Effectiveness of ultrasound-guided shockwave lithotripsy and predictors of its success rate in pediatric population: A report from a national reference center

Abstract

Shockwave lithotripsy (SWL) remains a well-established treatment modality for many of the pediatric renal and ureteral stones. Repeated SWL sessions carry limitations due to the use of general anesthesia and X-ray radiation. The objective of our study was to evaluate stone-free rate (SFR) of 1-session of SWL for the management of pediatric renal and ureteral stones less than 2cm performed exclusively under ultrasound guidance and identify factors influencing its success. The study utilized a retrospective cohort design including 124 consecutive pediatric patients with 133 renal and ureteral stones less than 2cm whom SWL was performed in the period of January 2008 to December 2019. SWL procedures were performed by one expert surgeon in a single, national reference center, exclusively under ultrasound guidance using Modulith® SLK lithotripter. Follow-up was performed in post-SWL 2nd, 4th, 12th weeks and 6 months. The mean age of the children was 10 years (SD=6.0) and the mean stone size was 10.4mm (SD=3.6mm). Sedation type of anesthesia was used in 80 patients (64.5%). No major complication was developed, and no ureteral stenting was required in any of the patient following SWL. The SFR following 1-session of SWL was 88.0% at 12-week. Younger age (P=0.002), sedation type of anesthesia (P=0.001) and presence of radiolucent stones (P=0.033) significantly improved post-SWL early stone clearance on univariate analysis, the latter being the only significant factor according to final model (P=0.031). Ultrasound-guided SWL represents a safe and effective method for the management of both renal and ureteral stones in children. The SFR following 1-session of SWL at 12-weeks was achieved in 88.0%, the overall success rate after all SWL sessions reaching 91.7%. A higher success rate was observed in children harboring radiolucent stones.