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Malatos S, Fazzini L, Raptis A, Nana P, Kouvelos G, Tasso P, Gallo D, Morbiducci U, Xenos MA, Giannoukas A, Matsagkas M. Evaluation of Hemodynamic Properties After Chimney and Fenestrated Endovascular Aneurysm Repair. Ann Vasc Surg 2024; 104:237-247. [PMID: 38492732 DOI: 10.1016/j.avsg.2023.12.084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 12/14/2023] [Accepted: 12/16/2023] [Indexed: 03/18/2024]
Abstract
BACKGROUND Fenestrated (FEVAR) and chimney (ChEVAR) endovascular aortic repair have been applied in anatomically suitable complex aortic aneurysms. However, local hemodynamic changes may occur after repair. This study aimed to compare FEVAR's and ChEVAR's hemodynamic properties, focusing on visceral arteries. METHODS Preoperative and postoperative computed tomography angiographies have been used to reconstruct patient-based models. Data of 3 patients, for each modality, were analyzed. Following geometric reconstruction, computational fluid dynamics simulations were used to extract near-wall and intravascular hemodynamic indicators, such as pressure drops, velocity, wall shear stress, time averaged wall shear stress, oscillatory shear index, relative residence time, and local normalized helicity. RESULTS An overall improvement in hemodynamics was detected after repair, with either technique. Preoperatively, a disturbed prothrombotic wall shear stress profile was recorded in several zones of the sac. The local normalized helicity results showed a better organization of the helical structures at postoperative setting, decreasing thrombus formation, with both modalities. Similarly, time averaged wall shear stress increased and oscillatory shear index decreased postoperatively, signaling nondisturbed blood flow. The relative residence time was locally reduced. The flow in visceral arteries tended to be more streamlined in ChEVAR, compared to evident recirculation regions at renal and superior mesenteric artery fenestrations (P = 0.06). CONCLUSIONS ChEVAR and FEVAR seem to improve hemodynamics toward normal values with a reduction of recirculation zones in the main graft and aortic branches. Visceral artery flow comparison revealed that ChEVAR tended to present lower recirculation regions at parallel grafts' entries while FEVAR showed less intense flow regurgitation in visceral stents.
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Affiliation(s)
- Stavros Malatos
- Laboratory for Vascular Simulations, Institute of Vascular Diseases, Larissa, Greece
| | - Laura Fazzini
- Department of Mechanical and Aerospace Engineering, Biomedical Engineering, Politecnico di Torino, Torino, Italy
| | - Anastasios Raptis
- Laboratory for Vascular Simulations, Institute of Vascular Diseases, Larissa, Greece
| | - Petroula Nana
- Department of Vascular Surgery, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece.
| | - George Kouvelos
- Department of Vascular Surgery, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
| | - Paola Tasso
- Department of Mechanical and Aerospace Engineering, Biomedical Engineering, Politecnico di Torino, Torino, Italy
| | - Diego Gallo
- Department of Mechanical and Aerospace Engineering, Biomedical Engineering, Politecnico di Torino, Torino, Italy
| | - Umberto Morbiducci
- Department of Mechanical and Aerospace Engineering, Biomedical Engineering, Politecnico di Torino, Torino, Italy
| | - Michail A Xenos
- Department of Vascular Surgery, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece; Department of Mathematics, Section of Applied and Computational Mathematics, University of Ioannina, Ioannina, Greece
| | - Athanasios Giannoukas
- Laboratory for Vascular Simulations, Institute of Vascular Diseases, Larissa, Greece; Department of Vascular Surgery, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
| | - Miltiadis Matsagkas
- Laboratory for Vascular Simulations, Institute of Vascular Diseases, Larissa, Greece; Department of Vascular Surgery, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
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Teng A, Sun A, Chen Z, Deng X, Fan Y. Sex different abdominal artery anatomy may induce different displacement force on stent-graft after endovascular aneurysm repair. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2023; 39:e3739. [PMID: 37317060 DOI: 10.1002/cnm.3739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 05/19/2023] [Accepted: 05/25/2023] [Indexed: 06/16/2023]
Abstract
Women with abdominal aortic aneurysm (AAA) have a higher incidence of complications after Endovascular aneurysm repair (EVAR), most of which are related to the migration of stent-graft. The different force acting on the stent-graft after EVAR caused by different abdominal artery anatomy of male and female AAA patients may be the reason for the sex-different complications. This article aims to explore the possible biomechanical mechanisms of sex differences by making a comparison of displacement force acting on the stent graft of male and female AAA patients. To explore the effect of different vascular anatomy on stent-graft migration, the uniformed models were constructed according to the specific vascular anatomy parameters of AAA patients of different sex, which have been measured before. The computational fluid dynamics method was used to quantitate the pulsatile force acting on the stent-graft after EVAR in a cardiac cycle. Then the displacement force was calculated with the pressure and the wall shear stress, and the total and area-weighted average of displacement force acting on the stent-graft were compared respectively. In one cardiac cycle, the wall pressure for the male model is greater than that of the female model (2.7-4.4 vs. 2.2-3.4 N), and the wall shear force for the female model is slightly greater (0-0.0065 vs. 0-0.0055 N). The displacement force is mainly provided by the wall pressure, which is also greater in the male model. However, the area-averaged displacement force is greater for the female model than that for the male model (180-290 vs. 160-250 Pa). Because of the different vascular anatomies, the impact caused by the pulsating aortic blood flow on the AAA stent-graft of women after EVAR was greater than that of men. Women's vascular anatomy leads to greater area-averaged displacement force after stent-graft implantation, resulting in a greater risk of stent-graft migration, which might be one of the reasons why women had a higher incidence of complications after EVAR.
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Affiliation(s)
- Anna Teng
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Anqiang Sun
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Zengsheng Chen
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Xiaoyan Deng
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Yubo Fan
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
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Sturla F, Caimi A, Romarowski RM, Nano G, Glauber M, Redaelli A, Votta E, Marrocco-Trischitta MM. Fast Approximate Quantification of Endovascular Stent Graft Displacement Forces in the Bovine Aortic Arch Variant. J Endovasc Ther 2023; 30:756-768. [PMID: 35588222 PMCID: PMC10503258 DOI: 10.1177/15266028221095403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Displacement forces (DFs) identify hostile landing zones for stent graft deployment in thoracic endovascular aortic repair (TEVAR). However, their use in TEVAR planning is hampered by the need for time-expensive computational fluid dynamics (CFD). We propose a novel fast-approximate computation of DFs merely exploiting aortic arch anatomy, as derived from the computed tomography (CT) and a measure of central aortic pressure. MATERIALS AND METHODS We tested the fast-approximate approach against CFD gold-standard in 34 subjects with the "bovine" aortic arch variant. For each dataset, a 3-dimensional (3D) model of the aortic arch lumen was reconstructed from computed tomography angiography and CFD then employed to compute DFs within the aortic proximal landing zones. To quantify fast-approximate DFs, the wall shear stress contribution to the DF was neglected and blood pressure space-distribution was averaged on the entire aortic wall to reliably approximate the patient-specific central blood pressure. Also, DF values were normalized on the corresponding proximal landing zone area to obtain the equivalent surface traction (EST). RESULTS Fast-approximate approach consistently reflected (r2=0.99, p<0.0001) the DF pattern obtained by CFD, with a -1.1% and 0.7° bias in DFs magnitude and orientation, respectively. The normalized EST progressively increased (p<0.0001) from zone 0 to zone 3 regardless of the type of arch, with proximal landing zone 3 showing significantly greater forces than zone 2 (p<0.0001). Upon DF normalization to the corresponding aortic surface, fast-approximate EST was decoupled in blood pressure and a dimensionless shape vector (S) reflecting aortic arch morphology. S showed a zone-specific pattern of orientation and proved a valid biomechanical blueprint of DF impact on the thoracic aortic wall. CONCLUSION Requiring only a few seconds and quantifying clinically relevant biomechanical parameters of proximal landing zones for arch TEVAR, our method suits the real preoperative decision-making process. It paves the way toward analyzing large population of patients and hence to define threshold values for a future patient-specific preoperative TEVAR planning.
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Affiliation(s)
- Francesco Sturla
- 3D and Computer Simulation Laboratory, IRCCS Policlinico San Donato, San Donato Milanese, Italy
- Department of Electronics Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - Alessandro Caimi
- Department of Electronics Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - Rodrigo M. Romarowski
- 3D and Computer Simulation Laboratory, IRCCS Policlinico San Donato, San Donato Milanese, Italy
| | - Giovanni Nano
- Vascular Surgery Unit, Cardiovascular Department, IRCCS Policlinico San Donato, San Donato Milanese, Italy
- Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Milano, Italy
| | - Mattia Glauber
- Minimally Invasive Cardiac Surgery Unit, Istituto Clinico Sant’Ambrogio, Milano, Italy
| | - Alberto Redaelli
- Department of Electronics Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - Emiliano Votta
- 3D and Computer Simulation Laboratory, IRCCS Policlinico San Donato, San Donato Milanese, Italy
- Department of Electronics Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - Massimiliano M. Marrocco-Trischitta
- Vascular Surgery Unit, Cardiovascular Department, IRCCS Policlinico San Donato, San Donato Milanese, Italy
- Clinical Research Unit, Cardiovascular Department, IRCCS Policlinico San Donato, San Donato Milanese, Italy
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Brand M, Yoel B, Eichler E, Speter C, Halak M, Marom G. The effect of stent graft curvature on the hemodynamic displacement force after abdominal aortic aneurysm endovascular repair. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230563. [PMID: 37416831 PMCID: PMC10320339 DOI: 10.1098/rsos.230563] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 06/12/2023] [Indexed: 07/08/2023]
Abstract
Endovascular aortic aneurysm repair is a minimally invasive procedure with low mortality and morbidity. Clinical studies have revealed that a displacement force (DF) can cause stent graft (SG) migration in some circumstances requiring repeated intervention. This study aims to determine the relationship between the SG curvature and the calculated DF from four patient-specific computational fluid dynamics models. The SG's curvature was defined according to the centrelines of the implanted SG's branches. The centrelines were defined as either intersecting or separated lines. The centreline curvature (CLC) metrics were calculated based on the local curvature radii and the distances from the centrelines of idealized straight branches. The average CLC value and average variation were calculated to represent the entire graft's curvature. These CLC calculations were compared, and the method that gave the best correlation to the calculated DF was found. The optimal correlation is obtained from calculating the CLC average variation using separated centrelines and distance from straight lines, with an R2 = 0.89. Understanding the relationship between vascular morphology and DF can help identify at-risk patients before the procedure. In these cases, we can provide appropriate treatment and follow up with the patient to prevent future failure.
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Affiliation(s)
| | | | | | - Chen Speter
- Department of Vascular Surgery, The Chaim Sheba Medical Centre, Tel Hashomer, Israel
| | - Moshe Halak
- Department of Vascular Surgery, The Chaim Sheba Medical Centre, Tel Hashomer, Israel
| | - Gil Marom
- Tel Aviv University, Ramat Aviv, Tel Aviv, Israel
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5
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Sengupta S, Yuan X, Maga L, Pirola S, Nienaber CA, Xu XY. Aortic haemodynamics and wall stress analysis following arch aneurysm repair using a single-branched endograft. Front Cardiovasc Med 2023; 10:1125110. [PMID: 37283581 PMCID: PMC10240084 DOI: 10.3389/fcvm.2023.1125110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 05/08/2023] [Indexed: 06/08/2023] Open
Abstract
Introduction Thoracic endovascular aortic repair (TEVAR) of the arch is challenging given its complex geometry and the involvement of supra-aortic arteries. Different branched endografts have been designed for use in this region, but their haemodynamic performance and the risk for post-intervention complications are not yet clear. This study aims to examine aortic haemodynamics and biomechanical conditions following TVAR treatment of an aortic arch aneurysm with a two-component single-branched endograft. Methods Computational fluid dynamics and finite element analysis were applied to a patient-specific case at different stages: pre-intervention, post-intervention and follow-up. Physiologically accurate boundary conditions were used based on available clinical information. Results Computational results obtained from the post-intervention model confirmed technical success of the procedure in restoring normal flow to the arch. Simulations of the follow-up model, where boundary conditions were modified to reflect change in supra-aortic vessel perfusion observed on the follow-up scan, predicted normal flow patterns but high levels of wall stress (up to 1.3M MPa) and increased displacement forces in regions at risk of compromising device stability. This might have contributed to the suspected endoleaks or device migration identified at the final follow up. Discussion Our study demonstrated that detailed haemodynamic and biomechanical analysis can help identify possible causes for post-TEVAR complications in a patient-specific setting. Further refinement and validation of the computational workflow will allow personalised assessment to aid in surgical planning and clinical decision making.
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Affiliation(s)
- Sampad Sengupta
- Department of Chemical Engineering, Imperial College London, London, United Kingdom
| | - Xun Yuan
- National Heart and Lung Institute, Faculty of Medicine, Imperial College London, London, United Kingdom
- Cardiology and Aortic Centre, Royal Brompton and Harefield Hospitals, Guy’s and St Thomas’ NHS Foundation Trust, London, United Kingdom
| | - Ludovica Maga
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
- Department of Biomechanical Engineering, Delft University of Technology, Delft, Netherlands
| | - Selene Pirola
- Department of Biomechanical Engineering, Delft University of Technology, Delft, Netherlands
| | - Christoph A. Nienaber
- National Heart and Lung Institute, Faculty of Medicine, Imperial College London, London, United Kingdom
- Cardiology and Aortic Centre, Royal Brompton and Harefield Hospitals, Guy’s and St Thomas’ NHS Foundation Trust, London, United Kingdom
| | - Xiao Yun Xu
- Department of Chemical Engineering, Imperial College London, London, United Kingdom
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Haemodynamic Analysis of Branched Endografts for Complex Aortic Arch Repair. Bioengineering (Basel) 2022; 9:bioengineering9020045. [PMID: 35200399 PMCID: PMC8868591 DOI: 10.3390/bioengineering9020045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/11/2022] [Accepted: 01/13/2022] [Indexed: 11/17/2022] Open
Abstract
This study aims to investigate the haemodynamic response induced by implantation of a double-branched endograft used in thoracic endovascular aortic repair (TEVAR) of the aortic arch. Anatomically realistic models were reconstructed from CT images obtained from patients who underwent TEVAR using the RelayPlus double-branched endograft implanted in the aortic arch. Two cases (Patient 1, Patient 2) were included here, both patients presented with type A aortic dissection before TEVAR. To examine the influence of inner tunnel branch diameters on localised flow patterns, three tunnel branch diameters were tested using the geometric model reconstructed for Patient 1. Pulsatile blood flow through the models was simulated by numerically solving the Navier–Stokes equations along with a transitional flow model. The physiological boundary conditions were imposed at the model inlet and outlets, while the wall was assumed to be rigid. Our simulation results showed that the double-branched endograft allowed for the sufficient perfusion of blood to the supra-aortic branches and restored flow patterns expected in normal aortas. The diameter of tunnel branches in the device plays a crucial role in the development of flow downstream of the branches and thus must be selected carefully based on the overall geometry of the vessel. Given the importance of wall shear stress in vascular remodelling and thrombus formation, longitudinal studies should be performed in the future in order to elucidate the role of tunnel branch diameters in long-term patency of the supra-aortic branches following TEVAR with the double-branched endograft.
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Qing M, Qiu Y, Wang J, Zheng T, Yuan D. A Comparative Study on the Hemodynamic Performance Within Cross and Non-cross Stent-Grafts for Abdominal Aortic Aneurysms With an Angulated Neck. Front Physiol 2021; 12:795085. [PMID: 34925075 PMCID: PMC8674644 DOI: 10.3389/fphys.2021.795085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 11/10/2021] [Indexed: 02/05/2023] Open
Abstract
Objectives: Cross-limb stent grafts for endovascular aneurysm repair (EVAR) are often employed for abdominal aortic aneurysms (AAAs) with significant aortic neck angulation. Neck angulation may be coronal or sagittal; however, previous hemodynamic studies of cross-limb EVAR stent grafts (SGs) primarily utilized simplified planar neck geometries. This study examined the differences in flow patterns and hemodynamic parameters between crossed and non-crossed limb SGs at different spatial neck angulations. Methods: Ideal models consisting of 13 cross and 13 non-cross limbs were established, with coronal and sagittal angles ranging from 0 to 90°. Computational fluid dynamics (CFD) was used to capture the hemodynamic information, and the differences were compared. Results: With regards to the pressure drop index, the maximum difference caused by the configuration and angular direction was 4.6 and 8.0%, respectively, but the difference resulting from the change in aneurysm neck angle can reach 27.1%. With regards to the SAR-TAWSS index, the maximum difference caused by the configuration and angular direction was 7.8 and 9.8%, respectively, but the difference resulting from the change in aneurysm neck angle can reach 26.7%. In addition, when the aneurysm neck angle is lower than 45°, the configuration and angular direction significantly influence the OSI and helical flow intensity index. However, when the aneurysm neck angle is greater than 45°, the hemodynamic differences of each model at the same aneurysm neck angle are reduced. Conclusion: The main factor affecting the hemodynamic index was the angle of the aneurysm neck, while the configuration and angular direction had little effect on the hemodynamics. Furthermore, when the aneurysm neck was greatly angulated, the cross-limb technique did not increase the risk of thrombosis.
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Affiliation(s)
- Ming Qing
- Department of Applied Mechanics, Sichuan University, Chengdu, China.,Yibin Institute of Industrial Technology/Sichuan University Yibin Park, Yibin, China
| | - Yue Qiu
- Department of Applied Mechanics, Sichuan University, Chengdu, China.,West China Biomedical Big Data Center, West China Hospital, Sichuan University, Chengdu, China
| | - Jiarong Wang
- Department of Vascular Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Tinghui Zheng
- Department of Applied Mechanics, Sichuan University, Chengdu, China.,Med-X Center for Informatics, Sichuan University, Chengdu, China
| | - Ding Yuan
- West China Biomedical Big Data Center, West China Hospital, Sichuan University, Chengdu, China.,Med-X Center for Informatics, Sichuan University, Chengdu, China
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