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Gonzalez-Urquijo M, Fumagal González GA, Cárdenas Castro HM, Morales Guzman AA, Guzman Valladares AA, MacDonald DC, Moya Bencomo MD, Botello Arredondo I, Fabiani MA. Analysis of Aortic Arch Hemodynamics With Simulated Bird's Beak Effects. Vasc Endovascular Surg 2024; 58:595-601. [PMID: 38607697 DOI: 10.1177/15385744241247272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2024]
Abstract
OBJECTIVE The objective of this study was to investigate the flow effects in different degrees of thoracic aortic stent graft protrusion extension by creating bird beak effect simulations using accurate 3D geometry and a realistic, nonlinear, elastic biomechanical model using computer-aided software SolidWorks. METHODS Segmentation in 3D of an aortic arch from a computed tomography (CT) scan of a real-life patient was performed using SolidWorks. A parametric analysis of three models was performed: (A) Aortic arch with no stent, (B) 3 mm bird-beak configuration, and (C) 6.5 mm bird-beak configuration. Flow velocity, pressure, vorticity, wall shear stress (WSS), and time average WSS were assessed. RESULTS The flow velocity in Model A remained relatively constant and low in the area of the ostium of the brachiocephalic artery and doubled in the left subclavian artery. On the contrary, Models B and C showed a decrease in velocity of 52.3 % in the left subclavian artery. Furthermore, Model B showed a drop in velocity of 82.7% below the bird-beak area, whereas Model C showed a decline of 80.9% in this area. The pressure inside the supra-aortic branches was higher in Model B and C compared with Model A. In Model A, vorticity only appeared at the level of the descending aorta, with low to non-vorticity in the aortic arch. In contrast, Models B and C had an average vorticity of 241.4 Hz within the bird beak area. Regarding WSS, Model A, and Model B shared similar WSS in the peak systolic phase, in the aortic arch, and the bird beak area, whereas Model C had an increased WSS by 5 Pa on average at these zones. CONCLUSION In the present simulations' lower velocities, higher pressures, vortices, and WSS were observed around the bird beak zone, the aortic arch, and the supra-aortic vessels.
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Luan J, Qiao Y, Mao L, Fan J, Zhu T, Luo K. The role of aorta distal to stent in the occurrence of distal stent graft-induced new entry tear: A computational fluid dynamics and morphological study. Comput Biol Med 2023; 166:107554. [PMID: 37839217 DOI: 10.1016/j.compbiomed.2023.107554] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 09/04/2023] [Accepted: 09/28/2023] [Indexed: 10/17/2023]
Abstract
Distal stent graft-induced new entry tear (dSINE) is an important complication of thoracic endovascular aortic repair (TEVAR) for the treatment of type B aortic dissection (TBAD). This study aims to explore whether the aorta distal to the stent plays an important role in the occurrence of dSINE. Sixty-nine patient-specific geometrical models of twenty-three enrolled patients were reconstructed from preoperative, postoperative, and predSINE computed tomography scans. Computational fluid dynamics (CFD) simulations were performed to calculate the von Mises stress in the CFD group. Meanwhile, morphological measurements were performed in all patients, including measurements of the inverted pyramid index at different follow-up time points and the postoperative true lumen volume change rate. In the CFD study, the time-averaged von Mises stress of the true lumen distal to the stent in dSINE patients was significantly higher than that in the CFD controls (20.42 kPa vs. 15.47 kPa). In the morphological study, a special aortic plane (plane A) with an extremely small area distal to the stent was observed in dSINE patients, which resulted in an inverted pyramid structure in the true lumen distal to the stent. This structure in dSINE patients became increasingly obvious during the follow-up period and finally reached the maximum value before dSINE occurred (mean, 3.91 vs. 1.23). At the same time, enlargement of the true lumen distal to the stent occurs before dSINE, manifesting as a continuous increase in the true lumen volume (mean, 0.70 vs. 013). A new theory of what causes dSINE to occur has been proposed: the inverted pyramid structure of the true lumen distal to the stent caused an increase in the von Mises stress in this region and aortic enlargement, which ultimately led to the occurrence of dSINE.
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Affiliation(s)
- Jingyang Luan
- Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yonghui Qiao
- State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, China
| | - Le Mao
- Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Jianren Fan
- State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, China; Shanghai Institute for Advanced Study of Zhejiang University, Shanghai, China
| | - Ting Zhu
- Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China.
| | - Kun Luo
- State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, China; Shanghai Institute for Advanced Study of Zhejiang University, Shanghai, China.
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Arima D, Suzuki K, Kando Y, Ishigami N. Stent Graft Collapse after Zone 0 Landing Thoracic Endovascular Aortic Repair. Ann Vasc Dis 2023; 16:234-237. [PMID: 37779658 PMCID: PMC10539125 DOI: 10.3400/avd.cr.23-00030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 06/30/2023] [Indexed: 10/03/2023] Open
Abstract
A zone 0 landing thoracic endovascular aortic repair was performed on a 69-year-old man with a saccular aortic arch aneurysm. Seven days after the surgery, the patient experienced diminished consciousness and lower limb paralysis. Stent graft collapse was seen on a computed tomography scan. Thereafter, the patient underwent total arch replacement and emergency stent graft removal.
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Affiliation(s)
- Daisuke Arima
- Department of Cardiovascular Surgery, Fujieda Municipal General Hospital, Fujieda, Shizuoka, Japan
| | - Kazuchika Suzuki
- Department of Cardiovascular Surgery, Fujieda Municipal General Hospital, Fujieda, Shizuoka, Japan
| | - Yumi Kando
- Department of Cardiovascular Surgery, Fujieda Municipal General Hospital, Fujieda, Shizuoka, Japan
| | - Naoyuki Ishigami
- Department of Cardiovascular Surgery, Fujieda Municipal General Hospital, Fujieda, Shizuoka, Japan
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Wang X, Carpenter HJ, Ghayesh MH, Kotousov A, Zander AC, Amabili M, Psaltis PJ. A review on the biomechanical behaviour of the aorta. J Mech Behav Biomed Mater 2023; 144:105922. [PMID: 37320894 DOI: 10.1016/j.jmbbm.2023.105922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 05/14/2023] [Accepted: 05/20/2023] [Indexed: 06/17/2023]
Abstract
Large aortic aneurysm and acute and chronic aortic dissection are pathologies of the aorta requiring surgery. Recent advances in medical intervention have improved patient outcomes; however, a clear understanding of the mechanisms leading to aortic failure and, hence, a better understanding of failure risk, is still missing. Biomechanical analysis of the aorta could provide insights into the development and progression of aortic abnormalities, giving clinicians a powerful tool in risk stratification. The complexity of the aortic system presents significant challenges for a biomechanical study and requires various approaches to analyse the aorta. To address this, here we present a holistic review of the biomechanical studies of the aorta by categorising articles into four broad approaches, namely theoretical, in vivo, experimental and combined investigations. Experimental studies that focus on identifying mechanical properties of the aortic tissue are also included. By reviewing the literature and discussing drawbacks, limitations and future challenges in each area, we hope to present a more complete picture of the state-of-the-art of aortic biomechanics to stimulate research on critical topics. Combining experimental modalities and computational approaches could lead to more comprehensive results in risk prediction for the aortic system.
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Affiliation(s)
- Xiaochen Wang
- School of Electrical and Mechanical Engineering, The University of Adelaide, Adelaide, South Australia 5005, Australia.
| | - Harry J Carpenter
- School of Electrical and Mechanical Engineering, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Mergen H Ghayesh
- School of Electrical and Mechanical Engineering, The University of Adelaide, Adelaide, South Australia 5005, Australia.
| | - Andrei Kotousov
- School of Electrical and Mechanical Engineering, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Anthony C Zander
- School of Electrical and Mechanical Engineering, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Marco Amabili
- Department of Mechanical Engineering, McGill University, Montreal H3A 0C3, Canada
| | - Peter J Psaltis
- Adelaide Medical School, The University of Adelaide, Adelaide, South Australia 5005, Australia; Department of Cardiology, Central Adelaide Local Health Network, Adelaide, South Australia 5000, Australia; Vascular Research Centre, Heart Health Theme, South Australian Health & Medical Research Institute (SAHMRI), Adelaide, South Australia 5000, Australia
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5
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Shahbazian N, Romero DA, Forbes TL, Amon CH. Prediction of bird-beak configuration in thoracic endovascular aortic repair preoperatively using patient-specific finite element simulations. JVS Vasc Sci 2023; 4:100108. [PMID: 37519336 PMCID: PMC10372321 DOI: 10.1016/j.jvssci.2023.100108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 04/03/2023] [Indexed: 08/01/2023] Open
Abstract
Objectives Formation of bird-beak configuration in thoracic endovascular aortic repair (TEVAR) has been shown to be correlated with the risk of complications such as type Ia endoleaks, stent graft migration, and collapse. The aim of this study was to use patient-specific computational simulations of TEVAR to predict the formation of bird-beak configuration preoperatively. Methods Patient-specific TEVAR computational simulations are developed using a retrospective cohort of patients treated for thoracic aortic aneurysm. The preoperative computed tomography images were segmented to develop three-dimensional geometry of the thoracic aorta. These geometries were used in finite element simulations of stent graft deployment during TEVAR. Simulated results were compared against the postoperative computed tomography images to assess the accuracy of simulations in predicting the proximal position of a deployed stent graft and presence of bird-beak. In cases with a bird-beak configuration, the length and angle of the bird-beak were measured and compared between the simulated and postoperative results. Results Twelve TEVAR patient cases were simulated. Computational simulations were able to accurately predict whether the proximal stent graft was fully apposed, proximal bare stents were protruded, or bird-beak configuration was present. In three cases with bird-beak configuration, simulations predicted the length and angle of the bird-beak with less than 10% and 24% error, respectively. Other factors such as a small aortic arch angle, small oversizing value, and landing zones close to the arch apex may have played a role in formation of bird-beak in these patients. Conclusions Computational simulations of TEVAR accurately predicted the proximal position of a deployed stent graft and the presence of bird-beak preoperatively. The computational models were able to predict the length and angle of bird-beak configurations with good accuracy. These simulations can provide insight into the surgical planning process with the goal of minimizing bird-beak occurrence.
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Affiliation(s)
- Negin Shahbazian
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada
| | - David A. Romero
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada
| | - Thomas L. Forbes
- Division of Vascular Surgery, Department of Surgery, Peter Munk Cardiac Centre, University Health Network, University of Toronto, Toronto, ON, Canada
| | - Cristina H. Amon
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada
- Department of Mechanical and Industrial Engineering, Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada
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Shahbazian N, Doyle MG, Forbes TL, Amon CH. A modeling framework for computational simulations of thoracic endovascular aortic repair. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2023; 39:e3578. [PMID: 35107881 DOI: 10.1002/cnm.3578] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 01/29/2022] [Indexed: 05/12/2023]
Abstract
Thoracic endovascular aortic repair (TEVAR) is a minimally invasive treatment for thoracic aortic conditions including aneurysms and is associated with a number of postoperative stent graft related complications. Computational simulations of TEVAR have the potential to predict surgical outcomes and complications preoperatively. When using simulations for stent graft design and prediction of complications in a population, it is difficult to generalize patient-specific TEVAR computational models due to patient variability. This study proposes a novel modeling framework for creating realistic population-based computational models of TEVAR focused on aneurysms that allow for developing various clinically relevant geometric configurations and scenarios that are not easily attainable with limited patient data. The framework includes a methodology for developing population-based thoracic aortic geometries and defining age-dependent aortic tissue material models, as well as detailed steps and boundary conditions for finite element modeling of stent graft deployment during TEVAR. The simulation framework is illustrated for predicting the formation of a bird-beak configuration, a wedge-shaped gap at the proximal end of the deployed stent graft in TEVAR that leads to incomplete seal. A baseline TEVAR simulation model was developed along with three simulations in which the value of aortic curvature, aortic arch angle, or aortic tissue properties varied from the baseline model. Analyzing the length and angle of the bird-beak configuration in each case shows that the bird-beak size is sensitive to different values of the aortic geometry highlighting the importance of using realistic parameter values.
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Affiliation(s)
- Negin Shahbazian
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Matthew G Doyle
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario, Canada
- Department of Surgery, Division of Vascular Surgery, Peter Munk Cardiac Centre, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Thomas L Forbes
- Department of Surgery, Division of Vascular Surgery, Peter Munk Cardiac Centre, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Cristina H Amon
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada
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Identification of geometric and mechanical factors predictive of bird-beak configuration in thoracic endovascular aortic repair using computational models of stent graft deployment. JVS Vasc Sci 2022; 3:259-273. [PMID: 35938091 PMCID: PMC9352945 DOI: 10.1016/j.jvssci.2022.05.056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 05/25/2022] [Indexed: 11/21/2022] Open
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Qiao Y, Mao L, Ding Y, Zhu T, Luo K, Fan J. Fluid-structure interaction: Insights into biomechanical implications of endograft after thoracic endovascular aortic repair. Comput Biol Med 2021; 138:104882. [PMID: 34600328 DOI: 10.1016/j.compbiomed.2021.104882] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 09/04/2021] [Accepted: 09/19/2021] [Indexed: 10/20/2022]
Abstract
Thoracic endovascular aortic repair (TEVAR) has developed to be the most effective treatment for aortic diseases. This study aims to evaluate the biomechanical implications of the implanted endograft after TEVAR. We present a novel image-based, patient-specific, fluid-structure computational framework. The geometries of blood, endograft, and aortic wall were reconstructed based on clinical images. Patient-specific measurement data was collected to determine the parameters of the three-element Windkessel. We designed three postoperative scenarios with rigid wall assumption, blood-wall interaction, blood-endograft-wall interplay, respectively, where a two-way fluid-structure interaction (FSI) method was applied to predict the deformation of the composite stent-wall. Computational results were validated with Doppler ultrasound data. Results show that the rigid wall assumption fails to predict the waveforms of blood outflow and energy loss (EL). The complete storage and release process of blood flow energy, which consists of four phases is captured by the FSI method. The endograft implantation would weaken the buffer function of the aorta and reduce mean EL by 19.1%. The closed curve area of wall pressure and aortic volume could indicate the EL caused by the interaction between blood flow and wall deformation, which accounts for 68.8% of the total EL. Both the FSI and endograft have a slight effect on wall shear stress-related-indices. The deformability of the composite stent-wall region is remarkably limited by the endograft. Our results highlight the importance of considering the interaction between blood flow, the implanted endograft, and the aortic wall to acquire physiologically accurate hemodynamics in post-TEVAR computational studies and the deformation of the aortic wall is responsible for the major EL of the blood flow.
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Affiliation(s)
- Yonghui Qiao
- State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, China
| | - Le Mao
- Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Ying Ding
- Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Ting Zhu
- Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Kun Luo
- State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, China.
| | - Jianren Fan
- State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, China.
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Development of an FEA framework for analysis of subject-specific aortic compliance based on 4D flow MRI. Acta Biomater 2021; 125:154-171. [PMID: 33639309 DOI: 10.1016/j.actbio.2021.02.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 02/15/2021] [Accepted: 02/18/2021] [Indexed: 12/30/2022]
Abstract
This paper presents a subject-specific in-silico framework in which we uncover the relationship between the spatially varying constituents of the aorta and the non-linear compliance of the vessel during the cardiac cycle uncovered through our MRI investigations. A microstructurally motivated constitutive model is developed, and simulations reveal that internal vessel contractility, due to pre-stretched elastin and actively generated smooth muscle cell stress, must be incorporated, along with collagen strain stiffening, in order to accurately predict the non-linear pressure-area relationship observed in-vivo. Modelling of elastin and smooth muscle cell contractility allows for the identification of the reference vessel configuration at zero-lumen pressure, in addition to accurately predicting high- and low-compliance regimes under a physiological range of pressures. This modelling approach is also shown to capture the key features of elastin digestion and SMC activation experiments. The volume fractions of the constituent components of the aortic material model were computed so that the in-silico pressure-area curves accurately predict the corresponding MRI data at each location. Simulations reveal that collagen and smooth muscle volume fractions increase distally, while elastin volume fraction decreases distally, consistent with reported histological data. Furthermore, the strain at which collagen transitions from low to high stiffness is lower in the abdominal aorta, again supporting the histological finding that collagen waviness is lower distally. The analyses presented in this paper provide new insights into the heterogeneous structure-function relationship that underlies aortic biomechanics. Furthermore, this subject-specific MRI/FEA methodology provides a foundation for personalised in-silico clinical analysis and tailored aortic device development. STATEMENT OF SIGNIFICANCE: This study provides a significant advance in in-silico medicine by capturing the structure/function relationship of the subject-specific human aorta presented in our previous MRI analyses. A physiologically based aortic constitutive model is developed, and simulations reveal that internal vessel contractility must be incorporated, along with collagen strain stiffening, to accurately predict the in-vivo non-linear pressure-area relationship. Furthermore, this is the first subject-specific model to predict spatial variation in the volume fractions of aortic wall constituents. Previous studies perform phenomenological hyperelastic curve fits to medical imaging data and ignore the prestress contribution of elastin, collagen, and SMCs and the associated zero-pressure reference state of the vessel. This novel MRI/FEA framework can be used as an in-silico diagnostic tool for the early stage detection of aortic pathologies.
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Wu W, Pu J. A Stent-Graft Fracture After a 14-Year Thoracic Endovascular Aortic Repair. Cardiovasc Intervent Radiol 2020; 43:1413-1415. [DOI: 10.1007/s00270-020-02595-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 07/04/2020] [Indexed: 10/23/2022]
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Computational Fluid Dynamics Modeling of Hemodynamic Parameters in the Human Diseased Aorta: A Systematic Review. Ann Vasc Surg 2020; 63:336-381. [DOI: 10.1016/j.avsg.2019.04.032] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 03/09/2019] [Accepted: 04/18/2019] [Indexed: 02/07/2023]
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12
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Biomechanical implications of the fenestration structure after thoracic endovascular aortic repair. J Biomech 2020; 99:109478. [DOI: 10.1016/j.jbiomech.2019.109478] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Revised: 10/28/2019] [Accepted: 10/30/2019] [Indexed: 12/11/2022]
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Affiliation(s)
- Mourad Boufi
- Department of Vascular Surgery, APHM, University Hospital Nord, Marseille, France.,Aix-Marseille Université, IFSTTAR, Marseille, France
| | - Giorgiana Alexandru
- Department of Vascular Surgery, APHM, University Hospital Nord, Marseille, France
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14
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Desyatova A, MacTaggart J, Kamenskiy A. Effects of longitudinal pre-stretch on the mechanics of human aorta before and after thoracic endovascular aortic repair (TEVAR) in trauma patients. Biomech Model Mechanobiol 2019; 19:401-413. [PMID: 31489481 DOI: 10.1007/s10237-019-01217-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 08/21/2019] [Indexed: 12/14/2022]
Abstract
Thoracic endovascular aortic repair (TEVAR) has evolved as a first-line therapy for trauma patients. Most trauma patients are young, and their aortas are compliant and longitudinally pre-stretched. We have developed a method to include longitudinal pre-stretch in computational models of human thoracic aortas of different ages before and after TEVAR. Finite element models were built using computerized tomography angiography data obtained from human subjects in 6 age groups 10-69 years old. Aortic properties were determined with planar biaxial testing, and pre-stretch was simulated using a series of springs. GORE C-Tag stent-graft was computationally deployed in aortas with and without pre-stretch, and the stress-strain fields were compared. Pre-stretch had significant qualitative and quantitative effects on the aortic stress-strain state before and after TEVAR. Before TEVAR, mean intramural aortic stresses with and without pre-stretch decreased with age from 108 kPa and 83 kPa in the youngest age group, to 60 kPa in the oldest age group. TEVAR increased intramural stresses by an average of 73 ± 15 kPa and 48 ± 10 kPa for aortas with and without pre-stretch and produced high stress concentrations near the aortic isthmus. Inclusion of pre-stretch in young aortas increased intramural stresses by 30%, while in > 50-year-old subjects it did not change the results. Computational modeling of aorta-stent-graft interaction that includes pre-stretch can be instrumental for device design and assessment of its long-term performance, and in the future may help more accurately determine the stress-strain characteristics associated with TEVAR complications.
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Affiliation(s)
| | - Jason MacTaggart
- Department of Surgery, University of Nebraska Medical Center, 987690 Nebraska Medical Center, Omaha, NE, 68198-7690, USA
| | - Alexey Kamenskiy
- Department of Biomechanics, University of Nebraska, Omaha, NE, USA
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15
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Marrocco-Trischitta MM, Spampinato B, Mazzeo G, Mazzaccaro D, Milani V, Alaidroos M, Ambrogi F, Nano G. Impact of the Bird-Beak Configuration on Postoperative Outcome After Thoracic Endovascular Aortic Repair: A Meta-analysis. J Endovasc Ther 2019; 26:771-778. [DOI: 10.1177/1526602819865906] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Purpose: To investigate the association between the bird-beak configuration (BBC), a wedge-shaped gap between the undersurface of a thoracic endograft and the lesser curvature of the arch after thoracic endovascular aortic repair (TEVAR), and postoperative outcome after TEVAR. Methods: The study was performed according to the PRISMA guidelines. The PubMed, EMBASE, and Cochrane databases were searched to identify all case series reporting BBC after TEVAR between 2006 and April 2018. Data analysis was performed considering the difference in the risk of complications for presence vs absence of BBC. After screening 1633 articles, 21 studies were identified that matched the selection criteria; 12 of these reported detailed information to investigate the postoperative outcome using proportion meta-analysis with a random effects model. The pooled risk difference is reported with the 95% confidence interval (CI). Heterogeneity of the included studies was assessed with the I2 statistic (low 25%, medium 50%, high 75%). Results: Complications occurred within a range of 0 to 72 months in 14.7% (95% CI 7.4% to 27.3%) of patients with BBC and in 6.3% (95% CI 2.5% to 15.4%) of patients without BBC. A cumulative incidence could not be assessed. The summary risk difference was 11.1% (95% CI −0.1% to 22.3%, p=0.052). There was significant heterogeneity ( I2=85.6%). The Egger test did not show evidence of publication bias (p=0.975). When specifically considering type Ia endoleak and endograft migration, the risk difference between BBC and non-BBC patients was 8.2% (95% CI 0.3% to 16.1%, p=0.042; I2=69.0%). The specific risk difference for endograft collapse/infolding and thrombosis was 3.7% (95% CI −3.5% to 11.1%, p=0.308; I2=10.2%). Conclusion: At present the literature does not provide statistical evidence to establish an overall prognostic value of the BBC. Nevertheless, the BBC appears to be associated with a high risk of type Ia endoleak and endograft migration, which warrants specific and long-term surveillance. Clinically relevant values for BBC grading should be established to perhaps define indications for preemptive treatment based on the presence of BBC only.
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Affiliation(s)
- Massimiliano M. Marrocco-Trischitta
- Clinical Research Unit, Cardiovascular Department, IRCCS Policlinico San Donato, Milan, Italy
- Vascular Surgery Unit, Cardiovascular Department, IRCCS Policlinico San Donato, Milan, Italy
| | - Benedetta Spampinato
- Vascular Surgery Unit, Cardiovascular Department, IRCCS Policlinico San Donato, Milan, Italy
- Residency Program in Vascular Surgery, University of Milan, Italy
| | - Girolomina Mazzeo
- Vascular Surgery Unit, Cardiovascular Department, IRCCS Policlinico San Donato, Milan, Italy
- Residency Program in Vascular Surgery, University of Milan, Italy
| | - Daniela Mazzaccaro
- Vascular Surgery Unit, Cardiovascular Department, IRCCS Policlinico San Donato, Milan, Italy
| | - Valentina Milani
- Biostatistics Service, IRCCS Policlinico San Donato, Milan Italy
| | - Moad Alaidroos
- Vascular Surgery Unit, Policlinico San Marco, Zingonia, Italy
| | - Federico Ambrogi
- Biostatistics Service, IRCCS Policlinico San Donato, Milan Italy
- Laboratory of Medical Statistics, University of Milan, Italy
| | - Giovanni Nano
- Vascular Surgery Unit, Cardiovascular Department, IRCCS Policlinico San Donato, Milan, Italy
- Department of “Scienze Biomediche per la Salute,” University of Milan, Italy
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Cosentino F, Scardulla F, D'Acquisto L, Agnese V, Gentile G, Raffa G, Bellavia D, Pilato M, Pasta S. Computational modeling of bicuspid aortopathy: Towards personalized risk strategies. J Mol Cell Cardiol 2019; 131:122-131. [PMID: 31047985 DOI: 10.1016/j.yjmcc.2019.04.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 04/09/2019] [Accepted: 04/26/2019] [Indexed: 11/18/2022]
Abstract
This paper describes current advances on the application of in-silico for the understanding of bicuspid aortopathy and future perspectives of this technology on routine clinical care. This includes the impact that artificial intelligence can provide to develop computer-based clinical decision support system and that wearable sensors can offer to remotely monitor high-risk bicuspid aortic valve (BAV) patients. First, we discussed the benefit of computational modeling by providing tangible examples of in-silico software products based on computational fluid-dynamic (CFD) and finite-element method (FEM) that are currently transforming the way we diagnose and treat cardiovascular diseases. Then, we presented recent findings on computational hemodynamic and structural mechanics of BAV to highlight the potentiality of patient-specific metrics (not-based on aortic size) to support the clinical-decision making process of BAV-associated aneurysms. Examples of BAV-related personalized healthcare solutions are illustrated.
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Affiliation(s)
- Federica Cosentino
- Promozione della Salute, Materno-Infantile, di Medicina Interna e Specialistica di Eccellenza "G. D'Alessandro", University of Palermo, Piazza delle Cliniche, n.2, 90128 Palermo, Italy; Fondazione Ri.MED, Via Bandiera n.11, 90133 Palermo, Italy
| | - Francesco Scardulla
- Department of Engineering, University of Palermo, Viale delle Scienze Ed.8, 90128 Palermo, Italy
| | - Leonardo D'Acquisto
- Department of Engineering, University of Palermo, Viale delle Scienze Ed.8, 90128 Palermo, Italy
| | - Valentina Agnese
- Department for the Treatment and Study of Cardiothoracic Diseases and Cardiothoracic Transplantation, IRCCS-ISMETT, Via Tricomi n.5, 90127 Palermo, Italy
| | - Giovanni Gentile
- Department for the Treatment and Study of Cardiothoracic Diseases and Cardiothoracic Transplantation, IRCCS-ISMETT, Via Tricomi n.5, 90127 Palermo, Italy
| | - Giuseppe Raffa
- Department for the Treatment and Study of Cardiothoracic Diseases and Cardiothoracic Transplantation, IRCCS-ISMETT, Via Tricomi n.5, 90127 Palermo, Italy
| | - Diego Bellavia
- Department for the Treatment and Study of Cardiothoracic Diseases and Cardiothoracic Transplantation, IRCCS-ISMETT, Via Tricomi n.5, 90127 Palermo, Italy
| | - Michele Pilato
- Department for the Treatment and Study of Cardiothoracic Diseases and Cardiothoracic Transplantation, IRCCS-ISMETT, Via Tricomi n.5, 90127 Palermo, Italy
| | - Salvatore Pasta
- Fondazione Ri.MED, Via Bandiera n.11, 90133 Palermo, Italy; Department for the Treatment and Study of Cardiothoracic Diseases and Cardiothoracic Transplantation, IRCCS-ISMETT, Via Tricomi n.5, 90127 Palermo, Italy.
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Proximal Bare Stent May Reduce Bird-Beak Configuration, Which is Associated with Distal Migration of Stent Graft in the Aortic Arch. Ann Vasc Surg 2019; 56:108-113. [DOI: 10.1016/j.avsg.2018.08.081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 08/03/2018] [Accepted: 08/07/2018] [Indexed: 11/18/2022]
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18
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Ma M, Feng X, Wang J, Dong Y, Chen T, Liu L, Wei X. Acute Type I aortic dissection: a propensity-matched comparison of elephant trunk and arch debranching repairs. Interact Cardiovasc Thorac Surg 2019; 26:183-189. [PMID: 29049664 DOI: 10.1093/icvts/ivx283] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 07/26/2017] [Indexed: 01/16/2023] Open
Abstract
OBJECTIVES Our goal was to compare the performance of the frozen elephant trunk (FET) and the hybrid aortic arch debranching procedures for acute Type I aortic dissection. METHODS From January 2013 to December 2015, 168 patients with Type I aortic disease underwent ascending aorta and total aortic arch replacement with FET implantation (the FET group, n = 132) or arch debranching with 1-stage aortic arch exclusion using an endovascular stent in a retrograde manner (the debranching group, n = 36). A propensity score-matched subgroup of 26 pairs was identified. Perioperative data and mid-term follow-up results were assessed. RESULTS In the FET and the debranching groups, the 30-day mortality rates were 14.4% and 5.6% (P = 0.254) and the incidence of stroke was 5.3% and 5.6% (P > 0.999). Cardiopulmonary bypass time was significantly shortened, and the circulatory arrest was exempted in the debranching group. Cardiopulmonary bypass time was identified as a predictor for 30-day mortality (P = 0.027, odds ratio 1.01). Body mass index ≥ 25 kg/m2 was associated with multiorgan dysfunction syndrome (P = 0.016, odds ratio 3.51). Surgical modality did not significantly affect early outcomes. The 3-year survival rate was 76.1% (95% confidence interval, 63.0-81.9%) in the FET group and 82.5% (95% confidence interval, 65.2-91.8%) in the debranching group (P = 0.330). CONCLUSIONS The hybrid aortic arch procedure without circulatory arrest can be safely performed on patients with acute Type I aortic dissection. Irrespective of cost-effectiveness, arch debranching was a promising alternative for patients who were unfit for the FET procedure.
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Affiliation(s)
- Mingjia Ma
- Division of Cardiothoracic and Vascular Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xin Feng
- Division of Cardiothoracic and Vascular Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jing Wang
- Division of Cardiothoracic and Vascular Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yiming Dong
- Division of Cardiothoracic and Vascular Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Taiqiang Chen
- Division of Cardiothoracic and Vascular Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ligang Liu
- Division of Cardiothoracic and Vascular Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiang Wei
- Division of Cardiothoracic and Vascular Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Wee I, Ong CW, Syn N, Choong A. Computational Fluid Dynamics and Aortic Dissections: Panacea or Panic? VASCULAR AND ENDOVASCULAR REVIEW 2018. [DOI: 10.15420/ver.2018.8.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
This paper reviews the methodology, benefits and limitations associated with computational flow dynamics (CFD) in the field of vascular surgery. Combined with traditional imaging of the vasculature, CFD simulation enables accurate characterisation of real-time physiological and haemodynamic parameters such as wall shear stress. This enables vascular surgeons to understand haemodynamic changes in true and false lumens, and exit and re-entry tears. This crucial information may facilitate triaging decisions. Furthermore, CFD can be used to assess the impact of stent graft treatment, as it provides a haemodynamic account of what may cause procedure-related complications. Efforts to integrate conventional imaging, individual patient data and CFD are paramount to its success, given its potential to replace traditional registry-based, population-averaged data. Nonetheless, methodological limitations must be addressed before clinical implementation. This must be accompanied by further research with large sample sizes, to establish the association between haemodynamic patterns as observed by CFD and progression of aortic dissection.
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Affiliation(s)
- Ian Wee
- SingVaSC, Singapore Vascular Surgical Collaborative; Yong Loo Lin School of Medicine, National University of Singapore
| | - Chi Wei Ong
- SingVaSC, Singapore Vascular Surgical Collaborative; Department of Biomedical Engineering, National University of Singapore
| | - Nicholas Syn
- SingVaSC, Singapore Vascular Surgical Collaborative; Yong Loo Lin School of Medicine, National University of Singapore
| | - Andrew Choong
- SingVaSC, Singapore Vascular Surgical Collaborative; Cardiovascular Research Institute, National University of Singapore; Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore; Division of Vascular Surgery, National University Heart Centre, Singapore
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20
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Menichini C, Pirola S, Guo B, Fu W, Dong Z, Xu XY. High Wall Stress May Predict the Formation of Stent-Graft-Induced New Entries After Thoracic Endovascular Aortic Repair. J Endovasc Ther 2018; 25:571-577. [PMID: 30056791 DOI: 10.1177/1526602818791827] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
PURPOSE To explore the potential role of morphological factors and wall stress in the formation of stent-graft-induced new entries (SINE) based on computed tomography (CT) images after thoracic endovascular aortic repair (TEVAR). CASE REPORT Two female patients aged 59 years (patient 1) and 44 years (patient 2) underwent TEVAR for type B dissection in the chronic (patient 1) or subacute (patient 2) phase. CT scans at 3-month follow-up showed varying degrees of false lumen thrombosis in both patients. At 14-month follow-up, a SINE was observed in patient 1 while the dissected aorta in the other patient remained stable. Morphological and finite element analyses were performed based on the first follow-up CT images. The computational results showed that the SINE patient had higher stent-graft tortuosity than the non-SINE patient and much higher wall stress in the region close to the distal SINE. CONCLUSION This case study suggests that high stent-graft tortuosity can lead to high wall stress, which is potentially linked to the formation of SINE. Further large population-based studies are needed to confirm this preliminary finding.
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Affiliation(s)
| | - Selene Pirola
- 1 Department of Chemical Engineering, Imperial College London, UK
| | - Baolei Guo
- 2 Department of Vascular Surgery, Zhongshan Hospital, and Institute of Vascular Surgery, Fudan University, Shanghai, China
| | - Weiguo Fu
- 2 Department of Vascular Surgery, Zhongshan Hospital, and Institute of Vascular Surgery, Fudan University, Shanghai, China
| | - Zhihui Dong
- 2 Department of Vascular Surgery, Zhongshan Hospital, and Institute of Vascular Surgery, Fudan University, Shanghai, China
| | - Xiao Yun Xu
- 1 Department of Chemical Engineering, Imperial College London, UK
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21
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Computational investigation of interaction between stent graft and aorta in retrograde type A dissection after thoracic endovascular aortic repair for type B aortic dissection. J Vasc Surg 2018; 68:14S-21S.e2. [PMID: 30064843 DOI: 10.1016/j.jvs.2018.06.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Accepted: 06/01/2018] [Indexed: 11/23/2022]
Abstract
OBJECTIVE Retrograde type A dissection (RTAD) after thoracic endovascular aortic repair (TEVAR) has been a major drawback of endovascular treatment. To our knowledge, no studies have evaluated aortic injuries caused by stent grafts (SGs). Therefore, the aim of this study was to evaluate and to quantify the SG-aorta interaction and to analyze the risk factors for injury through computational simulation. METHODS The aortic geometry was extracted from an RTAD case. Five SG models were assembled based on Valiant and Talent (Medtronic Vascular, Santa Rosa, Calif) SGs, and modifications were made to the original SG design by adding and removing the connecting bar. TEVAR simulations were performed seven times for each SG model with 0% and 15% oversizing ratio (OSR), and the maximum aortic stress (MAS) was calculated and compared within the groups. RESULTS In all TEVAR models, MAS was seen at the proximal bare stent (PBS). The PBS in the Valiant and Talent SGs generated higher stress toward the aortic wall than other SG parts did. MAS was significantly higher for the 15% OSR (0.54 ± 0.07 MPa) than for the 0% OSR (1.32 ± 0.74 MPa) in 172.5-mm Valiant models. MAS was significantly higher in the Talent with connecting bar SG model (0.73 ± 0.24 MPa) than in the Talent without connecting bar SG model (0.51 ± 0.11 MPa). MAS was significantly higher in the Valiant with connecting bar SG model (0.82 ± 0.29 MPa) than in the Valiant without connecting bar SG model (0.54 ± 0.07 MPa). MAS was not significantly different in models with 172.5-mm and 140-mm Valiant SG implantations with 0% OSR (0.54 ± 0.07 MPa vs 0.60 ± 0.12 MPa) and 15% OSR (1.32 ± 0.74 MPa vs 1.12 ± 0.33 MPa). CONCLUSIONS The characteristic MAS distribution remained at the location where the apexes of the PBS interacted with the aortic wall at its greater curve. Both higher OSR and the presence of a connecting bar can significantly increase the MAS after SG implantation. Moreover, the chronic MAS at the PBS area may injure the aortic wall, causing RTAD.
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Owen B, Bojdo N, Jivkov A, Keavney B, Revell A. Structural modelling of the cardiovascular system. Biomech Model Mechanobiol 2018; 17:1217-1242. [PMID: 29911296 PMCID: PMC6154127 DOI: 10.1007/s10237-018-1024-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 04/25/2018] [Indexed: 02/02/2023]
Abstract
Computational modelling of the cardiovascular system offers much promise, but represents a truly interdisciplinary challenge, requiring knowledge of physiology, mechanics of materials, fluid dynamics and biochemistry. This paper aims to provide a summary of the recent advances in cardiovascular structural modelling, including the numerical methods, main constitutive models and modelling procedures developed to represent cardiovascular structures and pathologies across a broad range of length and timescales; serving as an accessible point of reference to newcomers to the field. The class of so-called hyperelastic materials provides the theoretical foundation for the modelling of how these materials deform under load, and so an overview of these models is provided; comparing classical to application-specific phenomenological models. The physiology is split into components and pathologies of the cardiovascular system and linked back to constitutive modelling developments, identifying current state of the art in modelling procedures from both clinical and engineering sources. Models which have originally been derived for one application and scale are shown to be used for an increasing range and for similar applications. The trend for such approaches is discussed in the context of increasing availability of high performance computing resources, where in some cases computer hardware can impact the choice of modelling approach used.
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Affiliation(s)
- Benjamin Owen
- School of Mechanical, Aerospace and Civil Engineering, University of Manchester, George Begg Building, Manchester, M1 3BB, UK.
| | - Nicholas Bojdo
- School of Mechanical, Aerospace and Civil Engineering, University of Manchester, George Begg Building, Manchester, M1 3BB, UK
| | - Andrey Jivkov
- School of Mechanical, Aerospace and Civil Engineering, University of Manchester, George Begg Building, Manchester, M1 3BB, UK
| | - Bernard Keavney
- Division of Cardiovascular Sciences, University of Manchester, AV Hill Building, Manchester, M13 9PT, UK
| | - Alistair Revell
- School of Mechanical, Aerospace and Civil Engineering, University of Manchester, George Begg Building, Manchester, M1 3BB, UK
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Lashkarinia SS, Piskin S, Bozkaya TA, Salihoglu E, Yerebakan C, Pekkan K. Computational Pre-surgical Planning of Arterial Patch Reconstruction: Parametric Limits and In Vitro Validation. Ann Biomed Eng 2018; 46:1292-1308. [PMID: 29761422 PMCID: PMC6097742 DOI: 10.1007/s10439-018-2043-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 05/04/2018] [Indexed: 02/06/2023]
Abstract
Surgical treatment of congenital heart disease (CHD) involves complex vascular reconstructions utilizing artificial and native surgical materials. A successful surgical reconstruction achieves an optimal hemodynamic profile through the graft in spite of the complex post-operative vessel growth pattern and the altered pressure loading. This paper proposes a new in silico patient-specific pre-surgical planning framework for patch reconstruction and investigates its computational feasibility. The proposed protocol is applied to the patch repair of main pulmonary artery (MPA) stenosis in the Tetralogy of Fallot CHD template. The effects of stenosis grade, the three-dimensional (3D) shape of the surgical incision and material properties of the artificial patch are investigated. The release of residual stresses due to the surgical incision and the extra opening of the incision gap for patch implantation are simulated through a quasi-static finite-element vascular model with shell elements. Implantation of different unloaded patch shapes is simulated. The patched PA configuration is pressurized to the physiological post-operative blood pressure levels of 25 and 45 mmHg and the consequent post-operative stress distributions and patched artery shapes are computed. Stress–strain data obtained in-house, through the biaxial tensile tests for the mechanical properties of common surgical patch materials, Dacron, Polytetrafluoroethylene, human pericardium and porcine xenopericardium, are employed to represent the mechanical behavior of the patch material. Finite-element model is experimentally validated through the actual patch surgery reconstructions performed on the 3D printed anatomical stenosis replicas. The post-operative recovery of the initially narrowed lumen area and post-op tortuosity are quantified for all modeled cases. A computational fluid dynamics solver is used to evaluate post-operative pressure drop through the patch-reconstructed outflow tract. According to our findings, the shorter incisions made at the throat result in relatively low local peak stress values compared to other patch design alternatives. Longer cut and double patch cases are the most effective in repairing the initial stenosis level. After the patch insertion, the pressure drop in the artery due to blood flow decreases from 9.8 to 1.35 mmHg in the conventional surgical configuration. These results are in line with the clinical experience where a pressure gradient at or above 50 mmHg through the MPA can be an indication to intervene. The main strength of the proposed pre-surgical planning framework is its capability to predict the intra-operative and post-operative 3D vascular shape changes due to intramural pressure, cut length and configuration, for both artificial and native patch materials.
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Affiliation(s)
- S Samaneh Lashkarinia
- Department of Mechanical Engineering, Koc University, Rumeli Feneri Kampüsü, Sarıyer, Istanbul, Turkey
| | - Senol Piskin
- Department of Mechanical Engineering, Koc University, Rumeli Feneri Kampüsü, Sarıyer, Istanbul, Turkey
- Department of Mechanical Engineering, University of Texas at San Antonio, San Antonio, TX, USA
| | - Tijen A Bozkaya
- Department of Cardiovascular Surgery, Koc University Medical School, Istanbul, Turkey
| | - Ece Salihoglu
- Department of Cardiovascular Surgery, Istanbul Medipol University, Istanbul, Turkey
| | - Can Yerebakan
- Cardiovascular Surgery, Children's National Heart Institute, The George Washington University School of Medicine, Washington, DC, USA
| | - Kerem Pekkan
- Department of Mechanical Engineering, Koc University, Rumeli Feneri Kampüsü, Sarıyer, Istanbul, Turkey.
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Aortic Anatomy and Complications of the Proximal Sealing Zone after Endovascular Treatment of the Thoracic Aorta. Ann Vasc Surg 2018; 48:141-150. [DOI: 10.1016/j.avsg.2017.09.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Revised: 07/25/2017] [Accepted: 09/01/2017] [Indexed: 11/21/2022]
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Piskin S, Unal G, Arnaz A, Sarioglu T, Pekkan K. Tetralogy of Fallot Surgical Repair: Shunt Configurations, Ductus Arteriosus and the Circle of Willis. Cardiovasc Eng Technol 2017; 8:107-119. [PMID: 28382440 PMCID: PMC5446850 DOI: 10.1007/s13239-017-0302-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 03/27/2017] [Indexed: 11/09/2022]
Abstract
In this study, hemodynamic performance of three novel shunt configurations that are considered for the surgical repair of tetralogy of Fallot (TOF) disease are investigated in detail. Clinical experience suggests that the shunt location, connecting angle, and its diameter can influence the post-operative physiology and the neurodevelopment of the neonatal patient. An experimentally validated second order computational fluid dynamics (CFD) solver and a parametric neonatal diseased great artery model that incorporates the ductus arteriosus (DA) and the full patient-specific circle of Willis (CoW) are employed. Standard truncated resistance CFD boundary conditions are compared with the full cerebral arterial system, which resulted 21, -13, and 37% difference in flow rate at the brachiocephalic, left carotid, and subclavian arteries, respectively. Flow splits at the aortic arch and cerebral arteries are calculated and found to change with shunt configuration significantly for TOF disease. The central direct shunt (direct shunt) has pulmonary flow 5% higher than central oblique shunt (oblique shunt) and 23% higher than modified Blalock Taussig shunt (RPA shunt) while the DA is closed. Maximum wall shear stress (WSS) in the direct shunt configuration is 9 and 60% higher than that of the oblique and RPA shunts, respectively. Patent DA, significantly eliminated the pulmonary flow control function of the shunt repair. These results suggests that, due to the higher flow rates at the pulmonary arteries, the direct shunt, rather than the central oblique, or right pulmonary artery shunts could be preferred by the surgeon. This extended model introduced new hemodynamic performance indices for the cerebral circulation that can correlate with the post-operative neurodevelopment quality of the patient.
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Affiliation(s)
- Senol Piskin
- Department of Mechanical Engineering, Koç University, Rumeli Feneri Kampüsü, Sarıyer, Istanbul, Turkey
| | - Gozde Unal
- Faculty of Engineering and Natural Sciences, Sabancı University, Tuzla, Istanbul, Turkey
| | - Ahmet Arnaz
- Department of Cardiovascular Surgery, Acıbadem Bakırköy Hospital, Istanbul, Turkey
| | - Tayyar Sarioglu
- Department of Pediatric Cardiovascular Surgery, School of Medicine, Acıbadem University, Istanbul, Turkey
| | - Kerem Pekkan
- Department of Mechanical Engineering, Koç University, Rumeli Feneri Kampüsü, Sarıyer, Istanbul, Turkey.
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Kotha VK, Herget EJ, Appoo JJ. Complications at the Proximal Landing Zone of Endovascular Stent Grafts Deployed in Surgically Replaced Ascending Aorta. Ann Thorac Surg 2016; 102:1490-1497. [DOI: 10.1016/j.athoracsur.2016.04.046] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Revised: 02/29/2016] [Accepted: 04/11/2016] [Indexed: 10/21/2022]
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Characterization of Hemodynamics in Great Arteries of Wild-Type Mouse Using Computational Fluid Dynamics Based on Ultrasound Images. Ultrasound Q 2016; 32:51-7. [PMID: 26938034 DOI: 10.1097/ruq.0000000000000164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Hemodynamic factors in cardiovascular system are hypothesized to play a significant role in causing structural heart development. It is thus important to improve our understanding of velocity characteristics and parameters. We present such a study on wild-type mouse to characterize the vessel geometry, flow pattern, and wall shear stress in great arteries. Microultrasound imaging for small animals was used to measure blood boundary and velocity of the great arteries. Subsequently, specimens' flow boundary conditions were used for 3-dimensional reconstructions of the great artery and aortic arch dimensions, and blood flow velocity data were input into subject-specific computational fluid dynamics for modeling hemodynamics. Measurement by microultrasound imaging showed that blood velocities in the great artery and aortic arch had strong correlations with vascular sizes, whereas blood pressure had a weak trend in relation to vascular size. Wall shear stress magnitude increased when closer to arterial branches and reduced proximally in the aortic root and distally in the descending aorta, and the parameters were related to the fluid mechanics in branches in some degree. We developed a method to investigate fluid mechanics in mouse arteries, using a combination of microultrasound and computational fluid dynamics, and demonstrated its ability to reveal detailed geometric, kinematic, and fluid mechanics parameters.
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28
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Biomechanical implications of excessive endograft protrusion into the aortic arch after thoracic endovascular repair. Comput Biol Med 2015; 66:235-41. [DOI: 10.1016/j.compbiomed.2015.09.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 09/01/2015] [Accepted: 09/14/2015] [Indexed: 12/12/2022]
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29
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Pasta S, Scardulla F, Rinaudo A, Raffa GM, D’Ancona G, Pilato M, Scardulla C. An In Vitro Phantom Study on the Role of the Bird-Beak Configuration in Endograft Infolding in the Aortic Arch. J Endovasc Ther 2015; 23:172-81. [DOI: 10.1177/1526602815611888] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Purpose: To assess endograft infolding for excessive bird-beak configurations in the aortic arch in relation to hemodynamic variables by quantifying device displacement and rotation of oversized stent-grafts deployed in a phantom model. Methods: A patient-specific, compliant, phantom pulsatile flow model was reconstructed from a patient who presented with collapse of a Gore TAG thoracic endoprosthesis. Device infolding was measured under different flow and pressure conditions for 3 protrusion extensions (13, 19, and 24 mm) of the bird-beak configuration resulting from 2 TAG endografts with oversizing of 11% and 45%, respectively. Results: The bird-beak configuration with the greatest protrusion extension exhibited the maximum TAG device displacement (1.66 mm), while the lowest protrusion extension configuration led to the minimum amount of both displacement and rotation parameters (0.25 mm and 0.6°, respectively). A positive relationship was found between the infolding parameters and the flow circulating in the aorta and left subclavian artery. Similarly, TAG device displacement was positively and significantly (p<0.05) correlated with the pulse pressure for all bird-beak configurations and device sizes. However, no collapse was observed under chronic perfusion testing maintained for 30 days and pulse pressure of 100 mm Hg. Conclusion: These findings suggest that endograft infolding depends primarily on the amount of aortic pulsatility and flow rate and that physiological flows do not necessarily engender hemodynamic loads on the proximal bird-beak segment sufficient to cause TAG collapse. Hemodynamic variables may allow for identification of patients at high risk of endograft infolding and help guide preventive intervention to avert its occurrence.
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Affiliation(s)
- Salvatore Pasta
- Fondazione Ri.MED, Palermo, Italy
- Cardiac Surgery and Heart Transplantation Unit, Department for the Treatment and Study of Cardiothoracic Diseases and Cardiothoracic Transplantation, Mediterranean Institute for Transplantation and Advanced Specialized Therapies (ISMETT), Palermo, Italy
| | | | | | - Giuseppe Maria Raffa
- Cardiac Surgery and Heart Transplantation Unit, Department for the Treatment and Study of Cardiothoracic Diseases and Cardiothoracic Transplantation, Mediterranean Institute for Transplantation and Advanced Specialized Therapies (ISMETT), Palermo, Italy
| | - Giuseppe D’Ancona
- Cardiovascular Medicine Clinical and Research Unit, Vivantes Klinikum im Friedrichschein und Am Urban, Berlin, Germany
| | - Michele Pilato
- Cardiac Surgery and Heart Transplantation Unit, Department for the Treatment and Study of Cardiothoracic Diseases and Cardiothoracic Transplantation, Mediterranean Institute for Transplantation and Advanced Specialized Therapies (ISMETT), Palermo, Italy
| | - Cesare Scardulla
- Cardiac Surgery and Heart Transplantation Unit, Department for the Treatment and Study of Cardiothoracic Diseases and Cardiothoracic Transplantation, Mediterranean Institute for Transplantation and Advanced Specialized Therapies (ISMETT), Palermo, Italy
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30
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Nauta FJH, Conti M, Kamman AV, van Bogerijen GHW, Tolenaar JL, Auricchio F, Figueroa CA, van Herwaarden JA, Moll FL, Trimarchi S. Biomechanical Changes After Thoracic Endovascular Aortic Repair in Type B Dissection. J Endovasc Ther 2015; 22:918-33. [DOI: 10.1177/1526602815608848] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Thoracic endovascular aortic repair (TEVAR) has evolved into an established treatment option for type B aortic dissection (TBAD) since it was first introduced 2 decades ago. Morbidity and mortality have decreased due to the minimally invasive character of TEVAR, with adequate stabilization of the dissection, restoration of true lumen perfusion, and subsequent positive aortic remodeling. However, several studies have reported severe setbacks of this technique. Indeed, little is known about the biomechanical behavior of implanted thoracic stent-grafts and the impact on the vascular system. This study sought to systematically review the performance and behavior of implanted thoracic stent-grafts and related biomechanical aortic changes in TBAD patients in order to update current knowledge and future perspectives.
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Affiliation(s)
- Foeke J. H. Nauta
- Thoracic Aortic Research Center, Policlinico San Donato IRCCS, University of Milan, Italy
- Departments of Surgery and Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
- Department of Vascular Surgery, University Medical Center Utrecht, the Netherlands
| | - Michele Conti
- Department of Civil Engineering and Architecture, University of Pavia, Italy
| | - Arnoud V. Kamman
- Thoracic Aortic Research Center, Policlinico San Donato IRCCS, University of Milan, Italy
- Departments of Surgery and Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
- Department of Vascular Surgery, University Medical Center Utrecht, the Netherlands
| | | | - Jip L. Tolenaar
- Department of General Surgery, St. Antonius Hospital, Nieuwegein, the Netherlands
| | | | - C. Alberto Figueroa
- Departments of Surgery and Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | | | - Frans L. Moll
- Department of Vascular Surgery, University Medical Center Utrecht, the Netherlands
| | - Santi Trimarchi
- Thoracic Aortic Research Center, Policlinico San Donato IRCCS, University of Milan, Italy
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31
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Boufi M, Guivier-Curien C, Deplano V, Boiron O, Loundou A, Dona B, Hartung O, Alimi Y. Risk Factor Analysis of Bird Beak Occurrence after Thoracic Endovascular Aortic Repair. Eur J Vasc Endovasc Surg 2015; 50:37-43. [DOI: 10.1016/j.ejvs.2015.04.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 04/12/2015] [Indexed: 11/17/2022]
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32
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Lin CJ, Chang FC, Guo WY, Hung SC, Luo CB, Beilner J, Kowarschik M, Chu WF. Changes of time-attenuation curve blood flow parameters in patients with and without carotid stenosis. AJNR Am J Neuroradiol 2015; 36:1176-81. [PMID: 25721077 DOI: 10.3174/ajnr.a4239] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Accepted: 12/01/2014] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE From the time-attenuation curves of DSA flow parameters, maximal intensity, maximal slope, and full width at half maximum of selected vascular points are defined. The study explores the reliability of defining the flow parameters by the time-attenuation curves of DSA. MATERIALS AND METHODS Seventy patients with unilateral carotid artery stenosis (group A) and 56 healthy controls (group B) were retrospectively enrolled. Fixed contrast injection protocols and DSA acquisition parameters were used with all patients. The M1, sigmoid sinus, and internal jugular vein on anteroposterior view DSA and the M2, parietal vein, and superior sagittal sinus on lateral view DSA were chosen as ROI targets for measuring flow parameters. The difference of time of maximal intensity between 2 target points was defined as the circulation time between the target points. RESULTS The maximal intensity difference of 2 selected points from the ICA to the M1, sigmoid sinus, internal jugular vein, M2, parietal vein, and superior sagittal sinus was significantly longer in group A than in group B. The maximum slope of M1, M2, and the superior sagittal sinus was significantly lower in group A than in group B. The full width at half maximum of M1 and M2 was significantly larger in group A than in group B. The maximal slope of M1 demonstrated the best diagnostic performance. CONCLUSIONS The maximal intensity difference of 2 selected points derived from DSA can be used as a definitive alternative flow parameter for intracranial circulation time measurement. Maximal slope and full width at half maximum complement the maximal intensity difference of 2 selected points in defining flow characteristics of healthy subjects and patients with carotid stenosis.
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Affiliation(s)
- C-J Lin
- From the Department of Radiology (C.-J.L., F.-C.C., W.-Y.G., S.-C.H., C.-B.L., W.-F.C.), Taipei Veterans General Hospital, Taipei, Taiwan School of Medicine (C.-J.L., F.-C.C., W.-Y.G., S.-C.H., C.-B.L.), National Yang-Ming University, Taipei, Taiwan
| | - F-C Chang
- From the Department of Radiology (C.-J.L., F.-C.C., W.-Y.G., S.-C.H., C.-B.L., W.-F.C.), Taipei Veterans General Hospital, Taipei, Taiwan School of Medicine (C.-J.L., F.-C.C., W.-Y.G., S.-C.H., C.-B.L.), National Yang-Ming University, Taipei, Taiwan
| | - W-Y Guo
- From the Department of Radiology (C.-J.L., F.-C.C., W.-Y.G., S.-C.H., C.-B.L., W.-F.C.), Taipei Veterans General Hospital, Taipei, Taiwan School of Medicine (C.-J.L., F.-C.C., W.-Y.G., S.-C.H., C.-B.L.), National Yang-Ming University, Taipei, Taiwan
| | - S-C Hung
- From the Department of Radiology (C.-J.L., F.-C.C., W.-Y.G., S.-C.H., C.-B.L., W.-F.C.), Taipei Veterans General Hospital, Taipei, Taiwan School of Medicine (C.-J.L., F.-C.C., W.-Y.G., S.-C.H., C.-B.L.), National Yang-Ming University, Taipei, Taiwan
| | - C-B Luo
- From the Department of Radiology (C.-J.L., F.-C.C., W.-Y.G., S.-C.H., C.-B.L., W.-F.C.), Taipei Veterans General Hospital, Taipei, Taiwan School of Medicine (C.-J.L., F.-C.C., W.-Y.G., S.-C.H., C.-B.L.), National Yang-Ming University, Taipei, Taiwan
| | - J Beilner
- Angiography and Interventional X-Ray Systems (J.B.), Siemens Ltd China, Healthcare Sector, Shanghai, P.R. China
| | - M Kowarschik
- Angiography and Interventional X-Ray Systems (M.K.), Siemens AG, Healthcare Sector, Erlangen, Germany
| | - W-F Chu
- From the Department of Radiology (C.-J.L., F.-C.C., W.-Y.G., S.-C.H., C.-B.L., W.-F.C.), Taipei Veterans General Hospital, Taipei, Taiwan
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Pasta S, Raffa GM, D'Ancona G, Pilato M. Commentary: The bird-beak stent-graft configuration: the end of aortic arch endograft collapse? J Endovasc Ther 2014; 21:803-4. [PMID: 25453881 DOI: 10.1583/14-4778c.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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34
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van Bogerijen GHW, Auricchio F, Conti M, Lefieux A, Reali A, Veneziani A, Tolenaar JL, Moll FL, Rampoldi V, Trimarchi S. Aortic Hemodynamics After Thoracic Endovascular Aortic Repair, With Particular Attention to the Bird-Beak Configuration. J Endovasc Ther 2014; 21:791-802. [DOI: 10.1583/14-4778mr.1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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35
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Orr N, Minion D, Bobadilla JL. Thoracoabdominal aortic aneurysm repair: current endovascular perspectives. Vasc Health Risk Manag 2014; 10:493-505. [PMID: 25170271 PMCID: PMC4145733 DOI: 10.2147/vhrm.s46452] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Thoracoabdominal aneurysms account for roughly 3% of identified aneurysms annually in the United States. Advancements in endovascular techniques and devices have broadened their application to these complex surgical problems. This paper will focus on the current state of endovascular thoracoabdominal aneurysm repair, including specific considerations in patient selection, operative planning, and perioperative complications. Both total endovascular and hybrid options will be considered.
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Affiliation(s)
- Nathan Orr
- Vascular and Endovascular Surgery, Department of Surgery, University of Kentucky, Lexington, KY, USA
| | - David Minion
- Vascular and Endovascular Surgery, Department of Surgery, University of Kentucky, Lexington, KY, USA
| | - Joseph L Bobadilla
- Vascular and Endovascular Surgery, Department of Surgery, University of Kentucky, Lexington, KY, USA
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36
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Mosquera VX, Marini M, Velasco C, Estévez-Cid F, Herrera-Noreña JM, Cao I, Gulías D, Cuenca JJ. Análisis morfológico del arco aórtico en pacientes sometidos a cirugía híbrida y correlación con resultados a medio plazo. CIRUGIA CARDIOVASCULAR 2014. [DOI: 10.1016/j.circv.2013.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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37
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Rinaudo A, Pasta S. Regional variation of wall shear stress in ascending thoracic aortic aneurysms. Proc Inst Mech Eng H 2014; 228:627-638. [DOI: 10.1177/0954411914540877] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The development of an ascending thoracic aortic aneurysm is likely caused by excessive hemodynamic loads exerted on the aneurysmal wall. Computational fluid-dynamic analyses were performed on patient-specific ascending thoracic aortic aneurysms obtained from patients with either bicuspid aortic valve or tricuspid aortic valve to evaluate hemodynamic and wall shear parameters, imparting aneurysm enlargement. Results showed an accelerated flow along the outer aortic wall with helical flow in the aneurysm center for bicuspid aortic valve ascending thoracic aortic aneurysms. In a different way, tricuspid aortic valve ascending thoracic aortic aneurysms exhibited normal systolic flow without substantial secondary pattern. Analysis of wall shear parameters evinced a high and locally varying wall shear stress on the outer aortic wall and high temporal oscillations in wall shear stress (oscillatory shear index) on either left or right side of aneurysmal aorta. These findings may explain the asymmetric dilatation typically observed in ascending thoracic aortic aneurysms. Simulations of a hypertensive scenario revealed an increase in wall shear stress upon 44% compared to normal systemic pressure models. Computational fluid-dynamics–based analysis may allow identification of wall shear parameters portending aneurysm dilatation and hence guide preventative intervention.
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Affiliation(s)
- Antonino Rinaudo
- Dipartimento di Ingegneria Chimica, Gestionale, Informatica e Meccanica (DICGIM), Universita’ di Palermo, Palermo, Italy
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38
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Rinaudo A, D’Ancona G, Lee JJ, Pilato G, Amaducci A, Baglini R, Follis F, Pilato M, Pasta S. Predicting Outcome of Aortic Dissection with Patent False Lumen by Computational Flow Analysis. Cardiovasc Eng Technol 2014. [DOI: 10.1007/s13239-014-0182-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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39
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Rinaudo A, D'Ancona G, Baglini R, Amaducci A, Follis F, Pilato M, Pasta S. Computational fluid dynamics simulation to evaluate aortic coarctation gradient with contrast-enhanced CT. Comput Methods Biomech Biomed Engin 2014; 18:1066-1071. [PMID: 24460213 DOI: 10.1080/10255842.2013.869321] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Coarctation of aorta (CoA) is a narrowing of the aorta leading to a pressure gradient (ΔP) across the coarctation, increased afterload and reduced peripheral perfusion pressures. Indication to invasive treatment is based on values of maximal (systolic) trans-coarctation ΔP. A computational fluid dynamic (CFD) approach is herein presented for the non-invasive haemodynamic assessment of ΔP across CoA. Patient-specific CFD simulations were created from contrast-enhanced computed tomography (CT) and appropriate flow boundary conditions. Computed ΔP was validated with invasive intravascular trans-CoA pressure measurements. Haemodynamic indices, including pressure loss coefficient (PLc), time-averaged wall shear stress (TAWSS) and oscillatory shear index (OSI), were also quantified. CFD-estimated ΔP values were comparable to the invasive ones. Moreover, the aorta proximal to CoA was exposed to altered TAWSS and OSI suggesting hypertension. PLc was found as a further geometric marker of CoA severity. Finally, CFD-estimated ΔP confirmed a significant reduction after percutaneous balloon dilatation and stenting of the CoA in one patient (e.g. from ΔP∼52 mmHg to ΔP∼3 mmHg). The validation of the ΔP computations with catheterisation measurements suggests that CFD simulation, based on CT-derived anatomical data, is a useful tool to readily quantify CoA severity.
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Affiliation(s)
- Antonino Rinaudo
- a Dipartimento di Ingegneria Chimica , Gestionale, Informatica e Meccanica, Universita' di Palermo , Viale delle Scienze Ed. 8, 90128 Palermo , Italy
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40
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Hsu HL, Chen CK, Chen PL, Chen IM, Hsu CP, Chen CW, Shih CC. The impact of bird-beak configuration on aortic remodeling of distal arch pathology after thoracic endovascular aortic repair with the Zenith Pro-Form TX2 thoracic endograft. J Vasc Surg 2014; 59:80-8. [DOI: 10.1016/j.jvs.2013.07.098] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 07/16/2013] [Accepted: 07/17/2013] [Indexed: 10/26/2022]
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41
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Hayes N, Podnar T, Qureshi S. Collapse of the advanta V12 large diameter covered stent following implantation for aortic coarctation. Catheter Cardiovasc Interv 2013; 83:109-14. [DOI: 10.1002/ccd.25139] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Revised: 05/14/2013] [Accepted: 07/21/2013] [Indexed: 11/10/2022]
Affiliation(s)
- Nicholas Hayes
- Evelina Children's Hospital; Guy's and St Thomas' NHS Trust, Westminster Bridge Road, London E1 7EH United Kingdom
| | - Tomaž Podnar
- Department of Paediatrics; University Medical Center Ljubljana; Bohoričeva 20, 1000 Ljubljana Slovenia
| | - Shakeel Qureshi
- Evelina Children's Hospital; Guy's and St Thomas' NHS Trust, Westminster Bridge Road, London E1 7EH United Kingdom
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42
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D'Ancona G, Amaducci A, Rinaudo A, Pasta S, Follis F, Pilato M, Baglini R. Haemodynamic predictors of a penetrating atherosclerotic ulcer rupture using fluid-structure interaction analysis. Interact Cardiovasc Thorac Surg 2013; 17:576-8. [PMID: 23736658 DOI: 10.1093/icvts/ivt245] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present preliminary data on the flow-induced haemodynamic and structural loads exerted on a penetrating atherosclerotic aortic ulcer (PAU). Specifically, one-way fluid-structure interaction analysis was performed on the aortic model reconstructed from a 66-year-old male patient with a PAU that evolved into an intramural haematoma and rupture of the thoracic aorta. The results show that elevated blood pressure (117 mmHg) and low flow velocity at the aortic wall (0.15 m/s(2)) occurred in the region of the PAU. We also found a low value of time-averaged wall shear stress (1.24 N/m(2)) and a high value of the temporal oscillation in the wall shear stress (oscillatory shear index = 0.13) in the region of the PAU. After endovascular treatment, these haemodynamic parameters were distributed uniformly on the luminal surface of the stent graft. These findings suggest that wall shear stress could be considered one of the major haemodynamic factors indicating the structural fragility of the PAU wall, which ultimately lead to PAU growth and rupture.
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Affiliation(s)
- Giuseppe D'Ancona
- Cardiothoracic Department, Mediterranean Institute for Transplantation and Advanced Medical Therapies (ISMETT), Palermo, Italy
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