ANALYSIS OF A BIOMECHANICAL FACTOR AFFECTING TYPE I ENDOLEAKS IN A STENTED ABDOMINAL AORTIC ANEURYSM

Anne AMBLARD

anne.amblard@insa-lyon.fr

Hélène WALTER-LE BERRE

Benyeka BOU-SAÏD

Michel BRUNET

Laboratoire de Mécanique des Contacts et des Solides, INSA Lyon, FRANCE

Abstract. In order to improve endovascular graft used for the treatment of abdominal aortic aneurysm, we develop a methodology to analyse phenomena of type I endoleaks in a non invasive stented abdominal aorta. On the one hand, this study provides an evaluation of the parietal stresses generated by the blood flow. As blood is a shear-thinning, non-Newtonian fluid, we use the Phan-Thien and Tanner model, resulting from the polymer rheology. On the other hand, we develop an axisymmetric finite-element model of the complete system. Plast2, an explicit dynamic finite element code, is used to simulate the behavior of the system subjected to hydrostatic pressure and to the stresses generated by the blood flow. As the response of the solids is strongly affected by the response of the fluid, and vice versa, a coupled fluid-structure interaction is necessary and achieved in this work.
 

Keywords: abdominal aortic aneurysm, endovascular graft, type I endoleaks, fluid-structure interaction, computational parametric sensitivity analysis

References

1. Zarins, C.K., 1999, “Aneurx Stent Graft Versus Open Surgical Repair of Abdominal Aortic Aneurysms: Multicenter Prospective Clinique Trial,” Journal of Vascular Surgery; 29; 2.

2. May, J., 1998, “Concurrent Comparison of Endoluminal Versus Open Repair in the Treatment of Abdominal Aortic Aneurysms: Analysis of 303 Patients by Life Table Method,” Jnl. of Vascular Surgery; 27; 2.

3. Brewster, D.C., 2003, “Guidelines for the Treatment of Abdominal Aortic Aneurysm,” Journal of Vascular Surgery; 37; 5.

4. Veith, F.J., 2002, “Nature and Significance of Endoleaks and Endotension: Summary of Opinions Expressed at an International Conference,” Journal of Vascular Surgery; 35; 5.

5. Li, Z., 2004, “Blood Flow and Structure Interactions in a Stented Abdominal Aortic Aneurysm Model,” Medical Engineering and Physics; 27; 369-382.

6. Li, Z., 2005, “Analysis of Biomechanical Factors Affecting Stent-Graft Migration in an Abdominal Aortic Aneurysm Model,” Journal of Biomechanics.

7. Li, Z., 2005, “Computational Analysis of Type II Endoleaks in a Stented Abdominal Aortic Aneurysm Model,” Journal of Biomechanics.

8. Comolet, R., 1984, Biomécanique circulatoire, Editions Masson.

9. Fung, Y.C., 1993, Biomechanics Mechanical properties of Living Tissues, Second Edition, Springer Edition,.

10. Byron, B.R., 1987, Dynamics of polymeric liquids Volume 1, John Wiley & Sons Edition.

11. Tanner, R. I., 2000, Engineering rheology Second Edition, Oxford Engineering Science Series.

12. Amblard, A., Bou-Saïd, B., 2004, “Modelling The Blood Flow in an Aorta,” Leeds-Lyon Symposium.

13. Amblard, A., Walter-Leberre, H., Bou-Saïd, B., Brunet M., “Tribological Analysis of Type I Endoleaks in a Stented Abdominal Aortic Aneurysm,” Journal of Biomechanical Engineering, under review.

14. Zarins, C.K., 2003, “Stent Graft Migration after Endovascular Aneurysm Repair: Importance of Proximal Fixation,” Journal of Vascular Surgery, vol.38, n°6.