Kumar A et al, 2014: A prospective randomized comparison between shock wave lithotripsy and flexible ureterorenoscopy for lower calyceal stones ≤ 2 cm:A single center experience.
Kumar A, Vasudeva P, Nanda B, Kumar N, das MK, Jha SK
VMMC and Safdarjung Hospital, Urology , Department of Urology , New Delhi, Delhi, India
Abstract
Aims and Objectives: The optimal management method of lower calyceal calculi is still undefined. We performed a prospective randomized comparison to evaluate safety and efficacy of shock wave lithotripsy and flexible ureteroscopy for lower calyceal calculus ≤ 2 cm. Materials and Methods: Between Dec 2011 and Jan 2012, 195 patients with single radio-opaque lower calyceal calculi ≤ 2 cm were included in the study. Randomization was done into 2 groups - Group A: SWL performed as an outpatient procedure using electromagnetic lithotripter (Dornier compact delta) and Group B: RIRS was performed using 6/7.5 F flexible ureteroscope (Richard Wolf, Germany) 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 12.1mm 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 to 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 calyceal calculi ≤ 20mm. 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.
J Endourol. 2014 Sep 9. [Epub ahead of print]
Comments 1
Although a lower rate of stone- or fragment clearance can be expected after SWL in comparison with RIRS, the re-treatment rates in the SWL-treated patients was surprisingly high. One could speculate that by only using surface anaesthesia and diclophenac, it sometimes was impossible to use the energy levels necessary for optimal stone disintegration. Nevertheless it is interesting that albeit the higher degree of stone clearance following RIRS, the results were not remarkably different. It is of note that as many as 29.3% of the RIRS-treated patients required auxiliary procedures.
In terms of STI (stone treatment index; [1]) calculated after corrections of minor errors in the tables and with an estimated short diameter of the stones, higher - and better - values were recorded for patients treated with SWL. This difference is mainly explained by absence of general or regional anaesthesia (STI-calculations shown in the table below).
Reference.
1. Tiselius HG, Ringdén I. Stone treatment index: a mathematical summary of the procedure for removal of stones from the urinary tract. J Endourol. 2007 21:1261-1269.