Mechanical properties of metallic stents: how do these properties influence the choice of stent for specific lesions?

Cardiovasc Intervent Radiol. Jan-Feb 2000;23(1):47-54. doi: 10.1007/s002709910007.

Abstract

Purpose: To assess selected balloon-expandable and self-expanding stents for radial force, flexibility, radio-opacity, and trackability, and to relate these physical characteristics to potential indications for placement.

Methods: Force-strain curves were plotted for each stent and the force required to produce 50% luminal narrowing was recorded. The ability of the stent to show elastic recoil following deformation was also noted. Flexibility was measured by bending the stents against a force transducer and recording the force required per degree of flexion. Radio-opacity was measured by comparing each stent against a standard aluminum step wedge. Trackability was measured by testing the ability of the stent on its delivery system to track over angles of 90 degrees and 60 degrees.

Results: The balloon-expandable stents showed greater radial strength and radio-opacity but, apart from the AVE Iliac Bridge stent, showed poorer flexibility and trackability. The self-expanding stents showed less radial force but were able to re-expand following deformity. They were generally more flexible and had better trackability but lower radio-opacity.

Conclusion: There is no stent which exhibits all the ideal properties required and therefore the interventionist will need to keep a range of stents available if all lesions are to be addressed.

Publication types

  • Comparative Study

MeSH terms

  • Alloys
  • Catheterization
  • Chromium Alloys
  • Equipment Design
  • Humans
  • Pliability
  • Stainless Steel
  • Stents*
  • Stress, Mechanical
  • Tantalum
  • Tensile Strength

Substances

  • Alloys
  • Chromium Alloys
  • Stainless Steel
  • nitinol
  • Tantalum