Effect of over/under-expanding on the mechanical behavior in provisional stenting using bioresorbable scaffold

Abstract

The purpose of this study is to contribute to the design and development by analyzing the expected mechanical behavior of bioresorbable scaffolds. Bioresorbable scaffolds are a type of medical device ‘stent’ that treats heart disease by physically removing plaque inside the coronary arteries. Unlike conventional metal-based stents, bioresorbable scaffolds are manufactured using polymeric materials that achieve dissolution properties within 1-2 years in vivo through hydrolysis with blood. Thus, bioresorbable scaffolds have the advantage of reducing postoperative side effects. However, due to the mechanical properties of the polymeric materials used, bioresorbable scaffolds are currently only applied to simple lesions. In particular, for branched lesions that separate from one main vessel into two branched vessels, the stenting procedures are still being studied through various clinical trials, but there are not many reports of studies and results through interpretation. A provisional stent method of placing a single stent in the blood vessel is commonly used to treat branched lesions. Since the diameter of the blood vessel before and after the branching is different, the selection of the stent diameter is applied as the first step before the stent operation. Conventional metal-based stent operations do not require this consideration, but it is needed for bioresorbable scaffolds due to the low tensile strength of the polymeric material. In this study, temporary stents with two different diameter bioresorbable scaffolds corresponding to the diameter of the main vessel at both ends were evaluated using the calculation method. In this study, these two stents with different diameters were compared in terms of device failure and damage to the inner wall of the blood vessel.