1
|
Sugimoto M, Horiguchi R, Ikeda S, Kawai Y, Niimi K, Hyodo R, Banno H. The immediate post-operative impact of infrarenal aortic endografts on renal arterial flow dynamics: Insights from four-dimensional flow magnetic resonance imaging analysis. Vascular 2024:17085381241277651. [PMID: 39180198 DOI: 10.1177/17085381241277651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/26/2024]
Abstract
OBJECTIVES This study aims to quantify changes in renal blood flow before and after endovascular aneurysm repair (EVAR) using four-dimensional (4D) flow magnetic resonance imaging (MRI) and evaluate its correlation with renal impairment. METHODS In this retrospective analysis, 18 patients underwent elective EVAR for infrarenal fusiform abdominal aortic aneurysms using Excluder or Endurant endografts. 4D flow MRI scans were conducted before and 1-4 days after EVAR. Hemodynamics were quantified at the suprarenal aorta (SupAo), bilateral renal arteries (RRA and LRA), and infrarenal aorta (InfAo). Cardiac phase-resolved blood flow values (BFVs), relative flow distribution (RFD), and flow change rates (FCRs) were assessed. Estimated glomerular filtration rate (eGFR) was measured pre- and postoperatively. RESULTS A total of 16 patients were analyzed after excluding two outliers. Pre-EVAR BFVs were 23.1 ± 8.3, 3.7 ± 1.3, 3.4 ± 1.2, and 15.1 ± 5.9 mL/cycle, while post-EVAR BFVs were 20.9 ± 6.9, 3.8 ± 1.1, 3.2 ± 0.9, and 12.1 ± 4.3 mL/cycle in SupAo, RRA, LRA, and InfAo, respectively. Comparing Excluder (N = 8) and Endurant (N = 8), the total renal FCR was 121.8% [106.6-144.7] versus 101.3% [63.8-121.8] (p = 0.110), suggesting a potential improvement in renal blood flow with the Excluder, although not statistically significant. A significant correlation was found between the total renal FCR and the relative eGFR at 6 months (Spearman correlation coefficient, 0.789; p < 0.001). CONCLUSIONS The endografts, particularly the Excluder, showed potential in improving renal artery blood flow in some patients. The significant correlation between the total renal FCR and the relative eGFR at 6 months suggests that acute hemodynamic alterations induced by EVAR may impact post-operative renal function. Further research is needed to confirm these findings and assess their clinical implications.
Collapse
Affiliation(s)
- Masayuki Sugimoto
- Division of Vascular and Endovascular Surgery, Department of Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Ryota Horiguchi
- Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Shuta Ikeda
- Division of Vascular and Endovascular Surgery, Department of Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yohei Kawai
- Division of Vascular and Endovascular Surgery, Department of Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Kiyoaki Niimi
- Division of Vascular and Endovascular Surgery, Department of Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Ryota Hyodo
- Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Hiroshi Banno
- Division of Vascular and Endovascular Surgery, Department of Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Ioannidis G, Georgakarakos E, Raptis A, Xenos M, Manopoulos C, Matsagkas M, Giannoukas A. Modeling and Computational Comparison of the Displacement Forces Exerted between the AFX Unibody Aortic Stent Graft and its Hybrid Combination with a Nitinol-based Proximal Aortic Cuff. Ann Vasc Surg 2021; 74:400-409. [PMID: 33819590 DOI: 10.1016/j.avsg.2021.02.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 02/03/2021] [Accepted: 02/06/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND The bifurcated AFX (Endologix, Inc, Irvine, CA, USA) aortic stent-graft is the sole unibody endograft for the management of Abdominal Aortic Aneurysms (AAA). In order to improve the AFX central sealing and clinical efficacy in challenging cases, a replacement of the central chromium-cobaltium AFX extension with a Nitinol-based proximal aortic cuff has been suggested. Yet, comparative data regarding the hemodynamic performance of this design is missing. Aim of this study was to compare the displacement forces (DF) acting on the hybrid AFX-Endurant design, with the classic AFX and Endurant endografts, in angulated and non-angulated cases based on patient-specific Computational Fluid Dynamics (CFD) simulations. METHODS 3D endograft models of 11 treated AAA cases were reconstructed from Computed Tomography Angiography (CTA) imaging data: 5 cases of AFX, 3 cases of the combination AFX-Endurant and 3 cases of the classic Endurant design. The DF on the main-body, the iliac limbs, and the entire stent-graft was calculated by processing the velocity and pressure fields generated by pulsatile CFD simulations. RESULTS The range of total DF (acting on the whole endograft structure) in the AFX, hybrid AFX-Endurant and Endurant group was 2.5-5.2N, 2.0-5.9N and 1.9-2.9N respectively, with the maximum total DF being lower for Endurant. The DF on the main-body of the classic and hybrid AFX cases were higher than the right and left iliac limbs (2.5-4.9N vs. 0.6-5.3N and 0.7-3.6N respectively). Conversely, the DF on the main-body of the Endurant cases was comparable to the force exerted on the right and left limbs. When separating the cases with respect to their neck angulation, the DF on all endograft parts (main-body, limbs) and on the endograft as a whole were lower for the hybrid AFX-Endurant group compared to the classic AFX and Endurant groups, for cases with almost straight neck. CONCLUSION The off-label use of the hybrid AFX-Endurant stent-graft does not seem superior to the conventional AFX or Endurant endografts in angulated cases but was associated with lower DF than AFX or Endurant in non-angulated cases. The clinical value and utility of these findings remain to be elucidated.
Collapse
Affiliation(s)
- Georgios Ioannidis
- Department of Radiotherapy, University Hospital of Larissa, Larissa, Greece
| | - Efstratios Georgakarakos
- Department of Vascular Surgery, Medical School, Democritus University of Thrace, Alexandroupolis, Greece.
| | - Anastasios Raptis
- Laboratory for Vascular Simulations, Institute of Vascular Diseases, Larissa, Greece; Biofluid Mechanics and Biomedical Engineering Laboratory, Fluids Section, School of Mechanical Engineering, National Technical University of Athens, Greece
| | - Michalis Xenos
- Department of Mathematics, University of Ioannina, Ioannina, Greece
| | - Christos Manopoulos
- Biofluid Mechanics and Biomedical Engineering Laboratory, Fluids Section, School of Mechanical Engineering, National Technical University of Athens, Greece
| | - Miltiadis Matsagkas
- Department of Vascular Surgery, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, 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
| |
Collapse
|
5
|
Yazdi SG, Docherty PD, Khanafer A, Jermy M, Kabaliuk N, Geoghegan PH, Williamson P. In-vitro particle image velocimetry assessment of the endovascular haemodynamic features distal of stent-grafts that are associated with development of limb occlusion. J R Soc N Z 2020. [DOI: 10.1080/03036758.2020.1826988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Sina G. Yazdi
- Department of Mechanical Engineering, University of Canterbury, Christchurch, New Zealand
| | - Paul D. Docherty
- Department of Mechanical Engineering, University of Canterbury, Christchurch, New Zealand
- Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
| | - Adib Khanafer
- Department of Surgery, University of Otago, Christchurch, New Zealand
| | - Mark Jermy
- Department of Mechanical Engineering, University of Canterbury, Christchurch, New Zealand
| | - Natalia Kabaliuk
- Department of Mechanical Engineering, University of Canterbury, Christchurch, New Zealand
| | - Patrick H. Geoghegan
- Department of Biomedical Engineering, School of Life & Health Sciences, Aston University, Birmingham, UK
- Department of Mechanical and Industrial Engineering, University of South Africa, Johannesburg, South Africa
| | - Petra Williamson
- Department of Mechanical Engineering, University of Canterbury, Christchurch, New Zealand
| |
Collapse
|
6
|
Domanin M, Piazzoli G, Trimarchi S, Vergara C. Image-Based Displacements Analysis and Computational Blood Dynamics after Endovascular Aneurysm Repair. Ann Vasc Surg 2020; 69:400-412. [PMID: 32738387 DOI: 10.1016/j.avsg.2020.07.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 07/16/2020] [Accepted: 07/17/2020] [Indexed: 01/14/2023]
Abstract
BACKGROUND To examine intraheartbeat displacements (IHD) and geometrical changes of endografts for abdominal aortic aneurysm repair over the course of years, defined as follow-up displacements (FUD), and to correlate them with computational fluid dynamics (CFD). Despite the widespread use of endovascular aneurysm repair (EVAR), we still know little about endograft behavior after deployment. METHODS Two cases, treated with either expanded polytetrafluoroethylene on a nitinol stent frame (PI) or with woven polyester fabric sutured to a stainless-steel Z stent skeleton (PII), were submitted to dynamic computed tomography angiography at 1, 12, and 60 months after implantation. After segmentation, IHD were computed as displacements of the reconstructed surface with respect to the diastolic instant. Similarly, FUD were studied using imaging techniques that align temporal successive segmentations. In addition, numerical simulations for blood dynamics were performed to compute viscous forces, specifically wall shear stress and time-averaged wall shear stress (TAWSS). RESULTS IHD analysis showed slight translations without deformation for the PI endograft with respect to the stiffer stainless-steel endograft behavior of PII. FUD showed in PI motion of the metallic struts mainly focused on the distal main body of the endograft and in the zone overlapping with iliac branches. In PII, we observed a huge FUD in the middle and inferior-anterior regions of the main body. CFD analysis revealed changes of velocity patterns associated with remodeling of the iliac zone for PI and of the main body region for PII, where flow impinges the lumen wall and progressively induces deformation of the endograft wires. Measurement of TAWSS demonstrated flow disturbances in the enlarged region correlated with displacement analysis. CONCLUSIONS Image-based displacement analysis associated with CFD enabled very subtle evaluations of endograft behavior on different temporal scales. This kind of study could be helpful both for physicians, forecasting evolution during the life span of the endograft, and manufacturers, giving them useful information about endograft implant performance and design.
Collapse
Affiliation(s)
- Maurizio Domanin
- Department of Clinical Sciences and Community Health, Università di Milano, Milan, Italy; Unità Operativa di Chirurgia Vascolare, Fondazione I.R.C.C.S. Cà Granda Ospedale Maggiore Policlinico di Milano, Milan, Italy.
| | - Giulia Piazzoli
- MOX, Dipartimento di Matematica, Politecnico di Milano, Milan, Italy
| | - Santi Trimarchi
- Department of Clinical Sciences and Community Health, Università di Milano, Milan, Italy; Unità Operativa di Chirurgia Vascolare, Fondazione I.R.C.C.S. Cà Granda Ospedale Maggiore Policlinico di Milano, Milan, Italy
| | - Christian Vergara
- LABS, Dipartimento di Chimica, Materiali e Ingegneria Chimica, Politecnico di Milano, Milan, Italy
| |
Collapse
|
7
|
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]
|
8
|
Bilgi C, Atalık K. Numerical investigation of the effects of blood rheology and wall elasticity in abdominal aortic aneurysm under pulsatile flow conditions. Biorheology 2019; 56:51-71. [PMID: 31045509 DOI: 10.3233/bir-180202] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Previous studies on aneurysm modeling have focused on the blood rheology and vessel elasticity separately. The combined effects of blood shear thinning properties and wall elasticity need to be revealed. OBJECTIVE To provide insights on how pulsatile hemodynamics vary with blood rheology and vessel elasticity for a developed abdominal aortic aneurysm (AAA). METHOD An Arbitrary Lagrangian-Eulerian fluid-solid interaction method is adopted with the Newtonian and the shear thinning Carreau constitutive models for the fluid with the linearly elastic and the hyperelastic Yeoh models for the vessel. Finite element based numerical solver is used to simulate the blood flow in the AAA. RESULTS Newtonian model overestimates the velocity values compared to the Carreau model and the difference in the velocity field increases as the shear rate decreases at the instances of the cardiac cycle. The rigid walled simulations display higher deviations in the velocity and wall shear stress with the fluid rheology. The risk indicators show that Newtonian assumption combined with the linearly elastic model may overlook degeneration risk of arterial tissue. CONCLUSIONS Newtonian assumption for the blood as well as modelling the arterial wall as linearly elastic lead to significant differences in oscillatory hemodynamic properties with respect to the use of Carreau fluid together with hyperelastic vessel model, even in large vessel aneurysms.
Collapse
Affiliation(s)
- Coşkun Bilgi
- Mechanical Engineering Department, Boğaziçi University, Bebek, Istanbul, Turkey
| | - Kunt Atalık
- Mechanical Engineering Department, Boğaziçi University, Bebek, Istanbul, Turkey
| |
Collapse
|
9
|
Tasso P, Lodi Rizzini M, Raptis A, Matsagkas M, De Nisco G, Gallo D, Xenos M, Morbiducci U. In-stent graft helical flow intensity reduces the risk of migration after endovascular aortic repair. J Biomech 2019; 94:170-179. [PMID: 31421805 DOI: 10.1016/j.jbiomech.2019.07.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 07/25/2019] [Accepted: 07/27/2019] [Indexed: 10/26/2022]
Abstract
During the last years endovascular aneurysm repair (EVAR) became the elective treatment for abdominal aortic aneurysms (AAAs) thanks to lower mortality and morbidity rates than open surgery. In face of these advantages, stent-graft performances are still clinically suboptimal. In particular, post-surgical complications derive from device migration as a consequence of the hemodynamic forces acting on the endograft. In this regard, while the importance of hemodynamic surface forces is well recognized, the role of the in-stent flow is still unclear. Here we hypothesize that in-stent helical blood flow patterns might influence the distribution of the displacement forces (DFs) acting on the stent-graft and, ultimately, the risk of stent migration. To test this hypothesis, the hemodynamics of 20 post-EVAR models of patients treated with two different commercial endografts was analyzed using computational hemodynamics. The main findings of the study indicate that: (1) helical flow intensity decreases the risk of endograft migration, as given by an inverse correlation between helicity intensity (h2) and time-averaged displacement forces (TADFs) (p < 0.05); (2) unbalanced counter-rotating helical structures in the legs of the device contribute, in particular along the systole, to significantly suppress TADFs (p < 0.01); (3) as expected, helical flow intensity is positively correlated with pressure drop and resistance to flow (p < 0.001). The findings of this study suggest that a design strategy promoting in-stent helical flow structures could contribute to minimize the risk of migration of implanted EVAR devices.
Collapse
Affiliation(s)
- Paola Tasso
- Polito(BIO)Med Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Torino, Italy
| | - Maurizio Lodi Rizzini
- Polito(BIO)Med Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Torino, Italy
| | - Anastasios Raptis
- Laboratory for Vascular Simulations, Institute of Vascular Diseases, Larissa, Greece
| | - Mitialdis Matsagkas
- Department of Vascular Surgery, Faculty of Medicine, University of Thessaly, Larissa, Greece
| | - Giuseppe De Nisco
- Polito(BIO)Med Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Torino, Italy
| | - Diego Gallo
- Polito(BIO)Med Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Torino, Italy
| | - Michalis Xenos
- Department of Mathematics University of Ioannina, Ioannina, Greece
| | - Umberto Morbiducci
- Polito(BIO)Med Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Torino, Italy.
| |
Collapse
|
10
|
Xu H, Mei Y, Han X, Wei J, Watton PN, Jia W, Li A, Chen D, Xiong J. Optimization schemes for endovascular repair with parallel technique based on hemodynamic analyses. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2019; 35:e3197. [PMID: 30838798 DOI: 10.1002/cnm.3197] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 02/24/2019] [Accepted: 03/03/2019] [Indexed: 06/09/2023]
Abstract
Endovascular repair with parallel stent-grafts (SG) is a challenging technique that reconstructs the luminal flow pathways by implanting parallel-placed SGs into the vessel. After treatment, occlusion and shifting of the parallel SGs are sometimes reported, which could be fatal and difficult to be re-operated. These issues are highly related to the local hemodynamic conditions in the stented region. In this study, a patient case treated by the octopus endograft technique (a head-SG with three limb-SGs) and experienced limb-SG occlusion is studied. 3-D models are established based on computed tomography (CT) angiography datasets pretreatment and posttreatment as well as during follow-ups. Hemodynamic quantities such as pressure drop, wall shear stress-related parameters, and flow division in limb-SGs and visceral arteries are quantitatively investigated. Optimizations on the length of the head-SG and diameter of the limb-SGs are analyzed based on various scenarios. The results indicate that when reconstructing the flow pathways via octopus stenting, it is important to ensure the flow distribution as physiologically required with this new morphology. Position (or length) of the head-SG and diameter of the limb-SGs play an important role in controlling flow division, and high time average wall shear stress (TAWSS) around the head-SG acts as a main factor for graft immigration. This study, by proposing optimization suggestions with hemodynamic analyses for a specific case, implicates that pretreatment SG scenarios may assist in wise selection and placement of the device and thus may improve long-term effectiveness of this kind of challenging endovascular repair techniques.
Collapse
Affiliation(s)
- Huanming Xu
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Yuqian Mei
- Department of Computer Science and INSIGNEO Institute, University of Sheffield, Sheffield, UK
| | - Xiaofeng Han
- Department of Diagnostic and Interventional Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Jianyong Wei
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Paul N Watton
- Department of Computer Science and INSIGNEO Institute, University of Sheffield, Sheffield, UK
| | - Wan Jia
- Department of Vascular Surgery, The Second People's Hospital of Yunnan Province, Kunming, China
| | - Anqiang Li
- Department of Vascular Surgery, Gansu Provincial People's Hospital, Lanzhou, China
| | - Duanduan Chen
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Jiang Xiong
- Department of Vascular and Endovascular Surgery, Chinese PLA General Hospital, Beijing, China
| |
Collapse
|
11
|
Raptis A, Xenos M, Kouvelos G, Giannoukas A, Matsagkas M. Haemodynamic performance of AFX and Nellix endografts: a computational fluid dynamics study. Interact Cardiovasc Thorac Surg 2019; 26:826-833. [PMID: 29325136 DOI: 10.1093/icvts/ivx414] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 12/03/2017] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES The objective of this study is to analyse the flow conditions in the AFX and Nellix endografts (EGs) accounting for their postimplantation configuration in patients with an endovascular aneurysm repair-treated abdominal aortic aneurysm. METHODS We reconstructed post-endovascular aneurysm repair computed tomography scans of patients treated with an AFX or Nellix EG creating post-implantation EG models. We examined 16 patients, 8 in each group. The blood flow properties were obtained by computational fluid dynamics simulations and were subsequently compared with physiological infrarenal blood flow properties measured in 5 healthy subjects. Specifically, pressure drop, maximum velocity and wall shear stress were measured at peak systole and mean helicity at mid-diastole. RESULTS Our statistical analyses showed that the haemodynamic properties in both control regions did not vary statistically after the implantation of either the AFX or the Nellix EG, except for helicity that was significantly lower in the abdominal part of the Nellix EG compared with the expected physiological measurement. Regardless of the overall blood flow restoration, it is important to note that low pressure drop was detected along the limbs of the AFX and suppressed blood helical motion was detected at the entrance of the Nellix device. CONCLUSIONS It is observed from the results that the AFX EG has achieved absolute restoration of blood flow after endovascular aneurysm repair, although the development of secondary flow in the upper part of the EG and the low pressure drop in its limbs should be acknowledged. The Nellix EG also seems to be haemodynamically efficient. However, the suppression of helical flow before blood enters the device might raise concerns about its clinical application.
Collapse
Affiliation(s)
- Anastasios Raptis
- Laboratory for Vascular Simulations, Institute of Vascular Diseases, Ioannina, Greece
| | - Michalis Xenos
- Laboratory for Vascular Simulations, Institute of Vascular Diseases, Ioannina, Greece.,Department of Mathematics, University of Ioannina, Ioannina, Greece
| | - George Kouvelos
- Department of Vascular Surgery, Faculty of Medicine, University of Thessaly, Larissa, Greece
| | - Athanasios Giannoukas
- Laboratory for Vascular Simulations, Institute of Vascular Diseases, Ioannina, Greece.,Department of Vascular Surgery, Faculty of Medicine, University of Thessaly, Larissa, Greece
| | - Miltiadis Matsagkas
- Laboratory for Vascular Simulations, Institute of Vascular Diseases, Ioannina, Greece.,Department of Vascular Surgery, Faculty of Medicine, University of Thessaly, Larissa, Greece
| |
Collapse
|
12
|
Tasso P, Raptis A, Matsagkas M, Lodi Rizzini M, Gallo D, Xenos M, Morbiducci U. Abdominal aortic aneurysm endovascular repair: profiling post-implantation morphometry and hemodynamics with image-based computational fluid dynamics. J Biomech Eng 2018; 140:2682796. [PMID: 30029263 DOI: 10.1115/1.4040337] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Indexed: 11/08/2022]
Abstract
Endovascular aneurysm repair (EVAR) has disseminated rapidly as an alternative to open surgical repair for the treatment of abdominal aortic aneurysms (AAAs), because of its reduced invasiveness, low mortality and morbidity rate. The effectiveness of the endovascular devices used in EVAR is always at question as postoperative adverse events can lead to re-intervention or to a possible fatal scenario for the circulatory system. Motivated by the assessment of the risks related to thrombus formation, here the impact of two different commercial endovascular grafts on local hemodynamics is explored through 20 image-based computational hemodynamic models of EVAR-treated patients (N=10 per each endograft model). Hemodynamic features, susceptible to promote thrombus formation, such as flow separation and recirculation, are quantitatively assessed and compared with the local hemodynamics established in image-based infrarenal abdominal aortic models of healthy subjects (N=10). The hemodynamic analysis is complemented by a geometrical characterization of the EVAR-induced reshaping of the infrarenal abdominal aortic vascular region. The findings of this study indicate that: (1) the clinically observed propensity to thrombus formation in devices used in EVAR strategies can be explained in terms of local hemodynamics by means of image-based computational hemodynamics approach; (2) reportedly pro-thrombotic hemodynamic structures are strongly correlated with the geometry of the aortoiliac tract postoperatively. In perspective, our study suggests that future clinical follow up studies could include a geometric analysis of the region of the implant, monitoring shape variations that can lead to hemodynamic disturbances of clinical significance.
Collapse
Affiliation(s)
- Paola Tasso
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Torino 10129, Italy
| | - Anastasios Raptis
- Laboratory for Vascular Simulations, Institute of Vascular Diseases, Ioannina 45500, Greece
| | - Miltiadis Matsagkas
- Department of Vascular Surgery, Faculty of Medicine, University of Thessaly, Larissa 41334, Greece
| | - Maurizio Lodi Rizzini
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Torino 10129, Italy
| | - Diego Gallo
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Torino 10129, Italy
| | - Michalis Xenos
- Department of Mathematics, University of Ioannina, Ioannina 45500, Greece
| | - Umberto Morbiducci
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Torino 10129, Italy
| |
Collapse
|
13
|
Georgakarakos E, Kratimenos T, Koutsoumpelis A, Georgiadis GS. The Bolton Treo endograft for treatment of abdominal aortic aneurysms: just another trimodular platform? Expert Rev Med Devices 2017; 15:5-14. [DOI: 10.1080/17434440.2018.1419864] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Efstratios Georgakarakos
- Department of Vascular Surgery, Democritus University of Thrace, Alexandroupolis, Greece
- Department of Vascular Surgery, University Hospital of Alexandroupolis, Alexandroupolis, Greece
| | - Theodoros Kratimenos
- Department of Interventional Radiology, Evangelismos General Hospital of Athens, Athens, Greece
| | - Andreas Koutsoumpelis
- Department of Vascular Surgery, University Hospital of Alexandroupolis, Alexandroupolis, Greece
| | - George S. Georgiadis
- Department of Vascular Surgery, Democritus University of Thrace, Alexandroupolis, Greece
- Department of Vascular Surgery, University Hospital of Alexandroupolis, Alexandroupolis, Greece
| |
Collapse
|
14
|
Raptis A, Xenos M, Georgakarakos E, Kouvelos G, Giannoukas A, Matsagkas M. Hemodynamic Profile of Two Aortic Endografts Accounting for Their Postimplantation Position. J Med Device 2017. [DOI: 10.1115/1.4035687] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Endovascular aneurysm repair (EVAR) is a clinically effective technique for treating anatomically eligible abdominal aortic aneurysms (AAAs), involving the deployment of an endograft (EG) that is designed to prevent blood leakage in the aneurysmal sac. While most EGs have equivalent operating principles, the hemodynamic environment established by different EGs is not necessarily the same. So, to unveil the post-EVAR hemodynamic properties, we need an EG-specific computational approach that currently lacks from the literature. Endurant and Excluder are two EGs with similar pre-installation designs. We assumed that the flow conditions in the particular EGs do not vary significantly. The hypothesis was tested combining image reconstructions, computational fluid dynamics (CFD), and statistics, taking into account the postimplantation position of the EGs. Ten patients with Endurant EGs and ten patients with Excluder EGs were included in this study. The two groups were matched with respect to the preoperative morphological characteristics of the AAAs. The EG models are derived from image reconstructions of postoperative computed tomography scans. Wall shear stress (WSS), displacement force, velocity, and helicity were calculated in regions of interest within the EG structures, i.e., the main body, the upper and lower part of the limbs. Excluder generated higher WSS compared to Endurant, especially on the lower part of the limbs (p = 0.001). Spatial fluctuations of WSS were observed on the upper part of the Excluder limbs. Higher blood velocity was induced by Excluder in all the regions of interest (p = 0.04, p = 0.01, and p = 0.004). Focal points of secondary flow were detected in the main body of Endurant and the limbs of Excluder. The displacement force acting on the lower part of the Excluder limbs was stronger compared to the Endurant one (p = 0.03). The results showed that two similar EGs implanted in similar AAAs can induce significantly different flow properties. The delineation of the hemodynamic features associated with the various commercially available EGs could further promote the personalization of treatment offered to aneurysmal patients and inspire ideas for the improvement of EG designs in the future.
Collapse
Affiliation(s)
- Anastasios Raptis
- Cardiovascular Surgery Department, Sector of Surgery, Faculty of Medicine, School of Health Sciences, University of Ioannina, Ioannina 45500, Greece
- Laboratory for Vascular Simulations, Institute of Vascular Diseases, Ioannina 45500, Greece e-mails:
| | - Michalis Xenos
- Department of Mathematics, University of Ioannina, Ioannina 45500, Greece
- Laboratory for Vascular Simulations, Institute of Vascular Diseases, Ioannina 45500, Greece e-mail:
| | - Efstratios Georgakarakos
- Department of Vascular Surgery, “Democritus” Medical School, University Hospital of Alexandroupolis, Alexandroupolis 68100, Greece e-mail:
| | - George Kouvelos
- Department of Vascular Surgery, Faculty of Medicine, University of Thessaly, Larissa 41334, Greece e-mail:
| | - Athanasios Giannoukas
- Department of Vascular Surgery, Faculty of Medicine, University of Thessaly, Larissa 41334, Greece
- Laboratory for Vascular Simulations, Institute of Vascular Diseases, Ioannina 45500, Greece e-mail:
| | - Miltiadis Matsagkas
- Department of Vascular Surgery, Faculty of Medicine, University of Thessaly, Larissa 41334, Greece
- Laboratory for Vascular Simulations, Institute of Vascular Diseases, Ioannina 45500, Greece e-mails:
| |
Collapse
|