Objectives: To compare the safety and efficacy of retrograde intrarenal surgery (RIRS) and ultrasound-guided (US-guided) shockwave lithotripsy (SWL) for the treatment of radiolucent lower pole calculi of 1- 2cm. Materials and Methods: This prospective randomized study was performed at our tertiary care urology institute of Banha University Hospitals; cases were randomized either to undergo RIRS (group A) or US-guided SWL with 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 (≤2mm fragments), and Grade C (> 2mm up to 4mm
2
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). Also, 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 2 groups (P = 0.340), a significant distinction was observed in terms of the Clavien-Dindo classification.
Conclusion: RIRS is an effective and safe option for treating radiolucent lower calyceal stones of ≤ 2cm, 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.