Comparative Effectiveness and Safety of FANS-UAS with Flexible Ureteroscopy for Infected Upper Urinary Tract Stones

Overview

This retrospective cohort study compared flexible ureteroscopic lithotripsy (FURL) alone versus FURL combined with a flexible navigable suction ureteral access sheath (FANS-UAS) in treating infected upper urinary tract stones. The combined approach demonstrated improved stone clearance rates and reduced intrarenal pelvic pressure, enhancing procedural efficacy and safety.

Background

Infected upper urinary tract stones, comprising about 15% of urinary stones, are characterized by rapid growth, staghorn formations, and high recurrence rates, often associated with urease-producing bacteria. Complete stone removal and infection control with antibiotics are critical to prevent severe complications such as systemic inflammatory response syndrome. While percutaneous nephrolithotripsy is the gold standard, flexible ureteroscopic lithotripsy (FURL) is gaining favor due to less surgical trauma. However, conventional FURL may leave residual fragments, whereas combining FURL with a flexible navigable suction ureteral access sheath (FANS-UAS) can facilitate stone fragment extraction and reduce intrarenal pressure.

Data Highlights

Key Findings

• FURL combined with FANS-UAS significantly improves stone clearance rates compared to FURL alone.
• The use of FANS-UAS reduces intrarenal pelvic pressure during lithotripsy, potentially lowering complication risks.
• The suction sheath facilitates removal of stone fragments in a powdered state, enhancing procedural efficacy.
• Both treatment groups included patients with stones sized 2.5–4 cm and >4 cm, located in renal, ureteral, or mixed sites.
• Preoperative infection control with antibiotics was strictly implemented in all patients to minimize perioperative infection risks.

Clinical Implications

Incorporating a flexible navigable suction ureteral access sheath during flexible ureteroscopic lithotripsy can optimize stone clearance and reduce intrarenal pressure, potentially decreasing postoperative complications. Careful preoperative infection management remains essential to ensure surgical safety in patients with infected upper urinary tract stones.

Conclusion

The combination of FURL with FANS-UAS offers a safer and more effective surgical option for managing infected upper urinary tract stones compared to FURL alone, supporting its consideration as an optimized treatment strategy.

References

1. Comparative Analysis of FANS-UAS with Flexible Ureteroscopic Lithotripsy -- Retrospective Cohort Study