An endoprosthesis is a small, flexible tube called a stent, which is usually made of plastic and biocompatible material, which is used to repair or prevent body conduits. It is usually enters the body through a small incision and is used to treat the tubes that have been narrowed or blocked by diseases:the esophagus, bile ducts, trachea or bronchi. In addition, it is used in the treatment of aortic aneurysms. In this case, the stent is inserted through a small incision in the groin and advanced through the femoral artery into the aorta and the aneurysm to strengthen the vessel wall. Placed in the esophagus, the endoprosthesis is used to allow the passage of food;in the bile ducts used to open the passage of bile into the intestine;and the trachea and bronchi, allowing normal breathing. This method of surgery is minimally invasive vascular endoprosthesis.