A Prospective Randomized Comparison Between Shock Wave Lithotripsy and Flexible Ureterorenoscopy for Lower Caliceal Stones ≤2 cm: A Single-Center Experience

Abstract

The optimal management method of lower caliceal calculi is still undefined. We performed a prospective randomized comparison to evaluate safety and efficacy of shock wave lithotripsy (SWL) and flexible ureteroscopy (RIRS) for lower caliceal calculus ≤2 cm. Between December 2011 and January 2012, 195 patients with single radio-opaque lower caliceal calculi ≤2 cm were included in the study. Randomization was done into two groups-group A: SWL performed as an outpatient procedure using the electromagnetic lithotripter (Dornier compact delta) and group B: RIRS was performed using the 6F/7.5F flexible ureteroscope (Richard Wolf) with holmium laser intracorporeal lithotripsy. Demographic characteristics, success, retreatment, and auxiliary procedure rates and complications were analyzed statistically. Of 195 patients, 97 and 98 patients were enrolled in group A and B, respectively. Mean stone size was 12.1 mm in group A vs 12.3 mm in group B (p=0.52). The overall 3 month stone-free rate was (74/90) 82.2% for group A vs (78/90) 86.6% for group B (p=0.34); for stones <10 mm, it was (45/55) 84.9% for group A vs (43/51) 87.7% for group B (p=0.32) and for 10-20 mm stones, it was (29/35) 78.4% for group A vs (35/39) 85.4% for group B (p=0.12). Retreatment rate was significantly greater in group A compared with group B (61.1% vs 11.1%; p<0.001). Auxiliary procedure rate was comparable (21.1% vs 17.7%; p=0.45). The complication rate was 6.6% in group A vs 11.1% in group B (p=0.21). Both SWL and RIRS are safe and efficacious for lower caliceal calculi ≤20 mm. For stones <10 mm, SWL was less invasive and safer than RIRS with efficacy comparable to it. However, for 10-20 mm stones, RIRS was more effective, with lesser retreatment rate.