Article: A computational fluid dynamic study of stent graft remodeling after endovascular repair of thoracic aortic dissections

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TitleA computational fluid dynamic study of stent graft remodeling after endovascular repair of thoracic aortic dissections
AuthorsCheng, SWK1
Lam, ESK1
Fung, GSK1
Ho, P1
Ting, ACW1
Chow, KW1
Issue Date2008
PublisherMosby, Inc. The Journal's web site is located at http://www.elsevier.com/locate/jvs
CitationJournal Of Vascular Surgery, 2008, v. 48 n. 2, p. 303-310 [How to Cite?]
DOI: http://dx.doi.org/10.1016/j.jvs.2008.03.050
AbstractObjectives: Significant stent graft remodeling commonly occurs after endovascular repair of thoracic aortic dissections because of continuing expansion of the true lumen. A suboptimal proximal landing zone, minimal oversizing, and lack of a healthy distal attachment site are unique factors affecting long-term stent graft stability. We used computational fluid dynamic techniques to analyze the biomechanical factors associated with stent graft remodeling in these patients. Patients and Methods: A series of computational fluid dynamic models were constructed to investigate the biomechanical factors affecting the drag force on a thoracic stent graft. The resultant drag force as a net change of fluid momentum was calculated on the basis of varying three-dimensional geometry and deployment positions. A series of 12 patients with type B aortic dissections treated by thoracic stent graft and followed up for more than 12 months were then studied. Computed tomography transaxial images of each patient shortly after stent graft deployment and on subsequent follow-up were used to generate three-dimensional geometric models that were then fitted with a surface mesh. Computational fluid dynamic simulations were then performed on each stent graft model according to its geometric parameters to determine the actual change in drag force experienced by the stent graft as it remodels over time. Results: The drag force on the stent graft model increases linearly with its internal diameter and becomes highest when the deployment position is closer to the proximal arch. Aortic curvature is not a significant factor. Serial computed tomography scans of patients showed an increase in mean inlet area from 1030 mm2 to 1140 mm2, and mean outlet area from 586 mm2 to 884 mm2 (increase of 11% and 58%, respectively; P = .05, .01). These increases are associated with a change in resultant drag force on the stent graft from 21.0 N to 24.8 N (mean increase, 19.5%; range, 0%-63.2%; P = .002). There is a positive relationship between increase in drag force and increase in stent-graft area. Conclusion: The drag force on thoracic stent grafts is high. A significant change in stent-graft diameter occurs after endovascular repair for type B dissections, which is associated with an increase in hemodynamic drag force. These stent grafts may be subjected to a higher risk of distal migration, and continuing surveillance is mandatory. © 2008 The Society for Vascular Surgery.
ISSN0741-5214
2011 Impact Factor: 3.21
2011 SCImago Journal Rankings: 0.271
DOIhttp://dx.doi.org/10.1016/j.jvs.2008.03.050
ISI Accession Number IDWOS:000258035800008
ReferencesReferences in Scopus
DC Field
Value
dc.contributor.authorCheng, SWK
dc.contributor.authorLam, ESK
dc.contributor.authorFung, GSK
dc.contributor.authorHo, P
dc.contributor.authorTing, ACW
dc.contributor.authorChow, KW
dc.date.accessioned2010-05-31T03:36:33Z
dc.date.available2010-05-31T03:36:33Z
dc.date.issued2008
dc.description.abstractObjectives: Significant stent graft remodeling commonly occurs after endovascular repair of thoracic aortic dissections because of continuing expansion of the true lumen. A suboptimal proximal landing zone, minimal oversizing, and lack of a healthy distal attachment site are unique factors affecting long-term stent graft stability. We used computational fluid dynamic techniques to analyze the biomechanical factors associated with stent graft remodeling in these patients. Patients and Methods: A series of computational fluid dynamic models were constructed to investigate the biomechanical factors affecting the drag force on a thoracic stent graft. The resultant drag force as a net change of fluid momentum was calculated on the basis of varying three-dimensional geometry and deployment positions. A series of 12 patients with type B aortic dissections treated by thoracic stent graft and followed up for more than 12 months were then studied. Computed tomography transaxial images of each patient shortly after stent graft deployment and on subsequent follow-up were used to generate three-dimensional geometric models that were then fitted with a surface mesh. Computational fluid dynamic simulations were then performed on each stent graft model according to its geometric parameters to determine the actual change in drag force experienced by the stent graft as it remodels over time. Results: The drag force on the stent graft model increases linearly with its internal diameter and becomes highest when the deployment position is closer to the proximal arch. Aortic curvature is not a significant factor. Serial computed tomography scans of patients showed an increase in mean inlet area from 1030 mm2 to 1140 mm2, and mean outlet area from 586 mm2 to 884 mm2 (increase of 11% and 58%, respectively; P = .05, .01). These increases are associated with a change in resultant drag force on the stent graft from 21.0 N to 24.8 N (mean increase, 19.5%; range, 0%-63.2%; P = .002). There is a positive relationship between increase in drag force and increase in stent-graft area. Conclusion: The drag force on thoracic stent grafts is high. A significant change in stent-graft diameter occurs after endovascular repair for type B dissections, which is associated with an increase in hemodynamic drag force. These stent grafts may be subjected to a higher risk of distal migration, and continuing surveillance is mandatory. © 2008 The Society for Vascular Surgery.
dc.description.natureLink_to_subscribed_fulltext
dc.identifier.citationJournal Of Vascular Surgery, 2008, v. 48 n. 2, p. 303-310 [How to Cite?]
DOI: http://dx.doi.org/10.1016/j.jvs.2008.03.050
dc.identifier.doihttp://dx.doi.org/10.1016/j.jvs.2008.03.050
dc.identifier.epage310
dc.identifier.hkuros147926
dc.identifier.isiWOS:000258035800008
dc.identifier.issn0741-5214
2011 Impact Factor: 3.21
2011 SCImago Journal Rankings: 0.271
dc.identifier.issue2
dc.identifier.openurl
dc.identifier.pmid18644477
dc.identifier.scopuseid_2-s2.0-47249099917
dc.identifier.spage303
dc.identifier.urihttp://hdl.handle.net/10722/58767
dc.identifier.volume48
dc.languageeng
dc.publisherMosby, Inc. The Journal's web site is located at http://www.elsevier.com/locate/jvs
dc.publisher.placeUnited States
dc.relation.ispartofJournal of Vascular Surgery
dc.relation.referencesReferences in Scopus
dc.rightsJournal of Vascular Surgery. Copyright © Mosby, Inc.
dc.subject.meshAdult
dc.subject.meshAged
dc.subject.meshAneurysm, Dissecting - radiography - surgery
dc.subject.meshAngioplasty - methods
dc.subject.meshAortic Aneurysm, Thoracic - radiography - surgery
dc.subject.meshBiomechanics - methods
dc.subject.meshBlood Flow Velocity - physiology
dc.subject.meshComputer Simulation
dc.subject.meshFemale
dc.subject.meshHumans
dc.subject.meshMale
dc.subject.meshMiddle Aged
dc.subject.meshModels, Cardiovascular
dc.subject.meshProbability
dc.subject.meshProsthesis Design
dc.subject.meshProsthesis Failure
dc.subject.meshSampling Studies
dc.subject.meshSensitivity and Specificity
dc.subject.meshShear Strength
dc.subject.meshStents
dc.subject.meshStress, Mechanical
dc.subject.meshTreatment Outcome
dc.titleA computational fluid dynamic study of stent graft remodeling after endovascular repair of thoracic aortic dissections
dc.typeArticle
Author Affiliations
  1. The University of Hong Kong