placed in the descending aorta, a quantification of this value has not been reported. METHODS In this paper, CFD/FSI numerical simulation is conducted on an idealized geometry. We quantify the effect of placing a bileaflet mechanical heart valve in the descending aorta on a moderate-severe AR case. A three-element Windkessel model is employed to prescribe pressure outlet boundary conditions. We calculate the resulting flow rates and pressures at the aorta and first-generation vessels. Moreover, we evaluate several indices to assess the improvement due to the valve introduction. RESULTS AND CONCLUSIONS Regurgitation fraction (RF) is reduced from 37.5% (without valve) to 18.0% (with valve) in a single cardiac cycle. This reduction clearly shows the remarkable efficacy of the rescued technique. It will further ameliorate the left ventricle function in the long-term. Moreover, the calculations show that the implantation in that location introduces fewer incompatibilities' risks than a conventional one. The proposed methodology can be extended to any particular conditions (pressure waveforms/geometry) and is designed to assess usual clinical parameters employed by physicians.
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Affiliation(s)
- A García-Galindo
- Departamento de Ingeniería Mecánica, Energética y de los Materiales and Instituto de Computación Científica Avanzada (ICCAEx), Universidad de Extremadura, E-06006, Badajoz, Spain
| | - R Agujetas
- Departamento de Ingeniería Mecánica, Energética y de los Materiales and Instituto de Computación Científica Avanzada (ICCAEx), Universidad de Extremadura, E-06006, Badajoz, Spain
| | - J R López-Mínguez
- Sección de Cardiologıa Intervencionista, Servicio de Cardiologıa, Hospital Universitario de Badajoz, Avda. de Elvas s/n, E-06006, Badajoz, Spain
| | - C Ferrera
- Departamento de Ingeniería Mecánica, Energética y de los Materiales and Instituto de Computación Científica Avanzada (ICCAEx), Universidad de Extremadura, E-06006, Badajoz, Spain.
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Ando M, Ono M. Concomitant or late aortic valve intervention and its efficacy for aortic insufficiency associated with continuous-flow left ventricular assist device implantation. Front Cardiovasc Med 2022; 9:1029984. [DOI: 10.3389/fcvm.2022.1029984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 10/31/2022] [Indexed: 11/17/2022] Open
Abstract
Moderate to severe aortic insufficiency (AI) in patients who underwent continuous-flow left ventricular assist device (CF-LVAD) implantation is a significant complication. According to the INTERMACS registry analysis, at least mild AI occurs in 55% of patients at 6 months after CF-LVAD implantation and moderate to severe AI is significantly associated with higher rates of re-hospitalization and mortality. The clinical implications of these data may underscore consideration of prophylactic aortic valve replacement, or repair, at the time of CF-LVAD implantation, particularly with expected longer duration of support and in patients with preexisting AI that is more than mild. More crucially, even if a native aortic valve is seemingly competent at the time of VAD implantation, we frequently find de novo AI as time goes by, potentially due to commissural fusion in the setting of inconsistent aortic valve opening or persistent valve closure caused by CF-LVAD support, that alters morphological and functional properties of innately competent aortic valves. Therefore, close monitoring of AI is mandatory, as the prognostic nature of its longitudinal progression is still unclear. Clearly, significant AI during VAD support warrants surgical intervention at the appropriate timing, especially in patients of destination therapy. Nonetheless, such an uncertainty in the progression of AI translates to a lack of consensus regarding the management of this untoward complication. In practice, proposed surgical options are aortic valve replacement, repair, closure, and more recently transcatheter aortic valve implantation or closure. Transcatheter approach is of course less invasive, however, its efficacy in terms of long-term outcome is limited. In this review, we summarize the recent evidence related to the pathophysiology and surgical treatment of AI associated with CF-LVAD implantation.
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Rodenas-Alesina E, Brahmbhatt DH, Rao V, Salvatori M, Billia F. Prediction, prevention, and management of right ventricular failure after left ventricular assist device implantation: A comprehensive review. Front Cardiovasc Med 2022; 9:1040251. [PMID: 36407460 PMCID: PMC9671519 DOI: 10.3389/fcvm.2022.1040251] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 10/18/2022] [Indexed: 08/26/2023] Open
Abstract
Left ventricular assist devices (LVADs) are increasingly common across the heart failure population. Right ventricular failure (RVF) is a feared complication that can occur in the early post-operative phase or during the outpatient follow-up. Multiple tools are available to the clinician to carefully estimate the individual risk of developing RVF after LVAD implantation. This review will provide a comprehensive overview of available tools for RVF prognostication, including patient-specific and right ventricle (RV)-specific echocardiographic and hemodynamic parameters, to provide guidance in patient selection during LVAD candidacy. We also offer a multidisciplinary approach to the management of early RVF, including indications and management of right ventricular assist devices in this setting to provide tools that help managing the failing RV.
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Affiliation(s)
- Eduard Rodenas-Alesina
- Mechanical Circulatory Support Program, Peter Munk Cardiac Center, University Health Network, Toronto, ON, Canada
- Ted Roger’s Center for Heart Research, University Health Network, Toronto, ON, Canada
- Department of Cardiology, Vall d’Hebron University Hospital, Barcelona, Spain
| | - Darshan H. Brahmbhatt
- Mechanical Circulatory Support Program, Peter Munk Cardiac Center, University Health Network, Toronto, ON, Canada
- Ted Roger’s Center for Heart Research, University Health Network, Toronto, ON, Canada
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Vivek Rao
- Mechanical Circulatory Support Program, Peter Munk Cardiac Center, University Health Network, Toronto, ON, Canada
- Ted Roger’s Center for Heart Research, University Health Network, Toronto, ON, Canada
| | - Marcus Salvatori
- Department of Anesthesia, University Health Network, Toronto, ON, Canada
| | - Filio Billia
- Mechanical Circulatory Support Program, Peter Munk Cardiac Center, University Health Network, Toronto, ON, Canada
- Ted Roger’s Center for Heart Research, University Health Network, Toronto, ON, Canada
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Dimarakis I, Callan P, Khorsandi M, Pal JD, Bravo CA, Mahr C, Keenan JE. Pathophysiology and management of valvular disease in patients with destination left ventricular assist devices. Front Cardiovasc Med 2022; 9:1029825. [PMID: 36407458 PMCID: PMC9669306 DOI: 10.3389/fcvm.2022.1029825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Accepted: 09/29/2022] [Indexed: 11/06/2022] Open
Abstract
Over the last two decades, implantable continuous flow left ventricular assist devices (LVAD) have proven to be invaluable tools for the management of selected advanced heart failure patients, improving patient longevity and quality of life. The presence of concomitant valvular pathology, including that involving the tricuspid, mitral, and aortic valve, has important implications relating to the decision to move forward with LVAD implantation. Furthermore, the presence of concomitant valvular pathology often influences the surgical strategy for LVAD implantation. Concomitant valve repair or replacement is not uncommonly required in such circumstances, which increases surgical complexity and has demonstrated prognostic implications both short and longer term following LVAD implantation. Beyond the index operation, it is also well established that certain valvular pathologies may develop or worsen over time following LVAD support. The presence of pre-existing valvular pathology or that which develops following LVAD implant is of particular importance to the destination therapy LVAD patient population. As these patients are not expected to have the opportunity for heart transplantation in the future, optimization of LVAD support including ameliorating valvular disease is critical for the maximization of patient longevity and quality of life. As collective experience has grown over time, the ability of clinicians to effectively address concomitant valvular pathology in LVAD patients has improved in the pre-implant, implant, and post-implant phase, through both medical management and procedural optimization. Nevertheless, there remains uncertainty over many facets of concomitant valvular pathology in advanced heart failure patients, and the understanding of how to best approach these conditions in the LVAD patient population continues to evolve. Herein, we present a comprehensive review of the current state of the field relating to the pathophysiology and management of valvular disease in destination LVAD patients.
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Affiliation(s)
- Ioannis Dimarakis
- Division of Cardiothoracic Surgery, Department of Surgery, University of Washington Medical Center, Seattle, WA, United States
- Department of Cardiothoracic Transplantation, Manchester University Hospital NHS Foundation Trust, Wythenshawe Hospital, Manchester, United Kingdom
| | - Paul Callan
- Department of Cardiothoracic Transplantation, Manchester University Hospital NHS Foundation Trust, Wythenshawe Hospital, Manchester, United Kingdom
| | - Maziar Khorsandi
- Division of Cardiothoracic Surgery, Department of Surgery, University of Washington Medical Center, Seattle, WA, United States
| | - Jay D. Pal
- Division of Cardiothoracic Surgery, Department of Surgery, University of Washington Medical Center, Seattle, WA, United States
| | - Claudio A. Bravo
- Division of Cardiology, Department of Medicine, University of Washington Medical Center, Seattle, WA, United States
| | - Claudius Mahr
- Division of Cardiology, Department of Medicine, University of Washington Medical Center, Seattle, WA, United States
| | - Jeffrey E. Keenan
- Division of Cardiothoracic Surgery, Department of Surgery, University of Washington Medical Center, Seattle, WA, United States
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Kannojiya V, Das AK, Das PK. Effect of left ventricular assist device on the hemodynamics of a patient-specific left heart. Med Biol Eng Comput 2022; 60:1705-1721. [DOI: 10.1007/s11517-022-02572-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 04/07/2022] [Indexed: 11/28/2022]
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Shad R, Kaiser AD, Kong S, Fong R, Quach N, Bowles C, Kasinpila P, Shudo Y, Teuteberg J, Woo YJ, Marsden AL, Hiesinger W. Patient-Specific Computational Fluid Dynamics Reveal Localized Flow Patterns Predictive of Post-Left Ventricular Assist Device Aortic Incompetence. Circ Heart Fail 2021; 14:e008034. [PMID: 34139862 PMCID: PMC8292193 DOI: 10.1161/circheartfailure.120.008034] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Progressive aortic valve disease has remained a persistent cause of concern in patients with left ventricular assist devices. Aortic incompetence (AI) is a known predictor of both mortality and readmissions in this patient population and remains a challenging clinical problem. METHODS Ten left ventricular assist device patients with de novo aortic regurgitation and 19 control left ventricular assist device patients were identified. Three-dimensional models of patients' aortas were created from their computed tomography scans, following which large-scale patient-specific computational fluid dynamics simulations were performed with physiologically accurate boundary conditions using the SimVascular flow solver. RESULTS The spatial distributions of time-averaged wall shear stress and oscillatory shear index show no significant differences in the aortic root in patients with and without AI (mean difference, 0.67 dyne/cm2 [95% CI, -0.51 to 1.85]; P=0.23). Oscillatory shear index was also not significantly different between both groups of patients (mean difference, 0.03 [95% CI, -0.07 to 0.019]; P=0.22). The localized wall shear stress on the leaflet tips was significantly higher in the AI group than the non-AI group (1.62 versus 1.35 dyne/cm2; mean difference [95% CI, 0.15-0.39]; P<0.001), whereas oscillatory shear index was not significantly different between both groups (95% CI, -0.009 to 0.001; P=0.17). CONCLUSIONS Computational fluid dynamics serves a unique role in studying the hemodynamic features in left ventricular assist device patients where 4-dimensional magnetic resonance imaging remains unfeasible. Contrary to the widely accepted notions of highly disturbed flow, in this study, we demonstrate that the aortic root is a region of relatively stagnant flow. We further identified localized hemodynamic features in the aortic root that challenge our understanding of how AI develops in this patient population.
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Affiliation(s)
- Rohan Shad
- Department of Cardiothoracic Surgery, Stanford University School of Medicine
| | - Alexander D. Kaiser
- Institute for Computational and Mathematical Engineering, Stanford University
- Department of Pediatrics (Cardiology), Stanford University
| | - Sandra Kong
- Department of Cardiothoracic Surgery, Stanford University School of Medicine
| | - Robyn Fong
- Department of Cardiothoracic Surgery, Stanford University School of Medicine
| | - Nicolas Quach
- Department of Cardiothoracic Surgery, Stanford University School of Medicine
| | - Cayley Bowles
- Department of Cardiothoracic Surgery, Stanford University School of Medicine
| | - Patpilai Kasinpila
- Department of Cardiothoracic Surgery, Stanford University School of Medicine
| | - Yasuhiro Shudo
- Department of Cardiothoracic Surgery, Stanford University School of Medicine
| | - Jeffrey Teuteberg
- Department of Medicine (Cardiovascular Medicine), Stanford University
| | - Y Joseph Woo
- Department of Cardiothoracic Surgery, Stanford University School of Medicine
| | - Alison L. Marsden
- Department of Bioengineering, Stanford University
- Institute for Computational and Mathematical Engineering, Stanford University
- Department of Pediatrics (Cardiology), Stanford University
| | - William Hiesinger
- Department of Cardiothoracic Surgery, Stanford University School of Medicine
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Li S, Zimpfer D, Mahr C. Commentary: Transcending acceptable, moving toward optimal: Standardizing surgical configurations of ventricular assist device therapy. J Thorac Cardiovasc Surg 2020; 162:1566-1567. [PMID: 32534746 DOI: 10.1016/j.jtcvs.2020.05.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 04/30/2020] [Accepted: 05/04/2020] [Indexed: 11/26/2022]
Affiliation(s)
- Song Li
- Division of Cardiology, Department of Medicine, University of Washington, Seattle, Wash
| | - Daniel Zimpfer
- Department of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | - Claudius Mahr
- Division of Cardiology, Department of Medicine, University of Washington, Seattle, Wash.
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Loebe M, Ghodsizad A. Commentary: The feng shui of LVAD implantation. J Thorac Cardiovasc Surg 2020; 162:1564-1566. [PMID: 32534752 DOI: 10.1016/j.jtcvs.2020.04.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 04/16/2020] [Accepted: 04/17/2020] [Indexed: 10/24/2022]
Affiliation(s)
- Matthias Loebe
- Division of Thoracic Transplantation and Mechanical Support, Miami Transplant Institute, Miami, Fla.
| | - Ali Ghodsizad
- Division of Thoracic Transplantation and Mechanical Support, Miami Transplant Institute, Miami, Fla
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