A prospective randomized comparison between shock wave lithotripsy and flexible ureterorenoscopy lower calcyeal stones less than 2 cm: a single center experience

INTRODUCTION AND OBJECTIVES: We have performed a prospective randomized comparison between flexible ureterorenoscopy(URS) and shock wave lithotripsy(SWL) for lower calyceal stones less than 2 cm to evaluate safety and efficacy of these procedures. METHODS: All the patients with a single radio-opaque lower calyceal stone less than 2 cm undergoing treatment between Jan 2011 and May 2012 in our department were included. Patients were randomized into 2 groups : Group A .: SWL was performed as an outpatient procedure using the electromagnetic lithotripter (Dornier Alpha Compact); Group B: Flexible URS was performed using 6/8.8 Fr dual channel flexible ureterorenoscope with holmium laser intracorporeal lithotripsy energy. The statistical analysis was performed in 2 groups regarding patient demographic profile, success rates, retreatment rates, auxiliary procedures, and complications. RESULTS: 90 patients were enrolled in each group. The mean stone size was 12.1 mm in group A vs. 12.3 mm in group B (p= 0.43). The overall 3 month stone free rate was (60/90) 66.6% for group A vs (78/90) 86.6% for group B (p=0.02).For stone size 10 mm, 3 month stone free rates were (38/53) 71.6% for group A vs (43/49) 87.7% for group B(p=0.32).For stone size between 10-20 mm, 3 month stone free rates were (22/37) 59.4% for group A vs (35/41) 85.4% for group B ( p=0.02).The retreatment rate was significantly greater in group A in comparison to group B (67.1% vs 1.1%, respectively; p < 0.001). The auxiliary procedure rate was comparable in both groups (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: Flexible URS was safe and highly efficacious in the treatment of lower calyceal stones less than 20mm.For upper ureteric stones 10 mm,SWL was safer, less invasive and with comparable efficacy in comparison to flexible URS.However,for upper ureteric stones between 10-20 mm,flexible URS was more effective, with a lesser retreatment rate than SWL.