Monitoring the Wall Mechanics During Stent Deployment in a Vessel

Summary

Stent-induced arterial strain distributions are characterized using an optical surface strain measurement system. This visualization technique is used to gain insights into the impact of stent implantation on the host vessel.

Abstract

Clinical trials have reported different restenosis rates for various stent designs¹. It is speculated that stent-induced strain concentrations on the arterial wall lead to tissue injury, which initiates restenosis^2-7. This hypothesis needs further investigations including better quantifications of non-uniform strain distribution on the artery following stent implantation. A non-contact surface strain measurement method for the stented artery is presented in this work. ARAMIS stereo optical surface strain measurement system uses two optical high speed cameras to capture the motion of each reference point, and resolve three dimensional strains over the deforming surface^8,9. As a mesh stent is deployed into a latex vessel with a random contrasting pattern sprayed or drawn on its outer surface, the surface strain is recorded at every instant of the deformation. The calculated strain distributions can then be used to understand the local lesion response, validate the computational models, and formulate hypotheses for further in vivo study.

Protocol

1. Preparation of the Latex Vessel

1. Fix both ends of the latex vessel to barbed hose connections, which are fastened on a sturdy workbench.
2. Measure the area of interest on latex vessel to determine the field of view. The area of interest for a stent test should be centered between the barbed hose connectors and include approximately one inch on each side of the stent in order to observe the strains outside the stented area.
3. Record the distance from the outside edge of one barbed hose connector to the center location between the connectors, which is also the approximate center of the latex vessel. Translate the distance onto the catheter ....

Discussion

The stereo optical surface strain measurement system is used to measure the local strains over the deforming surface for both the in- and out-of-plane motions without contacting the specimen. This system uses two high-speed optical cameras to take pictures of a random contrasting pattern putting on the surface to construct accurate measurements of motions of each point, with a high accuracy of resolving surface strains.

It should be noted that the required contrasting pattern need adheres to .......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
ARAMIS Camera System	GOM: Optical Measuring Techniques
PALMAZ Genesis TRANSHEPATIC BILIARY STENT	Cordis Corporation	PG5910B	Balloon-expandable stent
Z-MED Balloon Dilatation Catheter	B. Braun Medical Inc.	PDZ336	Balloon dilatation catheter