Advertisement

European Radiology

, Volume 14, Issue 2, pp 292–301 | Cite as

Self-expanding nitinol stents: material and design considerations

  • Dieter StoeckelEmail author
  • Alan Pelton
  • Tom Duerig
Vascular–Interventional

Abstract

Nitinol (nickel–titanium) alloys exhibit a combination of properties which make these alloys particularly suited for self-expanding stents. Some of these properties cannot be found in engineering materials used for stents presently. This article explains the fundamental mechanism of shape memory and superelasticity, and how they relate to the characteristic performance of self-expanding stents. Nitinol stents are manufactured to a size slightly larger than the target vessel size and delivered constrained in a delivery system. After deployment, they position themselves against the vessel wall with a low, "chronic" outward force. They resist outside forces with a significantly higher radial resistive force. Despite the high nickel content of Nitinol, its corrosion resistance and biocompatibility is equal to that of other implant materials. The most common Nitinol stents are listed and described.

Keywords

Self-expanding Nitinol stents Nickel Titanium Shape memory Superelasticity 

References

  1. 1.
    Dotter CT, Buschmann PAC, McKinney MK, Rösch J (1983) Transluminal expandable nitinol coil stent grafting: preliminary report. Radiology 147:259PubMedGoogle Scholar
  2. 2.
    Shabalovskaya S (1996) On the nature of the biocompatibility and medical applications of NiTi shape memory and superelastic alloys. Bio Med Mat Eng 6:267Google Scholar
  3. 3.
    Duerig TW, Melton KN, Wayman CM, Stöckel D (1990) Engineering aspects of shape-memory alloys. Butterworth-Heinemann, LondonGoogle Scholar
  4. 4.
    Stoeckel D (2000) Nitinol medical devices and implants. Min Invas Ther Allied Technol 9:81Google Scholar
  5. 5.
    ASTM F 2063–00 (2002) Standard specification for wrought nickel–titanium shape-memory alloys for medical devices and surgical implantsGoogle Scholar
  6. 6.
    ASTM F 2004–00 (2002) Test method for transformation temperature of nickel-titanium alloys by thermal analysisGoogle Scholar
  7. 7.
    ASTM F 2082–01 (2002) Method for the determination of transformation temperature of nickel–titanium shape-memory alloys by bend and free recoveryGoogle Scholar
  8. 8.
    Pelton AR, DiCello J, Miyazaki S (2000) Optimisation of processing and properties of medical grade Nitinol wire. Min Invas Ther Allied Technol 9:107Google Scholar
  9. 9.
    Wever DJ, Veldhuizen AG, Sanders MM, Schakenraad JM (1997) Cytotoxic, allergic and genotoxic activity of a nickel–titanium alloy. Biomaterials 18:1115CrossRefPubMedGoogle Scholar
  10. 10.
    Wever DJ, Veldhuizen AG, de Vries J, Busscher HJ, Uges DRA, van Horn JR (1998) Electrochemical and surface characterization of a nickel–titanium alloy. Biomaterials 19:761CrossRefPubMedGoogle Scholar
  11. 11.
    Brown SA, Hughes PJ, Merritt K (1988) In vitro studies of fretting corrosion of orthopaedic materials. J Orthop Res 6:572PubMedGoogle Scholar
  12. 12.
    Barrett RD, Bishara SE, Quinn JK (1993) Biodegradation of orthodontic appliances: part I, biodegradation of nickel and chromium in vitro. Am J Orthod Dentofac Orthop 103:8Google Scholar
  13. 13.
    Bishara SE, Barrett RD, Selim MI (1993) Biodegradation of orthodontic appliances. Part II: Changes in the blood level of nickel. Am J Orthod Dentofac Orthop 103:115Google Scholar
  14. 14.
    Ryhanen J, Niemi E, Serlo W, Niemelä E, Sandvik P, Pernu H, Salo T (1997) Biocompatibility of nickel–titanium shape-memory metal and its corrosion behavior in human cell cultures. J Biomed Mater Res 35:451PubMedGoogle Scholar
  15. 15.
    Trepanier C, Venugopolan R, Messer R, Zimmerman J, Pelton AR (2000) Effect of passivation treatments on nickel release from Nitinol. Proc Soc Biomater:1043Google Scholar
  16. 16.
    ASTM F2129–01 (2002) Standard test method for conducting cyclic potentiodynamic polarization measurements to determine the corrosion susceptibility of small implant devicesGoogle Scholar
  17. 17.
    Trepanier C, Tabizian M, Yahia LH, Bilodeau L, Piron DL (1998) Effect of modification of oxide layer on NiTi stent corrosion resistance. J Biomed Mater Res 43:433CrossRefPubMedGoogle Scholar
  18. 18.
    Trepanier C, Fino J, Zhu L, Pelton AR (2002) Corrosion resistance of oxidized Nitinol. SMSTGoogle Scholar
  19. 19.
    Heintz C, Riepe G, Birken L, Kaiser E, Chafke N, Morlock M, Delling G, Imig H (2001) Corroded Nitinol wires in explanted aortic endografts: an important mechanism of failure? J Endovasc Ther 8:248PubMedGoogle Scholar
  20. 20.
    Kaiser E (2002) Cell-induced corrosion in vitro. Second European Sym Vasc Biomat, HamburgGoogle Scholar
  21. 21.
    Duerig TW, Pelton AR, Stöckel D (1996) The use of superelasticity in medicine. Metall 50:569Google Scholar
  22. 22.
    Duerig TW, Tolomeo DE, Wholey M (2000) An overview of superelastic stent design. Min Invas Ther Allied Technol 9:235Google Scholar
  23. 23.
    Harnek J, Zoucas E, Stenram U, Cwikiel W (2002) Insertion of self-expandable Nitinol stents without previous balloon angioplasty reduces restenosis compared with PTA prior to stenting. Cardiovasc Intervent Radiol 5:430CrossRefGoogle Scholar
  24. 24.
    Duda S, Wiskirchen J, Tepe G, Bitzer M, Kaulich TW, Stoeckel D, Claussen C (2000) Physical properties of endovascular stents: an experimental comparison. J Vasc Interv Radiol 11:645PubMedGoogle Scholar
  25. 25.
    Sigwart U (1996) The coiled sheet concept. In: Sigwart U (ed) Endoluminal stenting. Saunders, London, pp 249–250Google Scholar
  26. 26.
    Stoeckel D, Bonsignore C, Duda S (2002) A survey of stent designs. Min Invas Ther Allied Technol 11:137CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2004

Authors and Affiliations

  1. 1.Nitinol Devices and ComponentsFremontUSA

Personalised recommendations