Value of Stents in Management of Ureteral Stones with Extracorporeal Shock Wave Lithotripsy

Abstract

Extracorporeal shock wave lithotripsy was used as an elective treatment in 292 stones located in the upper two-thirds of the ureter and in 103 patients with stones located below the iliac crest. Ureteral stents were used in 192 cases of upper ureteral stones, and these stents proved particularly useful for precise radiological stone localization, as a mechanical means to create a fluid interface around the stone, and as a means of pushing the stone into the kidney. A statistically significant difference was observed for calculi treated in situ without stent (85% stone free) v those relocated in the pyelocalyceal system (97.5% stone free, p < 0.02).

With one exception, all patients with lower ureteral calculi had additional endoscopic maneuvers—the placement of a stent in 39 and of a Zeiss loop in 63—with an overall stone-free rate of 95.1%. Loops appeared useful for repositioning stones lodged below the sacroiliac joint, in addition to creating a wider expansion chamber and causing atraumatic dilatation of the ureteral orifice. Combining stent or loop placement with other endoscopic maneuvers simplifies treatment of all ureteral stones and in some cases improves the results.