In medicine, a stent is either an expandable wire mesh or hollow perforated tube that is inserted into a hollow structure of the body to keep it open.
The main purpose of a stent is to overcome important decreases in vessel or duct diameter. Stents are often used to diminish pressure differences in blood flow to organs beyond an obstruction in order to maintain an adequate delivery of oxygen. Although perhaps the most popular use of stents is linked to the coronary arteries, they are widely used in several other structures, such as peripheral arteriesand veins, bile ducts, esophagus, tracheaor large bronchi, ureters, and urethra.
Prior to deployment, a stent is collapsed into a small diameter; current stents are self-expandable or can be dilated using an inflatable balloon. After expansion, stents are affixed to the vessel or duct wall by their own radial tension. These devices are most commonly inserted under fluoroscopic guidance or endoscopy, procedures that are generally less invasive than conventional surgery. This makes stents suitable for patients with advanced disease or those for whom otherwise the risk of major surgery is high. In addition, general anesthesia is usually not required for stent insertion. For these reasons, stents have offered clear benefits over conventional surgery that include, overall, shorter recovery periods and hospital stays, together with decreased morbidity and mortality in appropriately selected patients, that is, as long as their placement is clinically and reasonably indicated.
One of the weak points of vascular stents, however, is the development of a thick endothelial tissue inside the lumen, the so-called neointima. Development of a neointima is variable but can at times be so severe as to occlude back the vessel lumen (restenosis), especially in the case of smaller diameter vessels, which often results in reintervention. Thus, there is a strong body of research focusing on the reduction of neointima after stent placement. Considerable improvements have been made, including the use of more bio-compatible materials, anti-inflammatory drug-eluting stents, resorbable stents, and others. Fortunately, even if stents are eventually covered by neointima, the minimally invasive nature of their deployment makes reintervention possible and usually straightforward.
Stenting originally describes the action of stiffening garments. The word 'stent' has erroneously been linked to the English dentist Charles Stent(1845?1901), who was however responsible for a number of other innovations in medical treatment.
- Cardiovascular and Interventional Radiological Society of Europe
Categories: Medical treatment stubs| Implants| Cardiology| Radiology
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It uses material from the http://en.wikipedia.org/wiki/Stent Wikipedia article Stent.