Stent Recoil, Foreshortening, Compression
Balloon Expandable Stent – After Balloon Deflation

Stent Recoil, Foreshortening, Compression: Measured parameters

  • Stent recoil: Percentage by which the diameter of a stent decreases from its expanded diameter (when the balloon is inflated at the nominal pressure) to its relaxed diameter (when the balloon is retrieved from the stent).
  • Stent foreshortening: Percentage by which the length of a stent decreases from its crimped state to its deployed state (when the balloon is retrieved from the stent).
  • Stent Longitudinal Compression: Percentage by which the length of a deployed stent decreases when recrossed by a catheter.

Stent Recoil, Foreshortening, Compression: Scope

  • Balloon Expandable Stents
  • SS, CrCo Stent

ASTM F2081

Stent Recoil, Foreshortening, Compression: Associated tests

  • Dimensional attributes - Cardiovascular implants characterization
  • Stent radial force measurement
  • Accelerated Fatigue
  • Device Radiopacity

Stent Recoil: Test method description

A contactless optical gauging machine (Smartscope, OGP) is used (highest magnification: x145) to measure the undeployed stent length. It is then used to measure diameter at different sections and at 2 planes (perpendicular direction one from each other), both when the balloon is inflated at a specified pressure and per IFU and when the balloon is deflated. Finally the length of the expanded stent is measured. The stent recoil for each location and the stent foreshortening are then calculated. Specified balloon pressure is held 30 seconds in order to allow the balloon and/or stent to stabilize. The stent is free from external stress.

Stent Longitudinal Compression test method in anatomical models using the IDTE 2000

Stent Longitudinal Compression Study - EBR 2012