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

Abstract

Aims and objectives: 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.

Materials and methods: 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.

Results: 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).

Conclusions: 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.