The materials used in the fabrication of self-retained internal ureteral stents should provide strength, flexibility, low surface friction, radiopacity, biodurability, biocompatibility, and reasonable unit cost. Polymeric biomaterials currently used for stent construction include polyurethane, silicone, Silitek, C-Flex, and Percuflex. Comparative evaluation of these materials in the context of the requirements for stent structure and function suggests advantages and disadvantages for all of them. We believe that the most important attributes for an internal ureteral stent are ease of insertion, effective restoration and maintenance of flow, resistance to migration, significant biodurability, and biocompatibility. Based on our physical testing of stents fabricated from these materials, as well as clinical and laboratory experience, we believe that C-Flex and Percuflex are the most suitable materials for stent construction.

Definitive surgical treatment of ureteral obstruction may not be appropriate in patients with advanced malignancy, complex benign ureteral disease or even simple obstructive disease accompanied by unacceptable operative risk. Endoscopic placement of self-retained internal ureteral catheters (stents) offers satisfactory relief for many of these patients. A new 6F pigtail ureteral stent and placement technique are described. These stents are placed easily, effective and well tolerated for short-term drainage in selected patients with ureteral obstruction.