Ultra-Mini-Percutaneous Nephrolithotomy in Flank-Free Modified Supine Position Prone Position in Treatment of Pediatric Renal Pelvic and Lower Caliceal Stones.

To report the safety and efficacy of ultra-mini-percutaneous nephrolithotomy (UMPCNL) in flank-free modified supine (FFMS) and prone positions in management of pediatric renal calculi. This prospective randomized study included 55 pediatric patients with symptomatic renal stones and suitable for UMPCNL. They were randomized into two groups. Group A included 28 patients who were treated by UMPCNL in FFMS position (with a pad below the ipsilateral shoulder and buttocks, putting ipsilateral upper limb over the chest, and crossing the extended ipsilateral lower limb over the flexed contralateral one) and Group B included 27 patients treated by UMPCNL in the prone position. In both groups dilatation was done to 13F sheath allowing the introduction of 6/7.5F semirigid ureteroscope and fragmentation of stones by Holmium: yttrium-aluminum-garnet laser with a 550-μm fiber laser lithotripter. The operation time in FFMS position UMPCNL group was significantly shorter than prone position UMPCNL group (84.3 ± 9.87 99.3 ± 8.75 minutes) with  = 0.022. There was no significant difference between both groups in terms of stone-free rate (89.3% 88.9%), overall complication rate (including transient fever; 21.4% 18.5%), postoperative pain (visual analog scale score; 3.4 ± 0.8 3.3 ± 0.9), or hospital stay (3.53 ± 0.8 4.1 ± 1.1 days). Both UMPCNL in FFMs and prone positions are feasible, safe, and effective in treatment of pediatric renal stones with relatively shorter operative time in FFMS position.