RESUMEN

Objectives: The objective is to compare the safety and efficacy of retrograde intrarenal surgery (RIRS) and ultrasound-guided (US-guided) shock wave lithotripsy (SWL) for the treatment of radiolucent lower pole calculi of 1-2 cm. Materials and Methods: This prospective randomized study was performed at our tertiary care urology institute of Benha University Hospitals; cases were randomized either to undergo RIRS (Group A) or US-guided SWL with a triple focus system (Group B). The safety and effectiveness of both therapies were compared using new criteria for stone-free rate (SFR): Grade A (absolutely stone free), Grade B (≤2 mm fragments), and Grade C (>2 mm up to 4 mm fragments), fluoroscopy time, operative time, auxiliary procedures, retreatment, and complications. Results: Out of 100 patients, 92 were eligible for this study. RIRS had a higher SFR of 88.9% compared to SWL, 72.3% (P = 0.045). Furthermore, stone-free classification significantly differed between the studied groups (P < 0.001), with Grade A being significantly higher in Group A. Conversely, Grades B and C were lower in Group A. On the other hand, operative and fluoroscopy times were significantly reduced with SWL (P = 0.004 and < 0.001, respectively). While complications did not significantly differ between the two groups (P = 0.340), a significant distinction was observed in terms of the Clavien-Dindo classification. Conclusions: RIRS is an effective and safe option for treating radiolucent lower calyceal stones of ≤2 cm, with a greater SFR and lower need for auxiliary operations. However, Sono SWL is a cost-effective alternative that can achieve a comparable success rate after retreatment sessions.