Plastic strains during stent deployment have a critical influence on the rate of corrosion in absorbable magnesium stents

Med Biol Eng Comput. 2017 Aug;55(8):1261-1275. doi: 10.1007/s11517-016-1584-8. Epub 2016 Oct 26.

Abstract

Magnesium stents are a promising candidate in the emerging field of absorbable metallic stents (AMSs). In this study, the mechanical and corrosion performance of dog-bone specimens and a specific stent design of a magnesium alloy, WE43, are assessed experimentally in terms of their corrosion behaviour and mechanical integrity. It is shown that plastic strains that are induced in the struts of the stent during stent deployment have a critical influence in directing subsequent corrosion behaviour within the material. In addition, the deployment and scaffolding characteristics of the magnesium stent are elucidated and contrasted with those of a commercial stainless steel stent. The magnesium stent is found to support higher levels of cyclic strain amplitude than the stainless steel stent, even prior to degradation, and this may play a role in reducing in-stent restenosis. This study provides new insights into the experimental performance of a current AMS design and material whilst demonstrating the critical influence of plastic strain on the corrosion performance and scaffolding ability of an AMS.

Keywords: Absorbable metallic stents; Biodegradable magnesium alloys; Biomaterials; Cyclic strain; WE43.

MeSH terms

  • Absorbable Implants*
  • Alloys / chemistry
  • Animals
  • Blood Vessel Prosthesis*
  • Compressive Strength
  • Computer-Aided Design*
  • Corrosion*
  • Dogs
  • Elastic Modulus
  • Equipment Failure Analysis
  • Magnesium / chemistry*
  • Prosthesis Design
  • Stents*
  • Stress, Mechanical
  • Surface Properties
  • Tensile Strength

Substances

  • Alloys
  • Magnesium