To Investigate The Biocompatibility And Crust-preventing Potential Of Urteral Stent Coated With Nano-silver After Being Inserted Into Ureter

Objective:To investigate the biocompatibility and crust-preventing potential of urteral stent coated with nano-silver after being inserted into ureter.Methods:48 male rabbits were divided two groups randomly, including the experimental group of 24 rabbits which were treated with ureteral stents coated with nanometer-silver, and the control group of 24 rabbits which were treated with uncoated ureteral stents. Every 8 rabbits in the two group were killed 2, 4 and 8 weeks after being stented. The stents were taken out to measure the depth of crust on the surface of them by scanning electron microscope. The ureter were histopathologically examined to evaluate the histological reaction with Lumiaho system.Results:On the early stage (2-4 weeks), similar epithelial hyperplasia and inflammatory cell infiltration into laminae propria were found on the two groups (P>0.05). On the later stage (8 weeks), inflammatory reaction nearly disappeared on the experimental group. However, inflammatory tissue reaction induced by non-coated stent lasted throughout the observation period, even deteriorated with time going (p<0.05). The depth of crust on the surface of coated stents were 17.15±1.48μm , 51.01±10.19μm, 116.25±14.79μm after 2, 4 and 8 weeks, respectively. Whereas the depth of crust on the surface of uncoated stents were 16.79±2.14μm, 89.99±16.26μm, 181.21±19.45μm after 2, 4 and 8 weeks, respectively. No statistical difference was observed after 2 weeks. With time going, the crusts on treatment group were statistically less than those on the controls group (P<0. 05). Conclusions:The inflammatory tissue reaction induced by the ureteral stents coated with nano-silver was retrievable and more lightly. And it produced less crusts formation on its surface. These results suggest that the ureteral stents coated with nanometer-silver has good biocompatibility and crust-preventing potential.