A<unk>  (or<unk>  is a<unk>  tube, or stent that holds open a structure in the gastrointestinal tract to allow the passage of food, chyme, stool, or other secretions related to digestion. Surgeons insert<unk>  by endoscopy, inserting a fibre optic camera—either through the mouth or colon—to reach an area of narrowing. As such, it is termed an endoprosthesis.<unk>  can also be inserted using fluoroscopy where the surgeon uses an X-ray image to guide insertion, or as an adjunct to endoscopy. The vast majority of<unk>  are used to alleviate symptoms caused by cancers of the gastrointestinal tract that obstruct the interior of the tube-like (or luminal) structures of the bowel — namely the esophagus, duodenum, common bile duct and colon.<unk>  are designed to be permanent and, as a result, are often used when the cancer is at an advanced stage and cannot be removed by surgery.
Self-expandable metallic stent
Endoscopic stenting
Bare-metal stent
Embolization
Endoscopic submucosal dissection
Bioresorbable stent
Jejunoileal bypass
Natural orifice transluminal endoscopic surgery