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Study of the coronary bifurcation flow for different stenting techniques with conventional and specific designed stents
Year:2015
Research Areas
  • Engineering
Information
Abstract
Nowadays, restenosis after percutaneous dilation is the major drawback of coronary angioplasty. It represents a special form of atherosclerosis due to the healing process secondary to extensive vessel trauma induced after intracoronary balloon inflation. The use of coronary stents may decrease the incidence of this phenomenon. Unfortunately, intra-stent restenosis still occurs in 20-30% of the cases following the stent implantation. This work is a result of previous investigations with conventional stents [1] [2] and arises after the recent emergence of several devices specifically designed for coronary bifurcations angioplasty. The aim is to compare the hemodynamic performance of these new devices (Stentys) compared to conventional devices and techniques in a coronary bifurcation model. Four different stenting techniques: simple stenting of the main vessel, simple stenting of the side vessel, culotte deploying the first stent in the main vessel and culotte deploying the first stent in the side vessel have been considered. To carry out this study an idealized geometry of a coronary bifurcation is used. A 45 degrees bifurcation angle is considered and the daughter branches diameters are obtained according to the Finet law. Both experiments in the laboratory and numerical simulations will be used, focusing on important factors for the atherosclerosis development, like the wall shear stress, the oscillation shear index, the pressure loss and the vorticity. Micro-CT images were used to reconstruct coronary stents implanted in silicone models. First, steady simulations (Fig. 1) are carried out with the commercial code ANSYS-Fluent, and then, experimental measurements with PIV (Particle Image Velocimetry) obtained in the laboratory are used to validate the numerical simulation. The fluid is assumed to be Newtonian with a viscosity ? =3.72 x 10-6 m2/s and density ? =1099.3 kg/m3 and the flow is assumed to be laminar. The steady computational simulations show a good overall agreement with the experimental data. For transient fluid dynamics simulations a pulsatile flow tracing which is representative of a human LAD was applied as a paraboloid-shaped velocity profile. The flow curve amplitude was tuned on the inlet in order to obtain the average flow rate proposed by van der Giessen et al. [3]. The same refereobtained permit to evaluate whether the new designs really result in an improvement in the hydrodynamic behavior of the devices. Obviously the present simulations focus only on the hemodynamic aspects and other factors should be taken into account before choosing the most appropriate stenting technique. Moreover, even if only fluid dynamic criteria are considered, it should be noticed that the configurations studied are idealized coronary bifurcations. The behavior patterns obtained in this work should be verified in more realistic geometries.nce is used to calculate the flow ratio through the branches. The results
International
Si
Congress
International Conference on Biomedical Technology - ICBT
960
Place
Hannover (Alemania)
Reviewers
Si
ISBN/ISSN
Start Date
28/10/2015
End Date
30/10/2015
From page
To page
Participants
  • Autor: Javier Garcia Garcia (UPM)
  • Autor: Pedro Garcia (Universidad de Valladolid)
  • Autor: Fernando Jaime Manuel Martin (UPM)
  • Autor: Yolanda Sofia Doce Carrasco (UPM)
  • Autor: Javier Goicolea (Hospital Puerta de Hierro)
  • Autor: José Antonio Fernández (Hospital Puerta de Hiero)
Research Group, Departaments and Institutes related
  • Creador: Grupo de Investigación: Mecánica de fluidos aplicada a la Ingeniería Industrial
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