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Scheffers LE, Helbing WA, Pereira T, Utens EMWJ, Dulfer K, Hirsch A, Koopman LP, van den Berg LE. Leg-focused high-weight resistance training improves ventricular stroke volume, exercise capacity and strength in young patients with a Fontan circulation. Eur J Prev Cardiol 2024; 31:389-399. [PMID: 37668334 DOI: 10.1093/eurjpc/zwad286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 07/21/2023] [Accepted: 08/29/2023] [Indexed: 09/06/2023]
Abstract
AIMS Effective therapy to improve exercise capacity in Fontan patients is lacking. Leg-focused high-weight resistance training might augment the peripheral muscle pump and thereby improve exercise capacity. METHODS AND RESULTS This randomized semi-cross-over controlled trial investigated the effects of a 12-week leg-focused high-weight resistance training plus high-protein diet, on (sub)maximal exercise capacity, cardiac function (assessed with cardiovascular magnetic resonance), muscle strength, and quality of life in paediatric Fontan patients. Twenty-eight paediatric Fontan patients were included, 27 patients, (median age 12.9 [10.5-15.7]), and successfully completed the programme. Peak oxygen uptake (PeakVO2) at baseline was reduced [33.3 mL/kg/min (27.1-37.4), 73% (62-79) of predicted]. After training PeakVO2/kg and Peak workload improved significantly with +6.2 mL/kg/min (95%CI: 3.4-9.0) (+18%) P < 0.001 and +22 Watts (95%CI: 12-32) (+18%) P < 0.001, respectively, compared to the control period. Indexed single ventricle stroke volume increased significantly [43 mL/beat/m2 (40-49) vs. 46 (41-53), P = 0.014], as did inferior vena cava flow [21 mL/beat/m2 (18-24) vs. 23 (20-28), P = 0.015], while superior vena cava flow remained unchanged. The strength of all measured leg-muscles increased significantly compared to the control period. Self-reported quality of life improved on the physical functioning and change in health domains of the child health questionnaire, parent-reported quality of life improved the bodily pain, general health perception, and change in health domains compared to the control period. CONCLUSION In a relatively large group of 27 older Fontan children, 12-weeks of leg-focused high-weight resistance training improved exercise capacity, stroke volume, (sub)maximal exercise capacity, muscle strength, and domains of quality of life. REGISTRATION International Clinical Trials: Trial NL8181.
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Affiliation(s)
- Linda E Scheffers
- Department of Pediatrics, Division of Pediatric Cardiology, Erasmus MC-Sophia Children's Hospital, Doctor Molewaterplein 40, 3015 GD, Rotterdam, Netherlands
- Department of Pediatric Gastroenterology, Division of Pediatric Cardiology, Erasmus MC-Sophia Children's Hospital, Rotterdam, Netherlands
- Respiratory Medicine and Allergology, Erasmus MC-Sophia Children's Hospital, Rotterdam, Netherlands
- Department of Pediatrics, Center for Lysosomal and Metabolic Diseases, Erasmus MC, Rotterdam, Netherlands
| | - Willem A Helbing
- Department of Pediatrics, Division of Pediatric Cardiology, Erasmus MC-Sophia Children's Hospital, Doctor Molewaterplein 40, 3015 GD, Rotterdam, Netherlands
- Department of Radiology and Nuclear Medicine, Erasmus MC-Sophia Children's Hospital, Doctor Molewaterplein 40, 3015 GD, Rotterdam, the Netherlands
| | - Thomas Pereira
- Department of Pediatrics, Division of Pediatric Cardiology, Erasmus MC-Sophia Children's Hospital, Doctor Molewaterplein 40, 3015 GD, Rotterdam, Netherlands
| | - Elisabeth M W J Utens
- Department of Child and Adolescent Psychiatry/Psychology, Erasmus MC-Sophia Children's Hospital, Rotterdam, Netherlands
- Research Institute of Child Development and Education, University of Amsterdam, Amsterdam, Netherlands
- Department of Child and Adolescent Psychiatry, Amsterdam University Medical Center/Level, Amsterdam, Netherlands
| | - Karolijn Dulfer
- Intensive Care Unit, Department of Pediatrics and Pediatric Surgery, Erasmus MC-Sophia Children's Hospital, Rotterdam, Netherlands
| | - Alexander Hirsch
- Department of Radiology and Nuclear Medicine, Erasmus MC-Sophia Children's Hospital, Doctor Molewaterplein 40, 3015 GD, Rotterdam, the Netherlands
- Department of Cardiology, Erasmus MC, Rotterdam, The Netherlands
| | - Laurens P Koopman
- Department of Pediatrics, Division of Pediatric Cardiology, Erasmus MC-Sophia Children's Hospital, Doctor Molewaterplein 40, 3015 GD, Rotterdam, Netherlands
| | - Linda E van den Berg
- Department of Orthopedics and Sports medicine, Erasmus MC, Rotterdam, Netherlands
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Ghosh RM, Whitehead KK, Harris MA, Kalb E, Chen JM, Partington SL, Biko DM, Faerber J, Fogel MA. Longitudinal Trends of Vascular Flow and Growth in Patients Undergoing Fontan Operation. Ann Thorac Surg 2022; 115:1486-1492. [PMID: 35988737 DOI: 10.1016/j.athoracsur.2022.07.051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 07/05/2022] [Accepted: 07/19/2022] [Indexed: 11/01/2022]
Abstract
BACKGROUND Single ventricle (SV) patients undergo multiple surgeries with subsequent changes in anatomy and hemodynamics. There is little cardiac magnetic resonance (CMR) data on serial changes in these patients. This study aimed to assess longitudinal changes of SV anatomy and hemodynamics in a large cohort. METHODS Anatomy and flow in SV patients with serial CMRs performed between 2008-2019 at a single institution were retrospectively reviewed. Mixed-effects linear regression was used to estimate changes over time at 3-9 months, 1-5 years, and >5 years after Fontan. RESULTS 119 patients were included (51% with hypoplastic left heart;77% underwent extra-cardiac Fontan). 88 patients had 3 serial CMRs. Indexed right superior vena cava (RSVC), inferior vena cava (IVC), neo-aortic valve and descending aorta area decreased over time (beta -0.19,-0.44,-0.23 respectively;p<0.01) as did indexed RSVC, neo and native aorta and descending aorta flow (beta -0.49,-0.53,-0.59 respectively;p<0.0001). IVC flow and its contribution to total caval flow increased (beta 0.33;p<0.0001). Indexed right and left right pulmonary artery (LPA) flow did not change, however indexed LPA area decreased (beta -0.16;p=0.0014) with time. Systemic to pulmonary collateral flow remained unchanged prior to, and early after Fontan (beta -0.54;p=0.42) but decreased with time from Fontan (beta coefficient -0.22;p<0.0001). CONCLUSIONS In this cohort of longitudinally followed SV patients, there are significant trends in vascular size and flow over time from Fontan. These findings can be used as a framework to interpret serial CMR data in the SV, and non-invasively identify deviations from expected patterns prior to the development of clinical symptoms.
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Affiliation(s)
- Reena M Ghosh
- Division of Cardiology, The Children's Hospital of Philadelphia, Philadelphia PA.
| | - Kevin K Whitehead
- Division of Cardiology, The Children's Hospital of Philadelphia, Philadelphia PA
| | - Matthew A Harris
- Division of Cardiology, The Children's Hospital of Philadelphia, Philadelphia PA
| | - Elizabeth Kalb
- Division of Cardiology, The Children's Hospital of Philadelphia, Philadelphia PA; Division of Cardiology, Ann and Robert Lurie Children's Hospital of Chicago, Chicago IL
| | - Jonathan M Chen
- Division of Cardiothoracic Surgery, The Children's Hospital of Philadelphia, Philadelphia PA
| | - Sara L Partington
- Division of Cardiology, The Children's Hospital of Philadelphia, Philadelphia PA
| | - David M Biko
- Department of Radiology, The Children's Hospital of Philadelphia, Philadelphia PA
| | - Jennifer Faerber
- Department of Biomedical and Health Informatics. The Children's Hospital of Philadelphia, Philadelphia PA
| | - Mark A Fogel
- Division of Cardiology, The Children's Hospital of Philadelphia, Philadelphia PA
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Craven TP, Tsao CW, La Gerche A, Simonetti OP, Greenwood JP. Exercise cardiovascular magnetic resonance: development, current utility and future applications. J Cardiovasc Magn Reson 2020; 22:65. [PMID: 32907587 PMCID: PMC7488086 DOI: 10.1186/s12968-020-00652-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 07/01/2020] [Indexed: 12/23/2022] Open
Abstract
Stress cardiac imaging is the current first line investigation for coronary artery disease diagnosis and decision making and an adjunctive tool in a range of non-ischaemic cardiovascular diseases. Exercise cardiovascular magnetic resonance (Ex-CMR) has developed over the past 25 years to combine the superior image qualities of CMR with the preferred method of exercise stress. Presently, numerous exercise methods exist, from performing stress on an adjacent CMR compatible treadmill to in-scanner exercise, most commonly on a supine cycle ergometer. Cardiac conditions studied by Ex-CMR are broad, commonly investigating ischaemic heart disease and congenital heart disease but extending to pulmonary hypertension and diabetic heart disease. This review presents an in-depth assessment of the various Ex-CMR stress methods and the varied pulse sequence approaches, including those specially designed for Ex-CMR. Current and future developments in image acquisition are highlighted, and will likely lead to a much greater clinical use of Ex-CMR across a range of cardiovascular conditions.
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Affiliation(s)
- Thomas P Craven
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK.
| | - Connie W Tsao
- Cardiovascular Division, Beth Israel Deaconess Medical Center, 330 Brookline Ave, RW-453, Boston, MA, 02215, USA
| | - Andre La Gerche
- Clinical Research Domain, Baker Heart and Diabetes Institute, Melbourne, Australia
- National Centre for Sports Cardiology, St Vincent's Hospital, Fitzroy, Australia
| | | | - John P Greenwood
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
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Bastkowski R, Bindermann R, Brockmeier K, Weiss K, Maintz D, Giese D. Respiration Dependency of Caval Blood Flow in Patients with Fontan Circulation: Quantification Using 5D Flow MRI. Radiol Cardiothorac Imaging 2019; 1:e190005. [PMID: 33778515 PMCID: PMC7977808 DOI: 10.1148/ryct.2019190005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 06/26/2019] [Accepted: 07/30/2019] [Indexed: 06/12/2023]
Abstract
PURPOSE To measure respiration-dependent blood flow in the total cavopulmonary connection (TCPC) of patients with Fontan circulation by using free-running, fully self-gated five-dimensional (5D) flow MRI. MATERIALS AND METHODS From July to November 2018, 10 volunteers (six female volunteers, mean age, 25.1 years ± 4.4 [standard deviation]) and six patients with Fontan circulation (two female patients, mean age, 19.7 years ± 7.5) with a TCPC were examined by using a cardiac- and respiration-resolved three-directional and three-dimensional phase-contrast MRI sequence (hereafter, 5D flow MRI). This prospective study was conducted with approval of the local ethics committee, and written informed consent was obtained from all participants and/or their representative. 5D flow data were acquired during free breathing. Data were reconstructed into 15-20 heart phases and four respiratory phases: end-expiration, inspiration, end-inspiration, and expiration. Respiration-dependent stroke volumes (SVs) and particle traces were analyzed from the caval circulation of volunteers and patients with Fontan circulation. Statistical analysis was performed by using parametric tests and scatterplots. RESULTS The respiration dependency of caval blood flow was evaluated in all participants and was significantly elevated in patients with Fontan circulation as compared with volunteers. In patients, SV in the inferior vena cava (IVC) showed variations of 120% between inspiration and expiration (P = .002). The flow distribution in the IVC and superior vena cava among the four respiratory phases was differentiated by 20% (range, 9%-30%) and 4% (range, 0%-13%), respectively. CONCLUSION Hemodynamic parameters (volume flow and blood flow distribution) throughout the cardiac and respiratory cycle can be measured using a single scan, potentially providing further insights into the Fontan circulation.© RSNA, 2019Supplemental material is available for this article.
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Fogel MA, Trusty PM, Nicolson S, Spray T, Gaynor JW, Whitehead KK, Yoganathan AP. Cross-Sectional Magnetic Resonance and Modeling Comparison From Just After Fontan to the Teen Years. Ann Thorac Surg 2019; 109:574-582. [PMID: 31518584 DOI: 10.1016/j.athoracsur.2019.07.066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 07/15/2019] [Accepted: 07/22/2019] [Indexed: 11/16/2022]
Abstract
BACKGROUND Little is known of baseline anatomic, hemodynamic, and fluid dynamic cardiac magnetic resonance data in single-ventricle patients immediately after Fontan. A comparison from that time point to the teen years can demonstrate clinical course, potentially predict future events, and may shed some light regarding how to optimize outcome. This cross-sectional study is meant to characterize these variables from just after Fontan to the teenage years. METHODS The anatomy, flows, and computational fluid dynamic modeling of 22 patients 3 to 9 months after Fontan (age 3 ± 1.1 years) and 25 teens (age 16 ± 1.8 years) were compared. Significance was defined as P less than .05. RESULTS The percentage of Fontan pathway stenosis was greater with cardiac index and fenestration flow while caval return was lower in teens than in younger patients (for Fontan pathway stenosis, 43% vs 21%, P = .009); however, hepatic flow distribution was more evenly distributed in older patients. Pulmonary artery size kept up with somatic growth. In the teen group, indexed power loss (R = .39), percentage of Fontan pathway stenosis (R = .62), and particle resident time (R = .42) deteriorated as time from Fontan increased (P < .04 for all). CONCLUSIONS There are mostly aspects of deterioration with a few bright spots of stability in anatomy, blood flow, and fluid dynamic variables in Fontan patients from the postoperative period to the teenage years. Most notably, Fontan pathway stenosis increases with decreasing flows while pulmonary artery size and hepatic flow distribution remain stable or improved. These data may be aid in designing improved Fontan reconstruction to optimize clinical outcome and to understand future complications.
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Affiliation(s)
- Mark A Fogel
- Division of Cardiology, Department of Pediatrics, The Children's Hospital of Philadelphia/The University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania; Department of Radiology, The Children's Hospital of Philadelphia/The University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania.
| | - Phillip M Trusty
- Department of Biomedical Engineering, The Georgia Institute of Technology, Atlanta, Georgia
| | - Susan Nicolson
- Department of Anesthesia, The Children's Hospital of Philadelphia/The University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
| | - Thomas Spray
- Department of Cardiothoracic Surgery, The Children's Hospital of Philadelphia/The University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
| | - J William Gaynor
- Department of Cardiothoracic Surgery, The Children's Hospital of Philadelphia/The University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
| | - Kevin K Whitehead
- Division of Cardiology, Department of Pediatrics, The Children's Hospital of Philadelphia/The University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania; Department of Radiology, The Children's Hospital of Philadelphia/The University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
| | - Ajit P Yoganathan
- Department of Biomedical Engineering, The Georgia Institute of Technology, Atlanta, Georgia
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Talwar S, Sankhyan L, Patel C, Sreenivas V, Choudhary SK, Airan B. Evaluation of differential pulmonary perfusion using 99mTc macroaggregated albumin after the Fontan procedure. Interact Cardiovasc Thorac Surg 2018; 26:651-659. [PMID: 29240900 DOI: 10.1093/icvts/ivx377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 10/30/2017] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES The Fontan procedure [total cavopulmonary connection (TCPC)] is the final palliation for patients with univentricular physiology. We studied differential perfusion ratio and percentage uptake of a radiotracer in different zones of each lung following TCPC. METHODS Between July 2015 and June 2017, 45 patients underwent 99mTc macroaggregated albumin lung perfusion scan at a mean follow-up period of 49.3 ± SD 26.1 days following TCPC. Differential perfusion ratio and percentage uptake of the radiotracer in the upper, middle and lower zones of each lung were calculated. RESULTS Post-foot injection [inferior vena cava (IVC) injection], preferential flow to the lungs was as follows: left lung (n = 13, 30.2%), right lung (n = 13, 30.2%) and uniformly to both lungs (n= 17, 39.6%). Post-arm injection [superior vena cava (SVC) injection], preferential flow to the lungs was as follows: left lung (n = 13, 30.2%), right lung (n = 22, 51.2%) and uniformly to both lungs (n= 8, 18.6%). The middle zone was perfused the most in both lungs. Total lower zone mean perfusion was higher than the upper zone following both SVC injection and IVC injection (34.1 ± SD 5.3% vs 17. ± SD 4.1% and 33 ± SD 5.0% vs 17.5 ± SD 4.1%, respectively). In patients with bilateral SVC, post-IVC injection, 6 (75%) patients had preferential flow to the right lung, whereas post-SVC injection, preferential flow to the left lung was visualized in 7 (87.5%) patients. CONCLUSIONS Following TCPC, IVC blood was distributed uniformly in both lungs. SVC blood preferentially perfused the right lung. The middle zone was perfused the most in both lungs.
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Affiliation(s)
- Sachin Talwar
- Department of Cardiothoracic and Vascular Surgery, Cardiothoracic Center, All India Institute of Medical Sciences, New Delhi, India
| | - Lakshmi Sankhyan
- Department of Cardiothoracic and Vascular Surgery, Cardiothoracic Center, All India Institute of Medical Sciences, New Delhi, India
| | - Chetan Patel
- Nuclear Medicine, All India Institute of Medical Sciences, New Delhi, India
| | | | - Shiv Kumar Choudhary
- Department of Cardiothoracic and Vascular Surgery, Cardiothoracic Center, All India Institute of Medical Sciences, New Delhi, India
| | - Balram Airan
- Department of Cardiothoracic and Vascular Surgery, Cardiothoracic Center, All India Institute of Medical Sciences, New Delhi, India
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Good BC, Weiss WJ, Deutsch S, Manning KB. Asynchronous Pumping of a Pulsatile Ventricular Assist Device in a Pediatric Anastomosis Model. World J Pediatr Congenit Heart Surg 2017; 8:511-519. [PMID: 28696878 DOI: 10.1177/2150135117713697] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Both pulsatile and continuous flow ventricular assist devices are being developed for pediatric congenital heart defect patients. Pulsatile devices are often operated asynchronously with the heart in either an "automatic" or a fixed beat rate mode. However, most studies have only investigated synchronized ejection. METHODS A previously validated viscoelastic blood solver is used to investigate the parameters of pulsatility, power loss, and graft failure in a pediatric aortic anastomosis model. RESULTS Pulsatility was highest with synchronized flow and lowest at a 90° phase shift. Power loss decreased at 90° and 180° phase shifts but increased at a 270° phase shift. Similar regions of potential intimal hyperplasia and graft failure were seen in all cases but with phase-shifted ejection leading to higher wall shear stress on the anastomotic floor and oscillatory shear index on the anastomotic toe. CONCLUSION The ranges of pulsatility and hemodynamics that can result clinically using asynchronous pulsatile devices were investigated in a pediatric anastomosis model. These results, along with the different postoperative benefits of pump modulation, can be used to design an optimal weaning protocol.
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Affiliation(s)
- Bryan C Good
- 1 Department of Biomedical Engineering, Pennsylvania State University, University Park, PA, USA
| | - William J Weiss
- 1 Department of Biomedical Engineering, Pennsylvania State University, University Park, PA, USA.,2 Department of Surgery, Penn State Hershey Medical Center, Hershey, PA, USA
| | - Steven Deutsch
- 1 Department of Biomedical Engineering, Pennsylvania State University, University Park, PA, USA
| | - Keefe B Manning
- 1 Department of Biomedical Engineering, Pennsylvania State University, University Park, PA, USA.,2 Department of Surgery, Penn State Hershey Medical Center, Hershey, PA, USA
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Jarvis K, Schnell S, Barker AJ, Garcia J, Lorenz R, Rose M, Chowdhary V, Carr J, Robinson JD, Rigsby CK, Markl M. Evaluation of blood flow distribution asymmetry and vascular geometry in patients with Fontan circulation using 4-D flow MRI. Pediatr Radiol 2016; 46:1507-19. [PMID: 27350377 PMCID: PMC5039076 DOI: 10.1007/s00247-016-3654-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 05/04/2016] [Accepted: 06/02/2016] [Indexed: 11/26/2022]
Abstract
BACKGROUND Asymmetrical caval to pulmonary blood flow is suspected to cause complications in patients with Fontan circulation. The aim of this study was to test the feasibility of 4-D flow MRI for characterizing the relationship between 3-D blood flow distribution and vascular geometry. OBJECTIVE We hypothesized that both flow distribution and geometry can be calculated with low interobserver variability and will detect a direct relationship between flow distribution and Fontan geometry. MATERIALS AND METHODS Four-dimensional flow MRI was acquired in 10 Fontan patients (age: 16 ± 4 years [mean ± standard deviation], range: 9-21 years). The Fontan connection was isolated by 3-D segmentation to evaluate flow distribution from the inferior vena cava (IVC) and superior vena cava (SVC) to the left and right pulmonary arteries (LPA, RPA) and to characterize geometry (cross-sectional area, caval offset, vessel angle). RESULTS Flow distribution results indicated SVC flow tended toward the RPA while IVC flow was more evenly distributed (SVC to RPA: 78% ± 28 [9-100], IVC to LPA: 54% ± 28 [4-98]). There was a significant relationship between pulmonary artery cross-sectional area and flow distribution (IVC to RPA: R(2)=0.50, P=0.02; SVC to LPA: R(2)=0.81, P=0.0004). Good agreement was found between observers and for flow distribution when compared to net flow values. CONCLUSION Four-dimensional flow MRI was able to detect relationships between flow distribution and vessel geometry. Future studies are warranted to investigate the potential of patient specific hemodynamic analysis to improve diagnostic capability.
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Affiliation(s)
- Kelly Jarvis
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Ave., Suite 1600, Chicago, IL, 60611, USA.
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, IL, USA.
| | - Susanne Schnell
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Ave., Suite 1600, Chicago, IL, 60611, USA
| | - Alex J Barker
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Ave., Suite 1600, Chicago, IL, 60611, USA
| | - Julio Garcia
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Ave., Suite 1600, Chicago, IL, 60611, USA
| | - Ramona Lorenz
- Department of Radiology, University Medical Center Freiburg, Freiburg, Germany
| | - Michael Rose
- Department of Medical Imaging, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | - Varun Chowdhary
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Ave., Suite 1600, Chicago, IL, 60611, USA
| | - James Carr
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Ave., Suite 1600, Chicago, IL, 60611, USA
| | - Joshua D Robinson
- Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
- Division of Cardiology, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | - Cynthia K Rigsby
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Ave., Suite 1600, Chicago, IL, 60611, USA
- Department of Medical Imaging, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | - Michael Markl
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N. Michigan Ave., Suite 1600, Chicago, IL, 60611, USA
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, IL, USA
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Rajabzadeh-Oghaz H, Firoozabadi B, Saidi MS, Monjezi M, Navabi Shirazi MA, Malakan Rad E. Pulsatile blood flow in total cavopulmonary connection: a comparison between Y-shaped and T-shaped geometry. Med Biol Eng Comput 2016; 55:213-224. [DOI: 10.1007/s11517-016-1499-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 03/26/2016] [Indexed: 11/30/2022]
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Good BC, Deutsch S, Manning KB. Hemodynamics in a Pediatric Ascending Aorta Using a Viscoelastic Pediatric Blood Model. Ann Biomed Eng 2016; 44:1019-35. [PMID: 26159560 PMCID: PMC4707135 DOI: 10.1007/s10439-015-1370-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 06/16/2015] [Indexed: 10/23/2022]
Abstract
Congenital heart disease is the leading cause of infant death in the United States with over 36,000 newborns affected each year. Despite this growing problem there are few mechanical circulatory support devices designed specifically for pediatric and neonate patients. Previous research has been done investigating pediatric ventricular assist devices (PVADs) assuming blood to be a Newtonian fluid in computational fluid dynamics (CFD) simulations, ignoring its viscoelastic and shear-thinning properties. In contrast to adult VADs, PVADs may be more susceptible to hemolysis and thrombosis due to altered flow into the aorta, and therefore, a more accurate blood model should be used. A CFD solver that incorporates a modified Oldroyd-B model designed specifically for pediatric blood is used to investigate important hemodynamic parameters in a pediatric aortic model under pulsatile flow conditions. These results are compared to Newtonian blood simulations at three physiological pediatric hematocrits. Minor differences are seen in both velocity and wall shear stress (WSS) during early stages of the cardiac cycle between the Newtonian and viscoelastic models. During diastole, significant differences are seen in the velocities in the descending aorta (up to 12%) and in the aortic branches (up to 30%) between the two models. Additionally, peak WSS differences are seen between the models throughout the cardiac cycle. At the onset of diastole, peak WSS differences of 43% are seen between the Newtonian and viscoelastic model and between the 20 and 60% hematocrit viscoelastic models at peak systole of 41%.
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Affiliation(s)
- Bryan C Good
- Department of Biomedical Engineering, The Pennsylvania State University, 205 Hallowell Building, University Park, PA, 16802, USA
| | - Steven Deutsch
- Department of Biomedical Engineering, The Pennsylvania State University, 205 Hallowell Building, University Park, PA, 16802, USA
| | - Keefe B Manning
- Department of Biomedical Engineering, The Pennsylvania State University, 205 Hallowell Building, University Park, PA, 16802, USA.
- Department of Surgery, Penn State Hershey Medical Center, Hershey, PA, 17033, USA.
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Good BC, Deutsch S, Manning KB. Continuous and Pulsatile Pediatric Ventricular Assist Device Hemodynamics with a Viscoelastic Blood Model. Cardiovasc Eng Technol 2016; 7:23-43. [PMID: 26643646 PMCID: PMC4767652 DOI: 10.1007/s13239-015-0252-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 11/23/2015] [Indexed: 11/25/2022]
Abstract
To investigate the effects of pulsatile and continuous pediatric ventricular assist (PVAD) flow and pediatric blood viscoelasticity on hemodynamics in a pediatric aortic graft model. Hemodynamic parameters of pulsatility, along with velocity and wall shear stress (WSS), are analyzed and compared between Newtonian and viscoelastic blood models at a range of physiological pediatric hematocrits using computational fluid dynamics. Both pulsatile and continuous PVAD flow lead to a decrease in pulsatility (surplus hemodynamic energy, ergs/cm(3)) compared to healthy aortic flow but with continuous PVAD pulsatility up to 2.4 times lower than pulsatile PVAD pulsatility at each aortic outlet. Significant differences are also seen between the two flow modes in velocity and WSS. The higher velocity jet during systole with pulsatile flow leads to higher WSSs at the anastomotic toe and at the aortic branch bifurcations. The lower velocity but continuous flow jet leads to a much different flow field and higher WSSs into diastole. Under a range of physiological pediatric hematocrit (20-60%), both velocity and WSS can vary significantly with the higher hematocrit blood model generally leading to higher peak WSSs but also lower WSSs in regions of flow separation. The large decrease in pulsatility seen from continuous PVAD flow could lead to complications in pediatric vascular development while the high WSSs during peak systole from pulsatile PVAD flow could lead to blood damage. Both flow modes lead to similar regions prone to intimal hyperplasia resulting from low time-averaged WSS and high oscillatory shear index.
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Affiliation(s)
- Bryan C Good
- Department of Biomedical Engineering, The Pennsylvania State University, 205 Hallowell Building, University Park, PA, 16802, USA
| | - Steven Deutsch
- Department of Biomedical Engineering, The Pennsylvania State University, 205 Hallowell Building, University Park, PA, 16802, USA
| | - Keefe B Manning
- Department of Biomedical Engineering, The Pennsylvania State University, 205 Hallowell Building, University Park, PA, 16802, USA.
- Department of Surgery, Penn State Hershey Medical Center, Hershey, PA, 17033, USA.
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Rajabzadeh Oghaz H, Firoozabadi B, Saidi M, Monjezi M, Navabi Shirazi M, Malakan Rad E. Evaluation of a novel extra-cardiac Fontan procedure with implantation of a biocompatible membrane. Ing Rech Biomed 2015. [DOI: 10.1016/j.irbm.2015.06.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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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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Abstract
The hemi-Fontan (HF) operation is a staging procedure in the journey towards an ultimate Fontan palliation. Although popular in the Western world, it has found limited application in the developing world. In this review we discuss the indications, techniques, merits, and demerits of this procedure along with its present day role in developing world where there is lack of awareness about this operation.
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Affiliation(s)
- Sachin Talwar
- Department of Cardiothoracic and Vascular Surgery, Cardiothoracic Center, All India Institute of Medical Sciences, New Delhi, India
| | - Vinitha Viswambharan Nair
- Department of Cardiothoracic and Vascular Surgery, Cardiothoracic Center, All India Institute of Medical Sciences, New Delhi, India
| | - Shiv Kumar Choudhary
- Department of Cardiothoracic and Vascular Surgery, Cardiothoracic Center, All India Institute of Medical Sciences, New Delhi, India
| | - Balram Airan
- Department of Cardiothoracic and Vascular Surgery, Cardiothoracic Center, All India Institute of Medical Sciences, New Delhi, India
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Bächler P, Valverde I, Pinochet N, Nordmeyer S, Kuehne T, Crelier G, Tejos C, Irarrazaval P, Beerbaum P, Uribe S. Caval blood flow distribution in patients with Fontan circulation: quantification by using particle traces from 4D flow MR imaging. Radiology 2013; 267:67-75. [PMID: 23297331 DOI: 10.1148/radiol.12120778] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To validate the use of particle traces derived from four-dimensional (4D) flow magnetic resonance (MR) imaging to quantify in vivo the caval flow contribution to the pulmonary arteries (PAs) in patients who had been treated with the Fontan procedure. MATERIALS AND METHODS The institutional review boards approved this study, and informed consent was obtained. Twelve healthy volunteers and 10 patients with Fontan circulation were evaluated. The particle trace method consists of creating a region of interest (ROI) on a blood vessel, which is used to emit particles with a temporal resolution of approximately 40 msec. The flow distribution, as a percentage, is then estimated by counting the particles arriving to different ROIs. To validate this method, two independent observers used particle traces to calculate the flow contribution of the PA to its branches in volunteers and compared it with the contribution estimated by measuring net forward flow volume (reference method). After the method was validated, caval flow contributions were quantified in patients. Statistical analysis was performed with nonparametric tests and Bland-Altman plots. P < .05 was considered to indicate a significant difference. RESULTS Estimation of flow contributions by using particle traces was equivalent to estimation by using the reference method. Mean flow contribution of the PA to the right PA in volunteers was 54% ± 3 (standard deviation) with the reference method versus 54% ± 3 with the particle trace method for observer 1 (P = .4) and 54% ± 4 versus 54% ± 4 for observer 2 (P = .6). In patients with Fontan circulation, 87% ± 13 of the superior vena cava blood flowed to the right PA (range, 63%-100%), whereas 55% ± 19 of the inferior vena cava blood flowed to the left PA (range, 22%-82%). CONCLUSION Particle traces derived from 4D flow MR imaging enable in vivo quantification of the caval flow distribution to the PAs in patients with Fontan circulation. This method might allow the identification of patients at risk of developing complications secondary to uneven flow distribution. SUPPLEMENTAL MATERIAL http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120778/-/DC1.
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Affiliation(s)
- Pablo Bächler
- Department of Radiology, School of Medicine, Pontificia Universidad Católica de Chile, Marcoleta 367, Santiago 8330024, Chile
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Menon PG, Teslovich N, Chen CY, Undar A, Pekkan K. Characterization of neonatal aortic cannula jet flow regimes for improved cardiopulmonary bypass. J Biomech 2013. [DOI: 10.1016/j.jbiomech.2012.10.029] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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18
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Yang W, Vignon-Clementel IE, Troianowski G, Reddy VM, Feinstein JA, Marsden AL. Hepatic blood flow distribution and performance in conventional and novel Y-graft Fontan geometries: A case series computational fluid dynamics study. J Thorac Cardiovasc Surg 2012; 143:1086-97. [DOI: 10.1016/j.jtcvs.2011.06.042] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Revised: 05/13/2011] [Accepted: 06/27/2011] [Indexed: 11/15/2022]
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20
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Quantification of caval flow contribution to the lungs in vivo after total cavopulmonary connection with 4-dimensional flow magnetic resonance imaging. J Thorac Cardiovasc Surg 2012; 143:742-3. [DOI: 10.1016/j.jtcvs.2011.11.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Accepted: 11/07/2011] [Indexed: 11/18/2022]
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21
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Caval flow reflects Fontan hemodynamics: quantification by magnetic resonance imaging. Clin Res Cardiol 2011; 101:133-8. [DOI: 10.1007/s00392-011-0374-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 10/21/2011] [Indexed: 10/15/2022]
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22
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de Zélicourt DA, Marsden A, Fogel MA, Yoganathan AP. Imaging and patient-specific simulations for the Fontan surgery: current methodologies and clinical applications. PROGRESS IN PEDIATRIC CARDIOLOGY 2010; 30:31-44. [PMID: 25620865 PMCID: PMC4302339 DOI: 10.1016/j.ppedcard.2010.09.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Diane A. de Zélicourt
- Wallace H. Coulter School of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA
| | - Alison Marsden
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, CA
| | - Mark A. Fogel
- Division of Cardiology, Children’s Hospital of Philadelphia, Philadelphia, PA
| | - Ajit P. Yoganathan
- Wallace H. Coulter School of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA
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Markl M, Geiger J, Kilner PJ, Föll D, Stiller B, Beyersdorf F, Arnold R, Frydrychowicz A. Time-resolved three-dimensional magnetic resonance velocity mapping of cardiovascular flow paths in volunteers and patients with Fontan circulation. Eur J Cardiothorac Surg 2010; 39:206-12. [PMID: 20598560 DOI: 10.1016/j.ejcts.2010.05.026] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Revised: 05/12/2010] [Accepted: 05/18/2010] [Indexed: 10/19/2022] Open
Abstract
OBJECTIVE To apply flow-sensitive magnetic resonance imaging for the evaluation of whole-heart flow characteristics in healthy volunteers and patients with Fontan circulation. METHODS Time-resolved three-dimensional magnetic resonance velocity mapping (spatial resolution = 2.5 × 2.8 × 2.8mm(3), temporal resolution = 38.4 ms) was acquired in normal controls and in four Fontan patients with extracardiac total cavopulmonary connection. Data analysis included flow connectivity mapping and flow quantification of arterial and venous blood flow. Haemodynamics in four patients with Fontan circulation were individually evaluated in the aorta, caval veins and left and right pulmonary arteries. RESULTS In four controls, nine distinct flow features were consistently identified with good feature clarity (median = 2 in 80.6% of readings) and image quality (median = 2 in 75.0% of readings). In patients, a marked variability of flow from the caval veins towards the left and right pulmonary arteries (flow ratio = 1.7 ± 0.6, range 1.2-2.6 vs 1.1 ± 0.1 in controls) was found. Increased offset of the caval venous connection resulted in enhanced pulmonary flow asymmetry. Compared with controls, reduced pulsatility in pulmonary arteries (1.4 ± 0.6 vs 4.1 ± 0.6 in controls) and caval veins (1.2 ± 0.4 vs 2.8 ± 1.1 in controls) were observed. Peak flow was reduced in both superior (22 ± 14 mls(-1) vs 76 ± 7 mls(-1) in controls) and inferior vena cava (61 ± 28 mls(-1) vs 187 ± 42 mls(-1) in controls). CONCLUSIONS This feasibility study demonstrated the potential of whole-heart three-dimensional magnetic resonance velocity mapping to reveal overt haemodynamic differences in surgically palliated congenital heart with similar extracardiac cavopulmonary connection geometry. Future studies are warranted to evaluate its diagnostic impact for improved evaluation of the pre- and postoperative status in the individual patient.
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Affiliation(s)
- Michael Markl
- Department of Radiology, Medical Physics, University Hospital Freiburg, Breisacher Str 60a, 79106 Freiburg, Germany.
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Hundley WG, Bluemke DA, Finn JP, Flamm SD, Fogel MA, Friedrich MG, Ho VB, Jerosch-Herold M, Kramer CM, Manning WJ, Patel M, Pohost GM, Stillman AE, White RD, Woodard PK. ACCF/ACR/AHA/NASCI/SCMR 2010 expert consensus document on cardiovascular magnetic resonance: a report of the American College of Cardiology Foundation Task Force on Expert Consensus Documents. J Am Coll Cardiol 2010; 55:2614-62. [PMID: 20513610 PMCID: PMC3042771 DOI: 10.1016/j.jacc.2009.11.011] [Citation(s) in RCA: 445] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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25
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Hundley WG, Bluemke DA, Finn JP, Flamm SD, Fogel MA, Friedrich MG, Ho VB, Jerosch-Herold M, Kramer CM, Manning WJ, Patel M, Pohost GM, Stillman AE, White RD, Woodard PK. ACCF/ACR/AHA/NASCI/SCMR 2010 expert consensus document on cardiovascular magnetic resonance: a report of the American College of Cardiology Foundation Task Force on Expert Consensus Documents. Circulation 2010; 121:2462-508. [PMID: 20479157 PMCID: PMC3034132 DOI: 10.1161/cir.0b013e3181d44a8f] [Citation(s) in RCA: 226] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Yang N, Deutsch S, Paterson EG, Manning KB. Hemodynamics of an end-to-side anastomotic graft for a pulsatile pediatric ventricular assist device. J Biomech Eng 2010; 132:031009. [PMID: 20459197 DOI: 10.1115/1.4000872] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Numerical simulations are performed to investigate the flow within the end-to-side proximal anastomosis of a pulsatile pediatric ventricular assist device (PVAD) to an aorta. The anastomotic model is constructed from a patient-specific pediatric aorta. The three great vessels originating from the aortic arch--brachiocephalic (innominate), left common carotid, and left subclavian arteries--are included. An implicit large eddy simulation method based on a finite volume approach is used to study the resulting turbulent flow. A resistance boundary condition is applied at each branch outlet to study flow splitting. The PVAD anastomosis is found to alter the aortic flow dramatically. More flow is diverted into the great vessels with the PVAD support. Turbulence is found in the jet impingement area at peak systole for 100% bypass, and a maximum principal normal Reynolds stress of 7081 dyn/cm(2) is estimated based on ten flow cycles. This may be high enough to cause hemolysis and platelet activation. Regions prone to intimal hyperplasia are identified by combining the time-averaged wall shear stress and oscillatory shear index. These regions are found to vary, depending on the percentage of the flow bypass.
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Affiliation(s)
- Ning Yang
- Department of Bioengineering, Pennsylvania State University, University Park, PA 16802, USA
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Dillman JR, Dorfman AL, Attili AK, Agarwal PP, Bell A, Mueller GC, Hernandez RJ. Cardiovascular magnetic resonance imaging of hypoplastic left heart syndrome in children. Pediatr Radiol 2010; 40:261-74; quiz 379-80. [PMID: 20107779 DOI: 10.1007/s00247-009-1473-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2009] [Revised: 10/31/2009] [Accepted: 11/09/2009] [Indexed: 11/26/2022]
Abstract
Cardiovascular magnetic resonance imaging (CMR) plays an important complementary role to echocardiography and conventional angiography in the evaluation of hypoplastic left heart syndrome. This imaging modality is particularly useful for assessing cardiovascular postsurgical changes, extracardiac vascular anatomy, ventricular and valvular function, and a variety of complications. The purpose of this article is to provide a contemporary review of the role of CMR in the management of untreated and surgically palliated hypoplastic left heart syndrome in children.
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Affiliation(s)
- Jonathan R Dillman
- Department of Radiology, Section of Pediatric Radiology, C.S. Mott Children's Hospital, University of Michigan Health System, Ann Arbor, MI 48109, USA.
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Yang N, Deutsch S, Paterson EG, Manning KB. Comparative Study of Continuous and Pulsatile Left Ventricular Assist Devices on Hemodynamics of a Pediatric End-to-Side Anastomotic Graft. Cardiovasc Eng Technol 2010; 1:10.1007/s13239-010-0006-6. [PMID: 24348881 PMCID: PMC3859142 DOI: 10.1007/s13239-010-0006-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Although there are many studies that focus on understanding the consequence of pumping mode (continuous vs. pulsatile) associated with ventricular assist devices (VADs) on pediatric vascular pulsatility, the impact on local hemodynamics has been largely ignored. Hence, we compare not only the hemodynamic parameters indicative of pulsatility but also the local flow fields in the aorta and the great vessels originating from the aortic arch. A physiologic graft anastomotic model is constructed based on a pediatric, patient specific, aorta with a graft attached on the ascending aorta. The flow is simulated using a previously validated second-order accurate Navier-Stokes flow solver based upon a finite volume approach. The major findings are: (1) pulsatile support provides a greater degree of vascular pulsatility when compared to continuous support, which, however, is still 20% less than pulsatility in the healthy aorta; (2) pulsatile support increases the flow in the great vessels, while continuous support decreases it; (3) complete VAD support results in turbulence in the aorta, with maximum principal Reynolds stresses for pulsatile support and continuous support of 7081 and 249 dyn/cm2, respectively; (4) complete pulsatile support results in a significant increase in predicted hemolysis in the aorta; and (5) pulsatile support causes both higher time-averaged wall shear stresses (WSS) and oscillatory shear indices (OSI) in the aorta than does continuous support. These findings will help to identify the risk of graft failure for pediatric patients with pulsatile and continuous VADs.
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Affiliation(s)
- Ning Yang
- Department of Bioengineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Steven Deutsch
- Department of Bioengineering, The Pennsylvania State University, University Park, PA 16802, USA
- The Applied Research Laboratory, The Pennsylvania State University, University Park, PA 16802, USA
| | - Eric G. Paterson
- The Applied Research Laboratory, The Pennsylvania State University, University Park, PA 16802, USA
- Department of Mechanical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Keefe B. Manning
- Department of Bioengineering, The Pennsylvania State University, University Park, PA 16802, USA
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Abstract
BACKGROUND In this study we sought to determine, first, whether maximal exercise capacity reflects ventricular function, and second, whether the age of the patient, and the age of completion of the Fontan circulation, influence ventricular function and exercise performance. METHODS AND RESULTS Cardiac magnetic resonance imaging and cardiopulmonary exercise testing were performed in 29 patients at a median time of 6.9 years after completion of the Fontan circulation. We divided the patients into 2 groups, the first 19 having their operation below the age of 18 years, and the second group, of 10 patients, having completion of the Fontan circulation when they were older than 18 years. Parameters for ventricular function and exercise were compared for both groups with controls. Compared to controls, the younger patients had normal end-diastolic ventricular volumes, but significantly impaired ventricular function, lower maximal work load and consumption of oxygen. The older patients had greater end-diastolic ventricular volumes, and significantly poorer ventricular function than both the younger patients and the controls. Maximal work load and consumption of oxygen were significantly lower in the older patients than in the younger ones and the controls. CONCLUSION Patients with the Fontan circulation have an impaired systolic ventricular function, which correlates with maximal exercise capacity and uptake of oxygen. Those having completion of the Fontan circulation when younger than 18 years had significantly better ventricular function and exercise performance than those who had completion of the Fontan circulation at an older age. An early creation of the Fontan circulation may preserve cardiac function and exercise capacity.
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30
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Whitehead KK, Sundareswaran KS, Parks WJ, Harris MA, Yoganathan AP, Fogel MA. Blood flow distribution in a large series of patients having the Fontan operation: a cardiac magnetic resonance velocity mapping study. J Thorac Cardiovasc Surg 2009; 138:96-102. [PMID: 19577063 DOI: 10.1016/j.jtcvs.2008.11.062] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2008] [Revised: 10/20/2008] [Accepted: 11/23/2008] [Indexed: 10/20/2022]
Abstract
OBJECTIVES Our goal was to determine flow distribution in the cavopulmonary connections of patients with and without bilateral superior venae cavae who had the Fontan procedure. No large series exists that establishes the flow distributions in Fontan patients, which would be an important resource for everyday clinical use and may affect future surgical reconstruction. METHODS We studied 105 Fontan patients (aged 2-24 years) with through-plane phase contrast velocity mapping to determine flow rates in the inferior and superior venae cavae and left and right pulmonary arteries. Superior caval anastomosis type included 40 bidirectional Glenn shunts (of which 15 were bilateral) and 53 hemi-Fontan anastomoses; Fontan type included 69 intra-atrial baffles, 28 extracardiac conduits, and 4 atriopulmonary connections. RESULTS Total caval flow was 2.9 +/- 1.0 L x min(-1) x m(-2), with an inferior vena cava contribution of 59% +/- 15%. Total pulmonary flow was 2.5 +/- 0.8 L x min(-1) x m(-2), statistically less than caval flow and not explained by fenestration presence. The right pulmonary artery contribution (55% +/- 13%) was statistically greater than the left. In patients with bilateral superior cavae, the right cava accounted for 52% +/- 14% of the flow, with no difference in pulmonary flow splits (50% +/- 16% to the right). Age and body surface area correlated with percent inferior caval contribution (r = 0.60 and 0.74, respectively). Superior vena cava anastomosis and Fontan type did not significantly affect pulmonary flow splits. CONCLUSIONS Total Fontan cardiac index was 2.9 L x min(-1) x m(-2), with normal pulmonary flow splits (55% to the right lung). Inferior vena caval contribution to total flow increases with body surface area and age, consistent with data from healthy children.
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Affiliation(s)
- Kevin K Whitehead
- Division of Cardiology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
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Pekkan K, Dasi LP, de Zélicourt D, Sundareswaran KS, Fogel MA, Kanter KR, Yoganathan AP. Hemodynamic performance of stage-2 univentricular reconstruction: Glenn vs. hemi-Fontan templates. Ann Biomed Eng 2008; 37:50-63. [PMID: 18987974 DOI: 10.1007/s10439-008-9591-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2007] [Accepted: 10/22/2008] [Indexed: 10/21/2022]
Abstract
Flow structures, hemodynamics and the hydrodynamic surgical pathway resistances of the final stage functional single ventricle reconstruction, namely the total cavopulmonary connection (TCPC) anatomy, have been investigated extensively. However, the second stage surgical anatomy (i.e., bi-directional Glenn or hemi-Fontan template) has received little attention. We thus initiated a multi-faceted study, involving magnetic resonance imaging (MRI), phase contrast MRI, computational and experimental fluid dynamics methodologies, focused on the second stage of the procedure. Twenty three-dimensional computer and rapid prototype models of 2nd stage TCPC anatomies were created, including idealized parametric geometries (n = 6), patient-specific anatomies (n = 7), and their virtual surgery variant (n = 7). Results in patient-specific and idealized models showed that the Glenn connection template is hemodynamically more efficient with (83% p = 0.08 in patient-specific models and 66% in idealized models) lower power losses compared to hemi-Fontan template, respectively, due to its direct end-to-side anastomosis. Among the several secondary surgical geometrical features, stenosis at the SVC anastomosis or in pulmonary branches was found to be the most critical parameter in increasing the power loss. The pouch size and flare shape were found to be less significant. Compared to the third stage surgery the hydrodynamic resistance of the 2nd stage is considerably lower (both in idealized models and in anatomical models at MRI resting conditions) for both hemi- and Glenn templates. These results can impact the surgical design and planning of the staged TCPC reconstruction.
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Affiliation(s)
- Kerem Pekkan
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
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Pekkan K, Dur O, Sundareswaran K, Kanter K, Fogel M, Yoganathan A, Ündar A. Neonatal Aortic Arch Hemodynamics and Perfusion During Cardiopulmonary Bypass. J Biomech Eng 2008; 130:061012. [DOI: 10.1115/1.2978988] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The objective of this study is to quantify the detailed three-dimensional (3D) pulsatile hemodynamics, mechanical loading, and perfusion characteristics of a patient-specific neonatal aortic arch during cardiopulmonary bypass (CPB). The 3D cardiac magnetic resonance imaging (MRI) reconstruction of a pediatric patient with a normal aortic arch is modified based on clinical literature to represent the neonatal morphology and flow conditions. The anatomical dimensions are verified from several literature sources. The CPB is created virtually in the computer by clamping the ascending aorta and inserting the computer-aided design model of the 10 Fr tapered generic cannula. Pulsatile (130 bpm) 3D blood flow velocities and pressures are computed using the commercial computational fluid dynamics (CFD) software. Second order accurate CFD settings are validated against particle image velocimetry experiments in an earlier study with a complex cardiovascular unsteady benchmark. CFD results in this manuscript are further compared with the in vivo physiological CPB pressure waveforms and demonstrated excellent agreement. Cannula inlet flow waveforms are measured from in vivo PC-MRI and 3 kg piglet neonatal animal model physiological experiments, distributed equally between the head-neck vessels and the descending aorta. Neonatal 3D aortic hemodynamics is also compared with that of the pediatric and fetal aortic stages. Detailed 3D flow fields, blood damage, wall shear stress (WSS), pressure drop, perfusion, and hemodynamic parameters describing the pulsatile energetics are calculated for both the physiological neonatal aorta and for the CPB aorta assembly. The primary flow structure is the high-speed canulla jet flow (∼3.0 m/s at peak flow), which eventually stagnates at the anterior aortic arch wall and low velocity flow in the cross-clamp pouch. These structures contributed to the reduced flow pulsatility (85%), increased WSS (50%), power loss (28%), and blood damage (288%), compared with normal neonatal aortic physiology. These drastic hemodynamic differences and associated intense biophysical loading of the pathological CPB configuration necessitate urgent bioengineering improvements—in hardware design, perfusion flow waveform, and configuration. This study serves to document the baseline condition, while the methodology presented can be utilized in preliminary CPB cannula design and in optimization studies reducing animal experiments. Coupled to a lumped-parameter model the 3D hemodynamic characteristics will aid the surgical decision making process of the perfusion strategies in complex congenital heart surgeries.
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Affiliation(s)
- Kerem Pekkan
- Department of Biomedical Engineering, Carnegie Mellon University, 2100 Doherty Hall, Pittsburgh, PA 15213-3890
| | - Onur Dur
- Department of Biomedical Engineering, Carnegie Mellon University, 2100 Doherty Hall, Pittsburgh, PA 15213-3890
| | - Kartik Sundareswaran
- Cardiovascular Fluid Mechanics Laboratory, Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, 315 Ferst Drive, Atlanta, GA 30332-0535
| | - Kirk Kanter
- Pediatric Cardiothoracic Surgery, Emory University School of Medicine, 1440 Clifton Road, Atlanta, GA 30322
| | - Mark Fogel
- Children’s Hospital of Philadelphia, 34th Street, Civic Center Boulevard, Philadelphia, PA 19104
| | - Ajit Yoganathan
- Cardiovascular Fluid Mechanics Laboratory, Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, 315 Ferst Drive, Atlanta, GA 30332-0535A
| | - Akif Ündar
- Department of Pediatrics, Surgery and Bioengineering, Penn State College of Medicine, Hershey, PA 17033
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Evaluation of the Extracardiac Conduit Modification of the Fontan Operation for Thrombus Formation using Magnetic Resonance Imaging. Heart Lung Circ 2008; 17:407-10. [DOI: 10.1016/j.hlc.2008.01.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2007] [Revised: 11/25/2007] [Accepted: 01/10/2008] [Indexed: 11/19/2022]
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Modeling the Fontan circulation: where we are and where we need to go. Pediatr Cardiol 2008; 29:3-12. [PMID: 17917765 DOI: 10.1007/s00246-007-9104-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2007] [Revised: 06/30/2007] [Accepted: 07/03/2007] [Indexed: 10/22/2022]
Abstract
The Fontan procedure and its subsequent modifications over the past 30 years can be described as a class of surgical procedures for patients born with complex congenital heart disease exhibiting a single-ventricle physiology. The long-term outcome for children currently undergoing a Fontan procedure remains worrisome because of multiple late morbidities observed. Despite significant modeling efforts spanning three decades, improvements to the Fontan procedure have occurred without comprehensive validation from these modeling studies. Careful examination shows that modeling studies to date offer only a "glimpse through a keyhole" into understanding and modeling a representative range of the variations in anatomy and physiology that exist in Fontan patients. Suggestions for future investigations are provided.
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Goo HW, Yang DH, Park IS, Ko JK, Kim YH, Seo DM, Yun TJ, Park JJ. Time-resolved three-dimensional contrast-enhanced magnetic resonance angiography in patients who have undergone a Fontan operation or bidirectional cavopulmonary connection: initial experience. J Magn Reson Imaging 2007; 25:727-36. [PMID: 17335039 DOI: 10.1002/jmri.20870] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To evaluate the usefulness of time-resolved three-dimensional (3D) magnetic resonance angiography (MRA) using diluted contrast agent (CA) in patients who had undergone a Fontan operation or bidirectional cavopulmonary connection (BCPC). MATERIALS AND METHODS Time-resolved 3D MRA (10 dynamic data sets, two seconds per dynamic data set) using parallel imaging and keyhole data sampling was performed on 15 patients (median age=10 years, range=1-20 years) who had undergone a Fontan operation (N=11) or BCPC (N=4). Diluted gadolinium (Gd) contrast agent (CA) was intravenously injected into the arm and/or leg veins. The flow dynamics and morphology of pulmonary circulation, and lung perfusion were assessed. RESULTS Preferential or balanced pulmonary blood flow from each systemic vein was visualized on time-resolved 3D MRA in all patients. In addition, occlusion/stenosis of the central thoracic vein (N=4) and pulmonary artery (N=6), systemic venous (N=5) and arterial (N=6) collaterals, and lung perfusion defect (N=4) were identified. Persistent hepatic venous plexus, pulmonary arteriovenous malformation, and axillary arteriovenous fistula were delineated in three patients, respectively. CONCLUSION Time-resolved 3D MRA with diluted CA is useful for evaluating patients who have undergone a Fontan operation or BCPC because it can reveal the flow dynamics and morphology of pulmonary circulation, and lung perfusion status.
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Affiliation(s)
- Hyun Woo Goo
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
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Soerensen DD, Pekkan K, de Zélicourt D, Sharma S, Kanter K, Fogel M, Yoganathan AP. Introduction of a New Optimized Total Cavopulmonary Connection. Ann Thorac Surg 2007; 83:2182-90. [PMID: 17532420 DOI: 10.1016/j.athoracsur.2006.12.079] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2006] [Revised: 11/28/2006] [Accepted: 12/04/2006] [Indexed: 10/23/2022]
Abstract
BACKGROUND Several variations of the total cavopulmonary connection (TCPC) have been investigated for favorable fluid mechanics and flow distribution. This study presents a hemodynamically optimized TCPC configuration code-named "OptiFlo." Featuring bifurcated vena cava (superior venacava to inferior vena cava SVC/IVC), it was designed to lower the fluid mechanical power losses in the connection and to ensure proper hepatic blood perfusion to both lungs. METHODS A rapid prototype model of the OptiFlo TCPC was built and in vitro control volume flow analysis was performed to evaluate the fluid mechanical power loss performance of the model. Furthermore, computational fluid dynamics simulations were used to investigate the flow patterns in the model, which were compared with those in the planar one-diameter offset TCPC with flared anastomosis sites, the best known TCPC configuration to date. RESULTS Compared with the one-diameter offset reference model, the OptiFlo showed lower power losses: -26%, -31%, and -42% for increasing cardiac outputs of 2, 4, and 6 L/minute, respectively. No statistically significant differences were found in power loss between 40:60 and 50:50 SVC/IVC flow ratios (p > 0.1) for the OptiFlo model. The power loss characteristic curve for different left and right pulmonary artery ratios was flatter for the OptiFlo than the one-diameter offset reference model. Pulmonary artery flow was much more streamlined in the OptiFlo compared with the one-diameter offset model. CONCLUSIONS The OptiFlo TCPC design exhibits lower power losses with better adaptive distribution of hepatic blood to both lungs and lower blood flow disturbances compared with the planar one-diameter offset TCPC model. Its significantly superior hemodynamic performance at higher cardiac outputs (exercise) rationalizes further design and feasibility studies toward a workable clinical model.
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Affiliation(s)
- Dennis D Soerensen
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332-0535, USA
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Klimes K, Abdul-Khaliq H, Ovroutski S, Hui W, Alexi-Meskishvili V, Spors B, Hetzer R, Felix R, Lange PE, Berger F, Gutberlet M. Pulmonary and caval blood flow patterns in patients with intracardiac and extracardiac Fontan: a magnetic resonance study. Clin Res Cardiol 2006; 96:160-7. [PMID: 17180575 DOI: 10.1007/s00392-007-0470-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2006] [Accepted: 10/20/2006] [Indexed: 11/27/2022]
Abstract
AIMS We compared in vivo blood flow and pulsatility after different types of Fontan operation using magnetic resonance imaging. MATERIAL AND METHODS A total of 37 consecutive patients (mean age 19+/-7.9 years, 7.3+/-3.2 years after Fontan operation), 7 with atriopulmonary anastomosis (APC), 18 with intra-atrial lateral tunnel (LTFO) and 12 with extracardiac Fontan (ECFO) were studied using magnetic resonance phase-contrast velocity mapping. Blood flow (volume flow) in the superior vena cava (SVC), inferior vena cava (IVC) and both pulmonary arteries were measured and a pulsatility index was calculated for each vessel. RESULTS For all modifications, the blood flow distribution between the SVC and IVC was normal (1:2). Patients with APC had a normal pulsatility, a dilated right atrium, partial backward flow in the IVC and physiological blood flow distribution between the pulmonary arteries. LTFO and ECFO patients had no retrograde flow in the IVC, equal blood flow distribution between the pulmonary arteries and very low or absent pulsatility. CONCLUSIONS MRI allows hemodynamic quantification and characterization of various types of Fontan modifications and may be a valuable tool to predict Fontan failure. Despite showing normal pulsatility, patients with APC have right atrial dilatation and partial backward flow in the IVC, demonstrating suboptimal Fontan circulation. LTFO and ECFO both produce unidirectional antegrade flow in the IVC but pulsatility is very low or absent, which may promote poor pulmonary artery growth and increase of pulmonary vascular resistance contributing to late Fontan failure.
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Affiliation(s)
- K Klimes
- Department of Congenital Heart Defects/Paediatric Cardiology, Deutsches Herzzentrum Berlin, Augustenburger Platz 1, 13353, Berlin, Germany.
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Yoo SJ, Kellenberger CJ, Roman KS, Al-Habshan F, Branson H, Sun AM, Macgowan CK. Magnetic resonance evaluation of pulmonary circulation in children. PROGRESS IN PEDIATRIC CARDIOLOGY 2006. [DOI: 10.1016/j.ppedcard.2006.07.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Fogel MA. Is routine cardiac catheterization necessary in the management of patients with single ventricles across staged Fontan reconstruction? No! Pediatr Cardiol 2005; 26:154-8. [PMID: 15868320 DOI: 10.1007/s00246-004-0960-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
With the advent of cardiac magnetic resonance imaging and high-resolution echocardiography, cardiac catheterization is unnecessary in clinical protocols in the "routine" single ventricle patient. Catheterization adds little to clinical care in these cases, and there are significant risks and costs associated with it. Catheterization should be reserved for cases in which noninvasive evaluations are equivocal, conflictory, demonstrate deterioration, or needed for intervention. This article delineates the role of noninvasive evaluations relative to cardiac catheterization in the routine single ventricle patient.
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Affiliation(s)
- M A Fogel
- Division of Cardiology, Department of Pediatrics, The Children's Hospital of Philadelphia, 34th Street and Civic Center Boulevard, Philadelphia, PA, 19104, USA.
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Pekkan K, de Zélicourt D, Ge L, Sotiropoulos F, Frakes D, Fogel MA, Yoganathan AP. Physics-Driven CFD Modeling of Complex Anatomical Cardiovascular Flows?A TCPC Case Study. Ann Biomed Eng 2005; 33:284-300. [PMID: 15868719 DOI: 10.1007/s10439-005-1731-0] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Recent developments in medical image acquisition combined with the latest advancements in numerical methods for solving the Navier-Stokes equations have created unprecedented opportunities for developing simple and reliable computational fluid dynamics (CFD) tools for meeting patient-specific surgical planning objectives. However, for CFD to reach its full potential and gain the trust and confidence of medical practitioners, physics-driven numerical modeling is required. This study reports on the experience gained from an ongoing integrated CFD modeling effort aimed at developing an advanced numerical simulation tool capable of accurately predicting flow characteristics in an anatomically correct total cavopulmonary connection (TCPC). An anatomical intra-atrial TCPC model is reconstructed from a stack of magnetic resonance (MR) images acquired in vivo. An exact replica of the computational geometry was built using transparent rapid prototyping. Following the same approach as in earlier studies on idealized models, flow structures, pressure drops, and energy losses were assessed both numerically and experimentally, then compared. Numerical studies were performed with both a first-order accurate commercial software and a recently developed, second-order accurate, in-house flow solver. The commercial CFD model could, with reasonable accuracy, capture global flow quantities of interest such as control volume power losses and pressure drops and time-averaged flow patterns. However, for steady inflow conditions, both flow visualization experiments and particle image velocimetry (PIV) measurements revealed unsteady, complex, and highly 3D flow structures, which could not be captured by this numerical model with the available computational resources and additional modeling efforts that are described. Preliminary time-accurate computations with the in-house flow solver were shown to capture for the first time these complex flow features and yielded solutions in good agreement with the experimental observations. Flow fields obtained were similar for the studied total cardiac output range (1-3 1/min); however hydrodynamic power loss increased dramatically with increasing cardiac output, suggesting significant energy demand at exercise conditions. The simulation of cardiovascular flows poses a formidable challenge to even the most advanced CFD tools currently available. A successful prediction requires a two-pronged, physics-based approach, which integrates high-resolution CFD tools and high-resolution laboratory measurements.
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Affiliation(s)
- Kerem Pekkan
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
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Cheng CP, Herfkens RJ, Lightner AL, Taylor CA, Feinstein JA. Blood flow conditions in the proximal pulmonary arteries and vena cavae: healthy children during upright cycling exercise. Am J Physiol Heart Circ Physiol 2004; 287:H921-6. [PMID: 15031121 DOI: 10.1152/ajpheart.00022.2004] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Diagnostic testing in patients with congenital heart disease is usually performed supine and at rest, conditions not representative of their typical hemodynamics. Upright exercise measurements of blood flow may prove valuable in the assessment of these patients, but data in normal subjects are first required. With the use of a 0.5-T open magnet, a magnetic resonance-compatible exercise cycle, and cine phase-contrast techniques, time-dependent blood flow velocities were measured in the right (RPA), left (LPA), and main (MPA) pulmonary arteries and superior (SVC) and inferior (IVC) vena cavae of 10 healthy 10- to 14-yr-old subjects. Measurements were made at seated rest and during upright cycling exercise (150% resting heart rate). Mean blood flow (l/min) and reverse flow index were computed from the velocity data. With exercise, RPA and LPA mean flow increased 2.0 +/- 0.5 to 3.7 +/- 0.7 (P < 0.05) and 1.6 +/- 0.4 to 2.9 +/- 0.8 (P < 0.05), respectively. Pulmonary reverse flow index (rest vs. exercise) decreased with exercise as follows: MPA: 0.014 +/- 0.012 vs. 0.006 +/- 0.006 [P = not significant (NS)], RPA: 0.005 +/- 0.004 vs. 0.000 +/- 0.000 (P < 0.05), and LPA: 0.041 +/- 0.019 vs. 0.014 +/- 0.016 (P < 0.05). SVC and IVC flow increased from 1.5 +/- 0.2 to 1.9 +/- 0.6 (P = NS) and 1.6 +/- 0.4 to 4.9 +/- 1.3 (P < 0.05), respectively. A 56/44% RPA/LPA flow distribution at both rest and during exercise suggests blood flow distribution is dominated by distal pulmonary resistance. Reverse flow in the MPA appears to originate solely from the LPA while the RPA is in relative isolation. During seated rest, the SVC-to-IVC venous return ratio is 50/50%. With light/moderate cycling exercise, IVC flow increases by threefold, whereas SVC remains essentially constant.
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Affiliation(s)
- Christopher P Cheng
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305-4038, USA.
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Hsia TY, Migliavacca F, Pittaccio S, Radaelli A, Dubini G, Pennati G, de Leval M. Computational fluid dynamic study of flow optimization in realistic models of the total cavopulmonary connections. J Surg Res 2004; 116:305-13. [PMID: 15013370 DOI: 10.1016/j.jss.2003.08.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2003] [Indexed: 12/01/2022]
Abstract
OBJECTIVES AND BACKGROUND In the Fontan circulation, pulmonary and systemic vascular resistances are in series. The influence of various inferior vena cava to pulmonary artery connections in this unique circulatory arrangement was evaluated using computation fluid dynamics methods. METHODS Realistic three-dimensional models of total cavopulmonary connections were created from angiographic measurements to include the hepatic vein, superior vena cava, and branches of the pulmonary arteries. Steady-state finite volume analyses were performed using identical in vivo boundary conditions. Computational solutions calculated the percent hydraulic power dissipation and left-to-right pulmonary arterial flow distribution. RESULTS Simulations of the lateral tunnel, intra-atrial tube, extracardiac conduit with left and right pulmonary artery anastomosis demonstrated extracardiac conduit with left pulmonary artery anastomosis having the lowest energy loss. Varying the extracardiac conduit from 10 to 30 mm resulted in the least energy dissipation at 20 mm. Serial dilation of the lateral tunnel pathway showed a small incremental worsening of energy loss. CONCLUSIONS Maximizing energy conservation in a low-energy flow domain, such as the Fontan circulation, can be significant to its fluid dynamic performance. Although computational modeling cannot predict postoperative failure or functional outcome, this study confirms the importance of local geometry of the surgically created pathway in the total cavopulmonary connection.
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Affiliation(s)
- Tain-Yen Hsia
- Bioengineering and Structural Engineering Department, Politecnico di Milano, Milan, Italy.
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Geva T, Sahn DJ, Powell AJ. Magnetic resonance imaging of congenital heart disease in adults. PROGRESS IN PEDIATRIC CARDIOLOGY 2003. [DOI: 10.1016/s1058-9813(03)00010-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Cheng CP, Herfkens RJ, Taylor CA. Inferior vena caval hemodynamics quantified in vivo at rest and during cycling exercise using magnetic resonance imaging. Am J Physiol Heart Circ Physiol 2003; 284:H1161-7. [PMID: 12595296 DOI: 10.1152/ajpheart.00641.2002] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Compared with the abdominal aorta, the hemodynamic environment in the inferior vena cava (IVC) is not well described. With the use of cine phase-contrast magnetic resonance imaging (MRI) and a custom MRI-compatible cycle in an open magnet, we quantified mean blood flow rate, wall shear stress, and cross-sectional lumen area in 11 young normal subjects at the supraceliac and infrarenal levels of the aorta and IVC at rest and during dynamic cycling exercise. Similar to the aorta, the IVC experienced significant increases in blood flow and wall shear stress as a result of exercise, with greater increases in the infrarenal level compared with the supraceliac level. At the infrarenal level during resting conditions, the IVC experienced higher mean flow rate than the aorta (1.2 +/- 0.5 vs. 0.9 +/- 0.4 l/min, P < 0.01) and higher mean wall shear stress than the aorta (2.0 +/- 0.6 vs. 1.3 +/- 0.6 dyn/cm(2), P < 0.005). During exercise, wall shear stress remained higher in the IVC compared with the aorta, although not significantly. It was also observed that, whereas the aorta tapers inferiorly, the IVC tapers superiorly from the infrarenal to the supraceliac location. The hemodynamic and anatomic data of the IVC acquired in this study add to our understanding of the venous circulation and may be useful in a clinical setting.
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Affiliation(s)
- Christopher P Cheng
- Department of Mechanical Engineering, Stanford University, Stanford, California 94305-3030, USA
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Amodeo A, Grigioni M, Oppido G, Daniele C, D'Avenio G, Pedrizzetti G, Giannico S, Filippelli S, Di Donato RM. The beneficial vortex and best spatial arrangement in total extracardiac cavopulmonary connection. J Thorac Cardiovasc Surg 2002; 124:471-8. [PMID: 12202862 DOI: 10.1067/mtc.2002.120349] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Total extracardiac cavopulmonary connection is an established procedure, but the best spatial arrangement remains controversial. On the basis of our clinical experience with total extracardiac cavopulmonary connection, we performed quantitative and qualitative flow analysis on total extracardiac cavopulmonary connection models simulating the two most frequent arrangements applied to our patients to determine the most favorable hydrodynamic pattern. METHODS We selected two main groups among 110 patients who underwent total extracardiac cavopulmonary connection, those with left-sided inferior vena cava anastomosis (type 1) and those with facing superior and inferior vena cava anastomoses (type 2). Blown-glass total extracardiac cavopulmonary connection phantom models were constructed on the basis of nuclear magnetic resonance and angiographic images. Flow measurements were performed with a Nd:YAG Q-switched laser and a particle imaging velocimetry system. A power dissipation study and a finite-element numeric simulation were also carried out. RESULTS When applying superior and inferior vena caval flow proportions of total systemic venous return of 40% and 60%, respectively, a vortex was visualized in the type 1 phantom that rotated counterclockwise at the junction of the caval streams. This apparent vortex was not a true vortex; rather, it represented a weakly dissipative recirculating zone modulating the flow distribution into the pulmonary arteries. The power dissipation and finite-element numeric stimulation confirmed the beneficial nature of the apparent vortex and a more energy-saving pattern in the type 1 phantom than in the type 2 phantom. CONCLUSION Total extracardiac cavopulmonary connection with left-sided diversion of the inferior vena caval conduit anastomosis is characterized by a central vortex that regulates the caval flow partitioning and provides a more favorable energy-saving pattern than is seen with the total extracardiac cavopulmonary connection with directly opposed cavopulmonary anastomoses.
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Affiliation(s)
- Antonio Amodeo
- Department of Cardiac Surgery, Bambino Gesù Hospital, and the Laboratory of Biomedical Engineering, Trieste, Italy.
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Pedersen EM, Stenbøg EV, Fründ T, Houlind K, Kromann O, Sørensen KE, Emmertsen K, Hjortdal VE. Flow during exercise in the total cavopulmonary connection measured by magnetic resonance velocity mapping. Heart 2002; 87:554-8. [PMID: 12010939 PMCID: PMC1767137 DOI: 10.1136/heart.87.6.554] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVE To measure caval and pulmonary flows at rest and immediately after exercise in patients with total cavopulmonary connection (TCPC). DESIGN An observational study using the patients as their own controls. SETTING Using a combination of magnetic resonance (MR) phase contrast techniques and an MR compatible bicycle ergometer, blood flow was measured in the superior vena cava, the tunnel from the inferior vena cava, and in the left and right pulmonary arteries during rest and on exercise (0.5 W/kg and 1.0 W/kg). PATIENTS Eleven patients aged 11.4 (4.6) years (mean (SD)) were studied 6.3 (3.8) years after TCPC operation. MAIN OUTCOME MEASURES Volume flow measured in all four branches of the TCPC connection during rest and exercise. RESULTS Systemic venous return (inferior vena cava plus superior vena cava) increased from 2.5 (0.1) l/min/m2 (mean (SEM)) to 4.4 (0.4) l/min/m2 (p < 0.05) during exercise, with even distribution to the two pulmonary arteries. At rest, inferior vena caval flow was higher than superior vena caval flow, at 1.4 (0.1) v 1.1 (0.1) l/min/m2 (p < 0.05). During exercise, inferior vena caval flow doubled (to 3.0 (0.3) l/min/m2) while superior vena caval flow only increased slightly (to 1.4 (0.1) l/min/m2) (p < 0.05). The increased blood flow mainly reflected an increase in heart rate. The inferior vena caval to superior vena caval flow ratio was 1.4 (0.1) at rest and increased to 1.8 (0.1) (p < 0.05) at 0.5 W/kg, and to 2.2 (0.2) at 1.0 W/kg (p < 0.05). CONCLUSIONS Quantitative flow measurements can be performed immediately after exercise using MR techniques. Supine leg exercise resulted in a more than twofold increase in inferior vena caval flow. This was equally distributed to the two lungs, indicating that pulmonary resistance rather than geometry decides flow distribution in the TCPC circulation.
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Affiliation(s)
- E M Pedersen
- Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark.
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Cavalcanti S, Gnudi G, Masetti P, Ussia GP, Marcelletti CF. Analysis by mathematical model of haemodynamic data in the failing Fontan circulation. Physiol Meas 2001; 22:209-22. [PMID: 11236882 DOI: 10.1088/0967-3334/22/1/324] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Several late complications jeopardize the clinical performance of recipients of the Fontan operation. The underlying causes have been referred to disturbed flow dynamics in the cavopulmonary connections. Presumably, the large pressure drops occurring in the inferior and superior connections play a pivotal role in the pressure level of the entire circulation, especially in the venous. To address this issue, we retrospectively reviewed catheterization data of six patients with failing Fontan circulation and compared them with those of six patients with functioning Fontan circulation. The impact on the systemic and pulmonary pressure of the increase in the cavopulmonary connection resistances was studied through a steady-state mathematical model of the univentricular closed-loop circulation. In the patients with failing Fontan, pressure in the venae cavae was found to be significantly higher, especially at the inferior cava (19.3 +/- 2.2 versus 12.5 +/- 2.3 mmHg) with the pressure drop at the inferior cavopulmonary connection significantly increased (4.7 +/- 3.1 versus 0.33 +/- 0.82 mmHg). The proposed mathematical model permits us to clearly relate the pressure increase in the venae cavae to an increased resistance in the cavopulmonary connections. Therefore, the present analysis confirms that, to avoid possible congestion of venous circulation, the definitive palliation of univentricular heart should not cause pressure drops at the cavopulmonary connections.
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Affiliation(s)
- S Cavalcanti
- Department of Electronics Informatics and Systems, University of Bologna, Italy
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Grigioni M, Amodeo A, Daniele C, D'Avenio G, Formigari R, Di Donato RM. Particle image velocimetry analysis of the flow field in the total cavopulmonary connection. Artif Organs 2000; 24:946-52. [PMID: 11121974 DOI: 10.1046/j.1525-1594.2000.06613.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The total cavopulmonary connection (TCPC) is a common operation, meant to restore a proper pulmonary blood flow in heart defects with only one functional ventricle. It consists of the direct connection of the venae cavae to the pulmonary arteries in a cross-shaped disposition which entails a peculiar hemodynamics: Side effects can occur, such as recirculation zones and pressure drop across the connection. Our study is aimed at the quantitative investigation of the flow field of a successful Fontan-type operation, in view of the clinical importance of assuring a nearly physiological pulmonary blood flow, especially if one considers that many pediatric patients are eligible for this operation. A glass-blown TCPC phantom, realized according to nuclear magnetic resonance data, was employed in a steady-flow loop. Thus, a realistic model of this Fontan-type operation was realized using materials which enable advanced measurement techniques such as particle image velocimetry (PIV). The mean flow rates at each branch of the cavopulmonary shunt could be independently varied with a vertical shift of the corresponding upstream reservoir. The PIV technique was used successfully in identifying the flow field characteristics. The flow field in this TCPC topology was shown to be well organized and regulated by the presence of a vortex at the confluence of the venae cavae. The effect of different loading conditions, which realistically can be found in vivo, is studied with a high spatial resolution, showing the possibility to use pulmonary resistance as a parameter in designing the surgical geometry.
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Affiliation(s)
- M Grigioni
- Istituto Superiore di Sanità, Laboratory of Biomedical Engineering, Rome, Italy.
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Abstract
Imaging algorithms in congenital heart disease, as in the patient with acquired heart diseases continue to evolve, with more and more information gleaned noninvasively. The emphasis will be on the newer aspects of imaging, not cross sectional echocardiography with color Doppler.
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Affiliation(s)
- J Russell
- Department of Pediatrics, The Hospital for Sick Children, Toronto, Ontario, Canada
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