Safety and efficacy of the supine versus the prone miniperc in preschool children: Prospective randomized study

Purpose: The use of the supine position is even less explored, although comparisons to the prone position are promising, with great advantages of the supine position. The reproducibility of the miniperc technique in the pediatric population prompted this study to focus on the proposed enhanced maneuverability of the mini-nephoscope to navigate the targeted intrarenal system while maintaining a comparable stone-free rate in the supine position. Materials and methods: This study analyzed 50 children, 7 years old or less, with renal stones (>1.5 cm) indicated for mini-percutaneous nephrolithotomy (mini-PNL) at the Tertiary University Hospital. Patients were randomly assigned to the supine position mini-PNL (group I) and the standard prone mini-PNL (group II). Patients were followed for 3 months from the last operative intervention. Perioperative variables, including patient and stone demographics, intraoperative accessibility, access fluoroscopy time, operative time, and operative adverse events, are documented. Stone free rate (SFR), complications, and the need for accessory measures were also reported, and all were compared between groups. Results: Both supine (96%) and prone (88%) positions primarily used a single access. The supine position demonstrated significantly greater accessibility to all calyces (84% vs 48%, P = 0.02). SFR was higher in the supine (96%) versus the prone position (84%), without significance. Shorter operative (53.9 min vs 65.4 min, P = 0.01) and fluoroscopy times (117.2 s vs 136.4 s, P = 0.02) in supine versus prone cases. Operative complications were comparable in both groups. Conclusion: The findings of this study support that supine miniperc in children offers a variety of access options, and it allows for more accessibility to the entire pelvicalyceal system than encountered in the prone position. This allows for enhanced stone clearance in a lesser operative time with comparable safety and SFR.