Self-expandable metallic stent

A self-expandable metallic stent (or SEMS) is a metallic tube, or stent, used in order to hold open a structure in the gastrointestinal tract in order to allow the passage of food, chyme, stool, or other secretions required for digestion. SEMS are inserted by endoscopy, wherein a fibre optic camera is inserted either through the mouth or retrograde through the colon, in order to reach an area of narrowing. As such, it is termed an endoprosthesis. SEMS can also be inserted using fluoroscopy where an X-ray image is used to guide insertion, or used as an adjunct to endoscopy.