Long-term outcomes of two types of metal stent for chronic benign ureteral strictures

Background: We aimed to compare the results of long-term use of two types of metal stent for chronic benign ureteral strictures. Methods: Our study included 46 ureter units (UUs) that underwent metal stent placement from 2010 to 2017. We included benign ureteral strictures causes by variety reasons that could not be solved by other treatment and malignant obstructions were excluded. Covered mesh stent (Uventa™) and a thermo-expandable stent (Memokath 051™) were used. Primary success was defined as maintaining patency without procedures and overall success was defined as maintaining patency with additional procedures. Results: We placed covered mesh stents in 25 UUs and thermo-expandable stents in 21 UUs. The mean follow-up duration of each stent was 41.4 ± 23.1 and 34.4 ± 16.5 months (p = 0.250). In the first year of stent insertion, primary success was achieved in 54.9 and 70.4% (p = 0.204). Overall success was achieved in 78.7 and 75.4% in same duration, respectively (p = 0.586). Longer stent placement had positive predictive value on both success rates (HR = 0.185, p = 0.047 and HR = 0.111, p = 0.018). Prior radiation therapy and non-pelvic ureter stricture both adversely affected the overall success rate (HR = 5.412, p = 0.048 and HR = 4.203, p = 0.030). Previous PCN status had negative predictive value for both success rates (HR = 4.014, p = 0.003 and HR = 3.064, p = 0.035). Conclusions: The treatment outcomes of two types of metal stent were comparable, especially in the first year of stent insertion.