Extracorporeal shock wave lithotripsy for obstructed proximal ureteral stones. A prospective randomized study comparing in situ, stent bypass and below stone catheter with irrigation strategies.

In an attempt to assess the usefulness of a ureteral stent in facilitating disintegration of obstructed proximal ureteral stone with extracorporeal shock wave lithotripsy (ESWL), a prospective randomized study on 120 patients with ultrasonic evidence of hydronephrosis whose stone sizes were greater than 1.0 x 0.6 cm on KUB film and located above the level of L5 were allocated into three distinct treatment strategies: group 1: in situ without stone manipulation; group 2: bypass stones with stent, and group 3: placement of a catheter below stone with continuous saline irrigation. Of 77 patients, 26, 27 and 24 in each group, followed up for a period of 6 months with sufficient data for analysis, the stone-free rates were 76.9, 59.3 and 62.5%, respectively. The average number of shock waves delivered to accomplish a stone-free state were 3,245, 3,250 and 3,880 for individual groups and the comparisons among them were statistically insignificant (p's > 0.1). ESWL retreatment was common, being 33.3, 29.4 and 43.8%, respectively. Hydronephrosis has a major impact on the outcome of ESWL treatment, as more stone-free cases were found in the mildly hydronephrotic category than in the severer counterparts. About 90% of cases who finally were stone-free, passed all their stone fragments within 28 days. Ancillary procedures were needed in 13 (16.9%), 7 received ureterolithotomy, whilst 6 were removed of their stones by ureteroscopy.