Document Detail

The influence of proximal stent compliance and geometrical parameters on stent-graft performance for the treatment of abdominal aortic aneurysms.
MedLine Citation:
PMID:  23218139     Owner:  NLM     Status:  Publisher    
The long-term success of the endovascular procedure for the treatment of Abdominal Aortic Aneurysms (AAAs ) depends on the secure fixation of the proximal end and the geometry of the stent-graft (SG) device. Variations in SG types can affect proximal fixation and SG hemodynamics. Such hemodynamic variations can have a catastrophic effect on the vascular system and may result from a SG/arterial wall compliance mismatch and the sudden decrease in cross-sectional area at the bifurcation, which may result in decreased distal perfusion, increased pressure wave reflection and increased stress at the interface between the stented and non-stented portion of the vessel. To examine this compliance mismatch, a commercial SG device was tested experimentally under a physiological pressure condition in a silicone AAA model based on computed tomography scans. There was a considerable reduction in compliance of 54% and an increase in the pulse wave velocity of 21%, with a significant amount of the forward pressure wave being reflected. To examine the SG geometrical effects, a commercial bifurcated geometry was compared computationally and experimentally with a geometrical taper in the form of a blended section, which provided a smooth transition from the proximal end to both iliac legs. The sudden contraction of commercial SG at the bifurcation region causes flow separation within the iliac legs, which is known to cause SG occlusion and increased proximal pressure. The blended section along the bifurcation region promotes a greater uniformity of the fluid flow field within the distal legs, especially, during the deceleration phase with reduced boundary layer reversal. In order to reduce the foregoing losses, abrupt changes of cross-section should be avoided. Geometrical tapers could lead to improved clinical outcomes for AAA SGs.
Liam Morris; Florian Stefanov; Tim McGloughlin
Related Documents :
9097349 - Non-invasive haemodynamic effects of two nasal positive pressure ventilation modalities...
19163299 - Predicting respiratory instability in the icu.
1864779 - Effects of left atrial pressure on the pulmonary vascular response to hypoxic ventilation.
2191059 - Pc-based training system for clinical use of a lung ventilator.
18464889 - Evaluation of pressure support ventilation with seven different ventilators using activ...
17971249 - Noninvasive positive-pressure ventilation with different interfaces in patients with re...
21701139 - Anatomic predictors of retropalatal mechanical loads in patients with obstructive sleep...
8019639 - Lack of protection of pbn in isolated heart during ischemia and reperfusion: implicatio...
7609499 - The use of lacidipine in the management of hypertensive crises: a comparative study wit...
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2012-12-3
Journal Detail:
Title:  Journal of biomechanics     Volume:  -     ISSN:  1873-2380     ISO Abbreviation:  J Biomech     Publication Date:  2012 Dec 
Date Detail:
Created Date:  2012-12-10     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0157375     Medline TA:  J Biomech     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Copyright Information:
Copyright © 2012 Elsevier Ltd. All rights reserved.
Galway Medical Technologies Centre (GMedTech), Department of Mechanical and Industrial, Engineering, Galway Mayo Institute of Technology, Galway, Ireland.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Finite element micro-modelling of a human ankle bone reveals the importance of the trabecular networ...
Next Document:  Computational fluid dynamics for the assessment of upper airway response to oral appliance treatment...