Efficacy of extracorporeal shock wave lithotripsy for isolated lower caliceal stones in children compared with stones in other renal locations

Objectives. To evaluate the efficacy of extracorporeal shock wave lithotripsy (ESWL) monotherapy for isolated lower caliceal calculi in a pediatric age group and compare it with that for isolated middle/upper caliceal and renal pelvic calculi. Methods. We retrospectively reviewed the data of 151 renal units in 126 children treated with ESWL for isolated caliceal and renal pelvic stones from March 1992 to February 2004. The stones were localized in the lower, middle/upper calices, and renal pelvis in 50, 26, and 75 renal units, respectively. The results were compared with respect to renal location and stone burden. Results. The median patient age was 8 years (range 1 to 16). The median stone burden in the lower and middle/upper caliceal groups was significantly lower than in the renal pelvis group at 0.6, 0.6, and 1 cm(2), respectively (P = 0.002). The overall stone-free rate was 62% for lower calices, 65.3% for middle/upper calices, and 80% for renal pelvis stones. For the group with a stone size greater than 2 cm(2), the stone-free rate decreased to 33% in both lower and middle/upper calices; however, it was almost the same in the renal pelvis (81.8%). A highly significant relation was found between the stone burden and number of sessions (P < 0.001), but none between the stone burden and stone-free rate. Conclusions. In our study, ESWL was equally effective for stones in all locations. We recommend ESWL as the primary treatment of choice for stones less than 2.0 cm(2) in all caliceal locations. For the management of caliceal stones greater than 2.0 cm(2), prospective randomized trials comparing ESWL and percutaneous nephrolithotomy are necessary.