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Kong F, Stocker S, Choi PS, Ma M, Ennis DB, Marsden A. SDF4CHD: Generative Modeling of Cardiac Anatomies with Congenital Heart Defects. ArXiv 2023:arXiv:2311.00332v2. [PMID: 37961745 PMCID: PMC10635288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Congenital heart disease (CHD) encompasses a spectrum of cardiovascular structural abnormalities, often requiring customized treatment plans for individual patients. Computational modeling and analysis of these unique cardiac anatomies can improve diagnosis and treatment planning and may ultimately lead to improved outcomes. Deep learning (DL) methods have demonstrated the potential to enable efficient treatment planning by automating cardiac segmentation and mesh construction for patients with normal cardiac anatomies. However, CHDs are often rare, making it challenging to acquire sufficiently large patient cohorts for training such DL models. Generative modeling of cardiac anatomies has the potential to fill this gap via the generation of virtual cohorts; however, prior approaches were largely designed for normal anatomies and cannot readily capture the significant topological variations seen in CHD patients. Therefore, we propose a type- and shape-disentangled generative approach suitable to capture the wide spectrum of cardiac anatomies observed in different CHD types and synthesize differently shaped cardiac anatomies that preserve the unique topology for specific CHD types. Our DL approach represents generic whole heart anatomies with CHD type-specific abnormalities implicitly using signed distance fields (SDF) based on CHD type diagnosis, which conveniently captures divergent anatomical variations across different types and represents meaningful intermediate CHD states. To capture the shape-specific variations, we then learn invertible deformations to morph the learned CHD type-specific anatomies and reconstruct patient-specific shapes. Our approach has the potential to augment the image-segmentation pairs for rarer CHD types for cardiac segmentation and generate cohorts of CHD cardiac meshes for computational simulation.
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Affiliation(s)
- Fanwei Kong
- Department of Pediatrics, Cardiovascular Institute, Stanford University, Stanford
| | - Sascha Stocker
- Department of Radiology, Stanford University, Stanford
- Institute for Biomedical Engineering, ETH Zurich and University Zurich, Zurich
| | - Perry S Choi
- Department of Cardiothoracic Surgery, Stanford University, Stanford
| | - Michael Ma
- Department of Cardiothoracic Surgery, Stanford University, Stanford
| | - Daniel B Ennis
- Department of Radiology, Cardiovascular Institute, Stanford University, Stanford
| | - Alison Marsden
- Department of Bioengineering, Department of Mechanical Engineering, Department of Pediatrics, Stanford University, Stanford
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Marsden A. Letter from Ofcom. J Public Health (Oxf) 2023; 45:e614. [PMID: 37302852 DOI: 10.1093/pubmed/fdad064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Indexed: 06/13/2023] Open
Affiliation(s)
- Alison Marsden
- Ofcom, Riverside House, 2a Southwark Bridge Road, London SE1 9HA, UK
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Marsden A. Correspondence with Ofcom. J Public Health (Oxf) 2023; 45:e617. [PMID: 37302854 DOI: 10.1093/pubmed/fdad066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 02/04/2023] [Indexed: 06/13/2023] Open
Affiliation(s)
- Alison Marsden
- Ofcom, Riverside House, 2a Southwark Bridge Road, London SE1 9HA, UK
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Marsden A. Correspondence with Ofcom. J Public Health (Oxf) 2023; 45:e618. [PMID: 37302853 DOI: 10.1093/pubmed/fdad067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Indexed: 06/13/2023] Open
Affiliation(s)
- Alison Marsden
- Director, Standards and Audience Protection, Broadcasting and Online Content, Ofcom, UK
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Sexton ZA, Hudson AR, Herrmann JE, Shiwarski DJ, Pham J, Szafron JM, Wu SM, Skylar-Scott M, Feinberg AW, Marsden A. Rapid model-guided design of organ-scale synthetic vasculature for biomanufacturing. ArXiv 2023:arXiv:2308.07586v1. [PMID: 37645046 PMCID: PMC10462165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Our ability to produce human-scale bio-manufactured organs is critically limited by the need for vascularization and perfusion. For tissues of variable size and shape, including arbitrarily complex geometries, designing and printing vasculature capable of adequate perfusion has posed a major hurdle. Here, we introduce a model-driven design pipeline combining accelerated optimization methods for fast synthetic vascular tree generation and computational hemodynamics models. We demonstrate rapid generation, simulation, and 3D printing of synthetic vasculature in complex geometries, from small tissue constructs to organ scale networks. We introduce key algorithmic advances that all together accelerate synthetic vascular generation by more than 230 -fold compared to standard methods and enable their use in arbitrarily complex shapes through localized implicit functions. Furthermore, we provide techniques for joining vascular trees into watertight networks suitable for hemodynamic CFD and 3D fabrication. We demonstrate that organ-scale vascular network models can be generated in silico within minutes and can be used to perfuse engineered and anatomic models including a bioreactor, annulus, bi-ventricular heart, and gyrus. We further show that this flexible pipeline can be applied to two common modes of bioprinting with free-form reversible embedding of suspended hydrogels and writing into soft matter. Our synthetic vascular tree generation pipeline enables rapid, scalable vascular model generation and fluid analysis for bio-manufactured tissues necessary for future scale up and production.
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Affiliation(s)
- Zachary A. Sexton
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Andrew R. Hudson
- Department of Biomedical Engineering Carnegie Mellon University, Pittsburgh, PA, USA
| | | | - Dan J. Shiwarski
- Department of Biomedical Engineering Carnegie Mellon University, Pittsburgh, PA, USA
| | - Jonathan Pham
- Department of Mechanical Engineering, Stanford University, Stanford, CA, USA
| | - Jason M. Szafron
- Cardiovascular Institute, Stanford University, Stanford, CA, USA
- Department of Materials Science and Engineering Carnegie Mellon University, Pittsburgh, PA, USA
| | - Sean M. Wu
- Cardiovascular Institute, Stanford University, Stanford, CA, USA
- Division of Cardiovascular Medicine, Department of Medicine Stanford University, Stanford, CA, USA
| | - Mark Skylar-Scott
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- Basic Science and Engineering Initiative Children’s Heart Center, Stanford University, Stanford, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Adam W. Feinberg
- Department of Biomedical Engineering Carnegie Mellon University, Pittsburgh, PA, USA
- Department of Materials Science and Engineering Carnegie Mellon University, Pittsburgh, PA, USA
| | - Alison Marsden
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- Department of Pediatrics, Stanford University, Stanford, CA, USA
- Institute of Computational and Mathematical Engineering Stanford University, CA, USA
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Woo JP, Dong ML, Kong F, McElhinney DB, Schiavone N, Chan F, Lui GK, Haddad F, Bernstein D, Marsden A. Improved Right Ventricular Energy Efficiency by 4-Dimensional Flow Magnetic Resonance Imaging After Harmony Valve Implantation. JACC Adv 2023; 2:100284. [PMID: 37691969 PMCID: PMC10487049 DOI: 10.1016/j.jacadv.2023.100284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Affiliation(s)
| | | | - Fanwei Kong
- Stanford University School of Medicine, 300 Pasteur Drive, 3rd Floor, Clinic A32 Rm A345 – MC: 5844 Stanford, California 94305, USA
| | - Doff B. McElhinney
- Stanford University School of Medicine, 300 Pasteur Drive, 3rd Floor, Clinic A32 Rm A345 – MC: 5844 Stanford, California 94305, USA
| | - Nicole Schiavone
- Stanford University School of Medicine, 300 Pasteur Drive, 3rd Floor, Clinic A32 Rm A345 – MC: 5844 Stanford, California 94305, USA
| | - Frandics Chan
- Stanford University School of Medicine, 300 Pasteur Drive, 3rd Floor, Clinic A32 Rm A345 – MC: 5844 Stanford, California 94305, USA
| | - George K. Lui
- Stanford University School of Medicine, 300 Pasteur Drive, 3rd Floor, Clinic A32 Rm A345 – MC: 5844 Stanford, California 94305, USA
| | - Francois Haddad
- Stanford University School of Medicine, 300 Pasteur Drive, 3rd Floor, Clinic A32 Rm A345 – MC: 5844 Stanford, California 94305, USA
| | - Daniel Bernstein
- Stanford University School of Medicine, 300 Pasteur Drive, 3rd Floor, Clinic A32 Rm A345 – MC: 5844 Stanford, California 94305, USA
| | - Alison Marsden
- Stanford University School of Medicine, 300 Pasteur Drive, 3rd Floor, Clinic A32 Rm A345 – MC: 5844 Stanford, California 94305, USA
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Khan MO, Nishi T, Imura S, Seo J, Wang H, Honda Y, Nieman K, Rogers IS, Tremmel JA, Boyd J, Schnittger I, Marsden A. Colocalization of Coronary Plaque with Wall Shear Stress in Myocardial Bridge Patients. Cardiovasc Eng Technol 2022; 13:797-807. [PMID: 35296987 DOI: 10.1007/s13239-022-00616-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 02/25/2022] [Indexed: 01/27/2023]
Abstract
PURPOSE Patients with myocardial bridges (MBs) have a higher prevalence of atherosclerosis. Wall shear stress (WSS) has previously been correlated with plaque in coronary artery disease patients, but such correlations have not been investigated in symptomatic MB patients. The aim of this paper was to use a multi-scale computational fluid dynamics (CFD) framework to simulate hemodynamics in MB patient, and investigate the co-localization of WSS and plaque. METHODS We identified N = 10 patients from a previously reported cohort of 50 symptomatic MB patients, all of whom had plaque in the proximal vessel. Dynamic 3D models were reconstructed from coronary computed tomography angiography (CCTA), intravascular ultrasound (IVUS) and catheter angiograms. CFD simulations were performed to compute WSS proximal to, within and distal to the MB. Plaque was quantified from IVUS images in 2 mm segments and registered to CFD model. Plaque area was compared to absolute and patient-normalized WSS. RESULTS WSS was lower in the proximal segment compared to the bridge segment (6.1 ± 2.9 vs. 16.0 ± 7.1 dynes/cm2, p value < 0.01). Plaque area and plaque burden measured from IVUS peaked at 1-3 cm proximal to the MB entrance, coinciding with the first diagonal branch. Normalized WSS showed a statistically significant moderate correlation with plaque area (r = 0.41, p < 0.01). CONCLUSION WSS may be obtained non-invasively in MB patients and provides a surrogate marker of plaque area. Using CFD, it may be possible to non-invasively assess the extent of plaque area, and identify patients who could benefit from frequent monitoring or medical management.
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Affiliation(s)
- Muhammad Owais Khan
- Department of Pediatrics, Stanford University School of Medicine, 318 Campus Drive, Clark Center E100b, Stanford, CA, 94305-5428, USA.,Institute for Computational and Mathematical Engineering, Stanford University, Stanford, CA, USA
| | - Takeshi Nishi
- Division of Cardiovascular Medicine, Stanford University School of Medicine and Stanford Cardiovascular Institute, Stanford, CA, USA
| | - Shinji Imura
- Division of Cardiovascular Medicine, Stanford University School of Medicine and Stanford Cardiovascular Institute, Stanford, CA, USA
| | - Jongmin Seo
- Department of Pediatrics, Stanford University School of Medicine, 318 Campus Drive, Clark Center E100b, Stanford, CA, 94305-5428, USA.,Institute for Computational and Mathematical Engineering, Stanford University, Stanford, CA, USA
| | - Hanjay Wang
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Yasuhiro Honda
- Division of Cardiovascular Medicine, Stanford University School of Medicine and Stanford Cardiovascular Institute, Stanford, CA, USA
| | - Koen Nieman
- Division of Cardiovascular Medicine, Stanford University School of Medicine and Stanford Cardiovascular Institute, Stanford, CA, USA.,Department of Radiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Ian S Rogers
- Division of Cardiovascular Medicine, Stanford University School of Medicine and Stanford Cardiovascular Institute, Stanford, CA, USA
| | - Jennifer A Tremmel
- Division of Cardiovascular Medicine, Stanford University School of Medicine and Stanford Cardiovascular Institute, Stanford, CA, USA
| | - Jack Boyd
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Ingela Schnittger
- Division of Cardiovascular Medicine, Stanford University School of Medicine and Stanford Cardiovascular Institute, Stanford, CA, USA
| | - Alison Marsden
- Department of Pediatrics, Stanford University School of Medicine, 318 Campus Drive, Clark Center E100b, Stanford, CA, 94305-5428, USA. .,Institute for Computational and Mathematical Engineering, Stanford University, Stanford, CA, USA. .,Department of Bioengineering, Stanford University, Stanford, CA, USA.
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Tikenoğulları OZ, Costabal FS, Yao J, Marsden A, Kuhl E. How viscous is the beating heart?: Insights from a computational study. Comput Mech 2022; 70:565-579. [PMID: 37274842 PMCID: PMC10237084 DOI: 10.1007/s00466-022-02180-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 04/08/2022] [Indexed: 06/07/2023]
Abstract
Understanding tissue rheology is critical to accurately model the human heart. While the elastic properties of cardiac tissue have been extensively studied, its viscous properties remain an issue of ongoing debate. Here we adopt a viscoelastic version of the classical Holzapfel Ogden model to study the viscous timescales of human cardiac tissue. We perform a series of simulations and explore stress-relaxation curves, pressure-volume loops, strain profiles, and ventricular wall strains for varying viscosity parameters. We show that the time window for model calibration strongly influences the parameter identification. Using a four-chamber human heart model, we observe that, during the physiologically relevant time scales of the cardiac cycle, viscous relaxation has a negligible effect on the overall behavior of the heart. While viscosity could have important consequences in pathological conditions with compromised contraction or relaxation properties, we conclude that, for simulations within the physiological range of a human heart beat, we can reasonably approximate the human heart as hyperelastic.
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Affiliation(s)
- Oğuz Ziya Tikenoğulları
- Department of Mechanical Engineering · Stanford University · Stanford, California, United States
| | - Francisco Sahli Costabal
- Department of Mechanical and Metallurgical Engineering and Institute for Biological and Medical Engineering · Pontificia Universidad Catolica de Chile, Chile
| | - Jiang Yao
- Dassault Systèmes Simulia Corporation · Johnston, Rhode Island, United States
| | - Alison Marsden
- Departments of Pediatrics and Bioengineering · Stanford University · Stanford, California, United States
| | - Ellen Kuhl
- Department of Mechanical Engineering · Stanford University · Stanford, California, United States
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Green D, Heales CJ, Hughes D, Marsden A, Mills JA. Exploring current undergraduate student perspectives on the introduction of the degree apprenticeship scheme in diagnostic radiography - a single institution study. Radiography (Lond) 2022; 28:1058-1063. [PMID: 35994974 DOI: 10.1016/j.radi.2022.08.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 07/20/2022] [Accepted: 08/02/2022] [Indexed: 10/31/2022]
Abstract
INTRODUCTION The first degree apprenticeship programme in diagnostic radiography was launched in March 2020. This route into radiography runs in parallel with 'conventional' pre-registration programmes where students apply to a higher education institution (HEI) and undertake discrete clinical placements. The aim of this study was to explore the perspectives of pre-registration students on the diagnostic radiographer degree apprenticeship route. METHODS A qualitative approach (online questionnaire) gathered attitudes and opinions of pre-registration students from a single HEI, regarding the degree apprenticeship programme. Participants were pre-registration medical imaging students from all stages of the programme (n = 204). Braun and Clarks's thematic analysis was employed for data analysis. RESULTS A response rate of 21% (n = 44) was recorded. Four themes emerged from data analysis: (1) misunderstandings surrounding the degree apprenticeship, (2) financial implications and (3) practical experience associated with both degree courses and (4) the experience the pre-registration degree has to offer. CONCLUSION There was an apparent lack of understanding regarding the degree apprenticeship leading students to misinterpret aspects of the course. Additionally, students highlighted the earning aspect of the apprenticeship to be an advantage in comparison to student debts associated with the traditional pre-registration programmes. Furthermore, students emphasised the advantage of the clinical focus practice associated with the degree apprenticeship. Nevertheless, students who have selected the HEI route still value what the traditional pre-registration degree offers. IMPLICATIONS FOR PRACTICE As degree apprenticeship programmes become widely available, a greater awareness should, therefore, follow. In the interim, there is scope for HEIs to seek to raise awareness of degree apprenticeship provision. HEIs should seek to allay any concerns and highlight the benefits of having this alternative route into the profession.
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Affiliation(s)
- D Green
- University of Exeter - Medical Imaging University of Exeter, St Lukes Campus, Heavitree Road, Exeter, Devon, EX12LU, UK.
| | - C J Heales
- University of Exeter - Medical Imaging University of Exeter, St Lukes Campus, Heavitree Road, Exeter, Devon, EX12LU, UK.
| | - D Hughes
- Danielle Hughes - University of Exeter Alumni - Medical Imaging University of Exeter, St Lukes Campus, Heavitree Road, Exeter, Devon, EX12LU, UK.
| | - A Marsden
- Annabel Marsden - University of Exeter Alumni - Medical Imaging University of Exeter, St Lukes Campus, Heavitree Road, Exeter, Devon, EX12LU, UK.
| | - J A Mills
- Julie Mills - University of Exeter - Medical Imaging University of Exeter, St Lukes Campus, Heavitree Road, Exeter, Devon, EX12LU, UK.
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Dual SA, Verdonk C, Amsallem M, Pham J, Obasohan C, Nataf P, McElhinney DB, Arunamata A, Kuznetsova T, Zamanian R, Feinstein JA, Marsden A, Haddad F. Elucidating tricuspid Doppler signal interpolation and its implication for assessing pulmonary hypertension. Pulm Circ 2022; 12:e12125. [PMID: 36016669 PMCID: PMC9395694 DOI: 10.1002/pul2.12125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 07/07/2022] [Accepted: 08/02/2022] [Indexed: 11/06/2022] Open
Abstract
Doppler echocardiography plays a central role in the assessment of pulmonary hypertension (PAH). We aim to improve quality assessment of systolic pulmonary arterial pressure (SPAP) by applying a cubic polynomial interpolation to digitized tricuspid regurgitation (TR) waveforms. Patients with PAH and advanced lung disease were divided into three cohorts: a derivation cohort (n = 44), a validation cohort (n = 71), an outlier cohort (n = 26), and a non-PAH cohort (n = 44). We digitized TR waveforms and analyzed normalized duration, skewness, kurtosis, and first and second derivatives of pressure. Cubic polynomial interpolation was applied to three physiology-driven phases: the isovolumic phase, ejection phase, and "shoulder" point phase. Coefficients of determination and a Bland-Altman analysis was used to assess bias between methods. The cubic polynomial interpolation of the TR waveform correlated strongly with expert read right ventricular systolic pressure (RVSP) with R 2 > 0.910 in the validation cohort. The biases when compared to invasive SPAP measured within 24 h were 6.03 [4.33; 7.73], -2.94 [1.47; 4.41], and -3.11 [-4.52; -1.71] mmHg, for isovolumic, ejection, and shoulder point interpolations, respectively. In the outlier cohort with more than 30% difference between echocardiographic estimates and invasive SPAP, cubic polynomial interpolation significantly reduced underestimation of RVSP. Cubic polynomial interpolation of the TR waveform based on isovolumic or early ejection phase may improve RVSP estimates.
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Affiliation(s)
- Seraina A. Dual
- Department of Cardiothoracic SurgeryStanford University School of MedicineStanfordCaliforniaUSA
- Cardiovascular InstituteStanford UniversityStanfordCaliforniaUSA
| | - Constance Verdonk
- Department of Medicine, Division of Cardiovascular MedicineStanford University School of MedicineStanfordCaliforniaUSA
- Department of Cardiothoracic SurgeryHospital BichatParisFrance
- INSERM U1148, Cardiovascular BioengineeringParisFrance
| | - Myriam Amsallem
- Cardiovascular InstituteStanford UniversityStanfordCaliforniaUSA
- Department of Medicine, Division of Cardiovascular MedicineStanford University School of MedicineStanfordCaliforniaUSA
- KU Leuven Department of Cardiovascular Sciences, Research Unit Hypertension and Cardiovascular EpidemiologyUniversity of LeuvenLeuvenBelgium
| | - Jonathan Pham
- Department of PediatricsDivision of Pediatric Cardiology, Stanford University School of MedicinePalo AltoCaliforniaUSA
- Department of BioengineeringStanford University School of MedicineStanfordCaliforniaUSA
| | - Courtney Obasohan
- Department of MedicineDivision of Pulmonary and Critical Care Medicine, Stanford University School of MedicineStanfordCaliforniaUSA
| | - Patrick Nataf
- Department of Cardiothoracic SurgeryHospital BichatParisFrance
- INSERM U1148, Cardiovascular BioengineeringParisFrance
| | - Doff B. McElhinney
- Department of Cardiothoracic SurgeryStanford University School of MedicineStanfordCaliforniaUSA
- Cardiovascular InstituteStanford UniversityStanfordCaliforniaUSA
| | - Alisa Arunamata
- Department of PediatricsDivision of Pediatric Cardiology, Stanford University School of MedicinePalo AltoCaliforniaUSA
| | - Tatiana Kuznetsova
- KU Leuven Department of Cardiovascular Sciences, Research Unit Hypertension and Cardiovascular EpidemiologyUniversity of LeuvenLeuvenBelgium
| | - Roham Zamanian
- Department of Mechanical EngineeringStanford UniversityCaliforniaStanfordUSA
- Vera Moulton Wall Center for Pulmonary Vascular Disease at StanfordStanfordCaliforniaUSA
| | - Jeffrey A. Feinstein
- Department of PediatricsDivision of Pediatric Cardiology, Stanford University School of MedicinePalo AltoCaliforniaUSA
- Department of BioengineeringStanford University School of MedicineStanfordCaliforniaUSA
- Department of Mechanical EngineeringStanford UniversityCaliforniaStanfordUSA
| | - Alison Marsden
- Cardiovascular InstituteStanford UniversityStanfordCaliforniaUSA
- Department of PediatricsDivision of Pediatric Cardiology, Stanford University School of MedicinePalo AltoCaliforniaUSA
- Department of BioengineeringStanford University School of MedicineStanfordCaliforniaUSA
- Department of Mechanical EngineeringStanford UniversityCaliforniaStanfordUSA
| | - François Haddad
- Cardiovascular InstituteStanford UniversityStanfordCaliforniaUSA
- Department of Medicine, Division of Cardiovascular MedicineStanford University School of MedicineStanfordCaliforniaUSA
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Pain C, Murray A, Dinsdale G, Marsden A, Manning J, Herrick A. POS1304 CORRELATION OF SKIN SCORES (LoSCAT) WITH PATIENT REPORTED OUTCOMES IN JUVENILE LOCALISED SCLERODERMA. Ann Rheum Dis 2022. [DOI: 10.1136/annrheumdis-2022-eular.1553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BackgroundJuvenile localised scleroderma (JLS) or morphea is a rare condition, causing inflammation and fibrosis in skin and underlying tissues. A validated skin score (Localized Scleroderma Cutaneous Assessment Tool, LoSCAT) has been developed [1]. This tool has both activity (mLoSSi) and damage indices (LoSDI). Several patient-reported outcomes (PRO) have been studied in JLS including visual analogue scales (VAS), functional and health-related quality of life measures.ObjectivesTo assess the associations between different PROs and the activity and damage indices of the LoSCAT.MethodsParticipants aged 4 to 17 were recruited from 3 tertiary paediatric rheumatology centres in the UK and attended 4 visits at 3 monthly intervals as part of a program of research on JLS. Patient-reported VAS (6 different scales), the Children’s Dermatology Life Quality Index (CDLQI) and Childhood Health Assessment Questionnaires (CHAQ) were completed at each visit. LoSCAT was completed by the two same clinicians throughout the study (both trained in skin score techniques). Pearson correlation coefficients were calculated between each PRO and each component of the LoSCAT.Results24 participants completed all 4 visits and 1 attended 3 visits. 20 participants were female (80%) and 5 were male (20%). Mean age at diagnosis was 7.6 years with mean disease duration of 4.9 years. Subtype of disease was linear head in 5/25 (20%), linear limb 12/25 (48%), generalised morphoea 1/25 (4%), mixed 5/25 (20%) and superficial plaque in 2/25 (8%). Table 1 shows the correlations with figures in bold highlighting positive correlations which were statistically significant (p<0.05) and medium-sized (r>0.3).Table 1.Correlation between patient reported outcomes and LoSCATPROTotal skin activity (mLoSSi)Total skin damage (LoSDI)r (95% CI)p-valuer (95% CI)p-valueCDLQI0.61 (0.02, 1.20)0.0440.42 (0.01, 0.83)0.044CHAQ0.30 (0.03, 0.57)0.0270.20 (-0.14, 0.54)0.244VAS 1: How much IMPACT has your disease had on your life in the PAST MONTH?0.49 (0.00, 0.98)0.0500.38 (0.06, 0.71)0.021VAS 2: How much has your condition (localized scleroderma) affected you OVERALL in the PAST MONTH?0.59 (0.09, 1.09)0.0220.42 (0.13, 0.72)0.005VAS 3: Have your lesions felt itchy and/or scratchy in PAST MONTH?0.40 (-0.01, 0.81)0.0560.31 (0.03, 0.59)0.028VAS 4: Have you felt numbness, tingling, and/or other “funny” feeling in or around your lesion in PAST MONTH?0.55 (0.04, 1.05)0.0330.33 (-0.04, 0.71)0.084VAS 5: How much WORRY do you have about LONG- -TERM problems from your disease?0.40 (-0.01, 0.81)0.0530.32 (0.00, 0.63)0.047VAS 6: How much WORRY do you have about problems from MEDICATIONS used to treat your condition?0.41 (0.00, 0.82)0.0500.29 (-0.09, 0.66)0.131The VAS of symptoms of numbness/tingling showed a strong positive correlation with mLoSSi but a weak and/or non-significant correlation with LoSDI. VAS itchy/scratchy did not show a strong correlation with mLoSSi but showed a moderate correlation with LoSDI. Patient global VAS correlated with both mLoSSi and LoSDI, as did CDLQI. CHAQ correlated with activity only.ConclusionSymptoms within lesions are often interpreted as indicating disease activity. A previous study in adults and children showed itch positively correlated with mLoSSi suggesting it may be a marker of active disease [2]. However, in our study numbness/tingling correlated with disease activity whereas itch did not. Further work is required to understand whether itch correlates to both activity and damage and whether numbness/tingling is a better indicator of activity than itch. Limitations of our study include a heterogenous group of participants with longstanding high-burden disease.References[1]Arkachaisri et al. Rheumatology 2010. 49(2): 373-81.[2]Klimas et al. Br J Derm 2015; 175:1329-1337AcknowledgementsThis study was funded by Scleroderma & Raynaud’s UK.Disclosure of InterestsNone declared
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Pain C, Murray A, Dinsdale G, Marsden A, Manning J, Herrick A. POS0168 NON-INVASIVE IMAGING IN JUVENILE LOCALISED SCLERODERMA: HIGH-FREQUENCY ULTRASOUND, THERMOGRAPHY, LASER DOPPLER & MULTISPECTRAL IMAGING. Ann Rheum Dis 2022. [DOI: 10.1136/annrheumdis-2022-eular.4961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BackgroundOutcome measures which can differentiate activity (inflammation) from damage (fibrosis/atrophy) would facilitate development of new treatment strategies in juvenile localized scleroderma (JLS) to target the inflammatory phase of the disease.ObjectivesTo evaluate whether in JLS, non-invasive imaging modalities (high frequency ultrasounds (HFUS), multispectral imaging (MSI), laser doppler imaging (LDI) & infra-red thermography (IRT)) can detect differences between affected & non-affected skin, as a next step in developing these as outcome measures. Our hypothesis was that blood flow (and therefore temperature & oxygenation) would be increased in lesional skin.MethodsParticipants aged 4-17 were recruited from 3 paediatric rheumatology centres in the UK. For each participant, a single lesion was selected. HFUS (30MHz), MSI (bespoke camera and tuneable liquid crystal filter, coupled to custom analysis software, 500nm/710nm wavelengths), LDI and IRT imaging were performed at four sites relating to each lesion: two of affected skin (centre & inner edge of lesion) and two of non-affected skin (one cm from edge of lesion (‘outer’) & contralateral unaffected side). Imaging was performed at 4 visits at 3 monthly intervals. Mean values were compared between the four sites using data from all visits by mixed-effects linear regression to account for individual-level clustering.Results24 participants completed all 4 visits and 1 attended 3. 20 participants were female (80%) & 5 male (20%). Mean age at diagnosis was 7.6 years & disease duration 4.9 years. Subtype of disease was linear head in 5/25 (20%), linear limb 12/25 (48%), generalised morphea 1/25 (4%), mixed 5/25 (20%) and superficial plaque in 2/25 (8%).Table 1 shows a subset of data. All 4 imaging techniques could detect differences between healthy (outer/contralateral) & affected skin (centre/inner edge). For HFUS, there was strong evidence of a difference between affected & unaffected skin (p<0.001) indicating affected skin is thinner than unaffected. Higher mean values of oxygenation, perfusion & temperature were observed in affected compared to non-affected skin in MSI, LDI and IRT respectively. There was no statistical difference seen between inner edge and centre of the lesion in any of the methods.Table 1.Mean differences between different locations for each imaging techniqueImaging techniqueLocationOverall mean difference (95% CI)p-valueHFUS (mm)Centre - Contralateral-0.34 (-0.46, -0.22)<0.001Inner edge - Contralateral-0.30 (-0.40, -0.20)<0.001Centre - Outer-0.35 (-0.46, -0.24)<0.001Inner edge - Outer-0.31 (-0.40, -0.21)<0.001Centre - Inner edge-0.04 (-0.10, 0.02)0.168MSI (rel units)Centre - Contralateral0.06 (0.03, 0.10)<0.001Inner edge - Contralateral0.06 (0.03, 0.09)<0.001Centre - Outer0.04 (0.01, 0.07)0.012Inner edge - Outer0.03 (0.00, 0.06)0.028Centre - Inner edge0.01 (0.00, 0.02)0.251LDI Relative perfusion unitsCentre - Contralateral44.8 (24.4, 65.2)<0.001Inner edge - Contralateral47.9 (21.0, 74.8)<0.001Centre - Outer19.1 (1.0, 37.1)0.039Inner edge - Outer24.8 (6.7, 42.9)0.007Centre - Inner edge-3.5 (-20.3, 13.2)0.679IRT oCCentre - Contralateral0.58 (0.24, 0.91)0.001Inner edge - Contralateral0.44 (0.13, 0.75)0.005Centre - Outer0.44 (0.22, 0.66)<0.001Inner edge - Outer0.30 (0.09, 0.52)0.006Centre - Inner edge0.14 (-0.05, 0.32)0.153The overall mean difference is the measurement of the first location minus the measurement from the second location (e.g. centre minus contralateral), averaged across the four visits.ConclusionOur results suggest non-invasive imaging can detect differences between healthy & unaffected skin in JLS. Whether each technique is only measuring activity & not damage requires further evaluation. The leading edge of lesions has historically been considered as most active compared to the centre. However, no difference was seen between centre & inner edge measurements suggesting that in future studies, imaging protocols can be simplified.AcknowledgementsThis study was funded by Scleroderma & Raynaud’s UK.Disclosure of InterestsNone declared
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Van Hout MC, Bigland C, Marsden A, Bangura A, Ngcobo F, Mponela LM, McMahon G. Precarious migrants and COVID-19 responses: leave no one behind. Public Health 2022; 207:e1-e2. [PMID: 35469659 PMCID: PMC8940564 DOI: 10.1016/j.puhe.2022.03.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 03/13/2022] [Indexed: 11/29/2022]
Affiliation(s)
- M-C Van Hout
- Public Health Institute, Liverpool John Moores University, Liverpool, UK.
| | - C Bigland
- Public Health Institute, Liverpool John Moores University, Liverpool, UK
| | - A Marsden
- Refugee and Asylum Seeker Participatory Action Research, Manchester, UK
| | - A Bangura
- Refugee and Asylum Seeker Participatory Action Research, Manchester, UK
| | - F Ngcobo
- Refugee and Asylum Seeker Participatory Action Research, Manchester, UK
| | - L M Mponela
- Refugee and Asylum Seeker Participatory Action Research, Manchester, UK
| | - G McMahon
- Refugee and Asylum Seeker Participatory Action Research, Manchester, UK
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Tran K, Kaladji A, Yang W, Marsden A, Lee J. Comparison of Hemodynamic Changes Associated With Two- Versus Four-Vessel Fenestrated Endovascular Aneurysm Repair Using Patient-specific Computational Flow Modeling. J Vasc Surg 2022. [DOI: 10.1016/j.jvs.2021.12.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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15
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Verdonk C, Dual S, Amsallem M, Nataf P, Marsden A, Haddad F. A novel semi-automated method to improve estimation of right ventricular systolic pressure by Doppler ultrasound. Archives of Cardiovascular Diseases Supplements 2022. [DOI: 10.1016/j.acvdsp.2021.09.104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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16
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Woo J, Dong M, Kong F, McElhinney D, Schiavone N, Chan F, Lui G, Haddad F, Bernstein D, Marsden A. Increased right ventricular energy efficiency by 4DMR after harmony valve implantation. International Journal of Cardiology Congenital Heart Disease 2021. [DOI: 10.1016/j.ijcchd.2021.100242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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17
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Tran K, Deslarzes C, Marsden A, Lee J, Déglise S. Patient-specific computational fluid dynamic simulation for assessing hemodynamic changes following branched endovascular aneurysm repair: A pilot study. Br J Surg 2021. [DOI: 10.1093/bjs/znab202.068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
Objective
This pilot study assessed the hypothesis that patient-specific computational fluid dynamic (CFD) modelling can detect aortic branch hemodynamic changes following branched endovascular aneurysm repair (bEVAR).
Methods
Patients who underwent bEVAR with the Jotec E-xtra Design for thoracoabdominal aortic aneurysms were retrospectively selected. Using open-source SimVascular software, pre- and post-operative aortic finite element volume meshes were constructed from CT imaging. Pulsatile in-flow conditions were derived and adjusted for patient-specific clinical variables. Outlet boundary conditions consisted of Windkessel models approximated from physiologic flow splits. Rigid wall flow simulations were then performed on pre- and post-operative models with equivalent boundary conditions. Computations were performed with an incompressible Navier-Stokes flow solver on a 72-core cluster.
Results
Pre- and post-operative flow simulations were performed on 10 patients undergoing bEVAR with a total of 40 target vessels (10 celiac, 20 superior mesenteric, 20 renal stents). Compared to pre-operative values, bEVAR was associated with a decrease in peak renal artery pressure (116.8 ± 11.5 vs 112.8 ± 11.6 mmHg, p<.001) and flow rate (13.7 ± 2.3 vs 12.9 ± 2.4 ml/s, p<.001). No post-operative differences were observed in pressure or flow rates in the celiac or mesenteric arteries (p=.10-.55). Representative perfusion waveforms from a single patient are shown in Figure 1. bEVAR resulted in a significant increase in aortic (1.4 ± 0.5 vs 4.3 ± 2.9 dynes/cm2, p=.009) and renal artery (24.3 ± 7.1 vs 35.4 ± 12.4 dynes/cm2, p=.23) wall shear stress; however, these values remained within the physiologic range. In certain graft configurations, 3D visualization of blood flow streamlines revealed areas of turbulent flow at the origin of external branches which were associated with decreased target artery perfusion (Figure 2).
Conclusion
Changes in para-visceral aortic geometry after bEVAR is associated with a decrease in computationally estimated renal perfusion, without significant changes to celiac or mesenteric hemodynamics. Further CFD simulation-based studies are needed to assess whether changes in branch configuration or hemodynamics after bEVAR can predict loss of branch patency.
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Affiliation(s)
- K Tran
- Department of Vascular Surgery, Stanford University Hospital, Palo Alto, USA
| | - C Deslarzes
- Department of Vascular Surgery, Lausanne University Hospital, Lausanne, Switzerland
| | - A Marsden
- Cardiovascular Biomechanics Computational Lab, Stanford University, Palo Alto, USA
| | - J Lee
- Department of Vascular Surgery, Stanford University Hospital, Palo Alto, USA
| | - S Déglise
- Department of Vascular Surgery, Lausanne University Hospital, Lausanne, Switzerland
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Arana VT, Chan F, Schiavone N, Reddy S, Hanley F, Marsden A, McElhinney D. RIGHT VENTRICULAR OUTFLOW TRACT AND PULMONARY ARTERY GEOMETRY IN PATIENTS WITH REPAIRED TETRALOGY OF FALLOT PRIOR TO PULMONARY VALVE REPLACEMENT-CHARACTERIZATION AND LONGITUDINAL ASSOCIATION WITH BIOPROSTHETIC VALVE FUNCTION. J Am Coll Cardiol 2021. [DOI: 10.1016/s0735-1097(21)02768-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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19
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Tran K, Yang W, Marsden A, Lee JT. Patient-specific computational flow modelling for assessing hemodynamic changes following fenestrated endovascular aneurysm repair. JVS Vasc Sci 2021; 2:53-69. [PMID: 34258601 PMCID: PMC8274562 DOI: 10.1016/j.jvssci.2020.11.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Objective This study aimed to develop an accessible patient-specific computational flow modelling pipeline for evaluating the hemodynamic performance of fenestrated endovascular aneurysm repair (fEVAR), with the hypothesis that computational flow modelling can detect aortic branch hemodynamic changes associated with fEVAR graft implantation. Methods Patients who underwent fEVAR for juxtarenal aortic aneurysms with the Cook ZFEN were retrospectively selected. Using open-source SimVascular software, preoperative and postoperative visceral aortic anatomy was manually segmented from computed tomography angiograms. Three-dimensional geometric models were then discretized into tetrahedral finite element meshes. Patient-specific pulsatile in-flow conditions were derived from known supraceliac aortic flow waveforms and adjusted for patient body surface area, average resting heart rate, and blood pressure. Outlet boundary conditions consisted of three-element Windkessel models approximated from physiologic flow splits. Rigid wall flow simulations were then performed on preoperative and postoperative models with the same inflow and outflow conditions. We used SimVascular's incompressible Navier-Stokes solver to perform blood flow simulations on a cluster using 72 cores. Results Preoperative and postoperative flow simulations were performed for 10 patients undergoing fEVAR with a total of 30 target vessels (20 renal stents, 10 mesenteric scallops). Postoperative models required a higher mean number of mesh elements to reach mesh convergence (3.2 ± 1.8 × 106 vs 2.6 ± 1.1 × 106; P = .005) with a longer mean computational time (10.3 ± 6.3 hours vs 7.8 ± 3.5 hours; P = .04) compared with preoperative models. fEVAR was associated with small but statistically significant increases in mean peak proximal aortic arterial pressure (140.3 ± 11.0 mm Hg vs 136.9 ± 8.7 mm Hg; P = .02) and peak renal artery pressure (131.6 ± 14.8 mm Hg vs 128.9 ± 11.8 mm Hg; P = .04) compared with preoperative simulations. No differences were observed in peak pressure in the celiac, superior mesenteric, or distal aortic arteries (P = .17-.96). When measuring blood flow, the only observed difference was an increase in peak renal flow rate after fEVAR (17.5 ± 3.8 mL/s vs 16.9 ± 3.5 mL/s; P = .04). fEVAR was not associated with changes in the mean pressure or the mean flow rate in the celiac, superior mesenteric, or renal arteries (P = .06-.98). Stenting of the renal arteries did not induce significant changes time-averaged wall shear stress in the proximal renal artery (23.4 ± 8.1 dynes/cm2 vs 23.2 ± 8.4 dynes/cm2; P = .98) or distal renal artery (32.7 ± 13.9 dynes/cm2 vs 29.6 ± 11.8 dynes/cm2; P = .23). In addition, computational visualization of cross-sectional velocity profiles revealed low flow disturbances associated with protrusion of renal graft fabric into the aortic lumen. Conclusions In a pilot study involving a selective cohort of patients who underwent uncomplicated fEVAR, patient-specific flow modelling was a feasible method for assessing the hemodynamic performance of various two-vessel fenestrated device configurations and revealed subtle differences in computationally derived peak branch pressure and blood flow rates. Structural changes in aortic flow geometry after fEVAR do not seem to affect computationally estimated renovisceral branch perfusion or wall shear stress adversely. Additional studies with invasive angiography or phase contrast magnetic resonance imaging are required to clinically validate these findings. (JVS–Vascular Science 2021;2:53-69.) Clinical Relevance Using a computational flow modelling for assessing the hemodynamic performance of fenestrated endovascular aneurysm repair (fEVAR), this real-world, patient-specific study included 10 participants and found that structural changes in aortic flow geometry after fEVAR did not seem to adversely impact estimated renal or visceral branch perfusion metrics (eg, peak and mean arterial pressure and flow rates) or wall shear stress. These findings overall support the ongoing clinical use of commercially available fEVAR devices for repair of juxtarenal aortic aneurysms, and provides a computational framework for future evaluation of fEVAR configurations in a preoperative or postoperative settings.
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Affiliation(s)
- Kenneth Tran
- Division of Vascular Surgery, Stanford University.,Cardiovascular Institute, Stanford University
| | - Weiguang Yang
- Department of Pediatrics (Cardiology), Stanford University
| | - Alison Marsden
- Department of Pediatrics (Cardiology), Stanford University.,Department of Bioengineering, Stanford University
| | - Jason T Lee
- Division of Vascular Surgery, Stanford University.,Cardiovascular Institute, Stanford University
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20
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Maher G, Parker D, Wilson N, Marsden A. Neural Network Vessel Lumen Regression for Automated Lumen Cross-Section Segmentation in Cardiovascular Image-Based Modeling. Cardiovasc Eng Technol 2020; 11:621-635. [PMID: 33179176 DOI: 10.1007/s13239-020-00497-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 10/15/2020] [Indexed: 11/29/2022]
Abstract
PURPOSE We accelerate a pathline-based cardiovascular model building method by training machine learning models to directly predict vessel lumen surface points from computed tomography (CT) and magnetic resonance (MR) medical image data. METHODS We formulate vessel lumen detection as a regression task using a polar coordiantes representation. RESULTS Neural networks trained with our regression formulation allow predictions to be made with significantly higher accuracy than existing methods that identify the vessel lumen through binary pixel classification. The regression formulation enables machine learning models to be trained end-to-end for vessel lumen detection without post-processing steps that reduce accuracy. CONCLUSION By employing our models in a pathline-based cardiovascular model building pipeline we substantially reduce the manual segmentation effort required to build accurate cardiovascular models, and reduce the overall time required to perform patient-specific cardiovascular simulations. While our method is applied here for cardiovascular model building it is generally applicable to segmentation of tree-like and tubular structures from image data.
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Affiliation(s)
- Gabriel Maher
- Institute for Computational and Mathematical Engineering, Stanford University, Stanford, CA, USA
| | - David Parker
- Research Computing, Stanford University, Stanford, CA, USA
| | - Nathan Wilson
- Open Source Medical Software Corporation, Los Angeles, CA, USA
| | - Alison Marsden
- Pediatric Cardiology, Bioengineering, Stanford University, Stanford, CA, USA.
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21
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Gijsen F, Katagiri Y, Barlis P, Bourantas C, Collet C, Coskun U, Daemen J, Dijkstra J, Edelman E, Evans P, van der Heiden K, Hose R, Koo BK, Krams R, Marsden A, Migliavacca F, Onuma Y, Ooi A, Poon E, Samady H, Stone P, Takahashi K, Tang D, Thondapu V, Tenekecioglu E, Timmins L, Torii R, Wentzel J, Serruys P. Expert recommendations on the assessment of wall shear stress in human coronary arteries: existing methodologies, technical considerations, and clinical applications. Eur Heart J 2020; 40:3421-3433. [PMID: 31566246 PMCID: PMC6823616 DOI: 10.1093/eurheartj/ehz551] [Citation(s) in RCA: 150] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 04/09/2019] [Accepted: 09/23/2019] [Indexed: 01/09/2023] Open
Affiliation(s)
- Frank Gijsen
- Department of Cardiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - Yuki Katagiri
- Amsterdam University Medical Centre, University of Amsterdam, Amsterdam, the Netherlands
| | - Peter Barlis
- Department of Medicine and Radiology, Melbourne Medical School, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, VIC, Australia.,Department of Cardiology, Northern Hospital, 185 Cooper Street, Epping, Australia.,St Vincent's Heart Centre, Building C, 41 Victoria Parade, Fitzroy, Australia
| | - Christos Bourantas
- Institute of Cardiovascular Sciences, University College of London, London, UK.,Department of Cardiology, Barts Heart Centre, London, UK.,School of Medicine and Dentistry, Queen Mary University London, London, UK
| | - Carlos Collet
- Amsterdam University Medical Centre, University of Amsterdam, Amsterdam, the Netherlands
| | - Umit Coskun
- Division of Cardiovascular Medicine, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Joost Daemen
- Department of Cardiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - Jouke Dijkstra
- LKEB-Division of Image Processing, Department of Radiology, Leiden University Medical Centre, Leiden, the Netherlands
| | - Elazer Edelman
- Division of Cardiovascular Medicine, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA.,Institute for Medical Engineering and Science, MIT, Cambridge, MA, USA
| | - Paul Evans
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, UK
| | - Kim van der Heiden
- Department of Cardiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - Rod Hose
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, UK.,Department of Circulation and Imaging, NTNU, Trondheim, Norway
| | - Bon-Kwon Koo
- Department of Internal Medicine and Cardiovascular Center, Seoul National University Hospital, Seoul, Korea.,Institute of Aging, Seoul National University, Seoul, Korea
| | - Rob Krams
- School of Engineering and Materials Science Queen Mary University of London, London, UK
| | - Alison Marsden
- Departments of Bioengineering and Pediatrics, Institute of Computational and Mathematical Engineering, Stanford University, Stanford, CA, USA
| | - Francesco Migliavacca
- Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Milan, Italy
| | - Yoshinobu Onuma
- Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Andrew Ooi
- Department of Mechanical Engineering, Melbourne School of Engineering, The University of Melbourne, Melbourne, VIC, Australia
| | - Eric Poon
- Department of Mechanical Engineering, Melbourne School of Engineering, The University of Melbourne, Melbourne, VIC, Australia
| | - Habib Samady
- Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA
| | - Peter Stone
- Division of Cardiovascular Medicine, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Kuniaki Takahashi
- Amsterdam University Medical Centre, University of Amsterdam, Amsterdam, the Netherlands
| | - Dalin Tang
- Department of Mathematics, Southeast University, Nanjing, China; Mathematical Sciences Department, Worcester Polytechnic Institute, Worcester, MA, USA
| | - Vikas Thondapu
- Department of Medicine and Radiology, Melbourne Medical School, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, VIC, Australia.,Department of Mechanical Engineering, Melbourne School of Engineering, The University of Melbourne, Melbourne, VIC, Australia.,Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Erhan Tenekecioglu
- Department of Interventional Cardiology, Thoraxcentre, Erasmus Medical Centre, Rotterdam, the Netherlands
| | - Lucas Timmins
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT.,Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT
| | - Ryo Torii
- Department of Mechanical Engineering, University College London, UK
| | - Jolanda Wentzel
- Department of Cardiology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - Patrick Serruys
- Erasmus University Medical Center, Rotterdam, the Netherlands.,Imperial College London, London, UK.,Melbourne School of Engineering, University of Melbourne, Melbourne, Australia
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Eslami P, Hartman E, Karady J, Thondapu V, Albaghdadi M, Jin Z, Cefalo N, Marsden A, Coksun A, Lu M, Stone P, Wentzel J, Hoffmann U. Endothelial Shear Stress Calculation In Human Coronary Arteries: Comparison Between 3d Reconstructions Based On Invasive And Noninvasive Imaging. J Cardiovasc Comput Tomogr 2020. [DOI: 10.1016/j.jcct.2020.06.083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Contijoch F, Li B, Yang W, Silva-Sepulveda JA, Vodkin I, Printz B, Vavinskaya V, Hegde S, Marsden A, El-Sabrout H, Alshawabkeh L, Moore JW, El-Said H. Exercise MRI highlights heterogeneity in cardiovascular mechanics among patients with Fontan circulation: proposed protocol for routine evaluation. J Thorac Dis 2020; 12:1204-1212. [PMID: 32274201 PMCID: PMC7139092 DOI: 10.21037/jtd.2019.09.59] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Single ventricle physiology and palliation via the Fontan operation lead to a series of cardiovascular changes. In addition, organs such as the kidneys and liver have been shown to experience insults and subsequent injury. This has led to routine surveillance of patients. We present findings from a small cohort of patients that was deeply phenotyped to illustrate the need for comprehensive evaluation. A cohort of four Fontan patients with fairly high cardiovascular function was recruited 5–10 years post-Fontan. Patients underwent a rigorous clinical work-up after which a research MRI scan was performed during which (I) data were obtained during exercise to evaluate changes in stroke volume during supine exercise and (II) magnetic resonance angiograms with phase-contrast images were obtained for computational modeling of flows through the Fontan circulation at rest. Clinical measures were consistent with a fairly homogeneous high function cohort (peak oxygen consumption >20 mL/kg/min, robust response to exercise, peak ventilatory efficiency below levels associated with heart failure, MR-derived ejection fraction >50%). Liver evaluation did not reveal clear signs of cirrhosis or extensive fibrosis. However, we observed considerable variability (27–162%) in the increase in stroke index with exercise [100%±64% increase, 53.9±17.4 mL/beat m2 (rest), 101.1±20.7 mL/beat m2, (exercise)]. Computational flow modeling at rest in two patients also showed marked differences in flow distribution and shear stress. We report marked differences in both changes in stroke index during an exercise MRI protocol as well as computational flow patterns at rest suggesting different compensation strategies may be associated with high functioning Fontan patients. The observed heterogeneity illustrates the need for deep phenotyping to capture patient-specific adaptive mechanisms.
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Affiliation(s)
- Francisco Contijoch
- Department of Bioengineering, UC San Diego, La Jolla CA, USA.,Department of Radiology, UC San Diego, La Jolla CA, USA
| | - Bochao Li
- Department of Bioengineering, UC San Diego, La Jolla CA, USA
| | - Weiguang Yang
- Department of Pediatrics, Stanford University, Palo Alto, CA, USA
| | | | - Irine Vodkin
- Department of Medicine, UC San Diego, La Jolla, CA, USA
| | - Beth Printz
- Department of Pediatric Cardiology, Rady Children's Hospital, San Diego, CA, USA
| | | | - Sanjeet Hegde
- Department of Pediatric Cardiology, Rady Children's Hospital, San Diego, CA, USA
| | - Alison Marsden
- Department of Pediatrics, Stanford University, Palo Alto, CA, USA.,Department of Bioengineering, Stanford University, Palo Alto, CA, USA
| | - Hannah El-Sabrout
- Department of Society and Genetics, UC Los Angeles, Los Angeles, CA, USA
| | | | - John W Moore
- Department of Pediatric Cardiology, Rady Children's Hospital, San Diego, CA, USA
| | - Howaida El-Said
- Department of Pediatric Cardiology, Rady Children's Hospital, San Diego, CA, USA
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Eslami P, Tran J, Jin Z, Karady J, Sotoodeh R, Lu MT, Hoffmann U, Marsden A. Effect of Wall Elasticity on Hemodynamics and Wall Shear Stress in Patient-Specific Simulations in the Coronary Arteries. J Biomech Eng 2019; 142:2733769. [PMID: 31074768 DOI: 10.1115/1.4043722] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Indexed: 11/08/2022]
Abstract
Wall shear stress (WSS) has been shown to be associated with myocardial infarction (MI) and progression of atherosclerosis. Wall elasticity is an important feature of hemodynamic modeling affecting WSS calculations. The objective of this study was to investigate the role of wall elasticity on WSS, and justify use of either rigid or elastic models in future studies. Digital anatomic models of the aorta and coronaries were created based on coronary computed tomography angiography (CCTA) in four patients. Hemodynamics was computed in rigid and elastic models using a finite element flow solver. WSS in five timepoints in the cardiac cycle and time averaged wall shear stress (TAWSS) were compared between the models at each 3 mm subsegment and 4 arcs in cross sections along the centerlines of coronaries. In the left main (LM), proximal left anterior descending (LAD), left circumflex (LCX), and proximal right coronary artery (RCA) of the elastic model, the mean percent radial increase 5.95 ± 1.25, 4.02 ± 0.97, 4.08 ± 0.94, and 4.84 ± 1.05%, respectively. WSS at each timepoint in the cardiac cycle had slightly different values; however, when averaged over the cardiac cycle, there were negligible differences between the models. In both the subsegments (n = 704) and subarc analysis, TAWSS in the two models were highly correlated (r = 0.99). In investigation on the effect of coronary wall elasticity on WSS in CCTA-based models, the results of this study show no significant differences in TAWSS justifying using rigid wall models for future larger studies.
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Affiliation(s)
- Parastou Eslami
- Cardiac MR PET CT Program, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
| | - Justin Tran
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305
| | - Zexi Jin
- Cardiac MR PET CT Program, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
| | - Julia Karady
- Cardiac MR PET CT Program, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
| | - Romina Sotoodeh
- Cardiac MR PET CT Program, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
| | - Michael T Lu
- Cardiac MR PET CT Program, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
| | - Udo Hoffmann
- Cardiac MR PET CT Program, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
| | - Alison Marsden
- Departments of Bioengineering and Pediatrics, Institute of Computational and Mathematical Engineering, Stanford University, Stanford, CA 94305
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Maher G, Wilson N, Marsden A. Accelerating cardiovascular model building with convolutional neural networks. Med Biol Eng Comput 2019; 57:2319-2335. [PMID: 31446517 PMCID: PMC7250144 DOI: 10.1007/s11517-019-02029-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 08/09/2019] [Indexed: 10/26/2022]
Abstract
The objective of this work is to reduce the user effort required for 2D segmentation when building patient-specific cardiovascular models using the SimVascular cardiovascular modeling software package. The proposed method uses a fully convolutional neural network (FCNN) to generate 2D cardiovascular segmentations. Given vessel pathlines, the neural network generates 2D vessel enhancement images along the pathlines. Thereafter, vessel segmentations are extracted using the marching-squares algorithm, which are then used to construct 3D cardiovascular models. The neural network is trained using a novel loss function, tailored for partially labeled segmentation data. An automated quality control method is also developed, allowing promising segmentations to be selected. Compared with a threshold and level set algorithm, the FCNN method improved 2D segmentation accuracy across several metrics. The proposed quality control approach further improved the average DICE score by 25.8%. In tests with users of SimVascular, when using quality control, users accepted 80% of segmentations produced by the best performing FCNN. The FCNN cardiovascular model building method reduces the amount of manual segmentation effort required for patient-specific model construction, by as much as 73%. This leads to reduced turnaround time for cardiovascular simulations. While the method was used for cardiovascular model building, it is applicable to general tubular structures. Graphical Abstract Proposed FCNN-based cardiovascular model building pipeline. a.) Image data and vessel pathline supplied by the user. b.) Path information is used to extract image pixel intensities in plane perpendicular to the vessel path. c.) 2D images extracted along vessel pathlines are input to the FCNN. d.) FCNN acts on the input images to compute local vessel enhancement images. e.) Vessel enhancement images computed by the FCNN, the pixel values are between 0 and 1 indicating vessel tissue likelihood. f.) The marching-squares algorithm is appliedto each enhanced image to extract the central vessel segmentation. g.) 2D extracted vessel surface points overlayed on original input images. h.) The 2D vessel surface points are transformed back to 3D space. i.) 3D crosssectional vessel surfaces are interpolated along the pathline to form the final vessel model.
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Affiliation(s)
- Gabriel Maher
- Institute for Computational and Mathematical Engineering, Stanford University, Stanford, CA, USA.
| | - Nathan Wilson
- Open Source Medical Software Corporation, Los Angeles, CA, USA
| | - Alison Marsden
- Pediatric Cardiology, Bioengineering, Stanford University, Stanford, CA, USA
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Kung E, Corsini C, Marsden A, Vignon-Clementel I, Pennati G, Figliola R, Hsia TY. Multiscale Modeling of Superior Cavopulmonary Circulation: Hemi-Fontan and Bidirectional Glenn Are Equivalent. Semin Thorac Cardiovasc Surg 2019; 32:883-892. [PMID: 31520732 DOI: 10.1053/j.semtcvs.2019.09.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 09/04/2019] [Indexed: 11/11/2022]
Abstract
Superior cavopulmonary circulation (SCPC) can be achieved by either the Hemi-Fontan (hF) or Bidirectional Glenn (bG) connection. Debate remains as to which results in best hemodynamic results. Adopting patient-specific multiscale computational modeling, we examined both the local dynamics and global physiology to determine if surgical choice can lead to different hemodynamic outcomes. Six patients (age: 3-6 months) underwent cardiac magnetic resonance imaging and catheterization prior to SCPC surgery. For each patient: (1) a finite 3-dimensional (3D) volume model of the preoperative anatomy was constructed to include detailed definition of the distal branch pulmonary arteries, (2) virtual hF and bG operations were performed to create 2 SCPC 3D models, and (3) a specific lumped network representing each patient's entire cardiovascular circulation was developed from clinical data. Using a previously validated multiscale algorithm that couples the 3D models with lumped network, both local flow dynamics, that is, power loss, and global systemic physiology can be quantified. In 2 patients whose preoperative imaging demonstrated significant left pulmonary artery (LPA) stenosis, we performed virtual pulmonary arterioplasty to assess its effect. In one patient, the hF model showed higher power loss (107%) than the bG, while in 3, the power losses were higher in the bG models (18-35%). In the remaining 2 patients, the power loss differences were minor. Despite these variations, for all patients, there were no significant differences between the hF and bG models in hemodynamic or physiological outcomes, including cardiac output, superior vena cava pressure, right-left pulmonary flow distribution, and systemic oxygen delivery. In the 2 patients with LPA stenosis, arterioplasty led to better LPA flow (5-8%) while halving the power loss, but without important improvements in SVC pressure or cardiac output. Despite power loss differences, both hF and bG result in similar SCPC hemodynamics and physiology outcome. This suggests that for SCPC, the pre-existing patient-specific physiology and condition, such as pulmonary vascular resistance, are more deterministic in the hemodynamic performance than the type of surgical palliation. Multiscale modeling can be a decision-assist tool to assess whether an extensive LPA reconstruction is needed at the time of SCPC for LPA stenosis.
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Affiliation(s)
- Ethan Kung
- Clemson University, Clemson, South Carolina
| | | | | | - Irene Vignon-Clementel
- National Institute for Research in Computer Science and Automation (INRIA), Paris, France
| | | | | | - Tain-Yen Hsia
- Pediatric Cardiac Surgery, Yale New Haven Children's Hospital, New Haven, Connecticut.
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Mahil SK, Wilson N, Dand N, Reynolds NJ, Griffiths CEM, Emsley R, Marsden A, Evans I, Warren RB, Stocken D, Barker JN, Burden AD, Smith CH. Psoriasis treat to target: defining outcomes in psoriasis using data from a real-world, population-based cohort study (the British Association of Dermatologists Biologics and Immunomodulators Register, BADBIR). Br J Dermatol 2019; 182:1158-1166. [PMID: 31286471 PMCID: PMC7317460 DOI: 10.1111/bjd.18333] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/05/2019] [Indexed: 12/16/2022]
Abstract
Background The ‘treat to target’ paradigm improves outcomes and reduces costs in chronic disease management but is not yet established in psoriasis. Objectives To identify treatment targets in psoriasis using two common measures of disease activity: Psoriasis Area and Severity Index (PASI) and Physician's Global Assessment (PGA). Methods Data from a multicentre longitudinal U.K. cohort of patients with psoriasis receiving systemic or biologic therapies (British Association of Dermatologists Biologics and Immunomodulators Register, BADBIR) were used to identify absolute PASI thresholds for 90% (PASI 90) and 75% (PASI 75) improvements in baseline disease activity, using receiver operating characteristic curves. The relationship between PGA (clear, almost clear, mild, moderate, moderate–severe, severe) and PASI (range 0–72) was described, and the concordance between absolute and relative definitions of response was determined. The same approach was used to establish treatment response and eligibility definitions based on PGA. Results Data from 13 422 patients were available (58% male, 91% white ethnicity, mean age 44·9 years), including over 23 000 longitudinal PASI and PGA scores. An absolute PASI ≤ 2 was concordant with PASI 90 and an absolute PASI ≤ 4 was concordant with PASI 75 in 90% and 88% of cases, respectively. These findings were robust to subgroups of timing of assessment, baseline disease severity and treatment modality. PASI and PGA were strongly correlated (Spearman's rank correlation coefficient 0·92). The median PASI increased from 0 (interquartile range 0–0, range 0–23) to 19 (interquartile range 15–25, range 0–64) for PGA clear to severe, respectively. PGA clear/almost clear was concordant with PASI ≤ 2 in 90% of cases, and PGA moderate–severe severe was concordant with the National Institute for Health and Care Excellence PASI eligibility criteria for biologics in 81% of cases. Conclusions An absolute PASI ≤ 2 and PGA clear/almost clear represent relevant disease end points to inform treat‐to‐target management strategies in psoriasis. What's already known about this topic? The most commonly used relative disease activity measure in psoriasis is ≥ 90% improvement in Psoriasis Area and Severity Index (PASI 90); however, it has several limitations including dependency on a baseline severity assessment. Defining an absolute target disease activity end point in psoriasis has the potential to improve patient outcomes and reduce costs, as demonstrated by treat‐to‐target approaches in other chronic diseases such as hypertension and diabetes. The Physician's Global Assessment (PGA) is a popular alternative measure of psoriasis severity in daily practice; however, its utility has not been formally assessed with respect to PASI.
What does this study add? An absolute PASI ≤ 2 corresponds with PASI 90 response and is a relevant disease end point for treat‐to‐target approaches in psoriasis. There is a strong correlation between PASI and PGA. PGA moderate–severe/severe may serve as an alternative eligibility criterion for biologics to PASI‐based definitions, and PGA clear/almost clear is an appropriate alternative absolute treatment end point.
What are the clinical implications of this work? Absolute PASI ≤ 2 and PGA clear/almost clear represent relevant disease end points to inform treat‐to‐target management strategies in psoriasis.
Linked Editorial: Takeshita. Br J Dermatol 2020; 182:1075–1076.
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Affiliation(s)
- S K Mahil
- St John's Institute of Dermatology, Guy's and St Thomas' NHS Foundation Trust, London, U.K
| | - N Wilson
- Institute of Health and Society, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, U.K
| | - N Dand
- Department of Medical and Molecular Genetics, King's College London, London, U.K
| | - N J Reynolds
- Dermatological Sciences, Institute of Cellular Medicine, Medical School, Newcastle University, Newcastle upon Tyne, U.K.,Department of Dermatology, Royal Victoria Infirmary, Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, U.K
| | - C E M Griffiths
- Dermatology Centre, Salford Royal NHS Foundation Trust, University of Manchester, Manchester Academic Health Science Centre, NIHR Manchester Biomedical Research Centre, Manchester, U.K
| | - R Emsley
- Department of Biostatistics & Health Informatics, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, U.K
| | - A Marsden
- Centre for Biostatistics, School of Health Sciences, University of Manchester, Manchester Academic Health Science Centre, Manchester, U.K
| | - I Evans
- Dermatology Centre, Salford Royal NHS Foundation Trust, University of Manchester, Manchester Academic Health Science Centre, NIHR Manchester Biomedical Research Centre, Manchester, U.K
| | - R B Warren
- Dermatology Centre, Salford Royal NHS Foundation Trust, University of Manchester, Manchester Academic Health Science Centre, NIHR Manchester Biomedical Research Centre, Manchester, U.K
| | - D Stocken
- Clinical Trials Research Unit, Leeds Institute of Clinical Trials Research, University of Leeds, Leeds, U.K
| | - J N Barker
- St John's Institute of Dermatology, Guy's and St Thomas' NHS Foundation Trust, London, U.K
| | - A D Burden
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, U.K
| | - C H Smith
- St John's Institute of Dermatology, Guy's and St Thomas' NHS Foundation Trust, London, U.K
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Peirce-Cottler SM, Marsden A. Multiscale computational modeling of biomedical systems: current approaches and payoffs. Current Opinion in Biomedical Engineering 2019. [DOI: 10.1016/j.cobme.2019.12.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Rodefeld MD, Marsden A, Figliola R, Jonas T, Neary M, Giridharan GA. Cavopulmonary assist: Long-term reversal of the Fontan paradox. J Thorac Cardiovasc Surg 2019; 158:1627-1636. [PMID: 31564543 DOI: 10.1016/j.jtcvs.2019.06.112] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 06/13/2019] [Accepted: 06/14/2019] [Indexed: 01/16/2023]
Abstract
OBJECTIVE Fontan circulatory inefficiency can be addressed by replacing the missing subpulmonary power source to reverse the Fontan paradox. An implantable cavopulmonary assist device is described that will simultaneously reduce systemic venous pressure and increase pulmonary arterial pressure, improving preload and cardiac output, in a univentricular Fontan circulation on a long-term basis. METHODS A rotary blood pump that was based on the von Karman viscous pump was designed for implantation into the total cavopulmonary connection (TCPC). It will impart modest pressure energy to augment Fontan flow without risk of obstruction. In the event of rotational failure, it is designed to default to a passive flow diverter. Pressure-flow performance was characterized in vitro in a Fontan mock circulatory loop with blood analog. RESULTS The pump performed through the fully specified operating range, augmenting flow in all 4 directions of the TCPC. Pressure rise of 6 to 8 mm Hg was readily achieved, ranging to 14 mm Hg at highest speed (5600 rpm). Performance was consistent across a wide range of cardiac outputs. In stalled condition (0 rpm), there was no discernible pressure loss across the TCPC. CONCLUSIONS A blood pump technology is described that can reverse the Fontan paradox and may permit a surgical strategy of long-term biventricular maintenance of a univentricular Fontan circulation. The technology is intended for Fontan failure in which right-sided circulatory inefficiencies predominate and ventricular systolic function is preserved. It may also apply before clinical Fontan failure as health maintenance to preempt the progression of Fontan disease.
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Affiliation(s)
- Mark D Rodefeld
- Section of Cardiothoracic Surgery, Department of Surgery, Indiana University School of Medicine and James Whitcomb Riley Hospital for Children, Indianapolis, Ind.
| | - Alison Marsden
- Department of Bioengineering and Pediatrics, Stanford University, Stanford, Calif
| | - Richard Figliola
- Department of Mechanical Engineering, Clemson University, Clemson, SC
| | | | - Michael Neary
- Rotor Bearing Technology and Software Inc, Phoenixville, Pa
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Zhong L, Schrauben EM, Garcia J, Uribe S, Grieve SM, Elbaz MS, Barker AJ, Geiger J, Nordmeyer S, Marsden A, Carlsson M, Tan RS, Garg P, Westenberg JJ, Markl M, Ebbers T. Intracardiac 4D Flow MRI in Congenital Heart Disease: Recommendations on Behalf of the ISMRM Flow & Motion Study Group. J Magn Reson Imaging 2019. [DOI: 10.1002/jmri.26893] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Liang Zhong
- National Heart Centre Singapore, Singapore; Duke-NUS Medical School Singapore; National University of Singapore; Singapore
| | | | - Julio Garcia
- Departments of Radiology and Cardiac Sciences; University of Calgary; Calgary Canada
| | - Sergio Uribe
- Millennium Nucleus for Cardiovascular Magnetic Resonance, Radiology Department and Biomedical Imaging Center, School of Medicine; Pontifica Universidad Catolica de Chile; Chile
| | - Stuart M. Grieve
- Sydney Translational Imaging Laboratory, Heart Research Institute, Charles Perkins Centre, University of Sydney, Australia; Department of Radiology, Royal Prince Alfred Hospital; Camperdown Australia
| | - Mohammed S.M. Elbaz
- Department of Radiology, Feinberg School of Medicine; Northwestern University; Chicago Illinois USA
| | - Alex J. Barker
- Department of Radiology and Bioengineering; University of Colorado, Anschutz Medical Campus; Denver Colorado USA
| | - Julia Geiger
- Department of Diagnostic Imaging, University Children's Hospital Zurich; Switzerland
| | - Sarah Nordmeyer
- Department of Pediatric Cardiology and Congenital Heart Diseases German Heart Center Berlin Germany; Institute for Cardiovascular Computer-assisted Medicine, Charité - Universitätsmedizin; Berlin Germany
| | - Alison Marsden
- Departments of Pediatrics and Bioengineering; Stanford University; Stanford California USA
| | | | - Ru-San Tan
- National Heart Centre Singapore, Singapore; Duke-NUS Medical School Singapore; National University of Singapore; Singapore
| | | | | | - Michael Markl
- Department of Radiology, Feinberg School of Medicine; Northwestern University; Chicago Illinois USA
| | - Tino Ebbers
- Department of Medical and Health Sciences and Center for Medical Imaging Sciences and Visualization, Linköping University; Sweden
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Zhong L, Schrauben EM, Garcia J, Uribe S, Grieve SM, Elbaz MSM, Barker AJ, Geiger J, Nordmeyer S, Marsden A, Carlsson M, Tan RS, Garg P, Westenberg JJM, Markl M, Ebbers T. Intracardiac 4D Flow MRI in Congenital Heart Disease: Recommendations on Behalf of the ISMRM Flow & Motion Study Group. J Magn Reson Imaging 2019; 50:677-681. [PMID: 31317587 DOI: 10.1002/jmri.26858] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 06/21/2019] [Accepted: 06/21/2019] [Indexed: 11/08/2022] Open
Abstract
LEVEL OF EVIDENCE 5 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2019;50:677-681.
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Affiliation(s)
- Liang Zhong
- National Heart Centre Singapore, Singapore; Duke-NUS Medical School Singapore, National University of Singapore, Singapore
| | - Eric M Schrauben
- Translational Medicine, Hospital for Sick Children, Toronto, Canada
| | - Julio Garcia
- Departments of Radiology and Cardiac Sciences, University of Calgary, Calgary, Canada
| | - Sergio Uribe
- Millennium Nucleus for Cardiovascular Magnetic Resonance, Radiology Department and Biomedical Imaging Center, School of Medicine, Pontifica Universidad Catolica de Chile, Chile
| | - Stuart M Grieve
- Sydney Translational Imaging Laboratory, Heart Research Institute, Charles Perkins Centre, University of Sydney, Australia; Department of Radiology, Royal Prince Alfred Hospital, Camperdown, Australia
| | - Mohammed S M Elbaz
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Alex J Barker
- Department of Radiology and Bioengineering, University of Colorado, Anschutz Medical Campus, Denver, Colorado, USA
| | - Julia Geiger
- Department of Diagnostic Imaging, University Children's Hospital Zurich, Switzerland
| | - Sarah Nordmeyer
- Department of Pediatric Cardiology and Congenital Heart Diseases German Heart Center Berlin Germany; Institute for Cardiovascular Computer-assisted Medicine, Charité - Universitätsmedizin, Berlin, Germany
| | - Alison Marsden
- Departments of Pediatrics and Bioengineering, Stanford University, Stanford, California, USA
| | | | - Ru-San Tan
- National Heart Centre Singapore, Singapore; Duke-NUS Medical School Singapore, National University of Singapore, Singapore
| | | | | | - Michael Markl
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Tino Ebbers
- Department of Medical and Health Sciences and Center for Medical Imaging Sciences and Visualization, Linköping University, Sweden
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Eslami P, Marsden A, Tran J, Lo J, Sotoodeh R, Coskun A, Stone P, Hoffmann U, Lu M. ENDOTHELIAL SHEAR STRESS DERIVED FROM SERIAL NONINVASIVE CORONARY CTA: EFFECT OF WALL ELASTICITY IN A FEASIBILITY STUDY. J Am Coll Cardiol 2019. [DOI: 10.1016/s0735-1097(19)32248-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Warren RB, Marsden A, Tomenson B, Mason KJ, Soliman MM, Burden AD, Reynolds NJ, Stocken D, Emsley R, Griffiths CEM, Smith C. Identifying demographic, social and clinical predictors of biologic therapy effectiveness in psoriasis: a multicentre longitudinal cohort study. Br J Dermatol 2018; 180:1069-1076. [PMID: 30155885 PMCID: PMC6519065 DOI: 10.1111/bjd.16776] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/08/2018] [Indexed: 01/28/2023]
Abstract
Background Biologic therapies have revolutionized the treatment of moderate‐to‐severe psoriasis. However, for reasons largely unknown, many patients do not respond or lose response to these drugs. Objectives To evaluate demographic, social and clinical factors that could be used to predict effectiveness and stratify response to biologic therapies in psoriasis. Methods Using a multicentre, observational, prospective pharmacovigilance study (BADBIR), we identified biologic‐naive patients starting biologics with outcome data at 6 (n = 3079) and 12 (n = 3110) months. Associations between 31 putative predictors and outcomes were investigated in univariate and multivariable regression analyses. Potential stratifiers of treatment response were investigated with statistical interactions. Results Eight factors associated with reduced odds of achieving ≥ 90% improvement in Psoriasis Area and Severity Index (PASI 90) at 6 months were identified (described as odds ratio and 95% confidence interval): demographic (female sex, 0·78, 0·66–0·93); social (unemployment, 0·67, 0·45–0·99); unemployment due to ill health (0·62, 0·48–0·82); ex‐ and current smoking (0·81, 0·66–0·99 and 0·79, 0·63–0·99, respectively); clinical factors (high weight, 0·99, 0·99–0·99); psoriasis of the palms and/or soles (0·75, 0·61–0·91); and presence of small plaques only compared with small and large plaques (0·78, 0·62–0·96). White ethnicity (1·48, 1·12–1·97) and higher baseline PASI (1·04, 1·03–1·04) were associated with increased odds of achieving PASI 90. The findings were largely consistent at 12 months. There was little evidence for predictors of differential treatment response. Conclusions Psoriasis phenotype and potentially modifiable factors are associated with poor outcomes with biologics, underscoring the need for lifestyle management. Effect sizes suggest that these factors alone cannot inform treatment selection. What's already known about this topic? Biologic therapy used in the treatment of moderate‐to‐severe psoriasis differs in its effectiveness across patients. Previous research has indicated that patients with a higher body mass index, who smoke or who have smoked, and with a lower baseline Psoriasis Area and Severity Index (PASI) are less likely to have a good outcome with biologic therapy for the treatment of moderate‐to‐severe psoriasis.
What does this study add? This large‐scale study in a real‐world setting confirms that weight, smoking status and baseline PASI are associated with effectiveness of biologic therapy. There is evidence that non‐white ethnicity, female sex, unemployment, psoriasis of the palms and soles and the presence of small chronic plaques are associated with poor outcomes with biologics. There is some evidence that men have a comparatively worse response to etanercept, relative to adalimumab, than women. Otherwise, most factors do not appear to be predictors of differential treatment response.
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Affiliation(s)
- R B Warren
- Dermatology Centre, Salford Royal NHS Foundation Trust, The University of Manchester, Manchester Academic Health Science Centre, NIHR Manchester Biomedical Research Centre, Manchester, U.K
| | - A Marsden
- Centre for Biostatistics, School of Health Sciences, The University of Manchester, Manchester Academic Health Science Centre, Manchester, U.K
| | - B Tomenson
- Centre for Biostatistics, School of Health Sciences, The University of Manchester, Manchester Academic Health Science Centre, Manchester, U.K
| | - K J Mason
- Division of Musculoskeletal and Dermatological Sciences, The University of Manchester, Manchester, U.K
| | - M M Soliman
- Department of Pharmacy Practice, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
| | - A D Burden
- Department of Dermatology, Royal Infirmary of Edinburgh, Edinburgh, U.K
| | - N J Reynolds
- Dermatological Sciences, Institute of Cellular Medicine, Medical School, Newcastle University, NIHR Newcastle Biomedical Research Centre and Department of Dermatology, Royal Victoria Infirmary, Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, U.K
| | - D Stocken
- Clinical Trials Research Unit, Leeds Institute of Clinical Trials Research, University of Leeds, Leeds, U.K
| | - R Emsley
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, U.K
| | - C E M Griffiths
- Dermatology Centre, Salford Royal NHS Foundation Trust, The University of Manchester, Manchester Academic Health Science Centre, NIHR Manchester Biomedical Research Centre, Manchester, U.K
| | - C Smith
- St John's Institute of Dermatology, Guy's and St Thomas' NHS Foundation Trust, London, U.K
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Abiri A, Ding Y, Abiri P, Packard RRS, Vedula V, Marsden A, Kuo CCJ, Hsiai TK. Simulating Developmental Cardiac Morphology in Virtual Reality Using a Deformable Image Registration Approach. Ann Biomed Eng 2018; 46:2177-2188. [PMID: 30112710 DOI: 10.1007/s10439-018-02113-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 08/07/2018] [Indexed: 10/28/2022]
Abstract
While virtual reality (VR) has potential in enhancing cardiovascular diagnosis and treatment, prerequisite labor-intensive image segmentation remains an obstacle for seamlessly simulating 4-dimensional (4-D, 3-D + time) imaging data in an immersive, physiological VR environment. We applied deformable image registration (DIR) in conjunction with 3-D reconstruction and VR implementation to recapitulate developmental cardiac contractile function from light-sheet fluorescence microscopy (LSFM). This method addressed inconsistencies that would arise from independent segmentations of time-dependent data, thereby enabling the creation of a VR environment that fluently simulates cardiac morphological changes. By analyzing myocardial deformation at high spatiotemporal resolution, we interfaced quantitative computations with 4-D VR. We demonstrated that our LSFM-captured images, followed by DIR, yielded average dice similarity coefficients of 0.92 ± 0.05 (n = 510) and 0.93 ± 0.06 (n = 240) when compared to ground truth images obtained from Otsu thresholding and manual segmentation, respectively. The resulting VR environment simulates a wide-angle zoomed-in view of motion in live embryonic zebrafish hearts, in which the cardiac chambers are undergoing structural deformation throughout the cardiac cycle. Thus, this technique allows for an interactive micro-scale VR visualization of developmental cardiac morphology to enable high resolution simulation for both basic and clinical science.
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Affiliation(s)
- Arash Abiri
- Department of Bioengineering, University of California, Los Angeles, CA, 90095, USA.,Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA.,Department of Biomedical Engineering, University of California, Irvine, CA, 92697, USA
| | - Yichen Ding
- Department of Bioengineering, University of California, Los Angeles, CA, 90095, USA.,Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Parinaz Abiri
- Department of Bioengineering, University of California, Los Angeles, CA, 90095, USA.,Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - René R Sevag Packard
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Vijay Vedula
- Department of Pediatrics (Cardiology), Stanford University, Stanford, CA, 94305, USA
| | - Alison Marsden
- Department of Pediatrics (Cardiology), Stanford University, Stanford, CA, 94305, USA.,Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA.,Institute for Computational and Mathematical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - C-C Jay Kuo
- Department of Electrical Engineering, University of Southern California, Los Angeles, CA, 90089, USA
| | - Tzung K Hsiai
- Department of Bioengineering, University of California, Los Angeles, CA, 90095, USA. .,Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA. .,Medical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA.
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Hsu JJ, Chen J, Vedula V, Chen C, Lee J, Tintut Y, Demer LL, Marsden A, Hsiai TK. Abstract 278: Developmental Contractile Function Modulates Notch1b-Mediated Valvular Leaflet Development. Arterioscler Thromb Vasc Biol 2018. [DOI: 10.1161/atvb.38.suppl_1.278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cardiac valve formation is a complex process affected by blood flow, but the mechanotransduction mechanisms underlying valvulogenesis remain incompletely understood. Using four-dimensional (4-D) light-sheet imaging, we evaluated the effects of pharmacological and genetic hemodynamic modulation on ventriculobulbar (VB) valve formation in the outflow tracts (OFT) of transgenic
Tg(fli1a:GFP)
zebrafish embryos. Treatment with isoproterenol increased heart rate and cardiac contractility, increased
Notch1b
activity in the OFT, and resulted in the development of hyperplastic VB valve leaflets. While metoprolol treatment reduced heart rate without affecting contractility, there were no significant differences in
Notch1b
expression in the OFT or valve morphology. Meanwhile, BDM treatment significantly reduced heart rate and contractility, reduced
Notch1b
expression in the OFT, and prevented the formation of normal VB valve leaflets. Similarly, no VB valve leaflets were seen in the
cloche
mutant or
Tnnt2a
MO-injected embryos. Additionally, increasing blood viscosity by micro-injection of embryos with
EPO
mRNA increased
Notch1b
activity in the OFT and led to hyperplastic VB valve leaflets, but decreasing blood viscosity by
gata1a
MO micro-injection did not have any significant effect. Further, activation of the Notch signaling pathway with micro-injection of
NICD
mRNA resulted in hyperplastic VB valve leaflets. By integrating advanced optics with zebrafish genetics at the interface of developmental cardiac mechanics, we provide mechanotransduction insights into cardiac valve development within the OFT.
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Conover T, Hlavacek AM, Migliavacca F, Kung E, Dorfman A, Figliola RS, Hsia TY, Taylor A, Khambadkone S, Schievano S, de Leval M, Hsia TY, Bove E, Dorfman A, Baker GH, Hlavacek A, Migliavacca F, Pennati G, Dubini G, Marsden A, Vignon-Clementel I, Figliola R, McGregor J. An interactive simulation tool for patient-specific clinical decision support in single-ventricle physiology. J Thorac Cardiovasc Surg 2018; 155:712-721. [DOI: 10.1016/j.jtcvs.2017.09.046] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 08/20/2017] [Accepted: 09/10/2017] [Indexed: 10/18/2022]
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Schmidt T, Rosenthal D, Reinhartz O, Riemer K, He F, Hsia TY, Marsden A, Kung E. Superior performance of continuous over pulsatile flow ventricular assist devices in the single ventricle circulation: A computational study. J Biomech 2017; 52:48-54. [DOI: 10.1016/j.jbiomech.2016.12.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 11/15/2016] [Accepted: 12/03/2016] [Indexed: 10/20/2022]
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Farrar G, Suinesiaputra A, Gilbert K, Perry JC, Hegde S, Marsden A, Young AA, Omens JH, McCulloch AD. Atlas-Based Ventricular Shape Analysis for Understanding Congenital Heart Disease. Prog Pediatr Cardiol 2016; 43:61-69. [PMID: 28082823 DOI: 10.1016/j.ppedcard.2016.07.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Congenital heart disease is associated with abnormal ventricular shape that can affect wall mechanics and may be predictive of long-term adverse outcomes. Atlas-based parametric shape analysis was used to analyze ventricular geometries of eight adolescent or adult single-ventricle CHD patients with tricuspid atresia and Fontans. These patients were compared with an "atlas" of non-congenital asymptomatic volunteers, resulting in a set of z-scores which quantify deviations from the control population distribution on a patient-by-patient basis. We examined the potential of these scores to: (1) quantify abnormalities of ventricular geometry in single ventricle physiologies relative to the normal population; (2) comprehensively quantify wall motion in CHD patients; and (3) identify possible relationships between ventricular shape and wall motion that may reflect underlying functional defects or remodeling in CHD patients. CHD ventricular geometries at end-diastole and end-systole were individually compared with statistical shape properties of an asymptomatic population from the Cardiac Atlas Project. Shape analysis-derived model properties, and myocardial wall motions between end-diastole and end-systole, were compared with physician observations of clinical functional parameters. Relationships between altered shape and altered function were evaluated via correlations between atlas-based shape and wall motion scores. Atlas-based shape analysis identified a diverse set of specific quantifiable abnormalities in ventricular geometry or myocardial wall motion in all subjects. Moreover, this initial cohort displayed significant relationships between specific shape abnormalities such as increased ventricular sphericity and functional defects in myocardial deformation, such as decreased long-axis wall motion. These findings suggest that atlas-based ventricular shape analysis may be a useful new tool in the management of patients with CHD who are at risk of impaired ventricular wall mechanics and chamber remodeling.
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Affiliation(s)
- Genevieve Farrar
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Avan Suinesiaputra
- Department of Anatomy and Medical Imaging, University of Auckland, Auckland, NZ
| | - Kathleen Gilbert
- Department of Anatomy and Medical Imaging, University of Auckland, Auckland, NZ
| | - James C Perry
- Division of Cardiology, Rady Children's Hospital, San Diego, CA, USA; Department of Pediatrics, University of California San Diego, La Jolla, CA, USA
| | - Sanjeet Hegde
- Division of Cardiology, Rady Children's Hospital, San Diego, CA, USA; Department of Pediatrics, University of California San Diego, La Jolla, CA, USA
| | - Alison Marsden
- Department of Pediatrics, Stanford University, Stanford, CA, USA
| | - Alistair A Young
- Department of Anatomy and Medical Imaging, University of Auckland, Auckland, NZ
| | - Jeffrey H Omens
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA; Department of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Andrew D McCulloch
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA; Department of Medicine, University of California San Diego, La Jolla, CA, USA
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Ward E, Schiavazzi D, Sood D, Lane J, Owens E, Marsden A, Barleben A. CT FFR Can Accurately Identify Culprit Lesions In Aorto-Iliac Occlusive Disease Using Minimally-Invasive Techniques. Ann Vasc Surg 2016. [DOI: 10.1016/j.avsg.2016.05.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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40
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Gilbert K, Farrar G, Cowan BR, Suinesiaputra A, Occleshaw C, Pontre B, Perry J, Hegde S, Marsden A, Omens J, McCulloch A, Young AA. Creating shape templates for patient specific biventricular modeling in congenital heart disease. Annu Int Conf IEEE Eng Med Biol Soc 2016; 2015:679-82. [PMID: 26736353 DOI: 10.1109/embc.2015.7318453] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Survival rates for infants with congenital heart disease (CHD) are improving, resulting in a growing population of adults with CHD. However, the analysis of left and right ventricular function is very time-consuming owing to the variety of congenital morphologies. Efficient customization of patient geometry and function depends on high quality shape templates specifically designed for the application. In this paper, we combine a method for creating finite element shape templates with an interactive template customization to patient MRI examinations. This enables different templates to be chosen depending on patient morphology. To demonstrate this pipeline, a new biventricular template with 162 elements was created and tested in place of an existing 82-element template. The method was able to provide fast interactive biventricular analysis with 0.31 sec per edit response time. The new template was customized to 13 CHD patients with similar biventricular topology, showing improved performance over the previous template and good agreement with clinical indices.
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Meoli A, Cutrì E, Krishnamurthy A, Dubini G, Migliavacca F, Hsia TY, Pennati G, Taylor A, Giardini A, Khambadkone S, Schievano S, de Leval M, Hsia TY, Bove E, Dorfman A, Baker GH, Hlavacek A, Migliavacca F, Pennati G, Dubini G, Marsden A, Feinstein J, Vignon-Clementel I, Figliola R, McGregor J. A multiscale model for the study of cardiac biomechanics in single-ventricle surgeries: a clinical case. Interface Focus 2015; 5:20140079. [PMID: 25844151 DOI: 10.1098/rsfs.2014.0079] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Complex congenital heart disease characterized by the underdevelopment of one ventricular chamber (single ventricle (SV) circulation) is normally treated with a three-stage surgical repair. This study aims at developing a multiscale computational framework able to couple a patient-specific three-dimensional finite-element model of the SV to a patient-specific lumped parameter (LP) model of the whole circulation, in a closed-loop fashion. A sequential approach was carried out: (i) cardiocirculatory parameters were estimated by using a fully LP model; (ii) ventricular material parameters and unloaded geometry were identified by means of the stand-alone, three-dimensional model of the SV; and (iii) the three-dimensional model of SV was coupled to the LP model of the circulation, thus closing the loop and creating a multiscale model. Once the patient-specific multiscale model was set using pre-operative clinical data, the virtual surgery was performed, and the post-operative conditions were simulated. This approach allows the analysis of local information on ventricular function as well as global parameters of the cardiovascular system. This methodology is generally applicable to patients suffering from SV disease for surgical planning at different stages of treatment. As an example, a clinical case from stage 1 to stage 2 is considered here.
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Affiliation(s)
- Alessio Meoli
- Laboratory of Biological Structure Mechanics, Chemistry, Materials and Chemical Engineering Department 'Giulio Natta', Politecnico di Milano, Milan , Italy
| | - Elena Cutrì
- Laboratory of Biological Structure Mechanics, Chemistry, Materials and Chemical Engineering Department 'Giulio Natta', Politecnico di Milano, Milan , Italy
| | | | - Gabriele Dubini
- Laboratory of Biological Structure Mechanics, Chemistry, Materials and Chemical Engineering Department 'Giulio Natta', Politecnico di Milano, Milan , Italy
| | - Francesco Migliavacca
- Laboratory of Biological Structure Mechanics, Chemistry, Materials and Chemical Engineering Department 'Giulio Natta', Politecnico di Milano, Milan , Italy
| | - Tain-Yen Hsia
- Department of Cardiothoracic Surgery , Great Ormond Street Hospital for Children, NHS Foundation Trust , London WC1N 3JH , UK
| | - Giancarlo Pennati
- Laboratory of Biological Structure Mechanics, Chemistry, Materials and Chemical Engineering Department 'Giulio Natta', Politecnico di Milano, Milan , Italy
| | | | - Andrew Taylor
- Laboratory of Biological Structure Mechanics, Chemistry, Materials and Chemical Engineering Department 'Giulio Natta', Politecnico di Milano, Milan , Italy
| | - Alessandro Giardini
- Laboratory of Biological Structure Mechanics, Chemistry, Materials and Chemical Engineering Department 'Giulio Natta', Politecnico di Milano, Milan , Italy
| | - Sachin Khambadkone
- Laboratory of Biological Structure Mechanics, Chemistry, Materials and Chemical Engineering Department 'Giulio Natta', Politecnico di Milano, Milan , Italy
| | - Silvia Schievano
- Laboratory of Biological Structure Mechanics, Chemistry, Materials and Chemical Engineering Department 'Giulio Natta', Politecnico di Milano, Milan , Italy
| | - Marc de Leval
- Laboratory of Biological Structure Mechanics, Chemistry, Materials and Chemical Engineering Department 'Giulio Natta', Politecnico di Milano, Milan , Italy
| | - T-Y Hsia
- Laboratory of Biological Structure Mechanics, Chemistry, Materials and Chemical Engineering Department 'Giulio Natta', Politecnico di Milano, Milan , Italy
| | - Edward Bove
- Laboratory of Biological Structure Mechanics, Chemistry, Materials and Chemical Engineering Department 'Giulio Natta', Politecnico di Milano, Milan , Italy
| | - Adam Dorfman
- Laboratory of Biological Structure Mechanics, Chemistry, Materials and Chemical Engineering Department 'Giulio Natta', Politecnico di Milano, Milan , Italy
| | - G Hamilton Baker
- Laboratory of Biological Structure Mechanics, Chemistry, Materials and Chemical Engineering Department 'Giulio Natta', Politecnico di Milano, Milan , Italy
| | - Anthony Hlavacek
- Laboratory of Biological Structure Mechanics, Chemistry, Materials and Chemical Engineering Department 'Giulio Natta', Politecnico di Milano, Milan , Italy
| | - Francesco Migliavacca
- Laboratory of Biological Structure Mechanics, Chemistry, Materials and Chemical Engineering Department 'Giulio Natta', Politecnico di Milano, Milan , Italy
| | - Giancarlo Pennati
- Laboratory of Biological Structure Mechanics, Chemistry, Materials and Chemical Engineering Department 'Giulio Natta', Politecnico di Milano, Milan , Italy
| | - Gabriele Dubini
- Laboratory of Biological Structure Mechanics, Chemistry, Materials and Chemical Engineering Department 'Giulio Natta', Politecnico di Milano, Milan , Italy
| | - Alison Marsden
- Laboratory of Biological Structure Mechanics, Chemistry, Materials and Chemical Engineering Department 'Giulio Natta', Politecnico di Milano, Milan , Italy
| | - Jeffrey Feinstein
- Laboratory of Biological Structure Mechanics, Chemistry, Materials and Chemical Engineering Department 'Giulio Natta', Politecnico di Milano, Milan , Italy
| | - Irene Vignon-Clementel
- Laboratory of Biological Structure Mechanics, Chemistry, Materials and Chemical Engineering Department 'Giulio Natta', Politecnico di Milano, Milan , Italy
| | - Richard Figliola
- Laboratory of Biological Structure Mechanics, Chemistry, Materials and Chemical Engineering Department 'Giulio Natta', Politecnico di Milano, Milan , Italy
| | - John McGregor
- Laboratory of Biological Structure Mechanics, Chemistry, Materials and Chemical Engineering Department 'Giulio Natta', Politecnico di Milano, Milan , Italy
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Figliola R, Esmaily-Moghadam M, Zhou J, Hsia TY, Marsden A. THE ASSISTED BIDIRECTIONAL GLENN: AN IN VITRO AND IN SILICO STUDY OF A SURGICAL APPROACH FOR FIRST STAGE SINGLE VENTRICLE HEART PALLIATION. J Am Coll Cardiol 2015. [DOI: 10.1016/s0735-1097(15)60518-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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43
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Esmaily-Moghadam M, Murtuza B, Hsia TY, Marsden A. Simulations reveal adverse hemodynamics in patients with multiple systemic to pulmonary shunts. J Biomech Eng 2015; 137:2087211. [PMID: 25531794 DOI: 10.1115/1.4029429] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Indexed: 11/08/2022]
Abstract
For newborns diagnosed with pulmonary atresia or severe pulmonary stenosis leading to insufficient pulmonary blood flow, cyanosis can be mitigated with placement of a modified Blalock-Taussig shunt (MBTS) between the innominate and pulmonary arteries. In some clinical scenarios, patients receive two systemic-to-pulmonary connections, either by leaving the patent ductus arteriosus (PDA) open or by adding an additional central shunt (CS) in conjunction with the MBTS. This practice has been motivated by the thinking that an additional source of pulmonary blood flow could beneficially increase pulmonary flow and provide the security of an alternate pathway in case of thrombosis. However, there have been clinical reports of premature shunt occlusion when more than one shunt is employed, leading to speculation that multiple shunts may in fact lead to unfavorable hemodynamics and increased mortality. In this study, we hypothesize that multiple shunts may lead to undesirable flow competition, resulting in increased residence time (RT) and elevated risk of thrombosis, as well as pulmonary overcirculation. Computational fluid dynamics-based multiscale simulations were performed to compare a range of shunt configurations and systematically quantify flow competition, pulmonary circulation, and other clinically relevant parameters. In total, 23 cases were evaluated by systematically changing the PDA/CS diameter, pulmonary vascular resistance (PVR), and MBTS position and compared by quantifying oxygen delivery (OD) to the systemic and coronary beds, wall shear stress (WSS), oscillatory shear index (OSI), WSS gradient (WSSG), and RT in the pulmonary artery (PA), and MBTS. Results showed that smaller PDA/CS diameters can lead to flow conditions consistent with increased thrombus formation due to flow competition in the PA, and larger PDA/CS diameters can lead to insufficient OD due to pulmonary hyperfusion. In the worst case scenario, it was found that multiple shunts can lead to a 160% increase in RT and a 10% decrease in OD. Based on the simulation results presented in this study, clinical outcomes for patients receiving multiple shunts should be critically investigated, as this practice appears to provide no benefit in terms of OD and may actually increase thrombotic risk.
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44
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Kung E, Pennati G, Migliavacca F, Hsia TY, Figliola R, Marsden A, Giardini A. A simulation protocol for exercise physiology in Fontan patients using a closed loop lumped-parameter model. J Biomech Eng 2015; 136:1852723. [PMID: 24658635 DOI: 10.1115/1.4027271] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Accepted: 03/24/2014] [Indexed: 11/08/2022]
Abstract
BACKGROUND Reduced exercise capacity is nearly universal among Fontan patients, though its etiology is not yet fully understood. While previous computational studies have attempted to model Fontan exercise, they did not fully account for global physiologic mechanisms nor directly compare results against clinical and physiologic data. METHODS In this study, we developed a protocol to simulate Fontan lower-body exercise using a closed-loop lumped-parameter model describing the entire circulation. We analyzed clinical exercise data from a cohort of Fontan patients, incorporated previous clinical findings from literature, quantified a comprehensive list of physiological changes during exercise, translated them into a computational model of the Fontan circulation, and designed a general protocol to model Fontan exercise behavior. Using inputs of patient weight, height, and if available, patient-specific reference heart rate (HR) and oxygen consumption, this protocol enables the derivation of a full set of parameters necessary to model a typical Fontan patient of a given body-size over a range of physiologic exercise levels. RESULTS In light of previous literature data and clinical knowledge, the model successfully produced realistic trends in physiological parameters with exercise level. Applying this method retrospectively to a set of clinical Fontan exercise data, direct comparison between simulation results and clinical data demonstrated that the model successfully reproduced the average exercise response of a cohort of typical Fontan patients. CONCLUSION This work is intended to offer a foundation for future advances in modeling Fontan exercise, highlight the needs in clinical data collection, and provide clinicians with quantitative reference exercise physiologies for Fontan patients.
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45
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Affiliation(s)
- Ethan Kung
- Department of Mechanical Engineering, Clemson University, Clemson, South Carolina, USA
| | - Alison Marsden
- Department of Mechanical Engineering, University of California San Diego, San Diego, California, USA
| | - Catriona Baker
- Department of Cardiothoracic Surgery, Great Ormond Street Hospital for Children, London, UK
| | | | - Richard Figliola
- Department of Mechanical Engineering, Clemson University, Clemson, South Carolina, USA
| | - Tain-Yen Hsia
- Department of Cardiothoracic Surgery, Great Ormond Street Hospital for Children, London, UK
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46
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Corsini C, Baker C, Baretta A, Biglino G, Hlavacek AM, Hsia TY, Kung E, Marsden A, Migliavacca F, Vignon-Clementel I, Pennati G. Integration of Clinical Data Collected at Different Times for Virtual Surgery in Single Ventricle Patients: A Case Study. Ann Biomed Eng 2014; 43:1310-20. [DOI: 10.1007/s10439-014-1113-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 09/05/2014] [Indexed: 11/25/2022]
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47
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Kung E, Perry JC, Davis C, Migliavacca F, Pennati G, Giardini A, Hsia TY, Marsden A. Computational modeling of pathophysiologic responses to exercise in Fontan patients. Ann Biomed Eng 2014; 43:1335-47. [PMID: 25260878 DOI: 10.1007/s10439-014-1131-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 09/19/2014] [Indexed: 11/29/2022]
Abstract
Reduced exercise capacity is nearly universal among Fontan patients. Although many factors have emerged as possible contributors, the degree to which each impacts the overall hemodynamics is largely unknown. Computational modeling provides a means to test hypotheses of causes of exercise intolerance via precisely controlled virtual experiments and measurements. We quantified the physiological impacts of commonly encountered, clinically relevant dysfunctions introduced to the exercising Fontan system via a previously developed lumped-parameter model of Fontan exercise. Elevated pulmonary arterial pressure was observed in all cases of dysfunction, correlated with lowered cardiac output (CO), and often mediated by elevated atrial pressure. Pulmonary vascular resistance was not the most significant factor affecting exercise performance as measured by CO. In the absence of other dysfunctions, atrioventricular valve insufficiency alone had significant physiological impact, especially under exercise demands. The impact of isolated dysfunctions can be linearly summed to approximate the combined impact of several dysfunctions occurring in the same system. A single dominant cause of exercise intolerance was not identified, though several hypothesized dysfunctions each led to variable decreases in performance. Computational predictions of performance improvement associated with various interventions should be weighed against procedural risks and potential complications, contributing to improvements in routine patient management protocol.
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Affiliation(s)
- Ethan Kung
- Mechanical Engineering Department, Clemson University, Clemson, SC, 29634, USA
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48
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Kung E, Pennati G, Migliavacca F, Hsia TY, Figliola R, Marsden A, Giardini A. Errata: “A Simulation Protocol for Exercise Physiology in Fontan Patients Using a Closed Loop Lumped-Parameter Model” [Journal of Biomechanical Engineering, 2014, 136(8), p. 081007, DOI:10.1115/1.4027271]. J Biomech Eng 2014. [DOI: 10.1115/1.4028108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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49
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Bao G, Bazilevs Y, Chung JH, Decuzzi P, Espinosa HD, Ferrari M, Gao H, Hossain SS, Hughes TJR, Kamm RD, Liu WK, Marsden A, Schrefler B. USNCTAM perspectives on mechanics in medicine. J R Soc Interface 2014; 11:20140301. [PMID: 24872502 PMCID: PMC4208360 DOI: 10.1098/rsif.2014.0301] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 05/07/2014] [Indexed: 01/09/2023] Open
Abstract
Over decades, the theoretical and applied mechanics community has developed sophisticated approaches for analysing the behaviour of complex engineering systems. Most of these approaches have targeted systems in the transportation, materials, defence and energy industries. Applying and further developing engineering approaches for understanding, predicting and modulating the response of complicated biomedical processes not only holds great promise in meeting societal needs, but also poses serious challenges. This report, prepared for the US National Committee on Theoretical and Applied Mechanics, aims to identify the most pressing challenges in biological sciences and medicine that can be tackled within the broad field of mechanics. This echoes and complements a number of national and international initiatives aiming at fostering interdisciplinary biomedical research. This report also comments on cultural/educational challenges. Specifically, this report focuses on three major thrusts in which we believe mechanics has and will continue to have a substantial impact. (i) Rationally engineering injectable nano/microdevices for imaging and therapy of disease. Within this context, we discuss nanoparticle carrier design, vascular transport and adhesion, endocytosis and tumour growth in response to therapy, as well as uncertainty quantification techniques to better connect models and experiments. (ii) Design of biomedical devices, including point-of-care diagnostic systems, model organ and multi-organ microdevices, and pulsatile ventricular assistant devices. (iii) Mechanics of cellular processes, including mechanosensing and mechanotransduction, improved characterization of cellular constitutive behaviour, and microfluidic systems for single-cell studies.
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Affiliation(s)
- Gang Bao
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Yuri Bazilevs
- Department of Structural Engineering, University of California, San Diego, CA, USA
| | - Jae-Hyun Chung
- Mechanical Engineering, University of Washington, Seattle, WA 98195, USA
| | - Paolo Decuzzi
- Department of Translational Imaging, The Methodist Hospital Research Institute in Houston, Houston, TX 77030, USA
| | - Horacio D Espinosa
- Department of Mechanical Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Mauro Ferrari
- Department of Translational Imaging, The Methodist Hospital Research Institute in Houston, Houston, TX 77030, USA
| | - Huajian Gao
- School of Engineering, Brown University, Providence, RI 02912, USA
| | - Shaolie S Hossain
- Molecular Cardiology, Texas Heart Institute, 6770 Bertner Avenue, MC 2-255, Houston, TX 77030, USA
| | - Thomas J R Hughes
- Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, TX 78712-1229, USA
| | - Roger D Kamm
- Mechanical Engineering, Biological Engineering, Massachusetts Institute of Technology, 77 Mass Avenue, Cambridge, MA, USA
| | - Wing Kam Liu
- Department of Mechanical Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Alison Marsden
- Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, CA, USA
| | - Bernhard Schrefler
- Centre for Mechanics of Biological Materials, University of Padova, Padova, Italy
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50
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Kung E, Kahn AM, Burns JC, Marsden A. In Vitro Validation of Patient-Specific Hemodynamic Simulations in Coronary Aneurysms Caused by Kawasaki Disease. Cardiovasc Eng Technol 2014; 5:189-201. [PMID: 25050140 DOI: 10.1007/s13239-014-0184-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
To perform experimental validation of computational fluid dynamics (CFD) applied to patient specific coronary aneurysm anatomy of Kawasaki disease. We quantified hemodynamics in a patient-specific coronary artery aneurysm physical phantom under physiologic rest and exercise flow conditions. Using phase contrast MRI (PCMRI), we acquired 3-component flow velocity at two slice locations in the aneurysms. We then performed numerical simulations with the same geometry and inflow conditions, and performed qualitative and quantitative comparisons of velocities between experimental measurements and simulation results. We observed excellent qualitative agreement in flow pattern features. The quantitative spatially and temporally varying differences in velocity between PCMRI and CFD were proportional to the flow velocity. As a result, the percent discrepancy between simulation and experiment was relatively constant regardless of flow velocity variations. Through 1D and 2D quantitative comparisons, we found a 5-17% difference between measured and simulated velocities. Additional analysis assessed wall shear stress differences between deformable and rigid wall simulations. This study demonstrated that CFD produced good qualitative and quantitative predictions of velocities in a realistic coronary aneurysm anatomy under physiological flow conditions. The results provide insights on factors that may influence the level of agreement, and a set of in vitro experimental data that can be used by others to compare against CFD simulation results. The findings of this study increase confidence in the use of CFD for investigating hemodynamics in the specialized anatomy of coronary aneurysms. This provides a basis for future hemodynamics studies in patient-specific models of Kawasaki disease.
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Affiliation(s)
- Ethan Kung
- Mechanical and Aerospace Engineering Department, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0411, USA
| | - Andrew M Kahn
- Departments of Medicine and Pediatrics, University of California San Diego School of Medicine, San Diego, CA, USA
| | - Jane C Burns
- Departments of Medicine and Pediatrics, University of California San Diego School of Medicine, San Diego, CA, USA ; Kawasaki Disease Research Center, Rady Children's Hospital, San Diego, CA, USA
| | - Alison Marsden
- Mechanical and Aerospace Engineering Department, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0411, USA
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