Chapter 4 STENT DESIGNS Stents are small meshed spring like tubular structures used in angiolplasty to treat the narrow or weak coronary arteries that carry blood. The implantation of stent prevents the arteries from blowing out for a longer duration after surgery. One of the causes for blockage of arteries is the plaque deposition in the inner parts that eventually block the blood flow and may also lead to heart attacks. Stents are embedded in the arteries by the process called as PCI. In PCI stents circum surfaces a balloon attached to a flexible tube which is inserted in the body through thighs. After reaching the desired location, balloon is inflated in order to expand the stent and compress them against the plaque depositions. Once the arterial wall is compressed and the stents are fixed in them, the balloon deflates and the flexible pipe is removed from the body. Thus after the surgery stent is expected to perform its function for tenure of 10-12 years but there are certain chances that the arteries will become narrow again. Stents expanded using balloon in artery Properties of Stents
Stents are expected to possess the following conventional properties - Excellent radial strength.
- Conformability to vessel walls
- Remarkable Deliverability
- Unique recoil
- Low foreshortening
- Optimal surface finish Advanced features
- Optimal design with minimum artery to stent surface…