N.Filipovic, M.Radovic, V.Isailovic, Z.Milosevic, D.Nikolic, I.Saveljic, M.Milosevic, D.Petrovic, M.Obradovic, D.Krsmanovic, E.Themis, A.Sakellarios, P.Siogkas, P.Marraccini, F.Vozzi, N.Meunier, Z.Teng, D.Fotiadis, O.Parodi, M.Kojic
(UDC: 004.921 ; 616.13-004.6-073)
Atherosclerosis is the number one cause of death worldwide. A three-dimensional computer model of plaque formation and development for artery is described. Stent deployment procedure for a specific patient is adopted and simulation of the temperature distribution for heating stent in the final position is analysed.
The three-dimensional blood flow is described by the Navier-Stokes equations, together with the continuity equation. Mass transfer within the blood lumen and through the arterial wall is coupled with the blood flow and is modeled by a convection- diffusion equations. The low density lipoproteins (LDL) transports in lumen of the vessel and through the vessel tissue are coupled by Kedem-Katchalsky equations. The inflammatory process is modeled using three additional reaction-diffusion partial differential equations. A fluid-structure interaction methodology is used to estimate effective wall stress distribution. Plaque growth functions for volume progression are correlated with shear stress and effective wall stress distributions.
We choose two patients from the MRI recording with significant plaque progression. Plaque volume progression is fitted using three time points for baseline, three and twelve months follow up. Our results for plaque localization correspond to low shear stress zone and we fitted parameters from our model using a nonlinear least square method.
In the arterial wall the maximal effective stress are found behind the stent and in the regions where the arterial wall was thinner. It was derermined that maximal stent temperature around 60ºC could give optimal temperature distribution between 45 ºC and 48 ºC for surrounding tissue and SMCs. These results suggest that heating of the implanted stent can be employed to prevent restenosis.