Dr.S.Venkatesan MD

Originally used in early 1990s,  self expanding coronary stents (Wall stent from Boston scientific )  subsequently lost interest because of delivery related issues. Many feel , it makes cardiologist judgment tentative and delivery system prevail over our hand skills. It is possible stents can longitudinally jump with high radial force making a geographical miss more likely.While it could be true with any technique till we master it, one should recall ,most endo-vascular work other than coronary still involve self expandable techniques.

Balloon expandable  stent is ruling the PCI field  for more than 2 decades. There has been recent surge of interest in the self expanding  technique and it could make a great difference in the PCI arena provided we take the proper cues.

Self expanding stents have some unique advantage

• It has  high radial force.
• Approximation with lesion is best
• It tends to take the shape of the vessel than any other stent
• Since the mal-opposition and gap between stent and vessel wall is minimal stent thrombosis is theoretically is  lower.

Where is self expanding stent useful ?

• Ectatic and very irregular lesions
• Bifurcation lesions where multi dimensional vessels with different shaped ostia converge.
• Eccentric lesions (Non calcified) may be benefited by self expanding stents
• Self expanding covered self (Is it available >)  may be the best bet for perforations and for thrombus  to be plastied against the wall.
• In some small vessels PCI
• Finally it may have a  role in primary PCI (APPOSITION 1 to 5 )

What are the self expanding stents available ?

1.  Devax system   ( 2003)
2.  Stentys
3.  Radius (Boston scientific)
4. Capella Sideguard.
5. Cardiomind Sparrow
6. vProtect luminal shield.

Final message

For some reason , self expanding stents were not tested widely  and  large scale data is not available. However ,  they are unique modalities in metal delivery and must be mastered and many patient subsets will be benefited by it. They are not obsolete yet, APPOSITION 5 study will answer some of the issues.

Reference