טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentBeletsky Ilya
SubjectDrug Distribution Analysis for Drug Eluting Stent
Applications with an Aaxisymmetric Pplaque
DepartmentDepartment of Mechanical Engineering
Supervisor Professor Emeritus Pinhas Bar-Yoseph


Abstract

Cardiovascular artery disease is one of the most common causes of death in the modern world. The disease is treated with a stenting procedure, which in many cases leads to in-stent restenosis (ISR). Lately a new approach of drug-eluting stents (DES) has been introduced to treat ISR. Drug distribution, governed by diffusion and convection of the drug through the artery wall plays a key role in successful treatment. The main goal of the current work is to investigate the influence of the plaque and its’ properties on the drug distribution and to formulate coating directives to improve that distribution. The stenting procedure is computationally simulated using finite element methods through it’s sub-dividing to the balloon inflation and the drug distribution. The balloon inflation is modeled as an elastic axisymmetric contact problem with large deformations and large strains. The drug distribution is governed by a 3D convection-diffusion equation in the deformed geometry. The model can be generalized for a more complicated plaque formation. The unique contribution of the current work is in the coupling of the two problems. It is shown that the plaque’s presence, shape, size and diffusion properties have a major influence on the drug distribution profiles. In addition, the rate of convection, stent geometry and the behavior of the used drug (e.g. hydrophobic vs. hydrophilic), also play an important role in the consequential distribution field. On the contrary, the artery elastic material properties and the balloon inflation model have a minor influence on the drug distribution.