Long-Term Indwelling Tandem Polymeric Ureteral Stents for Benign Ureteral Obstruction

Objective: To assess the outcome of tandem polymeric internal stents (TIS) for benign ureteral obstruction (BUO). Material and Methods: We conducted a retrospective study that included all consecutive patients treated for BUO by means of TIS in a single tertiary center. Stents were replaced routinely every 12 months or earlier, when indicated. The primary outcome was permanent stent failure, and the secondary outcomes included temporary failure, adverse events, and renal function status. Kaplan–Meier and regression analyses were used to estimate outcomes, and logistic regression was used to assess the association between clinical variables and outcomes. Results: Between July 2007 and July 2021, 26 patients (34 renal units) underwent a total of 141 stent replacements, with median follow-up of 2.6 years (interquartile range [IQR] 0.75–5). Retroperitoneal fibrosis was the leading cause of TIS placement (46%). Permanent failures occurred in 10 (29%) renal units, and the median time to permanent failure was 728 days (IQR 242–1532). There was no association between preoperative clinical variables and permanent failure. Temporary failure occurred in four renal units (12%), which were treated by nephrostomy and eventually returned to TIS. Urinary infection and kidney injury rates were one event for every four and eight replacements, respectively. There was no significant alteration in serum creatinine levels throughout the study (p = 0.18). Conclusion: TIS provides long-term relief for patients with BUO and offers a safe and effective solution for urinary diversion, while avoiding the need for external tubes.