Flexible vs Semi-rigid URS

Ureteroscopy (URS) is a widely accepted minimally invasive approach for treating ureteric stones, particularly proximal (upper) ureteral stones. Options include rigid, semirigid (often grouped as one), and flexible ureteroscopes. Flexible ureteroscopy allows deflection and access to the proximal ureter and intrarenal collecting system, facilitating treatment of stones that are difficult to reach with rigid ureteroscopes due to anatomical constraints or stone migration. Semirigid ureteroscopy has shown good efficacy, particularly for stones amenable to direct access without complex deflection, offering shorter operative times and lower costs. Studies report stone-free rates of approximately 90-93% for flexible URS and 81-90% for semirigid URS, with flexible URS having somewhat higher success in accessing stones and managing fragment migration. However, flexible URS typically incurs higher costs and longer operative times. Semirigid ureteroscopy is often the initial approach for upper ureteric stones where anatomy, stone size (\<2 cm), and location allow straightforward access.

• Flexible ureteroscopy is preferred when stones are located higher in the ureter, difficult to reach by semirigid scopes, or if stone migration into the kidney occurs. It is also favored when more maneuverability is required to treat complex anatomy or large stones.
• Both modalities use holmium laser lithotripsy for stone fragmentation.
• Treatment choice also depends on surgeon preference, availability of equipment, and cost considerations.

Despite advances, there is ongoing debate about the optimal first-line ureteroscopic approach for upper ureteric stones, balancing efficacy, safety, cost, and procedure time. Comparing flexible and rigid/semirigid ureteroscopy outcomes informs treatment algorithms, improving patient care and resource utilization, especially in differing healthcare settings.