Self-expandable metallic stent – wikipedia gas up


Self-expandable metallic stents are cylindrical in shape, and are devised in a number of diameters and lengths to suit the application in question. [1] They electricity 24 hours typically consist of cross-hatched, braided or interconnecting rows of metal that are assembled into a tube-like structure. SEMS, when unexpanded, are small enough to fit through the channel of an endoscope, which is meant for delivery of devices for therapeutic endoscopy. They expand through a deployment device which is placed at the end of the SEMS, and are held in place against the wall of the luminal surface by friction. [2]

SEMS may be coated with chemicals designed to prevent tumour ingrowth; these are f gas logo termed covered stents. Nitinol [3] (a shape memory nickel- titanium alloy), polyurethane, [4] and polyethylene [5] are typically used as coatings for SEMS. Covered stents carry the advantage of preventing tumours from growing into the stent, although they run the risk of increased migration after deployment. [6]

A plastic self-expanding stent (Polyflex, Boston Scientific) has also been wireless electricity how it works developed for similar applications. It confers an additional advantage as it is designed to be removable, and may have a less 4 gases in the atmosphere traumatic insertion than metal stents. The Polyflex stent has shown benefit in palliation of esophageal malignancies. [7] Applications [ edit ]

The primary application of SEMS is in the palliation of tumours that obstruct the gastrointestinal tract. When they expand within the lumen, they are able to hold open the structure and allow passage of material, such as food, stool, or other secretions. The usual applications are for cancers of the esophagus, pancreas, bile ducts and colon that are not 76 gas card login amenable to surgical therapy. SEMS may be used to treat additional complications of cancer, such as tracheoesophageal fistulas that may result from esophageal cancer, [8] and gastric outlet obstruction which may result from stomach, duodenal or pancreatic cancer. [9]

SEMS and self-expanding plastic stents have also been used for non-malignant conditions that cause narrowing or leaks of the esophagus gas works park address or colon. These include peptic strictures caused by esophageal reflux [10] and perforations of the esophagus. [11] SEMS may also be placed in tandem fashion to treat ingrowth or overgrowth tumours, and fractures or migration of other SEMS. For the latter, the second SEMS in usually deployed within the lumen of the gas dryer vs electric dryer operating cost first. [12]

Esophageal SEMS are placed after a gastroscopy is performed to identify the area of narrowing. The area may need to be dilated in order to allow the gastroscope to pass. [14] The tumour is usually better seen with the direct vision of endoscopy than on a fluoroscopic image. As a result, radio-opaque markers are usually placed on the surface of the patient in order to mark the area of narrowing on fluoroscopy. The SEMS gas x ultra strength directions is placed through the channel of the endoscope into the esophagus over a guidewire, marked on fluoroscopy, and mechanically deployed (using a device that sits outside of the endoscope) such that it expands when in position. Hypaque or other water-soluble dye may be placed through the passage to ensure patency of the stent on fluoroscopy. [15] Enteric and colonic SEMS are inserted in a similar electricity and magnetism worksheets 8th grade fashion, but in the duodenum and colon respectively. [16]

Biliary SEMS are used to palliatively treat tumours of the pancreas 8 gas laws or bile duct that obstruct the common bile duct. They are inserted at the time of ERCP, a procedure that uses endoscopy and fluoroscopy to access the common bile duct. The bile duct is cannulated with the assistance of a guidewire and the sphincter of Oddi that is located at its base is typically cut. A wire is kept in the bile duct, and the SEMS is deployed over gas mileage comparison the wire in a similar fashion as esophageal stents. The location of the SEMS is confirmed by fluoroscopy. [17] Complications [ edit ]

• ^ a b Yoshida H, Mamada Y, Taniai N, Mizuguchi Y, Shimizu T, Aimoto T, Nakamura Y, Nomura T, Yokomuro S, Arima Y, Uchida E, Misawa H, Uchida E, Tajiri T (2006). Fracture of an expandable metallic stent placed for biliary obstruction electricity production in usa due to common bile duct carcinoma. J Nippon Med Sch. 73 (3): 164–8. doi: 10.1272/jnms.73.164. PMID 16790985.

• ^ Garcia-Cano J; Gonzalez-Huix F; Juzgado D; Igea F; Perez-Miranda M; Lopez-Roses L; Rodriguez A; Gonzalez-Carro P; Yuguero L; Espinos J; Ducons J; Orive V; Rodriguez S. (2006). Use of self-expanding metal stents to treat malignant colorectal obstruction in general endoscopic practice (with videos). Gastrointest Endosc. 64 (6): 914–920. doi: 10.1016/j.gie.2006.06.034. PMID 17140898.

• ^ Vakil N, Morris A, Marcon N, Segalin A, Peracchia A, Bethge N, Zuccaro G, Bosco J, Jones W (2001). A prospective, randomized, controlled hp gas kushaiguda trial of covered expandable metal stents in the palliation of malignant esophageal obstruction at the gastroesophageal junction. Am J Gastroenterol. 96 (6): 1791–6. doi: 10.1111/j.1572-0241.2001.03923.x. PMID 11419831.