Comparison of Numerical Model with Experimental Measurements for the Purpose of Testing Partially and Fully Biodegradable Stents

Abstract

Atherosclerosis is a progressive disease characterized by the accumulation of lipids and fibrous elements in the arterial wall. This accumulation produces plaque in the arteries. Percutaneous transluminal coronary angioplasty (PTCA) is a minimally invasive procedure that opens narrowed coronary arteries because of the plaque growth. A medical device that can hold an artery open in the area of narrowing is called a stent and it usually resembles a mesh tube. Mechanical stent testDevicess are standard preclinical procedure used to simulate stent behavior for different physiological conditions. In this research, a mechanical testDevices called three-point bending testDevices was performed on a partially and fully bioresorbable vascular scaffold (BVS) manufactured by Boston Scientific Limited [1]. Poly-l-lactic acid (PLLA) material model was implemented for the numerical model inside in-house PAK [2] software. Measurements obtained by mechanical testing were compared with the numerical results. There is a strong correlation between the numerical simulation and real experiments with a coefficient of determination (R2) > 0.99 and a correlation coefficient (R) > 0.99. It can be concluded that in silico mechanical tests can partially or fully replace in vitro stent tests, which can open a new avenue for regulatory submission and change regulatory ISO standard procedures.