Ureteral stents: past, present and future.

For three decades, intraureteral tubular devices have been used to maintain ureteral patency. The contribution of stents to modern urology is invaluable, since these devices are closely associated with everyday urologic practice. Polymeric stents represent the most commonly used type of stent, while metal stents are indicated in selected cases. Nevertheless, several problems have been observed related to the use of stents. Constant development of new biomaterials, together with improvements in design, attempts to overcome any stent-related adverse events.