Biomechanics of abdominal aortic aneurysm in the presence of endoluminal thrombus: experimental characterisation and structural static computational analysis.

OBJECTIVES To evaluate the role played by biomechanical and geometrical parameters of endoluminal thrombus and of aortic wall on abdominal aortic aneurysm (AAA) behaviour. MATERIALS AND METHODS Tensile tests on 21 AAA thrombus specimens from six patients undergoing AAA repair and numerical evaluation of aneurysmal aortic wall stress and strain distribution. Parameters of the analysis were lumen eccentricity, thrombus Young's Modulus and the aortic wall constitutive equation. RESULTS There was a linear stress/strain for all the thrombus specimens. The numerical analyses show the mechanical behaviour of AAA as a function of lumen eccentricity and biomechanical parameters. CONCLUSIONS Well organised thrombus reduces the effect of the pressure load on the aneurysmal aortic wall.