[Antirreflux ureteral catheters.].

Double-J ureteral stents disposal is associated with the appearance of side effects in up to 90% of the patients. The main causes of these symptoms are related to stent's design and the materials they are manufactured from. Vesicoureteral reflux and bladder trigone irritation are the etiopathogenic causes of ureteral stents associated morbidity. Due to this, and in order to improve patients' quality of life, stents that avoid reflux have been developed. Among anti-reflux designs, the first was a double-J stent the bladder tip of which is provided with a polymeric membrane that prevents retrograde flow of urine through its internal drainage channel. This design showed satisfactory vesicaresults, although not statistically significant. Their use in renal transplantation has also been assessed not only to decrease morbidity and ascending infection but also to improve graft survival. Other designs try to thin the distal end and even change it to a surgical suture thread, with the aim of eliminating the internal drainage channel in order to cause the minimum interference with the UVJ. Recently, two prototypes were evaluated in animal models and have achieved reduction of VUR. The first consists of a valve attached to the distal end of a traditional double-J stent, acting as a backflow prevention device. The second design is an intra-ureteral stent that acts like a double-J stent, but without crossing the UVJ and therefore preventing reflux completely. Nowadays, the use of these devices is not implemented in hospitals due to the absence of scientific evidence supporting the superiority of these designs over conventional stents.