Abstract
Objectives: Endovascular aneurysm repair for abdominal aortic aneurysm (AAA) is now a widely adopted treatment. Several complications remain to be fully resolved and perhaps the most significant of these is graft migration. Haemodynamic drag forces are believed to be partly responsible for migration of the device. The objective of this work was to investigate the drag forces in patient-specific AAA stent-grafts. Methods: CT scan data was obtained from 10 post-operative AAA patients treated with stentgrafts. 3D models of the aneurysm, intraluminal thrombus and stent-graft were created. The drag forces were determined by fluid-structure interaction simulations. A worst case scenario was investigated by altering the aortic waveforms. Results: The median resultant drag force was 5.46 N (range: 2.53e10.84). An increase in proximal neck angulation resulted in an increase in the resultant drag force (p = 0.009). The primary force vector was found to act in an anterior caudal direction for most patients. The worst case scenario simulation resulted in a greatest drag force of 16 N. Conclusions: Numerical methods can be used to determine patient-specific drag forces which may help determine the likelihood of stent-graft migration. Anterioreposterior neck angulation appears to be the greatest determinant of drag force magnitude. Graft dislodgement may occur anteriorally as well as caudally.
Original language | English |
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Pages (from-to) | 332-339 |
Number of pages | 8 |
Journal | European Journal of Vascular and Endovascular Surgery |
Volume | 40 |
Issue number | 3 |
DOIs | |
Publication status | Published - Sep 2010 |
Keywords
- Abdominal aortic aneurysm
- Drag forces
- EVAR
- Graft migration