Evaluation of coronary stents: A review of types, materials, processing techniques, design, and problems

Abstract

In the world, one of the leading causes of death is coronary artery disease (CAD). There are several ways to treat this disease, and stenting is currently the most appropriate way in many cases. Nowadays, the use of stents has rapidly increased, and they have been introduced in various models, with different geometries and materials. To select the most appropriate stent required, it is necessary to have an analysis of the mechanical behavior of various types of stents. The purpose of this article is to provide a complete overview of advanced research in the field of stents and to discuss and conclude important studies on different topics in the field of stents. In this review, we introduce the types of coronary stents, materials, stent processing technique, stent design, classification of stents based on the mechanism of expansion, and problems and complications of stents. In this article, by reviewing the biomechanical studies conducted in this field and collecting and classifying their results, a useful set of information has been presented to continue research in the direction of designing and manufacturing more efficient stents, although the clinical-engineering field still needs to continue research to optimize the design and construction. The optimum design of stents in the future is possible by simulation and using numerical methods and adequate knowledge of stent and artery biomechanics.

Keywords: Coronary artery; Design; Materials; Mechanism of expansion; Processing technique; Vascular stents.

Graphical abstract

Fig. 1

(a) Structure of an artery; (b) presence of atheroma; (c) enlarged lumen diameter after stenting; and (d) in-stent restenosis [25].

Fig. 2

The stent designed by Dotter et al. [28].

Fig. 3

Vascular stent processing method: (a) braided [91]; (b) laser cutting [91]; (c) electrospinning technology [92]; (d) additive manufacturing [93].

Fig. 4

Micro-CT images of stents and the strut design [95].

Fig. 5

The sample of stent links [96].

Fig. 6

Open-cell and closed-cell shapes [102].

Fig. 7

A classification of stents based on the mechanism of expansion.

Fig. 8

Balloon-expandable stents [114].

Fig. 9

Steps involved in self-expanding stent delivery and deployment [115].

Fig. 10

Problems of stents.

Fig. 11

The working trend of documents on the stent (Lens Scholarly Search: Stent).

Fig. 12

The working trend of patents on the stent (Lens Patent Search: Stent).