Reverse Trendelenburg Positioning Minimizes Stone Retropulsion During Ureteroscopic Laser Lithotripsy: A Prospective Randomized Study

A Novel ±20° Gravity-Assisted Position for Tip-Bendable Suction Ureteral Access Sheath in Retrograde Intrarenal Surgery: A Multicenter Retrospective Study on Large Stone Management

Purpose: To evaluate the efficacy of combining a tip-bendable suction ureteral access sheath (S-UAS) with gravity-assisted positioning to improve stone-free rates (SFRs) in retrograde intrarenal surgery (RIRS) for upper urinary tract stones (UUTS). Methods: A multicenter retrospective cohort study was conducted across three urological centers from July 2023 to August 2024. A total of 369 patients with UUTS treated with RIRS using S-UAS were included. Patients were categorized into two groups based on surgical positioning: the ±20° gravity-assisted position group and the standard lithotomy group. SFRs were classified into three grades: Grade A (no residual fragments on CT), Grade B (≤2mm fragments), and Grade C (≤4mm fragments). Key outcomes measured included immediate and 3-month SFR, operative time, and complication rates. Logistic regression analysis was used to identify factors associated with improved SFR. Results: The ±20° gravity-assisted position group showed a significantly higher immediate Grade-A (71.3% vs 48.1%, p < 0.001) and Grade-B SFR (86.0% vs 67.2%, p < 0.001) compared to the standard lithotomy group. This superiority in Grade-A SFR persisted at 3 months (76.0% vs 49.6%, p < 0.001). The median operative time was shorter in the ±20° gravity-assisted position group (67 vs 71 minutes, p = 0.0032) and the frequency of stone basket use was lower in ±20° gravity-assisted position. Multivariate analysis revealed that the lithotomy position was independently associated with a lower stone-free probability (adjusted odds ratio 0.36, 95% confidence interval 0.17-0.80; p = 0.012). No significant differences were observed in complication rates between the two groups. Conclusion: The ±20° gravity-assisted position improves immediate SFR in RIRS for UUTS, with shorter operative times. Combining gravity-assisted positioning with S-UAS is an effective strategy to optimize surgical outcomes in RIRS.

The reverse Trendelenburg position in proximal ureteral stone management: A systematic review and meta-analysis

INTRODUCTION

Ureteroscopy lithotripsy (URSL) presents a therapeutic option for patients with proximal ureteral calculi warranting active removal. This systematic review and meta-analysis aimed to assess the efficacy of the reverse Trendelenburg (RT) position during this procedure.

MATERIALS

A comprehensive literature search was conducted across PubMed, Embase, and Cochrane databases to identify randomized controlled trials and observational studies comparing RT versus standard positioning (STD) in patients undergoing URSL for proximal ureteral stones. Heterogeneity was measured with the Cochran's Q test, I2 statistics, and prediction intervals (PI). A DerSimonian and Laird random-effects model was utilized for all outcomes.

RESULTS

Four studies encompassing 505 patients undergoing URSL were analyzed. Among the studied participants, 293 (58%) underwent RT positioning. Overall, RT was associated with a lower average incidence of stone retropulsion (RR 0.42; 95% CI 0.27-0.65; I2=48%; PI 0.08-2.10) and a higher mean stone-free rate (RR 1.33; 95% CI 1.18-1.49; I2=0%). However, no significant difference between groups was found in the mean rate of overall complications (RR 0.76; 95% CI 0.40-1.43; I2=51%; PI 0.00-520.22) and operative time (MD -0.65; 95% CI -9.58-8.27; I2=94%; PI -111.95-110.65). In those with proximal ureteral stones undergoing RT positioning at only the 20° angle, there was a reduction in stone retropulsion without any measured heterogeneity (RR 0.35; 95% CI 0.23-0.52; I2=0%).

CONCLUSION

These findings suggest that RT positioning is effective in improving outcomes for patients with proximal ureteral stones undergoing URSL, and its use should be considered during the procedure.