J Korean Radiol Soc.  1999 Aug;41(2):275-280. 10.3348/jkrs.1999.41.2.275.

Physical Properties of a New Type of Self-expandable Nitinol Stent

• Park S
• Kim TH
• Song SW
• Kang SG
• Huh SJ
• Kim ES
• Kim CS
• Song HY

• KMID: 2103381
• DOI: http://doi.org/10.3348/jkrs.1999.41.2.275

Abstract

PURPOSE: To study the physical properties including hoop strength and flexibility of a newly developed nitinol stent. MATERIALS AND METHODS: The new stent was made of a single nitinol wire 0.15 -0 . 25 mm in diameter. This was wound around a cylindrical metallic jig with a constant angle to the longitudinal direction, and stents which varied with regard to wire thickness, number of wires at a lateral cut surface, and number of longitudinal windings were constructed. Hoop strength of the stents was measured with a spring gauge and compared with that of Wallstent and Hanaro stents. The flexibility of the new stent was evaluated on the basis of changes in s-tent diameter when bent in the direction of 180 degrees. RESULTS: Hoop strength of the new nitinol stent was proportional to 3.8(+/-0.3)-th power of the wire thickness. A greater number of wires on a lateral cut surface or a greater number of longitudinal windings also resulted in increased strength. However, the former caused an increase in total wire area and the latter resulted increased stent length when compressed. Hoop strength of the new nitinol stent was superior to that of Wallstent and Hanaro stents, and stent diameter did not decrease when the stent was bent in the direction of 180 degrees. CONCLUSIONS: Hoop strength of the new nitinol stent was most significantly affected by wire thickness. The s-tent was very flexible and thus seemed suitable for an angled lumen.

Keyword

Stents and prostheses

MeSH Terms

Pliability
Stents*
Wind
Wounds and Injuries