Comparative evaluation of flexible ureterorenoscopy and mini-percutaneous nephrolithotomy for the management of renal pelvic stones less than 2 cm with high attenuation value in pediatric patients: a prospective randomized study

This study aimed to evaluate the effectiveness and safety of retrograde intrarenal surgery (RIRS) compared with mini-percutaneous nephrolithotomy (mini-PCNL) in children with renal pelvic stones < 2 cm and density > 1000 HU. A prospective randomized clinical trial was conducted at Beni-Suef University Hospitals including 70 children aged 3–14 years. Eligible participants had a single renal pelvic stone < 2 cm with density > 1000 HU on low-dose non-contrast CT and were randomized equally to undergo RIRS or mini-PCNL (n = 35 each). The stone-free rates at one month were 91.4% for RIRS and 94.3% for mini-PCNL (p = 0.643). RIRS was associated with shorter operative time (72.7 vs. 80.5 min), reduced hospital stay (1.1 vs. 1.3 days), shorter catheterization (1.2 vs. 2.1 days), and lower radiation exposure (34.6 vs. 115.1 s) (all p < 0.05). Hemoglobin drop was minimal and not significant in RIRS (0.01 g/dL; p = 0.097) and greater in mini-PCNL (0.74 g/dL; p < 0.001). Complication rates were similar (11.4% vs. 17.1%; p = 0.550). Both RIRS and mini-PCNL are effective and safe for managing pediatric renal stones < 2 cm with high density. RIRS offers comparable efficacy with less invasiveness, shorter recovery, and lower radiation exposure. Mini-PCNL remains a valuable option in anatomically complex or lower-calyceal cases.