Purpose: We determined the rate of stone clearance in children following percutaneous nephrolithotomy, endoscopic assessment of residual stone and the judicious use of second look nephroscopy.
Materials and methods: We retrospectively reviewed the charts of all children undergoing percutaneous nephrolithotomy from 1996 to 2007. Cases were reviewed for pertinent details including preoperative and postoperative imaging, specifics of the procedure and followup. On completion of percutaneous nephrolithotomy the collecting system was assessed via combined nephrostogram and direct nephroscopy. If the collecting system could not be completely visualized or all stone fragments could not be cleared, the patient was referred for second look nephroscopy. Any residual stone present on initial followup imaging constituted a treatment failure.
Results: A total of 24 patients underwent percutaneous nephrolithotomy for 30 separate renal calculi. Mean patient age was 9.6 years, and mean stone burden was 2.53 cm. The success rate for percutaneous nephrolithotomy (inclusive of second look nephroscopy) was 87%. Of 30 cases 16 were managed by second look nephroscopy, with findings of residual fragments in all 16. Treatment failure was noted in 1 patient without second look nephroscopy and in 3 patients with second look nephroscopy. Of the 4 patients with treatment failure all were eventually rendered stone-free.
Conclusions: Second look nephroscopy based on endoscopic findings during initial percutaneous nephrolithotomy is a reliable method of detecting and clearing residual stone fragments. Using such a protocol we achieved a high success rate of stone clearance in a population of patients with a significant stone burden.