Ureteric calculi in children: preliminary experience with holmium:YAG laser lithotripsy

OBJECTIVE: To determine the efficacy and safety of holmium:YAG laser lithotripsy in children with ureteric calculi. PATIENTS AND METHODS: Between 1999 and 2003, 28 ureteroscopic laser procedures were carried out on 26 children (14 boys and 12 girls, mean age 6.5 years) with ureteric calculi. The mean (range) stone size was 1.21 (0.4-2.2) cm. At ureteroscopy the calculi were in the upper ureter in six (23%), mid-ureter in five (19%) and lower ureter in 15 (58%) patients. A rigid 8 F ureteroscope was used and the Ho:YAG laser energy delivered at 0.6-1.4 J and 6-10 Hz. All patients were evaluated after 3 months with intravenous urography to confirm stone clearance and to exclude ureteric stricture formation. RESULTS: The overall stone-free rate was 92% (24 children) after 28 ureteroscopic procedures. Stones were completely cleared in 83%, 80% and 100% of the procedures in the upper, mid- and lower ureters, respectively. In two children the procedure failed; they were salvaged by ureterolithotomy in one and extracorporeal shockwave lithotripsy in the other. During the procedures, a ureteric perforation was caused by several factors, including a technically difficult procedure and higher laser energy. At the mean (range) follow-up of 18 (3-39) months, low grade vesico-ureteric reflux was detected in two children, and there were no ureteric strictures in any. CONCLUSION: Holmium:YAG laser lithotripsy is an efficient and safe treatment for ureteric calculi in children.