Metallic Stents in the Gastrointestinal Tract Shiro Miyayama, M.D., Tetsuya Komatsu, M.D., Keiichi Taki, M.D., Tetsuya Minami, M.D., Chiharu Ito, M.D., Rieko Shinmura, M.D., Shigeyuki Takamatsu, M.D., and Miki Kobayashi, M.D. Department of Radiology, Fukuiken Saiseikai Hospital NICHIDOKU-IHO Vol. 48 No. 3 74 84 (2003) Summary Treatment with metallic stents in the gastrointestinal (GI) tract is a minimally invasive alternative to surgery or plastic esophageal tube insertion. Metallic stents were used initially for esophageal strictures. Following satisfactory results in the esophagus, stents have been applied to manage lesions in the stomach, duodenum, and colon. Esophageal stent placement is indicated for patients with malignant dysphagia or fistula due to inoperable primary or secondary esophagogastric neoplasms. Especially in patients with esophagorespiratory fistula, stent placement should be performed as soon as possible, because it may worsen the patient s general condition. Stent placement is also indicated in patients with benign strictures that cannot be managed by balloon dilation; however, the rates of delayed complications are extremely high when currently available stents are placed. Therefore, this procedure is indicated for treating a limited number of patients in the absence of other therapeutic alternatives. In esophageal lesions, covered stents are generally used to prevent tumor ingrowth and to seal the fistula. Technical success and clinical success are achieved in almost all patients. The complication rates seem to be acceptable, but fatal complications including esophageal perforation and massive hemorrhage have been reported, especially in patients treated in combination with irradiation therapy. Obstruction of the stomach, duodenum, and colon due to primary or secondary malignancies is an indication for stent placement. Preoperative stent placement is also performed to facilitate primary anastomosis and to avoid colostomy in patients with colonic obstruction due to resectable colonic carcinoma. In benign colonic strictures, metallic stents do not represent a viable alternative for final treatment and seem to be suitable only for consideration as temporary treatment. Bare stents are mainly used in the stomach, duodenum, and colon to prevent migration of the stent. The technical success rates and clinical success rates are extremely high. In colonic lesions, complications including perforation, migration, and hemorrhage occur, especially when stents are used as palliative treatment. When an Ultraflex stent (Boston Scientific) is used in the stomach, duodenum, or colon, placement of the stent is sometimes difficult because of the high resistance of the corrugated surface of the mounted portion and the weakness of the delivery catheter. Several minor modifications of the delivery system are frequently needed. Stent placement appears to be a simple and effective procedure, and it can quickly improve the poor general condition of a patient with GI tract obstruction. However, complication rates related to stent placement in the GI tract are higher than those for other organs. Fatal complications, such as perforation or massive hemorrhage, may occur. Further refinements of stent design and delivery system are required. Stent placement in a benign stricture is controversial. A retrievable stent or biodegradable stent might enable stents to be used to treat benign strictures.
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