BackgroundMultiple studies have demonstrated comparable or superior stone-free and complication rates with percutaneous nephrolithotomy (PCNL) compared to ureteroscopy for stones ≥1cm in the pediatric population. PCNL-related complications such as hematuria and collecting system injury have been directly associated with tract size, and thus, mini (14-22Fr) and ultra-mini (11-13Fr) PCNL have become increasingly popular techniques. The purpose of this study is to demonstrate our techniques for complete ultrasound (US)-guided ultra-mini PCNL as a radiation-free option for definitive stone management in a series of seven pediatric patients.
MethodsAll patients were positioned supine for placement of a 5Fr open-ended ureteral stent and foley catheter. They were then transferred to prone position and US-guided renal access was obtained using a spinal needle with the 12th rib, lateral border of the paraspinous muscle, and anterior superior iliac spine as anatomical landmarks. After obtaining access, a 4mm skin incision was made and the tract was initially dilated using a 10Fr fascial dilator. Next, the 12Fr ClearPetra® sheath was advanced under ultrasound guidance. The ultra-mini 7.5Fr nephroscope and 273nm holmium laser fiber were then used to fragment and evacuate the stones. Once the procedure was complete, the kidney and ureter were inspected using a flexible ureteroscope. Depending on the extent of the procedure, either a nephrostomy tube or ureteral stent was left in place.
ResultsSeven ultra-mini PCNL cases, including one bilateral, between 2023 and 2024 were performed by a single surgeon. All patients but one were female. Mean age and BMI were 7.3 years (range 2-13) and 17.2 kg/m2 (14.5-32.5), respectively. Four stones were on the left, two on the right, and one was bilateral. The mean stone burden was 1.9cm (1.0-3.0). Four lower pole punctures, three mid pole, and one upper pole were performed. The mean procedure time was 167 minutes (112-225). Visual stone clearance was achieved in all except one patient, in which an anterior calyx could not safely be reached. All patients had their tubes removed prior to discharge, which was on average, postoperative day two. There were no major complications.
ConclusionsComplete US-guided ultra-mini PCNL is a safe, radiation-free surgical option for management of stones ≥1cm in pediatric patients. This video highlights key steps and provides tips and tricks for performing this procedure with US guidance.
