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NCT Number: NCT07247617

Flexible vs Semi-rigid URS

To compare the efficacy, safety, success rate, operative time, and cost-effectiveness of flexible ureteroscopy versus semirigid ureteroscopy in the management of upper ureteric stones smaller than 2 cm.

The investigators' main concern in this study is Upper third ureteric stones to determine which cases can be treated with Semi-Rigid Ureteroscopy, and which one needs flexible ureteroscopy. This depends on several factors:

1. Division of the upper third of the ureter 2. Stone size 3. Stone impaction 4. Surgeon experience 5. Anesthesia 6. Ureteric dilatation above the stone 7. Mini endoscopy

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Key information

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Patients ≥18 years
  • upper ureteric stone
  • ≤20 mm

Exclusion criteria

  • Associated renal stones
  • Any contraindications to Anesthesia

Treatment and study plan

flexible urs

Procedure

Flexible URS

Semi-Rigid URS

Procedure

Semi-Rigid URS

Primary outcomes

  1. - Stone-free rate at 3 months duration

    Time frame: 3 months

Study contacts

Contact information is provided by the study sponsor or research team.

Mohamed Ragab Abdallah, Doctor

CONTACT

[email protected]

+201066237580

Omar Ahmed Hamada Ali

CONTACT

[email protected]

+201092868286

Sponsors and collaborators

Lead sponsor

Assiut University

Other

Registry information

Official study title

Semi-rigid Ureteroscopy Versus Flexible Ureteroscopy in Upper Third Ureteric Stones Management: a Prospective Randomized Trial

Important dates

Study start
2025
Primary completion
2026
Study completion
2027
First posted
Nov 25, 2025
Registry last updated
Nov 25, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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