Micro-percutaneous nephrolithotomy in the treatment of pediatric nephrolithiasis: A single-center experience

We aimed to clarify the applicability and safety of micro-PNL (microperc) in the treatment of pediatric kidney stones.

A single center prospective trial was initiated, and microperc was performed in 40 children using the same two methods: the classical all-seeing needle and microsheath method. Stone fragmentation was performed using a 200-μm holmium:YAG laser fiber.

The mean age of the patients was 6.3±4.4years (range: 7months-16years). Fourteen were less than 3years old. The average calculous size was 16.5mm (range: 10-36mm). In 20 patients, access was achieved through the all-seeing needle method. In the other patients, access was achieved by the microsheath method. Conversion to mini-PNL was required in 2 patients due to intraoperative bleeding in one and a high stone burden in the other. The mean hospital stay was 3.8±1.2days (range: 1-10days), and the mean hemoglobin decrease was 0.7±0.3mg/dl (range: 0-1.7mg/dl).The duration of surgery and fluoroscopic screening was 75min and 3.7min, respectively. A DJ stent was placed in 11 patients due to a high stone burden. A ureteral stent was left for 1day in the rest of the cases. Complete clearance was achieved in the other 32 children. None of the patients required transfusion caused by renal hemorrhage. In 1 patient, extravasation of the irrigation fluid caused abdominal distention. As assessed by KUB and/or an ultrasound, the overall stone-free rate at 6weeks was 80%. There were residual fragments in 6 patients (15%).

Our results show that microperc is a safe and effective procedure for the treatment of pediatric kidney stones. Children with small renal calculi and with nonobstructed collecting systems are suitable for microperc.