Effects and side effects of ureteral stenting during extracorporeal shock wave lithotripsy

We retrospectively studied the effects and side effects of placing indwelling ureteral stents in 196 cases who underwent extracorporeal shock wave lithotripsy with a ureteral stent. The average period of ureteral stenting was approximately 22 days. Placing ureteral stents was mainly for large renal stones (79.3%), single kidney etc. There were no significant differences between the stunted and non-stunted patients with approximately 2 cm sized single renal stone with respect to the stone free rate, stone free period, and symptoms during stenting, which suggested that ureteral stenting might be unnecessary in those patients. High fever was highest in incidence of the symptoms and complications during stenting (17.2%). It occurred frequently in patients with infected stones or cystine stones. The percentages of pyrexia and stone street in patients using Towers type's stents were higher than those using the others. It was also shown that the bladder portions of the stents in patients using Towers peripheral ureteral stents were densely encased in calculous material and were very brittle. Fortunately the ureteral portions were removed intact. This study suggests that use of an indwelling ureteral stent may not contribute to the higher rate of being free of stones after the treatment of small to medium sized renal calculi, and that stents should be removed or changed early.