THE SCIMED RADIUS™ STENT-ARTERY INTERACTION

摘要

Main cause of restenosis after balloon angioplasty is due to the stresses generated in the artery as well as from the stent artery interaction. Understanding the factors that are involved in this interaction and. the ability to evaluate the stresses that are formed in the artery, could help to lessen the number of failures. The goal of the present study is to develop computationally efficient analytical model for estimating the potential damage factor as the contact stresses, and to investigate their influence upon stent design, artery and plaque parameters. The artery was stipulated to be thick walled cylinder and its stress-strain state was determined from analytic solution of Lame problem. An analytic model based on the analysis of the beams deformation in the framework Euler-Bernoulli assumptions was formulated for the stent. The radial pressure, which is exerted on the inner surface of the artery, is assumed to be an average of contact stresses applied by the stent and the blood pressure. The variation in the Potential Damage Factor value as a function of the mismatch between stent's and artery's diameters is linear, and as much as the diameter of the artery increases, the Potential Damage Factor for the same mismatch decreases. For arteries with 75% blocking and mismatch of 1mm, the potential damage factor is 4.5.