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

Key findings from this study

• The study found that RIRS and mini-PCNL achieved comparable stone-free rates (91.4% and 94.3%, respectively) for pediatric renal pelvic stones less than 2 cm with high attenuation.
• The authors report that RIRS resulted in shorter operative time, reduced hospital stay, abbreviated catheterization duration, and substantially lower radiation exposure compared with mini-PCNL.
• The researchers demonstrate that hemoglobin decline was negligible with RIRS (0.01 g/dL) but clinically significant with mini-PCNL (0.74 g/dL), indicating reduced tissue trauma with the retrograde approach.

Overview

This prospective randomized trial compared flexible ureterorenoscopy (RIRS) and mini-percutaneous nephrolithotomy (mini-PCNL) in 70 pediatric patients aged 3–14 years with renal pelvic stones measuring less than 2 cm and exhibiting high attenuation (>1000 HU). Both procedures targeted the same patient population to establish relative efficacy and safety profiles in a pediatric cohort with dense calculi.

Methods and approach

The researchers conducted a prospective randomized clinical trial at Beni-Suef University Hospitals. Eligible participants possessed a single renal pelvic stone less than 2 cm with density exceeding 1000 HU on low-dose non-contrast computed tomography. The trial randomized 70 children equally into two groups: 35 underwent RIRS and 35 underwent mini-PCNL. Primary outcome measured stone-free status at one month post-intervention. Secondary outcomes included operative duration, hospital length of stay, catheterization duration, radiation exposure, hemoglobin change, and complication rates.

Results

Stone-free rates achieved 91.4% for RIRS and 94.3% for mini-PCNL at one month (p = 0.643), demonstrating no statistically significant difference. RIRS demonstrated clinical advantages across multiple parameters: shorter operative time (72.7 versus 80.5 minutes), reduced hospitalization (1.1 versus 1.3 days), abbreviated catheterization (1.2 versus 2.1 days), and substantially lower fluoroscopy duration (34.6 versus 115.1 seconds) (all p < 0.05). Hemoglobin reduction remained negligible in the RIRS group (0.01 g/dL; p = 0.097) but significant in mini-PCNL recipients (0.74 g/dL; p < 0.001). Complication rates showed no significant difference: 11.4% for RIRS versus 17.1% for mini-PCNL (p = 0.550).

Implications

The comparable stone-free rates between RIRS and mini-PCNL establish both modalities as viable first-line options for managing pediatric renal pelvic stones less than 2 cm with high density. The significant reduction in operative time, hospital stay, and radiation exposure with RIRS supports its preferential selection in uncomplicated anatomic presentations. The minimal hemoglobin decline in RIRS versus clinically meaningful decrease in mini-PCNL suggests reduced hematologic stress and tissue trauma with the retrograde approach.

Clinical selection criteria should incorporate anatomic complexity beyond stone size and density parameters. Mini-PCNL retains utility for lower-calyceal stones and complex renal anatomy where retrograde access proves technically limited. The substantially reduced radiation burden with RIRS carries particular significance in the pediatric population, where cumulative radiation exposure carries documented long-term health implications.

These findings support algorithmic modification in pediatric stone management protocols. RIRS merits consideration as initial intervention in appropriately selected cases, with percutaneous approaches reserved for anatomically challenging presentations. Future investigation should clarify outcome variation across subcategories of calyceal location and elaborate selection criteria discriminating optimal procedural choice based on preoperative imaging characteristics.

Scope and limitations

This summary is based on the study abstract and available metadata. It does not include a full analysis of the complete paper, supplementary materials, or underlying datasets unless explicitly stated. Findings should be interpreted in the context of the original publication.