Enhancing lithotripsy efficiency in retrograde intrarenal surgery via a flexible kidney-fixed position: findings from...

Retrograde intrarenal surgery (RIRS) is recognized as an effective intervention for renal stones measuring less than 20 mm. This study aims to assess the efficacy and safety of a novel flexible kidney-fixed position compared to the conventional lithotomy position, focusing on lithotripsy efficiency and stone-free rates (SFR). A total of 100 patients undergoing unilateral RIRS between January 2023 and September 2024 were randomly allocated to either the conventional lithotomy position group or the kidney-fixed position group. Comparative analyses were conducted on demographic data, stone characteristics, intraoperative parameters, kidney movement metrics, and postoperative complications. A total of 97 patients successfully completed the study, with 47 participants assigned to the conventional lithotomy group and 49 to the kidney-fixed group. The kidney-fixed position was associated with a significant reduction in kidney movement (4.00 mm compared to 15.30 mm, p < 0.001) and a decrease in operative time (48.35 min versus 71.72 min, p < 0.001). Additionally, the SFR for stones measuring ≤ 4 mm was significantly higher in the kidney-fixed group (91.84% compared to 68.09%, p = 0.020). The implementation of a flexible kidney-fixed position markedly improves the efficacy of lithotripsy during RIRS, resulting in reduced operative time and an elevated SFR without a corresponding increase in postoperative complications. This technique holds promise for advancing the surgical management of renal calculi, warranting further investigation to substantiate these findings and assess long-term outcomes.