Biocompatibility of various indwelling double-J stents.

The biocompatibility of 8 double-J stent brands was evaluated both in vivo, by scanning electron microscopy and histological analysis of pig ureters intubated for 6 weeks, and in vitro, by cell culture methods. In vivo findings showed that superficial epithelial destruction was milder in the ureters intubated with hydrogel-coated stents than in those intubated with other stents. Inflammatory reactive changes were milder in the ureters intubated with silicone stents than in those intubated with other stents, while encrustation was more severe on silicone and Grey stents than the others. In vitro, the 3 stent brands made of "modified polyurethane" were found to be cytotoxic while the others were not. Overall, silicone and hydrogel-coated stents seemed to be more biocompatible than the others, and hydrogel-coated stents to be more suitable than silicone stents for long-term ureteral stenting, being less prone to encrustation. Although they are of an experimental nature, these findings may be of relevance to clinical practice.