Retrograde intrarenal surgery versus percutaneous nephrolithotomy in larger kidney stones. Could SuperPulsed Thulium-fiber laser change the game?

INTRODUCTION: The aim of this article was to compare retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) efficacy and safety with SuperPulsed Thulium-fiber laser (SP TFL) for stones 20 mm and larger. MATERIAL AND METHODS: Patients with large kidney stones (20 mm and larger) were recruited to undergo PCNL or RIRS with SP TFL lithotripsy. Both groups were comparable in terms of stone size and density, operation time, laser-on time (LOT), stone-free rate, residual fragments and complication rate. Stone retropulsion and visibility were assessed based on the surgeon's feedback using Likert scales. RESULTS: A total of 14 and 56 patients were included in the RIRS and PCNL groups, respectively. The mean stone density was 833.8 ±298.3 HU in the RIRS group and 882.3 ±408.5 HU in the PCNL group (p = 0.072). The median LOT was 11.7 (10.0–15.5) min for RIRS and 10.0 (6.0–12.1) min for PCNL (p = 0.207). The median total energy for stone ablation was 13.8 (11.8–25.0) kJ for RIRS and 12.0 (7.0–20.1) kJ for PCNL (p = 0.508). The median ablation speed was 3.9 (3.9–5.7) mm(3)/sec for RIRS and 5.0 (4.6–11.3) mm(3)/sec for PCNL (p = 0.085). We found a significant correlation between retropulsion and the type of surgery performed: with higher retropulsion in the PCNL (r = 0.298 with p = 0.012). The stone-free rate at 3-months was 85.7% in RIRS and 89.3% in PCNL (p = 0.505). CONCLUSIONS: SP TFL is a safe and effective modality for lithotripsy for both, RIRS and PCNL, achieving minimal retropulsion and good visibility. No discrepancies in procedure duration, complications, or LOT were identified between the different modalities.