Coronary Stents: History, Design, and Construction.

Torrey Schmidt,J Abbott

doi:10.3390/jcm7060126

Abstract

The history of percutaneous coronary intervention (PCI) is marked by rapid technological advancements that have taken place over the past 40 years. After a period of balloon angioplasty, which was marred by risk of abrupt vessel closure and vessel recoil, balloon expandable metal alloy stents were the mainstay of PCI. The introduction of drug eluting stents (DES) targeted in-stent restenosis, a common mode of stent failure, and ushered in the current PCI era. Since the first generation of DES, advances in polymer science and stent design have advanced the field. The current generation of DES has thin struts, are highly deliverable, have biocompatible or absorbable polymers, and outstanding safety and efficacy profiles. In this review, we discuss the technological advancements in stent development, design, and construction, with an emphasis on balloon expandable stents. The aspects of stent properties, metal alloys, bioresorbable vascular scaffolds, drug elution, and polymers will be covered.

Highlights

Cardiovascular disease is highly prevalent, affecting an estimated 92.1 million people in the United States in 2017 [1,2]
Developed by Dr Gruentzig, plain old balloon angioplasty (POBA) was effective in increasing the intracoronary lumen size through the mechanism of plaque fissuring, but it was limited by the risk of abrupt closure (1 percent) and the lack of durability because of the early vessel recoil (5–10 percent) and restenosis [4,5,6,7]
We effectively resolved the problem of the acute vessel closure with bare metal stents (BMS), and later developed drug eluting stents (DES) to minimize restenosis

Summary

Introduction

Cardiovascular disease is highly prevalent, affecting an estimated 92.1 million people in the United States in 2017 [1,2]. Developed by Dr Gruentzig, POBA was effective in increasing the intracoronary lumen size through the mechanism of plaque fissuring, but it was limited by the risk of abrupt closure (1 percent) and the lack of durability because of the early vessel recoil (5–10 percent) and restenosis [4,5,6,7]. The routine stent placement evolved to become the standard of care in PCI because of the lower rate of restenosis, compared to POBA [10,11]. A nickel titanium alloy, has a very low elastic modulus, so it will deform quickly when it is subjected to opposing forces along an axis. The materials with a high yield strength will maintain their original conformation unless they are subjected to a force that is higher than their yield strength [13]. Restenosis, inflammation, radial strength, radio-opacity Plaque prolapse, side branch access, gaps in drug delivery

Metal Alloy Component

Scaffold Construction

Self-Expanding Coronary Stents

Bioresorbable Vascular Scaffolds

Findings

Conclusions