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Hoganson DM, Govindarajan V, Schulz NE, Eickhoff ER, Breitbart RE, Marx GR, del Nido PJ, Hammer PE. Multiphysiologic State Computational Fluid Dynamics Modeling for Planning Fontan With Interrupted Inferior Vena Cava. JACC. ADVANCES 2024; 3:101057. [PMID: 39129987 PMCID: PMC11312337 DOI: 10.1016/j.jacadv.2024.101057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 03/01/2024] [Accepted: 04/21/2024] [Indexed: 08/13/2024]
Abstract
Background Single ventricle (SV) patients with interrupted inferior vena cava (iIVC) and azygos continuation are at high risk for unbalanced hepatic venous flow (HVF) distribution to the lungs after Fontan completion and subsequent pulmonary arteriovenous malformations (AVMs) formation. Objectives The aim of the study was to utilize computational fluid dynamics (CFD) analysis to avoid maldistribution of HVF to the lungs after Fontan surgery. Methods Four SV subjects with iIVC were prospectively studied with a 3-dimensional (3D) modeling workflow with digital 3D models created from segmented magnetic resonance images or computer tomography scans, virtual surgery, and CFD analysis over multiple physiologic states for the evaluation of operative plans to achieve balanced HVF to both lungs. Three of the patients were Fontan revision candidates with existing AVMs. All patients underwent Fontan completion or revision surgery. Results CFD predicted that existing or proposed Fontan completion in all patients would result in 100% of HVF to one lung. Improved HVF balance was achieved with CFD analysis of alternative surgical approaches resulting in the average distribution of HVF to the right/left pulmonary arteries of 37%/63% ± 10.4%. A hepatoazygos shunt was required in all patients and additional creation of an innominate vein in one. CFD analysis was validated by the comparison of pre-operative predicted and postoperative MRI-measured total right/left pulmonary flow (51%/49% ± 5.4% vs 49%/51% ± 8.5%). Conclusions A 3D modeling workflow with CFD simulation for SV patients with iIVC may avoid HVF maldistribution and development of AVMs after Fontan completion.
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Affiliation(s)
- David M. Hoganson
- Department of Cardiac Surgery, Boston Children’s Hospital, Boston, Massachusetts, USA
| | - Vijay Govindarajan
- Department of Cardiac Surgery, Boston Children’s Hospital, Boston, Massachusetts, USA
| | - Noah E. Schulz
- Department of Cardiac Surgery, Boston Children’s Hospital, Boston, Massachusetts, USA
| | - Emily R. Eickhoff
- Department of Cardiac Surgery, Boston Children’s Hospital, Boston, Massachusetts, USA
| | - Roger E. Breitbart
- Department of Cardiology, Boston Children’s Hospital, Boston, Massachusetts, USA
| | - Gerald R. Marx
- Department of Cardiology, Boston Children’s Hospital, Boston, Massachusetts, USA
| | - Pedro J. del Nido
- Department of Cardiac Surgery, Boston Children’s Hospital, Boston, Massachusetts, USA
| | - Peter E. Hammer
- Department of Cardiac Surgery, Boston Children’s Hospital, Boston, Massachusetts, USA
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Javadi E, Laudenschlager S, Kheyfets V, Di Maria M, Stone M, Jamali S, Powell AJ, Moghari MH. Predicting Hemodynamic Performance of Fontan Operation for Glenn Physiology using Computational Fluid Dynamics: Ten Patient-specific Cases. JOURNAL OF CLINICAL IMAGES AND MEDICAL CASE REPORTS 2022; 3:1916. [PMID: 36339935 PMCID: PMC9631545 DOI: 10.52768/2766-7820/1916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Single ventricle hearts have only one ventricle that can pump blood effectively and the treatment requires three stages of operations to reconfigure the heart and circulatory system. At the second stage, Glenn procedure is performed to connect superior vena cava (SVC) to the pulmonary arteries (PA). For the third and most complex operation, called Fontan, an extracardiac conduit is used to connect inferior vena cava (IVC) to the PL and thereafter no deoxygenated blood goes to the heart. Predicting Hemodynamic Performance of Fontan Operation using computational fluid dynamics (CFD) is hypothesized to improve outcomes and optimize this treatment planning in children with single-ventricle heart disease. An important reason for this surgical planning is to reduce the development of pulmonary arteriovenous malformations (PAVM) and the need to perform Fontan revisions. The purpose of this study was to develop amodel for Fontan surgical planning and use this model to compare blood circulation in two designed graft types of Fontan operation known as T-shape and Y-graft. The functionality of grafts was compared in terms of power loss (PL) and hepatic flow distribution (HFD), a known factor in PAVM development. To perform this study, ten single-ventricle children with Glenn physiology were included and a CFD model was developed to estimate the blood flow circulation to the left and right pulmonary arteries. The estimated blood flow by CFD was compared with that measured by cardiovascular magnetic resonance. Results showed that there was an excellent agreement between the net blood flow in the right and left pulmonary arteries computed by CFD and CMR (ICC= 0.98, P-value ≥0.21). After validating the accuracy of each CFD model, Fontan operations using T-shape and Y-graft conduits were performed in silico for each patient and the developed CFD model was used to predict the post-surgical PL and HFD. We found that the PL in the Y-graft was significantly lower than in the T-shape (P-value ≤0.001) and HFD was significantly better balanced in Y-graft compared to the T-shape (P-value=0.004).
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Affiliation(s)
- Elahe Javadi
- Mechanical and Industrial Engineering Department, Northeastern University, Boston, MA, USA
| | - Sebastian Laudenschlager
- School of Medicine, University of Colorado Aurora, and Department of Radiology, Children’s Hospital Colorado, Aurora, CO, USA
| | - Vitaly Kheyfets
- Paediatric Critical Care Medicine; Developmental Lung Biology and CVP Research Laboratories, School of Medicine, University of Colorado, Aurora, CO, USA
| | - Michael Di Maria
- Department of Pediatrics, University of Colorado, and Department of Cardiology, Children’s Hospital Colorado, Aurora, CO, USA
| | - Matthew Stone
- Department of Surgery, University of Colorado, and Children’s Hospital Colorado, Aurora, CO, USA
| | - Safa Jamali
- Mechanical and Industrial Engineering Department, Northeastern University, Boston, MA, USA
| | - Andrew J. Powell
- Department of Cardiology, Boston Children’s Hospital, Boston, MA, USA
| | - Mehdi H. Moghari
- School of Medicine, University of Colorado Aurora, and Department of Radiology, Children’s Hospital Colorado, Aurora, CO, USA
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Lashkarinia SS, Cicek M, Kose B, Rezaeimoghaddam M, Yılmaz EH, Aydemir NA, Rasooli R, Ozkok S, Yurtseven N, Erdem H, Pekkan K, Sasmazel A. OUP accepted manuscript. Interact Cardiovasc Thorac Surg 2022; 34:1095-1105. [PMID: 35134949 PMCID: PMC9159461 DOI: 10.1093/icvts/ivac001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 10/21/2021] [Accepted: 01/14/2022] [Indexed: 11/23/2022] Open
Affiliation(s)
| | - Murat Cicek
- Department of Cardiovascular Surgery, Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Training and Research Hospital, Istanbul, Turkey
| | - Banu Kose
- Department of Biomedical Engineering, Istanbul Medipol University, Istanbul, Turkey
| | | | - Emine Hekim Yılmaz
- Department of Cardiovascular Surgery, Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Training and Research Hospital, Istanbul, Turkey
| | - Numan Ali Aydemir
- Department of Cardiovascular Surgery, Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Training and Research Hospital, Istanbul, Turkey
| | - Reza Rasooli
- Department of Mechanical Engineering, Koc University, Istanbul, Turkey
| | - Sercin Ozkok
- Research Hospital Radiology Department, Medeniyet University Goztepe Training, Istanbul, Turkey
| | - Nurgul Yurtseven
- Anesthesiology, Pediatric Cardiac Intensive Care Unit, Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Training and Research Hospital, Istanbul, Turkey
| | - Hasan Erdem
- Department of Cardiovascular Surgery, Kosuyolu Yuksek Ihtisas Training and Research Hospital, Istanbul, Turkey
| | - Kerem Pekkan
- Department of Mechanical Engineering, Koc University, Istanbul, Turkey
- Mechanical Engineering Department Koç University Rumeli Feneri Campus, Sarıyer, 34450 Istanbul, Turkey. Tel: +90-(533)-356-35-95; e-mail: (K.Pekkan)
| | - Ahmet Sasmazel
- Department of Cardiovascular Surgery, Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Training and Research Hospital, Istanbul, Turkey
- Corresponding author. Pediatric Cardiovascular Surgery, Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Research Hospital, Tibbiye Cad. No: 13, Uskudar, 34668 Istanbul,Turkey. Tel: +90-(216)-542-44-44; e-mail: (A. Sasmazel)
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Téllez L, Rodríguez de Santiago E, Albillos A. Fontan-Associated Liver Disease: Pathophysiology, Staging, and Management. Semin Liver Dis 2021; 41:538-550. [PMID: 34399435 DOI: 10.1055/s-0041-1732355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Fontan-associated liver disease is the term used to encompass the disorders arising from abnormal hemodynamic alterations and systemic venous congestion after the Fontan procedure. The histological changes produced in the liver are similar but not equivalent to those seen in other forms of cardiac liver disease. While the natural history of this form of liver disease is poorly established, many Fontan patients ultimately develop portal hypertension-related complications such as ascites, esophageal varices, malnutrition, and encephalopathy. Fontan survivors also show an elevated risk of hepatocellular carcinoma. Adequate staging of the liver damage is essential to anticipate screening strategies and improve global management.
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Affiliation(s)
- Luis Téllez
- Department of Gastroenterology and Hepatology, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Centro de Investigación Biomédica en Red (CIBEREHD), Universidad de Alcalá, Madrid, Spain
| | - Enrique Rodríguez de Santiago
- Department of Gastroenterology and Hepatology, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Centro de Investigación Biomédica en Red (CIBEREHD), Universidad de Alcalá, Madrid, Spain
| | - Agustín Albillos
- Department of Gastroenterology and Hepatology, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Centro de Investigación Biomédica en Red (CIBEREHD), Universidad de Alcalá, Madrid, Spain
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Jia D, Peroni M, Khalapyan T, Esmaily M. An Efficient Assisted Bidirectional Glenn Design With Lowered Superior Vena Cava Pressure for Stage-One Single Ventricle Patients. J Biomech Eng 2021; 143:071008. [PMID: 33590839 DOI: 10.1115/1.4050170] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Indexed: 11/08/2022]
Abstract
Recently, the assisted bidirectional Glenn (ABG) procedure has been proposed as an alternative to the modified Blalock-Taussig shunt (mBTS) operation for neonates with single-ventricle physiology. Despite success in reducing heart workload and maintaining sufficient pulmonary flow, the ABG also raised the superior vena cava (SVC) pressure to a level that may not be tolerated by infants. To lower the SVC pressure, we propose a modified version of the ABG (mABG), in which a shunt with a slit-shaped nozzle exit is inserted at the junction of the right and left brachiocephalic veins. The proposed operation is compared against the ABG, the mBTS, and the bidirectional Glenn (BDG) operations using closed-loop multiscale simulations. Both normal (2.3 Wood units-m2) and high (7 Wood units-m2) pulmonary vascular resistance (PVR) values are simulated. The mABG provides the highest oxygen saturation, oxygen delivery, and pulmonary flow rate in comparison to the BDG and the ABG. At normal PVR, the SVC pressure is significantly reduced below that of the ABG and the BDG (mABG: 4; ABG: 8; BDG: 6; mBTS: 3 mmHg). However, the SVC pressure remains high at high PVR (mABG: 15; ABG: 16; BDG: 12; mBTS: 3 mmHg), motivating an optimization study to improve the ABG hemodynamics efficiency for a broader range of conditions in the future. Overall, the mABG preserves all advantages of the original ABG procedure while reducing the SVC pressure at normal PVR.
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Affiliation(s)
- Dongjie Jia
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14850
| | - Matthew Peroni
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14850
| | | | - Mahdi Esmaily
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14850
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A Tribute to Ajit Yoganathan's Cardiovascular Fluid Mechanics Lab: A Survey of Its Contributions to Our Understanding of the Physiology and Management of Single-Ventricle Patients. Cardiovasc Eng Technol 2021; 12:631-639. [PMID: 34018153 DOI: 10.1007/s13239-021-00540-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 04/30/2021] [Indexed: 12/29/2022]
Abstract
INTRODUCTION Among patients with congenital heart disease, those born with only a single working ventricle represent a particularly complex sub-population, typically requiring multiple surgeries and suffering from high levels of mortality and morbidity. Their cardiac care is complex and has evolved considerably since surgical palliation was first introduced more than 50 years ago. Improvements in treatment have been driven both by growing clinical experience and by knowledge gained through experimental and computational studies of blood flow in these patients. The Cardiovascular Fluid Mechanics Lab at the Georgia Institute of Technology, founded 30 years ago by Dr. Ajit Yoganathan, has pioneered work in this field. METHODS In this review, key contributions of Dr. Yoganathan's Cardiovascular Fluid Dynamics Lab are surveyed, including experimental flow loop studies as well as computational fluid dynamics analyses that address many of the critical challenges that cardiologists and surgeons face in treating these patients, including how to reconstruct cardiovascular anatomy to minimize power loss, balance blood flow distribution at key bifurcation points, and avoid other unfavorable hemodynamic conditions. CONCLUSIONS Among many contributions in this field, work from the Cardiovascular Fluid Mechanics Lab has led to novel medical devices and patient-specific computational modeling workflows and software tools. These key contributions from this group have enhanced our understanding of the physiology and management of single-ventricle patients.
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Kariya T, Washio T, Okada JI, Nakagawa M, Watanabe M, Kadooka Y, Sano S, Nagai R, Sugiura S, Hisada T. Personalized Perioperative Multi-scale, Multi-physics Heart Simulation of Double Outlet Right Ventricle. Ann Biomed Eng 2020; 48:1740-1750. [PMID: 32152800 DOI: 10.1007/s10439-020-02488-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 03/02/2020] [Indexed: 10/24/2022]
Abstract
For treatment of complex congenital heart disease, computer simulation using a three-dimensional heart model may help to improve outcomes by enabling detailed preoperative evaluations. However, no highly integrated model that accurately reproduces a patient's pathophysiology, which is required for this simulation has been reported. We modelled a case of complex congenital heart disease, double outlet right ventricle with ventricular septal defect and atrial septal defect. From preoperative computed tomography images, finite element meshes of the heart and torso were created, and cell model of cardiac electrophysiology and sarcomere dynamics was implemented. The parameter values of the heart model were adjusted to reproduce the patient's electrocardiogram and haemodynamics recorded preoperatively. Two options of in silico surgery were performed using this heart model, and the resulting changes in performance were examined. Preoperative and postoperative simulations showed good agreement with clinical records including haemodynamics and measured oxyhaemoglobin saturations. The use of a detailed sarcomere model also enabled comparison of energetic efficiency between the two surgical options. A novel in silico model of congenital heart disease that integrates molecular models of cardiac function successfully reproduces the observed pathophysiology. The simulation of postoperative state by in silico surgeries can help guide clinical decision-making.
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Affiliation(s)
- Taro Kariya
- Department of Cardiovascular Medicine, The University of Tokyo, Tokyo, Japan
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Takumi Washio
- UT-Heart Inc, The University of Tokyo, Tokyo, Kashiwa-no-ha Campus Station Satellite #304, 178-4-4 Wakashiba, Kashiwa, Chiba, 277-0871, Japan
| | - Jun-Ichi Okada
- UT-Heart Inc, The University of Tokyo, Tokyo, Kashiwa-no-ha Campus Station Satellite #304, 178-4-4 Wakashiba, Kashiwa, Chiba, 277-0871, Japan
| | - Machiko Nakagawa
- Next-Generation Healthcare Innovation Center, Fujitsu Ltd., Tokyo, Japan
| | - Masahiro Watanabe
- Next-Generation Healthcare Innovation Center, Fujitsu Ltd., Tokyo, Japan
| | - Yoshimasa Kadooka
- Next-Generation Healthcare Innovation Center, Fujitsu Ltd., Tokyo, Japan
| | - Shunji Sano
- Department of Cardiac Surgery, Okayama University, Okayama, Japan
- Division of Pediatric Cardiothoracic Surgery, Department of Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Ryozo Nagai
- Department of Cardiovascular Medicine, The University of Tokyo, Tokyo, Japan
- Jichi Medical University, Tochigi, Japan
| | - Seiryo Sugiura
- UT-Heart Inc, The University of Tokyo, Tokyo, Kashiwa-no-ha Campus Station Satellite #304, 178-4-4 Wakashiba, Kashiwa, Chiba, 277-0871, Japan.
| | - Toshiaki Hisada
- UT-Heart Inc, The University of Tokyo, Tokyo, Kashiwa-no-ha Campus Station Satellite #304, 178-4-4 Wakashiba, Kashiwa, Chiba, 277-0871, Japan
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8
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Rijnberg FM, Hazekamp MG, Wentzel JJ, de Koning PJ, Westenberg JJ, Jongbloed MR, Blom NA, Roest AA. Energetics of Blood Flow in Cardiovascular Disease. Circulation 2018; 137:2393-2407. [DOI: 10.1161/circulationaha.117.033359] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
| | | | - Jolanda J. Wentzel
- Leiden University Medical Center, The Netherlands. Department of Biomechanical Engineering, Erasmus Medical Center, Rotterdam, The Netherlands (J.J.W.)
| | | | | | | | - Nico A. Blom
- Department of Pediatric Cardiology (N.A.B., A.A.W.R.)
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9
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Yeong M, Loughborough W, Hamilton M, Manghat N. Role of cardiac MRI and CT in Fontan circulation. JOURNAL OF CONGENITAL CARDIOLOGY 2017. [DOI: 10.1186/s40949-017-0010-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
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10
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Lee JW, Park JJ, Goo HW, Ko JK. Fontan Revision with Y-Graft in a Patient with Unilateral Pulmonary Arteriovenous Malformation. THE KOREAN JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY 2017; 50:207-210. [PMID: 28593158 PMCID: PMC5460969 DOI: 10.5090/kjtcs.2017.50.3.207] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 10/27/2016] [Accepted: 10/28/2016] [Indexed: 11/18/2022]
Abstract
The extracardiac conduit Fontan procedure is the last surgical step in the treatment of patients with a functional single ventricle. An acquired pulmonary arteriovenous malformation may appear perioperatively or postoperatively due to an uneven hepatic flow distribution. Here we report a case of a bifurcated Y-graft Fontan operation in a 15-year-old male patient with a unilateral pulmonary arteriovenous malformation after an extracardiac conduit Fontan operation.
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Affiliation(s)
- Jeong-Woo Lee
- Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, University of Ulsan College of Medicine
| | - Jeong-Jun Park
- Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, University of Ulsan College of Medicine
| | - Hyun Woo Goo
- Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine
| | - Jae Kon Ko
- Department of Pediatric Cardiology, Asan Medical Center, University of Ulsan College of Medicine
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Tree M, Wei ZA, Munz B, Maher K, Deshpande S, Slesnick T, Yoganathan A. A Method for In Vitro TCPC Compliance Verification. J Biomech Eng 2017; 139:2621590. [DOI: 10.1115/1.4036474] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Indexed: 01/29/2023]
Abstract
The Fontan procedure is a common palliative intervention for sufferers of single ventricle congenital heart defects that results in an anastomosis of the venous return to the pulmonary arteries called the total cavopulmonary connection (TCPC). Local TCPC and global Fontan circulation hemodynamics are studied with in vitro circulatory models because of hemodynamic ties to Fontan patient long-term complications. The majority of in vitro studies, to date, employ a rigid TCPC model. Recently, a few studies have incorporated flexible TCPC models, but provide no justification for the model material properties. The method set forth in this study successfully utilizes patient-specific flow and pressure data from phase contrast magnetic resonance images (PCMRI) (n = 1) and retrospective pulse-pressure data from an age-matched patient cohort (n = 10) to verify the compliance of an in vitro TCPC model. These data were analyzed, and the target compliance was determined as 1.36 ± 0.78 mL/mm Hg. A method of in vitro compliance testing and computational simulations was employed to determine the in vitro flexible TCPC model material properties and then use those material properties to estimate the wall thickness necessary to match the patient-specific target compliance. The resulting in vitro TCPC model compliance was 1.37 ± 0.1 mL/mm Hg—a value within 1% of the patient-specific compliance. The presented method is useful to verify in vitro model accuracy of patient-specific TCPC compliance and thus improve patient-specific hemodynamic modeling.
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Affiliation(s)
- Mike Tree
- The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332
| | - Zhenglun Alan Wei
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332
| | - Brady Munz
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332
| | - Kevin Maher
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30332
| | - Shriprasad Deshpande
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30332
| | - Timothy Slesnick
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30332
| | - Ajit Yoganathan
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332
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Patient-specific in vitro models for hemodynamic analysis of congenital heart disease - Additive manufacturing approach. J Biomech 2017; 54:111-116. [PMID: 28242061 DOI: 10.1016/j.jbiomech.2017.01.048] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 01/25/2017] [Accepted: 01/27/2017] [Indexed: 02/07/2023]
Abstract
Non-invasive hemodynamic assessment of total cavopulmonary connection (TCPC) is challenging due to the complex anatomy. Additive manufacturing (AM) is a suitable alternative for creating patient-specific in vitro models for flow measurements using four-dimensional (4D) Flow MRI. These in vitro systems have the potential to serve as validation for computational fluid dynamics (CFD), simulating different physiological conditions. This study investigated three different AM technologies, stereolithography (SLA), selective laser sintering (SLS) and fused deposition modeling (FDM), to determine differences in hemodynamics when measuring flow using 4D Flow MRI. The models were created using patient-specific MRI data from an extracardiac TCPC. These models were connected to a perfusion pump circulating water at three different flow rates. Data was processed for visualization and quantification of velocity, flow distribution, vorticity and kinetic energy. These results were compared between each model. In addition, the flow distribution obtained in vitro was compared to in vivo. The results showed significant difference in velocities measured at the outlets of the models that required internal support material when printing. Furthermore, an ultrasound flow sensor was used to validate flow measurements at the inlets and outlets of the in vitro models. These results were highly correlated to those measured with 4D Flow MRI. This study showed that commercially available AM technologies can be used to create patient-specific vascular models for in vitro hemodynamic studies at reasonable costs. However, technologies that do not require internal supports during manufacturing allow smoother internal surfaces, which makes them better suited for flow analyses.
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Itu L, Sharma P, Suciu C, Moldoveanu F, Comaniciu D. Personalized blood flow computations: A hierarchical parameter estimation framework for tuning boundary conditions. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2017; 33:e02803. [PMID: 27194580 DOI: 10.1002/cnm.2803] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Revised: 04/08/2016] [Accepted: 05/15/2016] [Indexed: 06/05/2023]
Abstract
We propose a hierarchical parameter estimation framework for performing patient-specific hemodynamic computations in arterial models, which use structured tree boundary conditions. A calibration problem is formulated at each stage of the hierarchical framework, which seeks the fixed point solution of a nonlinear system of equations. Common hemodynamic properties, like resistance and compliance, are estimated at the first stage in order to match the objectives given by clinical measurements of pressure and/or flow rate. The second stage estimates the parameters of the structured trees so as to match the values of the hemodynamic properties determined at the first stage. A key feature of the proposed method is that to ensure a large range of variation, two different structured tree parameters are personalized for each hemodynamic property. First, the second stage of the parameter estimation framework is evaluated based on the properties of the outlet boundary conditions in a full body arterial model: the calibration method converges for all structured trees in less than 10 iterations. Next, the proposed framework is successfully evaluated on a patient-specific aortic model with coarctation: only six iterations are required for the computational model to be in close agreement with the clinical measurements used as objectives, and overall, there is a good agreement between the measured and computed quantities. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Lucian Itu
- Corporate Technology, Siemens SRL, B-dul Eroilor nr. 5, Brasov, 500007, Romania
- Transilvania University of Brasov, B-dul Eroilor nr. 29, 500036, Brasov, Romania
| | - Puneet Sharma
- Siemens Medical Solutions USA, Inc., 755 College Road East, Princeton, NJ 08540, USA
| | - Constantin Suciu
- Corporate Technology, Siemens SRL, B-dul Eroilor nr. 5, Brasov, 500007, Romania
- Transilvania University of Brasov, B-dul Eroilor nr. 29, 500036, Brasov, Romania
| | - Florin Moldoveanu
- Transilvania University of Brasov, B-dul Eroilor nr. 29, 500036, Brasov, Romania
| | - Dorin Comaniciu
- Siemens Medical Solutions USA, Inc., 755 College Road East, Princeton, NJ 08540, USA
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14
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Chen JM. It's in 3D, but is it truly the next dimension? J Thorac Cardiovasc Surg 2016; 153:923. [PMID: 27993363 DOI: 10.1016/j.jtcvs.2016.10.046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 10/27/2016] [Indexed: 10/20/2022]
Affiliation(s)
- Jonathan M Chen
- Section of Congenital Cardiac Surgery, Seattle Children's Hospital, Seattle, Wash.
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Hegde S, Hsiao A. Improving the Fontan: Pre-surgical planning using four dimensional (4D) flow, bio-mechanical modeling and three dimensional (3D) printing. PROGRESS IN PEDIATRIC CARDIOLOGY 2016. [DOI: 10.1016/j.ppedcard.2016.07.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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16
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A pulsatile hemodynamic evaluation of the commercially available bifurcated Y-graft Fontan modification and comparison with the lateral tunnel and extracardiac conduits. J Thorac Cardiovasc Surg 2016; 151:1529-36. [DOI: 10.1016/j.jtcvs.2016.03.019] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 03/01/2016] [Accepted: 03/05/2016] [Indexed: 11/22/2022]
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17
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Hsia TY. Taming the Fontan with the Y-graft: A nod and a wink to the great Yu. J Thorac Cardiovasc Surg 2016; 151:1537-9. [DOI: 10.1016/j.jtcvs.2016.03.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 03/18/2016] [Indexed: 11/26/2022]
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Adaptive outflow boundary conditions improve post-operative predictions after repair of peripheral pulmonary artery stenosis. Biomech Model Mechanobiol 2016; 15:1345-53. [PMID: 26843118 DOI: 10.1007/s10237-016-0766-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 01/19/2016] [Indexed: 12/21/2022]
Abstract
Peripheral pulmonary artery stenosis (PPS) is a congenital abnormality resulting in pulmonary blood flow disparity and right ventricular hypertension. Despite recent advance in catheter-based interventions, surgical reconstruction is still preferred to treat complex PPS. However optimal surgical strategies remain unclear. It would be of great benefit to be able to predict post-operative hemodynamics to assist with surgical planning toward optimizing outcomes. While image-based computational fluid dynamics has been used in cardiovascular surgical planning, most studies have focused on the impact of local geometric changes on hemodynamic performance. Previous experimental studies suggest morphological changes in the pulmonary arteries not only alter local hemodynamics but also lead to distal pulmonary adaptation. In this proof of concept study, a constant shear stress hypothesis and structured pulmonary trees are used to derive adaptive outflow boundary conditions for post-operative simulations. Patient-specific simulations showed the adaptive outflow boundary conditions by the constant shear stress model to provide better predictions of pulmonary flow distribution than the conventional strategy of maintaining outflow boundary conditions. On average, the relative difference, when compared to the gold standard clinical test, in blood flow distribution to the right lung is reduced from 20 to 4 %. This suggests adaptive outflow boundary conditions should be incorporated into post-operative modeling in patients with complex PPS.
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Kutty S, Rathod RH, Danford DA, Celermajer DS. Role of imaging in the evaluation of single ventricle with the Fontan palliation. Heart 2015; 102:174-83. [PMID: 26567230 DOI: 10.1136/heartjnl-2015-308298] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 10/08/2015] [Indexed: 12/29/2022] Open
Abstract
The Fontan operation for single ventricle palliation consists of the creation of a complete cavopulmonary connection, usually by incorporating inferior vena caval flow into a pulmonary arterial circulation already receiving flow from the superior vena cava. In single ventricle palliated in this way, the anatomy is complex, and the pathophysiological complications are frequent; so, cardiac imaging is a key aspect of clinical surveillance. Common problems that echocardiography and MRI may disclose and characterise in the Fontan palliation of single ventricle include obstruction of systemic venous and pulmonary arterial flow, atrioventricular and semilunar valve dysfunction, unintended collateral flow patterns, ventricular dysfunction, aortic arch obstruction, interatrial obstruction, fenestration flow and patch leaks. Despite the broad scope of these modalities for detection of such problems, often no single imaging method is comprehensive in any given patient. Therefore, physicians must recognise the limitations of each modality, and circumvent these by application of suitable alternatives. New imaging tools are becoming available, which may ultimately prove to be of value in the Fontan circulation. Proper application of diverse new technologies such as four dimensional flow, computational fluid dynamics and three-dimensional printing will require critical evaluation in the single ventricle population.
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Affiliation(s)
- Shelby Kutty
- Division of Pediatric Cardiology, University of Nebraska College of Medicine, Children's Hospital & Medical Center, Omaha, Nebraska, USA
| | - Rahul H Rathod
- Department of Cardiology, Boston Children's Hospital, Boston, Massachusetts, USA Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - David A Danford
- Division of Pediatric Cardiology, University of Nebraska College of Medicine, Children's Hospital & Medical Center, Omaha, Nebraska, USA
| | - David S Celermajer
- Faculty of Medicine, Sydney Medical School, University of Sydney, Sydney, Australia Department of Cardiology, Royal Prince Alfred Hospital, Sydney, Australia
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Restrepo M, Crouch AC, Haggerty CM, Rossignac J, Slesnick TC, Kanter KR, Yoganathan AP. Hemodynamic Impact of Superior Vena Cava Placement in the Y-Graft Fontan Connection. Ann Thorac Surg 2015; 101:183-9. [PMID: 26431925 DOI: 10.1016/j.athoracsur.2015.07.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 06/03/2015] [Accepted: 07/09/2015] [Indexed: 11/15/2022]
Abstract
BACKGROUND A Fontan Y-shaped graft using a commercially available aortoiliac graft has been used to connect the inferior vena cava (IVC) to the pulmonary arteries. This modification of the Fontan procedure seeks to improve hepatic flow distribution (HFD) to the lungs. However, patient-specific anatomical restrictions might limit the space available for graft placement. Altering the superior vena cava (SVC) positioning is hypothesized to provide more space for an optimal connection, avoiding caval flow collision. Computational modeling tools were used to retrospectively study the effect of SVC placement on Y-graft hemodynamics. METHODS Patient-specific anatomies (N = 10 patients) and vessel flows were reconstructed from retrospective cardiac magnetic resonance (CMR) images after Fontan Y-graft completion. Alternative geometries were created using a virtual surgery environment, altering the SVC position and the offset in relation to the Y-graft branches. Geometric characterization and computational fluid dynamics simulations were performed. Hemodynamic factors (power loss and HFD) were computed. RESULTS Patients with a higher IVC return showed less sensitivity to SVC positioning. Patients with low IVC flow showed varied HFD results, depending on SVC location. Balanced HFD values (50% to each lung) were obtained when the SVC lay completely between the Y-graft branches. The effect on power loss was patient specific. CONCLUSIONS SVC positioning with respect to the Y-graft affects HFD, especially in patients with lower IVC flow. Careful positioning of the SVC at the time of a bidirectional Glenn (BDG) procedure based on patient-specific anatomy can optimize the hemodynamics of the eventual Fontan completion.
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Affiliation(s)
- Maria Restrepo
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta
| | - A Colleen Crouch
- School of Material Sciences and Engineering, Georgia Institute of Technology, Atlanta
| | - Christopher M Haggerty
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta
| | - Jarek Rossignac
- College of Computing, Georgia Institute of Technology, Atlanta
| | - Timothy C Slesnick
- Division of Pediatric Cardiology, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, Georgia
| | - Kirk R Kanter
- Division of Cardiothoracic Surgery, Department of Surgery, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, Georgia
| | - Ajit P Yoganathan
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta.
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Abstract
PURPOSE OF REVIEW Recent methodological advances in computational simulations are enabling increasingly realistic simulations of hemodynamics and physiology, driving increased clinical utility. We review recent developments in the use of computational simulations in pediatric and congenital heart disease, describe the clinical impact in modeling in single-ventricle patients, and provide an overview of emerging areas. RECENT FINDINGS Multiscale modeling combining patient-specific hemodynamics with reduced order (i.e., mathematically and computationally simplified) circulatory models has become the de-facto standard for modeling local hemodynamics and 'global' circulatory physiology. We review recent advances that have enabled faster solutions, discuss new methods (e.g., fluid structure interaction and uncertainty quantification), which lend realism both computationally and clinically to results, highlight novel computationally derived surgical methods for single-ventricle patients, and discuss areas in which modeling has begun to exert its influence including Kawasaki disease, fetal circulation, tetralogy of Fallot (and pulmonary tree), and circulatory support. SUMMARY Computational modeling is emerging as a crucial tool for clinical decision-making and evaluation of novel surgical methods and interventions in pediatric cardiology and beyond. Continued development of modeling methods, with an eye towards clinical needs, will enable clinical adoption in a wide range of pediatric and congenital heart diseases.
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de Zélicourt DA, Kurtcuoglu V. Patient-Specific Surgical Planning, Where Do We Stand? The Example of the Fontan Procedure. Ann Biomed Eng 2015; 44:174-86. [PMID: 26183962 DOI: 10.1007/s10439-015-1381-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 07/02/2015] [Indexed: 11/30/2022]
Abstract
The Fontan surgery for single ventricle heart defects is a typical example of a clinical intervention in which patient-specific computational modeling can improve patient outcome: with the functional heterogeneity of the presenting patients, which precludes generic solutions, and the clear influence of the surgically-created Fontan connection on hemodynamics, it is acknowledged that individualized computational optimization of the post-operative hemodynamics can be of clinical value. A large body of literature has thus emerged seeking to provide clinically relevant answers and innovative solutions, with an increasing emphasis on patient-specific approaches. In this review we discuss the benefits and challenges of patient-specific simulations for the Fontan surgery, reviewing state of the art solutions and avenues for future development. We first discuss the clinical impact of patient-specific simulations, notably how they have contributed to our understanding of the link between Fontan hemodynamics and patient outcome. This is followed by a survey of methodologies for capturing patient-specific hemodynamics, with an emphasis on the challenges of defining patient-specific boundary conditions and their extension for prediction of post-operative outcome. We conclude with insights into potential future directions, noting that one of the most pressing issues might be the validation of the predictive capabilities of the developed framework.
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Affiliation(s)
- Diane A de Zélicourt
- The Interface Group, Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
- National Center of Competence 'Kidney.CH', Zurich, Switzerland
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Roldán-Alzate A, García-Rodríguez S, Anagnostopoulos PV, Srinivasan S, Wieben O, François CJ. Hemodynamic study of TCPC using in vivo and in vitro 4D Flow MRI and numerical simulation. J Biomech 2015; 48:1325-30. [PMID: 25841292 DOI: 10.1016/j.jbiomech.2015.03.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 03/06/2015] [Accepted: 03/10/2015] [Indexed: 01/17/2023]
Abstract
INTRODUCTION Altered total cavopulmonary connection (TCPC) hemodynamics can cause long-term complications. Patient-specific anatomy hinders generalized solutions. 4D Flow MRI allows in vivo assessment, but not predictions under varying conditions and surgical approaches. Computational fluid dynamics (CFD) improves understanding and explores varying physiological conditions. This study investigated a combination of 4D Flow MRI and CFD to assess TCPC hemodynamics, accompanied with in vitro measurements as CFD validation. 4D Flow MRI was performed in extracardiac and atriopulmonary TCPC subjects. Data was processed for visualization and quantification of velocity and flow. Three-dimensional (3D) geometries were generated from angiography scans and used for CFD and a physical model construction through additive manufacturing. These models were connected to a perfusion system, circulating water through the vena cavae and exiting through the pulmonary arteries at two flow rates. Models underwent 4D Flow MRI and image processing. CFD simulated the in vitro system, applying two different inlet conditions from in vitro 4D Flow MRI measurements; no-slip was implemented at rigid walls. Velocity and flow were obtained and analyzed. The three approaches showed similar velocities, increasing proportionally with high inflow. Atriopulmonary TCPC presented higher vorticity compared to extracardiac at both inflow rates. Increased inflow balanced flow distribution in both TCPC cases. Atriopulmonary IVC flow participated in atrium recirculation, contributing to RPA outflow; at baseline, IVC flow preferentially traveled through the LPA. The combination of patient-specific in vitro and CFD allows hemodynamic parameter control, impossible in vivo. Physical models serve as CFD verification and fine-tuning tools.
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Affiliation(s)
| | | | - Petros V Anagnostopoulos
- Department of Pediatric Cardiology, University of Wisconsin-Madison, USA; Department of Pediatric Cardiothoracic Surgery, University of Wisconsin-Madison, USA
| | - Shardha Srinivasan
- Department of Pediatric Cardiology, University of Wisconsin-Madison, USA
| | - Oliver Wieben
- Department of Radiology, University of Wisconsin-Madison, USA; Department of Medical Physics, University of Wisconsin-Madison, USA
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Haggerty CM, Whitehead KK, Bethel J, Fogel MA, Yoganathan AP. Relationship of single ventricle filling and preload to total cavopulmonary connection hemodynamics. Ann Thorac Surg 2015; 99:911-7. [PMID: 25620596 DOI: 10.1016/j.athoracsur.2014.10.043] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 10/14/2014] [Accepted: 10/21/2014] [Indexed: 11/17/2022]
Abstract
BACKGROUND Single ventricle lesions are associated with gradual attrition after surgical palliation with the total cavopulmonary connection (TCPC). Ventricular dysfunction is frequently noted, particularly impaired diastolic performance. This study seeks to relate TCPC hemodynamic energy losses to single ventricle volumes and filling characteristics. METHODS Cardiac magnetic resonance (CMR) data were retrospectively analyzed for 30 single ventricle patients at an average age of 12.7 ± 4.8 years. Cine ventricular short-axis scans were semiautomatically segmented for all cardiac phases. Ventricular volumes, ejection fraction, peak filling rate, peak ejection rate, and time to peak filling were calculated. Corresponding patient-specific TCPC geometry was acquired from a stack of transverse CMR images; relevant flow rates were segmented from through-plane phase contrast CMR data at TCPC inlets and outlets. The TCPC indexed power loss was calculated from computational fluid dynamics simulations using a validated custom solver. Time-averaged flow conditions and rigid vessel walls were assumed in all cases. Pearson correlations were used to detect relationships between variables, with p less than 0.05 considered significant. RESULTS Ventricular end-diastolic (R = -0.48) and stroke volumes (R = -0.37) had significant negative correlations with the natural logarithm of a flow-independent measure of power loss. This power loss measure also had a significant positive relationship to time to peak filling rate (normalized to cycle time; R = 0.67). CONCLUSIONS Flow-independent TCPC power loss is inversely related with ventricular end-diastolic and stroke volumes. Elevated power losses may contribute to impaired diastolic filling and limited preload reserve in single ventricle patients.
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Affiliation(s)
- Christopher M Haggerty
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia
| | - Kevin K Whitehead
- Division of Pediatric Cardiology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | | | - Mark A Fogel
- Division of Pediatric Cardiology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Ajit P Yoganathan
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia.
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25
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Flow simulations and validation for the first cohort of patients undergoing the Y-graft Fontan procedure. J Thorac Cardiovasc Surg 2015; 149:247-55. [DOI: 10.1016/j.jtcvs.2014.08.069] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 08/19/2014] [Accepted: 08/23/2014] [Indexed: 12/26/2022]
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Tang E, Yoganathan AP. Optimizing hepatic flow distribution with the Fontan Y-graft: Lessons from computational simulations. J Thorac Cardiovasc Surg 2015; 149:255-6. [DOI: 10.1016/j.jtcvs.2014.09.094] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Accepted: 09/25/2014] [Indexed: 10/24/2022]
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Liang F, Senzaki H, Kurishima C, Sughimoto K, Inuzuka R, Liu H. Hemodynamic performance of the Fontan circulation compared with a normal biventricular circulation: a computational model study. Am J Physiol Heart Circ Physiol 2014; 307:H1056-72. [DOI: 10.1152/ajpheart.00245.2014] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The physiological limitations of the Fontan circulation have been extensively addressed in the literature. Many studies emphasized the importance of pulmonary vascular resistance in determining cardiac output (CO) but gave little attention to other cardiovascular properties that may play considerable roles as well. The present study was aimed to systemically investigate the effects of various cardiovascular properties on clinically relevant hemodynamic variables (e.g., CO and central venous pressure). To this aim, a computational modeling method was employed. The constructed models provided a useful tool for quantifying the hemodynamic effects of any cardiovascular property of interest by varying the corresponding model parameters in model-based simulations. Herein, the Fontan circulation was studied compared with a normal biventricular circulation so as to highlight the unique characteristics of the Fontan circulation. Based on a series of numerical experiments, it was found that 1) pulmonary vascular resistance, ventricular diastolic function, and systemic vascular compliance play a major role, while heart rate, ventricular contractility, and systemic vascular resistance play a secondary role in the regulation of CO in the Fontan circulation; 2) CO is nonlinearly related to any single cardiovascular property, with their relationship being simultaneously influenced by other cardiovascular properties; and 3) the stability of central venous pressure is significantly reduced in the Fontan circulation. The findings suggest that the hemodynamic performance of the Fontan circulation is codetermined by various cardiovascular properties and hence a full understanding of patient-specific cardiovascular conditions is necessary to optimize the treatment of Fontan patients.
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Affiliation(s)
- Fuyou Liang
- Shanghai Jiao Tong University-Chiba University International Cooperative Research Center, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Hideaki Senzaki
- Department of Pediatrics and Pediatric Cardiology, Saitama Medical Center, Saitama Medical University, Kamoda, Kawagoe, Saitama, Japan
| | - Clara Kurishima
- Department of Pediatrics and Pediatric Cardiology, Saitama Medical Center, Saitama Medical University, Kamoda, Kawagoe, Saitama, Japan
| | - Koichi Sughimoto
- Department of Cardiac Surgery, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Ryo Inuzuka
- Pediatrics, University Hospital University of Tokyo, Tokyo, Japan; and
| | - Hao Liu
- Shanghai Jiao Tong University-Chiba University International Cooperative Research Center, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, China
- Graduate School of Engineering, Chiba University, Inage, Chiba, Japan
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Computational modeling of Fontan physiology: at the crossroads of pediatric cardiology and biomedical engineering. Int J Cardiovasc Imaging 2014; 30:1073-84. [DOI: 10.1007/s10554-014-0442-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Accepted: 04/29/2014] [Indexed: 02/05/2023]
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Haggerty CM, Restrepo M, Tang E, de Zélicourt DA, Sundareswaran KS, Mirabella L, Bethel J, Whitehead KK, Fogel MA, Yoganathan AP. Fontan hemodynamics from 100 patient-specific cardiac magnetic resonance studies: a computational fluid dynamics analysis. J Thorac Cardiovasc Surg 2013; 148:1481-9. [PMID: 24507891 DOI: 10.1016/j.jtcvs.2013.11.060] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 10/27/2013] [Accepted: 11/15/2013] [Indexed: 11/28/2022]
Abstract
OBJECTIVES This study sought to quantify average hemodynamic metrics of the Fontan connection as reference for future investigations, compare connection types (intra-atrial vs extracardiac), and identify functional correlates using computational fluid dynamics in a large patient-specific cohort. Fontan hemodynamics, particularly power losses, are hypothesized to vary considerably among patients with a single ventricle and adversely affect systemic hemodynamics and ventricular function if suboptimal. METHODS Fontan connection models were created from cardiac magnetic resonance scans for 100 patients. Phase velocity cardiac magnetic resonance in the aorta, vena cavae, and pulmonary arteries was used to prescribe patient-specific time-averaged flow boundary conditions for computational fluid dynamics with a customized, validated solver. Comparison with 4-dimensional cardiac magnetic resonance velocity data from selected patients was used to provide additional verification of simulations. Indexed Fontan power loss, connection resistance, and hepatic flow distribution were quantified and correlated with systemic patient characteristics. RESULTS Indexed power loss varied by 2 orders of magnitude, whereas, on average, Fontan resistance was 15% to 20% of published values of pulmonary vascular resistance in single ventricles. A significant inverse relationship was observed between indexed power loss and both systemic venous flow and cardiac index. Comparison by connection type showed no differences between intra-atrial and extracardiac connections. Instead, the least efficient connections revealed adverse consequences from localized Fontan pathway stenosis. CONCLUSIONS Fontan power loss varies from patient to patient, and elevated levels are correlated with lower systemic flow and cardiac index. Fontan connection type does not influence hemodynamic efficiency, but an undersized or stenosed Fontan pathway or pulmonary arteries can be highly dissipative.
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Affiliation(s)
- Christopher M Haggerty
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, Ga
| | - Maria Restrepo
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, Ga
| | - Elaine Tang
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, Ga
| | - Diane A de Zélicourt
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, Ga; Interface Group, Institute of Physiology, University of Zürich, Zürich, Switzerland
| | - Kartik S Sundareswaran
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, Ga
| | - Lucia Mirabella
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, Ga
| | | | - Kevin K Whitehead
- Division of Cardiology, Children's Hospital of Philadelphia, Philadelphia, Pa
| | - Mark A Fogel
- Division of Cardiology, Children's Hospital of Philadelphia, Philadelphia, Pa
| | - Ajit P Yoganathan
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, Ga.
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Abstract
The Fontan procedure, although an imperfect solution for children born with a single functional ventricle, is the only reconstruction at present short of transplantation. The haemodynamics associated with the total cavopulmonary connection, the modern approach to Fontan, are severely altered from the normal biventricular circulation and may contribute to the long-term complications that are frequently noted. Through recent technological advances, spear-headed by advances in medical imaging, it is now possible to virtually model these surgical procedures and evaluate the patient-specific haemodynamics as part of the pre-operative planning process. This is a novel paradigm with the potential to revolutionise the approach to Fontan surgery, help to optimise the haemodynamic results, and improve patient outcomes. This review provides a brief overview of these methods, presents preliminary results of their clinical usage, and offers insights into its potential future directions.
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Desai K, Haggerty CM, Kanter KR, Rossignac J, Spray TL, Fogel MA, Yoganathan AP. Haemodynamic comparison of a novel flow-divider Optiflo geometry and a traditional total cavopulmonary connection. Interact Cardiovasc Thorac Surg 2013; 17:1-7. [PMID: 23563054 DOI: 10.1093/icvts/ivt099] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES The total cavopulmonary connection (TCPC), the current palliation of choice for single-ventricle heart defects, is typically created with a single cylindrical tunnel or conduit routing inferior vena caval (IVC) flow to the pulmonary arteries. Previous studies have shown the haemodynamic efficiency of the TCPC to be sub-optimal due to the collision of vena caval flow, thus placing an extra energy burden on the single ventricle. The use of a bifurcated graft as the Fontan baffle (i.e. the 'Optiflo') has previously been proposed on the basis of theoretically improved flow efficiency; however, anatomical constraints may limit its effectiveness in some patients. METHODS In this study, an alternative approach to flow bifurcation is proposed, where a triangular insert is placed at the distal end of the IVC graft. The proof of concept for this design is demonstrated in two steps: first, determining the optimal insert size at a fixed Fontan graft size through a parametric study; then, characterizing the efficiency as a function of graft size when compared with a TCPC control. TCPC power loss and IVC flow distribution were the primary metrics of interest and were evaluated under both resting and simulated exercise conditions using an in-house computational fluid dynamics solver. RESULTS Results demonstrated that there was an optimal insert size that improved efficiency compared with the TCPC. For an 18-mm Fontan baffle, TCPC power loss was 4.1 vs 3.7 mW with the optimal flow-divider. The optimal insert was then scaled up for a 20-mm graft, with a similar reduction in power loss observed. Flow distribution results were inconsistent, based on sensitivity to the placement of the insert within the baffle. CONCLUSION This study demonstrated proof of concept that the flow-divider has the potential to reduce power loss and streamline IVC flow through the TCPC. An appropriate size for the insert in proportion to the Fontan baffle size was identified that reduced losses compared with a TCPC control under both resting and simulated exercise flow conditions.
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Affiliation(s)
- Kalpi Desai
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA 30332, USA
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Haggerty CM, de Zélicourt DA, Restrepo M, Rossignac J, Spray TL, Kanter KR, Fogel MA, Yoganathan AP. Comparing pre- and post-operative Fontan hemodynamic simulations: implications for the reliability of surgical planning. Ann Biomed Eng 2012; 40:2639-51. [PMID: 22777126 DOI: 10.1007/s10439-012-0614-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 06/27/2012] [Indexed: 11/25/2022]
Abstract
Virtual modeling of cardiothoracic surgery is a new paradigm that allows for systematic exploration of various operative strategies and uses engineering principles to predict the optimal patient-specific plan. This study investigates the predictive accuracy of such methods for the surgical palliation of single ventricle heart defects. Computational fluid dynamics (CFD)-based surgical planning was used to model the Fontan procedure for four patients prior to surgery. The objective for each was to identify the operative strategy that best distributed hepatic blood flow to the pulmonary arteries. Post-operative magnetic resonance data were acquired to compare (via CFD) the post-operative hemodynamics with predictions. Despite variations in physiologic boundary conditions (e.g., cardiac output, venous flows) and the exact geometry of the surgical baffle, sufficient agreement was observed with respect to hepatic flow distribution (90% confidence interval-14 ± 4.3% difference). There was also good agreement of flow-normalized energetic efficiency predictions (19 ± 4.8% error). The hemodynamic outcomes of prospective patient-specific surgical planning of the Fontan procedure are described for the first time with good quantitative comparisons between preoperatively predicted and postoperative simulations. These results demonstrate that surgical planning can be a useful tool for single ventricle cardiothoracic surgery with the ability to deliver significant clinical impact.
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Affiliation(s)
- Christopher M Haggerty
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Drive, Atlanta, GA 30332, USA
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