Comparison of conventional and step-wise shockwave lithotripsy in management of urinary calculi.

PURPOSE: In this clinical study, our aim was to evaluate the results of conventional and step-wise shockwave lithotripsy (SWL) in the management of urinary calculi.

PATIENTS AND METHODS: Fifty consecutive patients seen in our outpatient urology clinic were included and randomized in the clinical study. SWL was performed using a Dornier Compact Delta instrument. Treatment energy was set on 13 kV in the conventional group. In the step-wise SWL group, the patients were subjected to gradually increased (with every 500 shocks) output voltage as 11, 12, and 13 kV, respectively. The SWL session was completed with 13 kV thereafter. The maximum number of shocks in both groups was limited to 3,000.

RESULTS: Twenty-five patients in the conventional group and 25 patients in the step-wise SWL were included. The mean ages in the step-wise SWL group and the conventional group were 39.9 and 41.4 years (P > 0.05), respectively. The mean stone size was 0.83 +/- 0.51 cm in the step-wise SWL group and 0.70 +/- 0.41 cm in the conventional group (P > 0.05). There was no difference between the two groups as to the localization of stones in the ureter or kidney. Also, no statistical difference was observed in the number of lithotripsy treatments between the two groups. When we compared the results of two treatment procedures 8 weeks after the initial treatment, the success rate was significantly higher in the step-wise SWL group than in the conventional group (stone-free rate 96% (24/25) v 72% (18/25), P < 0.05)).

CONCLUSIONS: Step-wise SWL yielded better outcomes than conventional SWL without increased morbidity. Stepwise SWL can be considered as a management option for urinary calculi.