Treatment of ureteral calculi with extracorporeal shock wave lithotripsy using the Lithostar device

Abstract

Shock wave requirements for fragmentation and the ultimate outcome after extracorporeal shock wave lithotripsy (ESWL) with the Lithostar device were analyzed in 107 renal units with solitary ureteral calculi. In situ treatment was done in 54 stones without prior manipulation and in 15 after failure of endoscopic manipulation. A total of 25 ureteral calculi was treated after bypass with a ureteral catheter or stent and 13 after push back to the pelvicaliceal system. Shock wave requirement for fragmentation was significantly higher for calculi of 101 to 400 mm. X mm. when compared with the requirement for smaller calculi. Shock wave requirement was also significantly higher for patients with similar sized stones treated in the prone compared to the supine position. The average number of shock waves required for disintegration was not significantly different among in situ or any of the manipulation categories of similar sized stone populations. Over-all satisfactory clearance was achieved in 77.5% of the treated ureteral calculi. Clearance status was unaffected by size up to 400 mm. X mm. and the position of the patient during treatment (prone or supine). Clearance of ureteral stones treated in situ without prior manipulation (76.5%) was numerically inferior, although statistically insignificant, to that for successfully manipulated calculi (bypassed 88% and pushed back 92.3%) but it was significantly better than the outcome obtained after failed manipulation (46.2%). ESWL with the Lithostar device is a successful mode of treatment within the entire ureteral length, and a vigorous attempt at push back before lithotripsy is unnecessary.