A stent is a flexible, self-expandable, hollow metal or plastic tube that is used to help keep open an obstructed area of the GI tract that has been blocked by a late-stage malignant tumor. Enteral stents are used to help the patient continue to eat or as a preparation for surgery.
Upper GI stents were originally designed as rigid cylinders, resulting in poor efficacy and high complication rates. In recent decades, several types of flexible and self-expandable stents have been developed. Currently available upper GI stents include self-expandable metal stents (SEMS) for esophageal and gastroduodenal obstructions and self-expandable plastic stents (SEPS) for esophageal obstructions.