Nonvascular stents.

Stents or endoprostheses have evolved since their introduction. Initially used only in the vascular system, the use of stents has expanded to use in the biliary, urinary, and gastrointestinal tracts and in the tracheo-bronchial tree. Current use of stents includes treatment of both benign and malignant conditions, with the greatest impact in the palliation of malignant strictures. The biomechanics and types of stents used in each region is reviewed. The indications, insertion techniques, results, and complications of stents in each of the aforementioned regions are also reviewed.