Evaluation of a novel gel-based ureteral stent with biofilm-resistant characteristics

Purpose

Current ureteral stents, while effective at maintaining a ureteral lumen, provide a substrate for bacterial growth. This propensity for biofilm formation may be a nidus for bacterial growth leading to infection and a reason for early removal of a stent before it is clinically indicated. A newly devised stent, composed of a highly hydrated, partially hydrolyzed polyacrylonitrile polymer, is believed to have bacterial resistant properties. The objective of this study is to evaluate the biofilm growth and bacterial resistant properties of this novel stent.

Materials and methods

Multiple 1 cm sections of the pAguaMedicina? Pediatric Ureteral Stent (pAMS) (Q Urological, Natick, MA) and the conventional polymer stent (SS) (Boston Scientific, Natick, MA) were incubated for 3 days in the 3 different growth media. Afterward, J96 human pathogenic Escherichia coli was added. At 3, 6, 9, 12, and 15 days following bacterial inoculation, the stent segments were washed, sonicated, and analyzed for bacterial growth. Scanning electron microscopy (SEM) imaging was performed to assess biofilm formation.

Results

pAMS demonstrated significant reductions (43–71 %) in bacterial counts when compared to standard stents in all conditions tested. SEM imaging demonstrated biofilm formation on both types of stents in all media, with a relative reduction in apparent cell debris and bacteria on the pAMS.

Conclusions

In this study, the gel-based stent shows a demonstrable reduction in bacterial counts and biofilm formation. The use of the pAMS may reduce the risk of infection associated with stent usage.