Stents are implantable medical devices that are used in extending the life of a patient by propping open restricted passageways. In order to keep open the passageways, the stent should be made from a strong material, such as stainless steel. In additional, the material needs to be compatible with the human body. As stents, and implantable medical devices in general, are becoming more commonplace, understanding the materials and corrosion properties of the implants are essential in producing a high quality stent that can withstand the corrosive fluids of the human body.

Where does the word "stent" originate?
The word “stent” is commonly refered to a medical device that is implanted into the body to keep the blood vessels open. The word was first used in the 19th century to describe a dental impression compound. The inventor of the dental impression compound was Dr. Charles Stent. Dr. Stent was an English dentist that lived during the 19th century. He began selling his dental compound in 1856 through a dental supply company and he appropriately stamped the compound with “Stents”.

Examples
Stents are used in a variety of body parts; however, two of the more commonly known stent types are coronary and biliary.

Coronary Stent
A coronary stent is used to expand and open-up a constricted blood vessel. Typically, the stent is inserted into a coronary artery that has become blocked by fatty deposits. The stent expands and flattens the fatty deposits, thus opening the artery.

Biliary Stent
A biliary stent is used to open restrictions in the bile ducts. Bile, which is produced by the liver and is stored in the gale bladder, is a bodily fluid that helps to digest fats. The bile ducts can be constricted in a number of ways either by injury or by disease.