The great interest in Finite Element simulations of cardiovascular operations, such as stenting, angioplasty, aneurysm intervention, for improving the reliability of endovascular devices, is confirmed by the considerable number of papers published in this field. This paper presents the results of a numerical investigation aimed at identifying the most important parameters, among the tissue mechanical properties, that co-operate to the success of the angioplasty operation. In fact in angioplasty simulations mechanical properties of both artery and plaque tissues are fundamental for the success of the intervention, while they affect in a minor way the stenting operation. By means of the Finite Element program ANSYS, several 2D models, representing the longitudinal and the transversal cross section of the vessel with an atherosclerotic plaque, have been developed. The plaque has been considered an isotropic elasto-plastic material, with a bilinear or a Drucker Prager model; for the artery, an elastic isotropic or orthotropic material, with data taken from the literature, has been employed. In order to apply a more realistic loading condition, the angioplasty balloon has been modelled also; displacement has been assigned to the balloon and the behaviour of plaque and artery during its expansion and deflation has been analysed. The effect of a different interaction between the artery and the plaque, bonded always or sliding with friction, has been considered also. Employing the toolbox of probabilistic design of ANSYS, a probabilistic analysis has been carried out in order to assess the sensitivity of output parameters, such as maximum stress and lumen gain, with respect to input parameters, such as plaque material properties. Results show that in case of axisymmetric stenosis the plaque material properties are most significant, in particular the Young modulus and the yield stress, while in case of spur plaque the artery behaviour, linear or non-linear elastic, plays a more important role.
Sensitivity of angioplasty effects to vessel material properties by probabilistic analysis
CELI, SIMONA;DI PUCCIO, FRANCESCA;FORTE, PAOLA
2005-01-01
Abstract
The great interest in Finite Element simulations of cardiovascular operations, such as stenting, angioplasty, aneurysm intervention, for improving the reliability of endovascular devices, is confirmed by the considerable number of papers published in this field. This paper presents the results of a numerical investigation aimed at identifying the most important parameters, among the tissue mechanical properties, that co-operate to the success of the angioplasty operation. In fact in angioplasty simulations mechanical properties of both artery and plaque tissues are fundamental for the success of the intervention, while they affect in a minor way the stenting operation. By means of the Finite Element program ANSYS, several 2D models, representing the longitudinal and the transversal cross section of the vessel with an atherosclerotic plaque, have been developed. The plaque has been considered an isotropic elasto-plastic material, with a bilinear or a Drucker Prager model; for the artery, an elastic isotropic or orthotropic material, with data taken from the literature, has been employed. In order to apply a more realistic loading condition, the angioplasty balloon has been modelled also; displacement has been assigned to the balloon and the behaviour of plaque and artery during its expansion and deflation has been analysed. The effect of a different interaction between the artery and the plaque, bonded always or sliding with friction, has been considered also. Employing the toolbox of probabilistic design of ANSYS, a probabilistic analysis has been carried out in order to assess the sensitivity of output parameters, such as maximum stress and lumen gain, with respect to input parameters, such as plaque material properties. Results show that in case of axisymmetric stenosis the plaque material properties are most significant, in particular the Young modulus and the yield stress, while in case of spur plaque the artery behaviour, linear or non-linear elastic, plays a more important role.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
