Experience of retaining encrusted ureteral stents: URL by 4.5/6.5F ureteroscope can reduce the possibility of PCNL

The purpose of the study was to present our experience of retaining encrusted ureteral stents (EUS) and discuss the effectiveness of 4.5/6.5F ureteroscope (URS) in the procedure. The data of patients with EUS in our center from January 2012 to December 2016 were retrospectively analyzed. The inclusion criterion was ureteral stents that required intervention above the ureteral orifice to retain and was proved to be encrusted. Impacted stents would be removed by ureteroscope lithotripsy (URL) via 8/9.8F or 4.5/6.5F URS. Percutaneous nephrolithotomy (PCNL) then be the further step if URL failed. 46 cases of EUS were treated in 36 patients from January 2012 to December 2016 in our institution. All subjects consisted of 18 males and 18 females; the average age was 49.81 +/- 16.40 years (range 5-86). The mean time from stent insertion to encrustation was 9.28 +/- 17.15 months (range 1-120). URL was performed in 44 cases (95.7%), including 19 cases (41.3%) by 8/9.8F URS and 25 cases (54.4%) by 4.5/6.5F URS due to the conventional URS's failure to get into ureteral orifice or further part of ureter. Two patients (4.3%) underwent PCNL due to the inseparable circle developed by the intra-renal segment of encrusted stents. None of the patients underwent extracorporeal shock wave lithotripsy (ESWL) and open surgery. All stents were eventually removed without blood transfusion or ureteral injury, except three cases with post-operative fever. All procedures were performed under one-session anesthesia. URL by 4.5/6.5F ureteroscope might increase the success rate of retaining encrusted ureteral stents remarkably, and then reduce the possibility of PCNL effectively.