Comparison of suction and standard ureteral access sheath versus sheathless flexible ureteroscopy in management of upper ureteral and renal calculi

Clinical Snapshot

Key Findings

• P Value: p = 0.035 for stone clearance, p < 0.001 for operative time

• Effect Size: 23.4% absolute difference in stone clearance between suction UAS and no sheath

• Primary Outcome: Stone clearance rates: suction UAS 96.7% vs standard UAS 90.0% vs no sheath 73.3%

• Nnt Or Sensitivity: NNT = 4.3 for avoiding treatment failure with suction UAS versus no sheath

• Confidence Interval: Not reported

Clinical Application

Requires availability of suction UAS technology and surgeon training; may have higher equipment costs Relevant to Australian urological practice; suction UAS availability through TGA approval needed; potential PBS consideration for cost-effectiveness Patients with small-to-moderate renal stones (≤3cm) and upper ureteric stones (≤1.5cm) suitable for flexible ureteroscopy

Abstract

PURPOSE: Comparative effectiveness of suction versus traditional ureteral access sheath (UAS) remains an area of ongoing research. We aim to compare the outcomes of retrograde intrarenal surgery (RIRS) with suction and standard UAS versus without UAS in the management of renal and upper ureteric stones, with a specific focus on operative efficiency, stone-free rates, and postoperative complications. METHODS: This study was conducted between October 2023 and January 2025, including 90 patients with renal stones ≤ 3 cm and upper ureteric stones ≤ 1.5 cm. Patients were divided into three groups by random Allocation Software (version 2): Group A1 (standard UAS, n = 30), Group A2 (suction UAS, n = 30), and Group B (no UAS, n = 30). Operative time, vision quality, stone clearance, complications, and hospital stay were assessed. RESULTS: Group A2 had the shortest mean operative time (70.1 ± 10.3 min) with significantly better vision compared to Group A1 (114.3 ± 27.0 min) and Group B (125.0 ± 28.01 min) (p < 0.001). Residual stone rates were lowest in Group A2 (3.3%) compared to Group A1 (10.0%) and Group B (26.7%) (p = 0.035). The need for a second procedure was significantly higher in Group B (26.7%) compared to Group A1 (10.0%) and absent in Group A2 (p = 0.002). Hospital stay was significantly shorter in Group A2 compared to Group A1 and Group B (p = 0.005). Fever incidence (Clavien Grade II) was significantly higher in Group B (23.3%) compared to Group A1 (16.7%) and absent in Group A2 (p = 0.005). CONCLUSION: Suction ureteral access sheaths in flexible ureteroscopic lithotripsy for renal stones ≤ 3 cm and upper ureteric stones ≤ 1.5 cm was associated with improved stone clearance, reduced operative time and hospital stay, provide better endoscopic vision, minimized infectious complications and need for second procedure, compared to standard UAS or no sheath. However, outcomes may be influenced by surgeon experience and familiarity with suction-assisted systems. Prospective multicenter studies with larger sample sizes and varying surgeon experience levels are recommended.

References

1. 1.Zanaty, F., Ali, M., Elserafy, F., & Abozaid, M. (2024). Comparison of suction and standard ureteral access sheath versus sheathless flexible ureteroscopy in management of upper ureteral and renal calculi. BMC Urology. https://doi.org/10.1007/s00345-024-05325-2