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Xie Y, Zhu Y, Shi Y, Zhao Y, Zhang H, Li F, Song H, Chen L, Guo W. Impact of Cross-Limb Stent-Graft Configuration on Hemodynamics in Abdominal Aortic Aneurysm Interventional Therapy. Cardiovasc Eng Technol 2024; 15:137-146. [PMID: 37985614 DOI: 10.1007/s13239-023-00702-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Accepted: 11/07/2023] [Indexed: 11/22/2023]
Abstract
PURPOSE The cross-limb (CL) technique is a commonly used endovascular treatment for addressing unfavorable anatomical features in patients with abdominal aortic aneurysm (AAA). The configuration of CL stent-graft plays a critical role in determining the postoperative hemodynamic properties and physiological behaviors, which ultimately impact the efficacy and safety of endovascular AAA treatment. This study aims to investigate the relationship between hemodynamics and CL stent-graft configuration from a hemodynamic perspective. METHODS Five distinct geometric models of cross-limb (CL) stent-graft configurations were constructed by optimizing the real clinical computed tomography angiography (CTA) data. These models varied in main body lengths and cross angles and were used to perform numerical simulations to analyze various hemodynamic parameters. Flow pattern, distribution of wall shear stress (WSS)-related parameters, localized normalized helicity (LNH), pressure drop, and the displacement force of all models were examined in this paper. RESULTS In patient-specific cases, helical flow and WSS increase with the main body. However, it also generated secondary flow in localized areas, leading to increased oscillation in the WSS direction. Notably, increasing the stent graft's main body length or decreasing the cross angle reduced the displacement force exerted on the stent-graft. Reducing the cross angle did not significantly alter the hemodynamic characteristics. CONCLUSION In the clinical practice of CL deployment, it is crucial to carefully consider the stent-graft configuration and the patient specific to achieve optimal postoperative outcomes. This study provides valuable insights for guiding stent selection and treatment planning in patients with abdominal aortic aneurysm undergoing CL techniques, from a hemodynamic perspective.
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Affiliation(s)
- Yanqing Xie
- Department of Cardiology, The First Affiliated Hospital of Ningbo University, Ningbo, 315020, China
| | - Yating Zhu
- Department of Vascular Surgery, First Medical Center of Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China
| | - Yike Shi
- College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, 030024, China
| | - Yawei Zhao
- College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, 030024, China
| | - Hongpeng Zhang
- Department of Vascular Surgery, First Medical Center of Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China
| | - Fen Li
- College of Mechanical and Vehicle Engineering, Taiyuan University of Technology, 79 West Yingze Street, Taiyuan, 030024, China.
| | - Hui Song
- College of Mechanical and Vehicle Engineering, Taiyuan University of Technology, 79 West Yingze Street, Taiyuan, 030024, China
| | - Lingfeng Chen
- College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, 030024, China
| | - Wei Guo
- Department of Vascular Surgery, First Medical Center of Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, China.
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Bontinis V, Antonopoulos CN, Bontinis A, Sfyroeras GS, Kontopodis N, Ioannou CV, Ktenidis K, Geroulakos G. A systematic review and meta-analysis of the streamliner multilayer flow modulator stent for treatment of complex aortic lesions. J Vasc Surg 2021; 74:646-656.e9. [PMID: 34019986 DOI: 10.1016/j.jvs.2021.03.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Accepted: 03/14/2021] [Indexed: 11/24/2022]
Abstract
OBJECTIVE We evaluated the safety and efficacy of multilayer flow modulator (MFM) stents (Cardiatis, Isnes, Belgium) for the treatment of complex aortic lesions. METHODS A systematic electronic research was conducted for studies reported from December 2008 to May 2020. Data extracted from 15 eligible case series (CS) were appropriately pooled and analyzed in a meta-analysis. The patient baseline characteristics were recorded, and 16 outcomes of interest were studied. The primary end points included 30-day all-cause and aneurysm-related mortality, aneurysm-related mortality at 1 year, vessel patency, and any endoleaks, ruptures, reinterventions, and aneurysm exclusion at the end of follow-up. RESULTS A total of 39 studies (15 CS and 24 case reports), involving 429 patients, met the inclusion criteria. Overall, 436 lesions were treated, and 1521 aortic branches were covered by the multilayer stent. The mean follow-up for the 15 CS with 404 patients was 14.6 months. Compliance with the instructions for use was reported by eight CS, with 75% of the procedures performed within the instructions for use. However, 41% of the patients reported by 12 CS had undergone a previous aortic intervention. The pooled 30-day all-cause and 30-day aneurysm-related mortality rates were 0.56% (95% confidence interval [CI], 0.00%-2.54%) and 0.00% (95% CI, 0.00%-0.80%), respectively. The pooled aneurysm-related mortality at 1 year of follow-up was 5.25% (95% CI, 0.07%-14.91%). The pooled vessel patency at the end of follow-up was 99.12% (95% CI, 97.73%-99.93%). The pooled reintervention and endoleak rates at the end of follow-up were 10.94% (95% CI, 3.64%-20.67%) and 10.70% (95% CI, 4.45%-18.66%), respectively. The crude spinal cord ischemia and renal failure rates were 0.69% and 1.8%, respectively. CONCLUSIONS The results from the present review and meta-analysis have indicated the safety and efficacy of MFM stents for treating challenging aortic pathologic lesions when used as first-line treatment and within the instructions for use. The almost zero pooled 30-day all-cause and aneurysm-related mortality rates combined with the low crude spinal cord ischemia and renal failure rates indicate the use of MFM stents is a good treatment option for complex aortic lesions in the short- and mid-term periods. The lack of long-term follow-up warrants further research concerning the efficacy of the device in the long term.
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Affiliation(s)
- Vangelis Bontinis
- Department of Vascular Surgery, Aristotle University of Thessaloniki, AHEPA University General Hospital, Thessaloniki, Greece.
| | - Constantine N Antonopoulos
- Department of Vascular Surgery, National and Kapodistrian University of Athens, Attikon University Hospital, Athens, Greece
| | - Alkis Bontinis
- Department of Vascular Surgery, Aristotle University of Thessaloniki, AHEPA University General Hospital, Thessaloniki, Greece
| | - George S Sfyroeras
- Department of Vascular Surgery, National and Kapodistrian University of Athens, Attikon University Hospital, Athens, Greece
| | - Nikolaos Kontopodis
- Vascular Surgery Unit, Department of Cardiothoracic and Vascular Surgery, University Hospital Heraklion, University of Crete Medical School, Heraklion, Greece
| | - Christos V Ioannou
- Vascular Surgery Unit, Department of Cardiothoracic and Vascular Surgery, University Hospital Heraklion, University of Crete Medical School, Heraklion, Greece
| | - Kiriakos Ktenidis
- Department of Vascular Surgery, Aristotle University of Thessaloniki, AHEPA University General Hospital, Thessaloniki, Greece
| | - George Geroulakos
- Department of Vascular Surgery, National and Kapodistrian University of Athens, Attikon University Hospital, Athens, Greece
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Mei Y, Xu H, Ma W, Li Z, Yang R, Yuan H, Peng Y, Wu M, Chen Z, Guo W, Gao T, Xiong J, Chen D. Retrograde branched extension limb assembling stent of pararenal abdominal aortic aneurysm: A longitudinal hemodynamic analysis for stent graft migration. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2020; 36:e3394. [PMID: 32790046 DOI: 10.1002/cnm.3394] [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: 08/14/2019] [Revised: 03/31/2020] [Accepted: 08/02/2020] [Indexed: 06/11/2023]
Abstract
PURPOSE Pararenal abdominal aortic aneurysms (PRAAAs) are a life-threatening disease, and hemodynamic analysis may provide greater insight into the effectiveness and long-term outcomes of endovascular aneurysm repair (EVAR). However, the lack of patient-specific boundary conditions on the periphery compromises the accuracy. Windkessel (WK) boundary conditions coupled to hemodynamic follow-up models of a PRAAA patient, aims to provide insights into the link between hemodynamics and poor prognosis. METHOD One PRAAA patient underwent EVAR and reintervention after one branch of stent-graft (SG) had migrated. Totally five computational follow-up models were studied. Patient-specific flow data acquired via ultrasound were used to define the boundary conditions in the ascending aorta and the following three branches. Coupled zero-dimensional WK models representing the distal vasculature were used to define the outlet boundary conditions under the abdomen. RESULTS Flow divisions of the main SG branches were 40.7% and 24.7%, respectively. Time-averaged wall shear stress and oscillatory shear index (OSI) increased at the junction connected the SG branch and the stent leading to the right common iliac artery (RCIA) where the stent migrated. The OSI and relative residence time (RRT) value in superior mesenteric artery increased notably after the migration, the RRT continuously increased following the reintervention. CONCLUSION Unbalanced flow, resulting in locally high-speed flow, high WSS and OSI might significantly affect stent stability. Results suggest that diameters and interconnection design of stents in complex cases should take the flow division into consideration and computational simulations might be considered as a tool for intervention protocol design.
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Affiliation(s)
- Yuqian Mei
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Huanming Xu
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Wei Ma
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Zhenfeng Li
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Rui Yang
- Department of Vascular and Endovascular Surgery, Chinese PLA General Hospital, Beijing, China
| | - Hai Yuan
- Department of Vascular Surgery, Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Yan Peng
- Beijing CapitalBio Technology Corporation, Beijing, China
| | - Muyang Wu
- Department of Health Science Newark, University of Delaware, Newark, Delaware, USA
| | - Zhangtao Chen
- Department of Biomedical Engineering, Pennsylvania State University, State College, Pennsylvania, USA
| | - Wei Guo
- Department of Vascular and Endovascular Surgery, Chinese PLA General Hospital, Beijing, China
| | - Tianxin Gao
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Jiang Xiong
- Department of Vascular and Endovascular Surgery, Chinese PLA General Hospital, Beijing, China
| | - Duanduan Chen
- School of Life Science, Beijing Institute of Technology, Beijing, China
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Georgakarakos E, Gasser TC, Xenos M, Kontopodis N, Georgiadis GS, Ioannou CV. Applying findings of computational studies in vascular clinical practice: fact, fiction, or misunderstanding? J Endovasc Ther 2015; 21:434-8. [PMID: 24915594 DOI: 10.1583/14-4718e.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Efstratios Georgakarakos
- 1 Department of Vascular Surgery, "Democritus" University of Thrace, University Hospital of Alexandroupolis, Greece
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De Bock S, Iannaccone F, De Beule M, Vermassen F, Segers P, Verhegghe B. What if you stretch the IFU? A mechanical insight into stent graft Instructions For Use in angulated proximal aneurysm necks. Med Eng Phys 2014; 36:1567-76. [DOI: 10.1016/j.medengphy.2014.08.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 07/23/2014] [Accepted: 08/10/2014] [Indexed: 10/24/2022]
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Georgakarakos E, Argyriou C, Schoretsanitis N, Ioannou CV, Kontopodis N, Morgan R, Tsetis D. Geometrical Factors Influencing the Hemodynamic Behavior of the AAA Stent Grafts: Essentials for the Clinician. Cardiovasc Intervent Radiol 2014; 37:1420-9. [DOI: 10.1007/s00270-014-0927-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 04/27/2014] [Indexed: 11/29/2022]
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Georgakarakos E, Xenakis A, Manopoulos C, Georgiadis GS, Tsangaris S, Lazarides M. Geometric Factors Affecting the Displacement Forces in an Aortic Endograft With Crossed Limbs: A Computational Study. J Endovasc Ther 2013; 20:191-9. [DOI: 10.1583/1545-1550-20.2.191] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Krsmanovic D, Koncar I, Petrovic D, Milasinovic D, Davidovic L, Filipovic N. Computer modelling of maximal displacement forces in endoluminal thoracic aortic stent graft. Comput Methods Biomech Biomed Engin 2012; 17:1012-20. [DOI: 10.1080/10255842.2012.735661] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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9
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Virtual evaluation of stent graft deployment: A validated modeling and simulation study. J Mech Behav Biomed Mater 2012; 13:129-39. [DOI: 10.1016/j.jmbbm.2012.04.021] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Revised: 04/27/2012] [Accepted: 04/28/2012] [Indexed: 11/20/2022]
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10
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Georgakarakos E, Xenakis A, Manopoulos C, Georgiadis GS, Tsangaris S, Lazarides MK. Modeling and Computational Analysis of the Hemodynamic Effects of Crossing the Limbs in an Aortic Endograft (“Ballerina” Position). J Endovasc Ther 2012; 19:549-57. [DOI: 10.1583/12-3820.1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Wang X, Li X. Fluid-structure interaction based study on the physiological factors affecting the behaviors of stented and non-stented thoracic aortic aneurysms. J Biomech 2011; 44:2177-84. [DOI: 10.1016/j.jbiomech.2011.06.020] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 06/13/2011] [Accepted: 06/15/2011] [Indexed: 11/25/2022]
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12
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Scherer S, Treichel T, Ritter N, Triebel G, Drossel WG, Burgert O. Surgical stent planning: simulation parameter study for models based on DICOM standards. Int J Comput Assist Radiol Surg 2010; 6:319-27. [DOI: 10.1007/s11548-010-0511-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Accepted: 06/19/2010] [Indexed: 11/28/2022]
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13
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Conway BD, Greenberg RK, Mastracci TM, Hernandez AV, Coscas R. Renal Artery Implantation Angles in Thoracoabdominal Aneurysms and Their Implications in the Era of Branched Endografts. J Endovasc Ther 2010; 17:380-7. [DOI: 10.1583/10-3038.1] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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14
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Zipfel B, Buz S, Düsterhöft V, Hetzer R. Initial Experience With Abdominal Aneurysm Repair Using the E-vita Abdominal Stent-Graft:A Single-Center Study. J Endovasc Ther 2009; 16:577-89. [DOI: 10.1583/09-2824.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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15
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Chuter TAM. Durability of endovascular infrarenal aneurysm repair: when does late failure occur and why? Semin Vasc Surg 2009; 22:102-10. [PMID: 19573750 DOI: 10.1053/j.semvascsurg.2009.04.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The first commercially available stent grafts were unable to withstand the hemodynamic forces of the vascular environment. The past 15 years have seen a gradual improvement in long-term stent graft performance as designs evolved through the elimination of features associated with late failure and the replication of features associated with durable success. Clinical experience provides the following principles on which to base device design and implantation techniques. Few patients have an adequate length of non-dilated aorta distal to the aneurysm to allow implantation of an aorto-aortic stent graft; bifurcated stent grafts are usually required for AAA repair. Friction, column strength and tissue ingrowth do not prevent migration of the stent graft from its attachment within the neck into the aneurysm; some form of active fixation is required, usually in the form of barbs. Any movement between the apex of a stent and the overlying graft material will erode the fabric; stents and grafts need to move as a single unit. Nitinol is versatile, but fragile; Nitinol components must be polished to eliminate all surface irregularities and they cannot be subjected to compression loading, or excessive pulsatile movement. The neck of an aneurysm is unstable; it will dilate unless protected by a securely fixed, non-compliant stent graft. The aneurysm does not heal; freedom from risk of rupture depends on durable depressurization of the sac. The sole objective of image-based follow-up is the early detection, and catheter-based correction, of device failure. Once any given design has been in use long enough to identify its failure modes, the frequency of follow-up studies can be adjusted accordingly. However, it takes a long time to identify all the potential forms of late failure, and pre-clinical testing remains an imprecise science. New, or recently modified, devices cannot necessarily be assumed to be as durable as their predecessors.
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Affiliation(s)
- Timothy A M Chuter
- Division of Vascular Surgery, University of California San Francisco, San Francisco, CA 94143, USA.
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Zarins CK, Taylor CA. Endovascular device design in the future: transformation from trial and error to computational design. J Endovasc Ther 2009; 16 Suppl 1:I12-21. [PMID: 19317584 DOI: 10.1583/08-2640.1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Endovascular devices have been designed by trial and error, with bench and animal testing followed by human clinical trials to determine whether the devices are safe and effective. Despite remarkable advances over the past 15 years, there are persistent concerns regarding the long-term durability of endovascular devices. This may be due to deficiencies in device design, which has lagged behind other industries in adopting computational methods that are now routinely used to design, develop, and test new aircraft and automobiles. Similar computational design and failure mode simulations that evaluate performance under stress conditions have not been widely applied in the development of endovascular devices. Advances in medical imaging and computational modeling now allow simulation of physiological conditions in patient-specific 3-dimensional vascular models, which can provide a framework to design and test the next generation of endovascular devices. This modeling will allow the prospective design of devices that can withstand the force variations in the cardiovascular system that occur during bending, coughing, and varying degrees of exercise, as well as the extremes encountered during sudden impact in contact sports. Utilization of computational design methodology that takes into consideration the physiology of the cardiovascular system will improve future endovascular devices so that they are safer and more effective and durable.
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Affiliation(s)
- Christopher K Zarins
- Stanford University School of Medicine and School of Engineering, Stanford, California, USA.
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17
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Analysis of blood flow behaviour in custom stent grafts. J Biomech 2009; 42:1754-61. [DOI: 10.1016/j.jbiomech.2009.03.053] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Revised: 03/25/2009] [Accepted: 03/25/2009] [Indexed: 11/21/2022]
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Corbett TJ, Callanan A, Morris LG, Doyle BJ, Grace PA, Kavanagh EG, McGloughlin TM. A review of the in vivo and in vitro biomechanical behavior and performance of postoperative abdominal aortic aneurysms and implanted stent-grafts. J Endovasc Ther 2008; 15:468-84. [PMID: 18729555 DOI: 10.1583/08-2370.1] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Endovascular repair of abdominal aortic aneurysms has generated widespread interest since the procedure was first introduced two decades ago. It is frequently performed in patients who suffer from substantial comorbidities that may render them unsuitable for traditional open surgical repair. Although this minimally invasive technique substantially reduces operative risk, recovery time, and anesthesia usage in these patients, the endovascular method has been prone to a number of failure mechanisms not encountered with the open surgical method. Based on long-term results of second- and third-generation devices that are currently becoming available, this study sought to identify the most serious failure mechanisms, which may have a starting point in the morphological changes in the aneurysm and stent-graft. To investigate the "behavior" of the aneurysm after stent-graft repair, i.e., how its length, angulation, and diameter change, we utilized state-of-the-art ex vivo methods, which researchers worldwide are now using to recreate these failure modes.
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Affiliation(s)
- Timothy J Corbett
- Centre for Applied Biomedical Engineering Research, MSSI, Department of Mechanical and Aeronautical Engineering, University of Limerick, Ireland
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Fung GS, Lam S, Cheng SW, Chow K. On stent-graft models in thoracic aortic endovascular repair: A computational investigation of the hemodynamic factors. Comput Biol Med 2008; 38:484-9. [DOI: 10.1016/j.compbiomed.2008.01.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2007] [Accepted: 01/21/2008] [Indexed: 10/22/2022]
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Ziegler P, Avgerinos ED, Umscheid T, Perdikides T, Stelter WJ. Fenestrated Endografting for Aortic Aneurysm Repair:A 7-Year Experience. J Endovasc Ther 2007. [DOI: 10.1583/1545-1550(2007)14[609:fefaar]2.0.co;2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Kleinstreuer C, Li Z, Farber MA. Fluid-Structure Interaction Analyses of Stented Abdominal Aortic Aneurysms. Annu Rev Biomed Eng 2007; 9:169-204. [PMID: 17362195 DOI: 10.1146/annurev.bioeng.9.060906.151853] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Rupture of abdominal aortic aneurysms (AAAs) alone is the thirteenth leading cause of death in the United States. Thus, reliable AAA-rupture risk prediction is an important advancement. If repair becomes necessary, the minimally invasive technique of inserting a stent-graft (SG), commonly referred to as endovascular aneurysm repair (EVAR), is a viable option in many cases. However, postoperative complications, such as endoleaks and/or SG migration, may occur. Computational fluid-structure interaction simulations provide physical insight into the hemodynamics coupled with multi-wall mechanics' function as an assessment tool for optimal SG placement and improved device design.
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Affiliation(s)
- C Kleinstreuer
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA.
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Howell BA, Kim T, Cheer A, Dwyer H, Saloner D, Chuter TAM. Computational Fluid Dynamics Within Bifurcated Abdominal Aortic Stent-Grafts. J Endovasc Ther 2007. [DOI: 10.1583/1545-1550(2007)14[138:cfdwba]2.0.co;2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Zhou SSN, How TV, Vallabhaneni SR, Gilling-Smith GL, Brennan JA, Harris PL, McWilliams R. Comparison of the Fixation Strength of Standard and Fenestrated Stent-Grafts for Endovascular Abdominal Aortic Aneurysm Repair. J Endovasc Ther 2007. [DOI: 10.1583/1545-1550(2007)14[168:cotfso]2.0.co;2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Goodman M, Lawrence-Brown MMD, Hartley D, Allen YB, Semmens JB. Treatment of Infrarenal Abdominal Aortic Aneurysms With Oversized (36-mm) Zenith Endografts. J Endovasc Ther 2007; 14:23-9. [PMID: 17291145 DOI: 10.1583/06-1918.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE To evaluate the outcome of treating infrarenal abdominal aortic aneurysms with unfavorable necks using the 36-mm Zenith endograft. METHODS The indication for use of the 36-mm endograft for infrarenal aortic aneurysm was a minimum 20-mm-long sealing zone and a diameter >28 mm at any point but <34 mm, varying more than 3 mm in contour. A series of 67 patients (64 men; mean age 76.2 years, range 59.5 to 88.3) who had been treated with the 36-mm endografts between June 1999 and February 2004 were assessed for medium-term outcomes. The patients were identified from the device planning records. Follow-up was carried out using chart review and direct patient contact. The indication for use of the endograft was checked with the aneurysm neck profile from the original planning diagrams. Cause of death was ascertained from the treating clinician, the medical record, or the State Death Registry. Outcome endpoints were proximal type I and type III endoleaks, migration, sac size change, and death. RESULTS The mean diameter of the sealing zone was 31.9+/-1.6 mm within the 20-mm segment from the lowest renal artery. Stent-graft delivery was achieved in all 67 patients. Two (3%) patients died within 30 days from non-graft-related cardiorespiratory causes. Proximal type I endoleaks were identified in 3 (4.5%) patients: 2 during deployment and another at 9 days. The mean follow-up period for the 65 patients who survived 30 days was 26.9+/-12.6 months (range 2-66). Migration occurred in 1 patient with development of a type III endoleak and sac reperfusion due to separation of the graft body from the bare anchor stent owing to suture breakage. Forty-seven patients were alive at the last review. The aneurysm sac had contracted or was unchanged in 45 (96%) cases. Minor enlargements of the sac were observed in 2 patients. The re-intervention rate was 16.4% (11 patients). There was 1 conversion to open repair to treat perigraft sepsis. The aneurysm- and procedure-related mortality was 4.5%; no patient experienced rupture. All-cause mortality was 29.9% (20/67). CONCLUSION Large caliber endografts such as the Zenith 36-mm are an alternative option to open surgery or fenestrated endografting for some infrarenal aneurysms.
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Affiliation(s)
- Marcel Goodman
- Department of Vascular Surgery, Mount Hospital, Perth, Western Australia
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Abstract
PURPOSE To report the recanalization of an occluded common iliac artery (CIA) to allow endovascular repair of an abdominal aortic aneurysm (AAA) with a bifurcated stent-graft. CASE REPORT A 76-year-old man with a 75-mm infrarenal AAA and an occluded right CIA was successfully treated with a Zenith bifurcated stent-graft. The right CIA was recanalized allowing access, delivery, and deployment of the stent-graft. Follow-up computed tomography at 9 months showed no evidence of endoleak; maximum aneurysm diameter was reduced to 72 mm, and the iliac vessels were patent. CONCLUSION Bifurcated stent-graft repair of an AAA can be performed following recanalization of an occluded CIA. This option may be preferable to an open repair or an aortomonoiliac stent-graft with extra-anatomical bypass in some patients. Long-term surveillance will be necessary to ensure freedom from iliac-related secondary intervention.
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Affiliation(s)
- James Scurr
- Regional Vascular Unit, Royal Liverpool University Hospital, Liverpool, UK
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Greenberg RK. Aortic Aneurysm, Thoracoabdominal Aneurysm, Juxtarenal Aneurysm, Fenestrated Endografts, Branched Endografts, and Endovascular Aneurysm Repair. Ann N Y Acad Sci 2006; 1085:187-96. [PMID: 17182935 DOI: 10.1196/annals.1383.038] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The development of endovascular devices to treat aneurysms that abut or involve the visceral vessels has occurred in an effort to reduce the significant procedural morbidity and mortality associated with conventional repair. To accomplish this, three systems have been trialed. The first technique was developed to treat juxtarenal aneurysms and involves the placement of customized fenestrations strategically placed within the fabric of the graft. These are aligned with the ostia of the visceral vessels incorporated by the repair and supplemented by the placement of a balloon expandable stent. In a similar fashion, aneurysms that involve the visceral vessels can be treated with a fenestrated graft where the fenestration is reinforced with a nitinol ring. This is then mated with a balloon-expandable stentgraft, allowing the devices to seal at the level of the nitinol ring. An alternative means of incorporating the visceral vessels is to use directional branches where one or more additional limbs (typically 8 mm) are anastomosed to the aortic graft, through which access into the visceral vessel is attained. Mating stentgrafts for the later design can be of a self-expanding or balloon expandable nature. The experience with fenestrated devices is mature and associated with a low perioperative mortality (<2%) without many long-term complications. The treatment of thoracoabdominal aneurysms with branches has provided us with optimism regarding the technique, but results are only short term in nature. Further device development is ongoing and dissemination of this technology is now occurring in Europe, Australia and Canada.
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Affiliation(s)
- Roy K Greenberg
- Department of Vascular Surgery, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
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Semmens JB, Lawrence-Brown MMD, Hartley DE, Allen YB, Green R, Nadkarni S. Outcomes of Fenestrated Endografts in the Treatment of Abdominal Aortic Aneurysm in Western Australia (1997–2004). J Endovasc Ther 2006; 13:320-9. [PMID: 16784319 DOI: 10.1583/05-1686.1] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
PURPOSE To describe a 7-year experience with abdominal aortic aneurysm (AAA) repair using fenestrated Zenith endovascular endografts. METHODS Six endovascular surgeons from 7 medical centers in Perth, Western Australia, contributed data to this retrospective study of 58 AAA patients (51 men; mean age 75.5+/-8.5 years, range 60-94) treated with fenestrated endografts. Fenestrations were applied to 116 target vessels; more than half of patients had >/=2 target vessels. The results were based on satisfactory deployment of the stent-graft and fenestrations (technical success), technical success and no complications (procedural success), and aneurysm exclusion with no endoleak, rupture, unresolved complications, or dialysis (treatment success). RESULTS Technical success was 82.8% for patients (90.5% for target vessels), procedural success was 74.1%, and treatment success was 94.8%. There were no cases of conversion or rupture. The 30-day mortality rate was 3.4% (n=2). Over a mean follow-up of 1.4+/-1.2 years, 10 (17.2%) patients experienced loss of a target vessel (9.5% of target vessels). Factors associated with target vessel loss were no stent, >60 degrees neck angulation, multiple renal vessels, and vessel diameter </=4 mm. Four (6.9%) patients developed renal impairment, but none required dialysis. Fourteen (24.1%) patients had a secondary intervention. Unresolved endoleaks persisted in 1 (1.7%) patient. CONCLUSION Fenestrated endografts extend the treatment options for infrarenal AAAs with necks unsuitable for standard endovascular repair. This early data show a trend toward higher mortality of selected patients with fenestrated endografts than for standard stent-graft repair, but the mortality rate is comparable to open repair. Target vessel occlusion predominantly results from pre-existing disease or the lack of a stent. The lessons learned from this experience contributed toward guidelines for users of fenestrated endografts.
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Affiliation(s)
- James B Semmens
- Centre for Health Services Research, School of Population Health, The University of Western Australia, Nedlands, WA, Australia.
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Liffman K, Sutalo ID, Lawrence-Brown MMD, Semmens JB, Aldham B. Movement and Dislocation of Modular Stent-Grafts Due to Pulsatile Flow and the Pressure Difference Between the Stent-Graft and the Aneurysm Sac. J Endovasc Ther 2006; 13:51-61. [PMID: 16445324 DOI: 10.1583/05-1699.1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE To investigate the stability and movement of modular aortic stent-grafts subjected to oscillating forces from pulsatile blood flow, with particular reference to the thoracic aorta. METHODS Analytical mathematical modeling was used to understand the forces on modular grafts. In a benchtop experiment, a transparent acrylic box was filled with water to mimic an aneurysm. Two stent-grafts were placed inside the box in a nested, arched configuration where one component was partly inside the other. A pump produced a pulsatile approximately 5-L/min flow of water through the stent-grafts at a mean inlet pressure of approximately 100 mmHg (approximately 13,330 Pa), with systolic and diastolic pressures of approximately 130 and approximately 80 mmHg, respectively (pulse pressure 50 mmHg). The movement of the 2 modular stent-grafts was observed. RESULTS The curved stent-graft system oscillated transversely when there was zero mean pressure difference between the stent-graft and the aneurysm. As the mean pressure difference was increased, this transverse graft movement was damped and then disappeared. A relatively large pressure difference caused the stent-graft to inflate and become sturdier. In terms of stability, the analytical mathematical model for a 30-mm-diameter Zenith modular stent-graft curved through 90 degrees (with the ends of the graft fixed in place) showed that the modular components will separate at a pressure difference of 0 mmHg for 1 stent segment overlap (20 mm) and at an average 59 mmHg pressure difference for 2 stent overlaps, but the device would not separate at a pressure difference of 90 mmHg for 3 stent overlaps. CONCLUSION Transverse cyclic movement of the curved stent-graft system with pulsation indicates a pressurized sac. When the pressure difference is large and there is a blood-tight seal between the aneurysm and the stent-graft, then the transverse movement of the stent-graft is minimal, but the risk for modular separation is highest. Curved thoracic endografts are subject to forces that may cause migration or separation, the latter being more likely if the seal between the graft and the sac is blood tight, if the blood pressure is high, and if the diameter of the graft is small and the sac large. Operators should plan for maximum overlap of modular components when treating large or long thoracic aneurysms.
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Affiliation(s)
- Kurt Liffman
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Manufacturing and Infrastructure Technology, Highett, Victoria, Australia.
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Hinchliffe RJ, Natarajan S, Hopkinson BR. In Vitro Analysis of Modular Aortic Stent-Graft Failure. J Endovasc Ther 2006; 13:77-84. [PMID: 16445327 DOI: 10.1583/05-1622.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE To investigate the theoretical forces involved in and the nature of fixation between the modular components of a variety of aortic stent-grafts. METHODS An in vitro study of 6 aortic stent-grafts was performed using a tensometer. The modular stent-graft components were distracted until the iliac limb was completely separated from the main body. Tests were repeated at least 6 times for each stent-graft. RESULTS The maximum pullout force was 36.0 N using the Fortron stent-graft, which resulted in stent-graft disintegration. The maximum median forces of the other stent-grafts were 23.7 N (19.9-31.2) for the Aorfix, 7.3 N (6.9-7.6) for the AneuRx, 7.0 N (6.8-7.1) for the Zenith BiFab, 5.4 N (5.0-6.5) for the Talent, and 2.4 N (2.2-2.4) for the Vanguard II CONCLUSION: The results of this in vitro study suggest that current forms of iliac limb fixation in modular aortic stent-grafts are adequate provided the components are deployed with sufficient overlap. However, for many of the stent-grafts tested, the safety margin was small.
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Affiliation(s)
- Robert J Hinchliffe
- Department of Vascular and Endovascular Surgery, University Hospital, Nottingham, UK.
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Li Z, Kleinstreuer C. Analysis of biomechanical factors affecting stent-graft migration in an abdominal aortic aneurysm model. J Biomech 2006; 39:2264-73. [PMID: 16153654 DOI: 10.1016/j.jbiomech.2005.07.010] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2004] [Accepted: 07/16/2005] [Indexed: 11/26/2022]
Abstract
Focusing on a representative abdominal aortic aneurysm (AAA) with a bifurcating stent-graft (SG), a fluid-structure interaction (FSI) solver with user-supplied programs has been employed to solve for blood flow, AAA/SG deformation, sac pressure and wall stresses, as well as the downward forces acting on the SG. Simulation results indicate that implanting a SG can significantly reduce sac pressure, mechanical stress, pulsatile wall motion, and maximum diameter change in AAAs; hence, it may restore normal blood flow and prevent AAA rupture effectively. The transient SG drag force is similar in trend as the cardiac pressure. Its magnitude depends on multi-factors including blood flow conditions, as well as SG and aneurysm geometries. Specifically, AAA neck angle, iliac bifurcation angle, neck aorta-to-iliac diameter ratio, SG size, and blood waveform play important roles in generating a fluid flow force potentially leading to SG migration. It was found that the drag force can exceed 5N for an AAA with a large neck or iliac angle, wide aortic neck and narrow iliac arteries, large SG size, and/or abnormal blood waveform. Thus, the fixation of self-expandable or balloon-expandable SG contact may be inadequate to withstand the forces of blood flowing through the implant and hence means of extra fixation should be considered. A comprehensive FSI analysis of the coupled SG-AAA dynamics provides physical insight for evaluating the luminal hemodynamics, and maximum AAA-stresses as well as biomechanical factors leading potentially to SG migration.
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Affiliation(s)
- Z Li
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC, USA
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Linsen MAM, Vos AWF, Diks J, Rauwerda JA, Wisselink W. Fenestrated and Branched Endografts: Assessment of Proximal Aortic Neck Fixation. J Endovasc Ther 2005; 12:647-53. [PMID: 16363893 DOI: 10.1583/05-1639r.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE To investigate proximal fixation characteristics of different aortic endograft designs: a suprarenally placed fenestrated endograft, a modular branched endograft, an infrarenal endograft with suprarenal bare stent fixation, and the gold standard, a conventional hand-sewn anastomosis. METHODS Ten human cadaveric aortas were obtained at autopsy and transected 20 mm below the renal arteries to mimic an infrarenal aneurysm neck. In random order, the infrarenal, fenestrated, and branched endografts were deployed into the aorta. Using a hydraulic material testing machine, longitudinal load was applied to the distal end of each endograft until migration occurred, thus defining the displacement force (DF). Subsequently, a hand-sewn infrarenal anastomosis was tested in a similar manner. RESULTS The median DF was 4.67 N (3.82-6.37) for the infrarenal endograft, 9.17 N (8.03- 10.81) for the fenestrated endograft, and 16.95 N (14.78-19.67) for the branched endograft. The differences in DF between the infrarenal and fenestrated endografts and between the fenestrated and branched designs were statistically significant (both p=0.005). The median force to dislodge the graft from the conventional anastomosis was 89.16 N (71.24-105.23). CONCLUSIONS Suprarenally placed endografts, especially with additional branch grafts, provide improved proximal fixation compared to an infrarenal endograft with suprarenal bare stent fixation. However, none of the tested endografts approached the optimal, time-proven fixation, the hand-sewn anastomosis.
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Affiliation(s)
- Matteus A M Linsen
- Department of Surgery, VU University Medical Center, Amsterdam, The Netherlands
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Li Z, Kleinstreuer C. Blood flow and structure interactions in a stented abdominal aortic aneurysm model. Med Eng Phys 2005; 27:369-82. [PMID: 15863346 DOI: 10.1016/j.medengphy.2004.12.003] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2004] [Revised: 12/07/2004] [Accepted: 12/12/2004] [Indexed: 11/27/2022]
Abstract
Since the introduction of endovascular techniques in the early 1990s for the treatment of abdominal aortic aneurysms (AAAs), the insertion of an endovascular graft (EVG) into the affected artery segment has been greatly successful for a certain group of AAA patients and is continuously evolving. However, although minimally invasive endovascular aneurysm repair (EVAR) is very attractive, post-operative complications may occur. Typically, they are the result of excessive fluid-structure interaction dynamics, possibly leading to EVG migration. Considering a 3D stented AAA, a coupled fluid flow and solid mechanics solver was employed to simulate and analyze the interactive dynamics, i.e., pulsatile blood flow in the EVG lumen, pressure levels in the stagnant blood filling the AAA cavity, as well as stresses and displacements in the EVG and AAA walls. The validated numerical results show that a securely placed EVG shields the diseased AAA wall from the pulsatile blood pressure and hence keeps the maximum wall stress 20 times below the wall stress value in the non-stented AAA. The sac pressure is reduced significantly but remains non-zero and transient, caused by the complex fluid-structure interactions between luminal blood flow, EVG wall, stagnant sac blood, and aneurysm wall. The time-varying drag force on the EVG exerted by physiological blood flow is unavoidable, where for patients with severe hypertension the risk of EVG migration is very high.
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Affiliation(s)
- Zhonghua Li
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Campus Box 7910, 3198 Broughton Hall, Raleigh, NC 27695-7910, USA
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33
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Affiliation(s)
- Thien V How
- Clinical Engineering Division, School of Clinical Sciences, University of Liverpool, Liverpool L69 3GA, UK.
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Volodos SM, Sayers RD, Gostelow JP, Sir Bell PRF. An Investigation Into the Cause of Distal Endoleaks: Role of Displacement Force on the Distal End of a Stent-Graft. J Endovasc Ther 2005; 12:115-20. [PMID: 15683261 DOI: 10.1583/04-1315mr.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE To investigate if the forces developed by pulsatile flow on a stent-graft and dimensional changes of the graft material might contribute to distal endoleak and stent-graft kinking. METHODS An in vitro experimental model was used to measure the peak displacement force developed by pulsatile flow pressure on the distal end of a stent-graft. Polytetrafluoroethylene (PTFE) graft material (110 mm long, 22 mm in diameter) was evaluated in a flow circuit, with water as the circulating liquid. In addition, the effect of internal pressure on PTFE graft dimensions was measured under nonpulsatile conditions in 3 configurations (1 bifurcated and 2 straight). RESULTS Pressure in the PTFE graft did not cause a change in graft diameter but did increase the length of the graft. The mean load required to prevent retrograde displacement was 208.5+/-2.5 g. Peak retrograde displacement force developed on the distal end of the stent-graft by the pressure of pulsatile flow was strongly associated with the systolic phase of the cardiac cycle. CONCLUSIONS The distal end of the stent-graft is subject to a retrograde displacement force by the pressure of pulsatile arterial flow. In addition, pressure inside the PTFE graft causes its length to increase. Both of these factors may be important in the development of late complications of stent-grafting.
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Chuter TAM, Parodi JC, Lawrence-Brown M. Management of Abdominal Aortic Aneurysm: A Decade of Progress. J Endovasc Ther 2004. [DOI: 10.1583/04-1388.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Chuter TAM, Howell BA. Suprarenal stents and other advances in endovascular aneurysm repair. Surg Clin North Am 2004; 84:1319-35, vii. [PMID: 15364557 DOI: 10.1016/j.suc.2004.05.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The history of endovascular aneurysm repair has already passed through its phases of "endoexuberance" and "endoscepticism" and there is now a balanced and broad understanding of the technology,its limits and advantages. Current endovascular technique and stent-graft design is the refinement of the accumulated endovascular experience til now. It is important to make note of these technological features incorporated in current stent-grafts and the clinical experience that precipitated their introduction as the technology progresses and new applications are proposed.
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Affiliation(s)
- Timothy A M Chuter
- Division of Vascular Surgery, UCSF, 505 Parnassus Ave, M-488, San Francisco, CA 94143, USA.
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Murphy MG, McWilliams RG. Postoperative radiology of endovascular abdominal aortic aneurysm repair. Semin Ultrasound CT MR 2004; 25:261-76. [PMID: 15272550 DOI: 10.1053/j.sult.2004.03.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This article addresses the imaging appearances following endovascular abdominal aortic aneurysm repair (EVAR). EVAR is gaining popularity and hence there is increasing likelihood that radiologists who are unfamiliar with the procedure will report imaging investigations on these patients. We describe the technique, failure modes, complications, and postoperative imaging features of this procedure.
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Fearn S, Lawrence-Brown MMD, Semmens JB, Hartley D. Follow-Up After Endovascular Aortic Aneurysm Repair: The Plain Radiograph Has an Essential Role in Surveillance. J Endovasc Ther 2003. [DOI: 10.1583/1545-1550(2003)010<0894:faeaar>2.0.co;2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Vos AF, Wisselink W, Marcus JT, Vahl AC, Manoliu RA, Rauwerda JA. Cine MRI Assessment of Aortic Aneurysm Dynamics Before and After Endovascular Repair. J Endovasc Ther 2003. [DOI: 10.1583/1545-1550(2003)010<0433:cmaoaa>2.0.co;2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Liffman K, Lawrence-Brown MMD, Semmens JB, Šutalo ID, Bui A, White F, Hartley DE. Suprarenal Fixation:Effect on Blood Flow of an Endoluminal Stent Wire Across an Arterial Orifice. J Endovasc Ther 2003. [DOI: 10.1583/1545-1550(2003)010<0260:sfeobf>2.0.co;2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Mohan IV, Harris PL, van Marrewijk CJ, Laheij RJ, How TV. Factors and Forces Influencing Stent-Graft Migration After Endovascular Aortic Aneurysm Repair. J Endovasc Ther 2002. [DOI: 10.1583/1545-1550(2002)009<0748:fafisg>2.0.co;2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Liffman K, Lawrence-Brown MMD, Semmens JB. Reply. J Endovasc Ther 2002. [DOI: 10.1583/1545-1550(2002)009<0252:>2.0.co;2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Moore Jr. JE. Re: Analytical Modeling and Numerical Simulation of Forces in an Endoluminal Graft. J Endovasc Ther 2002. [DOI: 10.1583/1545-1550(2002)009<0251:ramans>2.0.co;2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Stanley BM, Semmens JB, Mai Q, Goodman MA, Hartley DE, Wilkinson C, Lawrence-Brown MMD. Evaluation of Patient Selection Guidelines for Endoluminal AAA Repair With the Zenith Stent-Graft:The Australasian Experience. J Endovasc Ther 2001. [DOI: 10.1583/1545-1550(2001)008<0457:eopsgf>2.0.co;2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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