Purpose: Ureteral stents often result in patient morbidity and the potential for a forgotten stent. When the suture tether is detached, a secondary procedure is required for removal. Previous attempts at developing biodegradable ureteral stents have been unsuccessful since those stents were not biocompatible or they failed to degrade in timely fashion. We evaluated a new biodegradable Double-J stent in a porcine model.
Materials and methods: A total of 36 Yorkshire pigs were stented unilaterally with a biodegradable Uriprene stent or a standard biostable control stent. Excretory urograms, and blood and urine tests were performed at weeks 2, 3, 4, 5, 7 and 10. Four animals per group were sacrificed after 2, 4, 7 and 10 weeks to determine stent degradation and obtain samples for pathological evaluation.
Results: Degradable ureteral stents began to degrade at 3 weeks. By weeks 7 and 10, 60% and 100% of the stents, respectively, were fully degraded. There was no significant difference in laboratory parameters or the amount of hydronephrosis between the 2 groups. However, ureteral dilatation was significantly more pronounced in the control group than in the Uriprene group. The novel stent was biocompatible on histological evaluation and it led to significantly less urinary tract infections than in controls.
Conclusions: The novel Uriprene stents provided drainage similar to that of regular stents and they were completely degraded by 10 weeks. Moreover, these stents resulted in less ureteral dilatation and fewer positive urine cultures. Biocompatibility was good and human trials will be forthcoming.