[Use of metal stents in gastroenterology]

A variety of metal stents have been increasingly used for malignant esophageal, biliary and colorectal stenoses. Esophageal self-expandable stents significantly reduce the early morbidity after implantation compared to conventional plastic prostheses. However they offer no benefit in the long-term due to various late complications. Biliary stents offer a significantly longer patency than plastic devices. This advantage is however clinically relevant only for patients with a survival time of more than three months. Preliminary trials indicate promising results for palliation of colorectal stenoses with metal stents in selected cases. Due to a lack of comparative studies the different types of metal stents must be selected on basis of their physical characteristics and clinical experiences. Most of the prostheses are irremovable which is a limitation for use in benign stenoses of the gastrointestinal and biliary tract. In addition metal stents are extremely expensive so that carefully designed trials are warranted for evaluation of the cost-benefit ratio.