Role of Pre-stenting Before Retrograde Intrarenal Surgery With Miniaturized Flexible Ureteroscopes

NCT07773090 | Recruiting

• 1 other identifier: UroAzhar_17_026
• Study Type: interventional
• Target: 270
• Locations: 1 country
• Sites: 1

Brief Summary

This prospective randomized controlled trial will compare retrograde intrarenal surgery performed after routine preoperative ureteral stenting with direct retrograde intrarenal surgery without planned preoperative stenting in adults with unilateral renal calculi measuring 10-20 mm. The study will evaluate stone-free rate, ureteral access, need for rescue stenting, operative outcomes, complications, staged procedures, postoperative recovery, and auxiliary treatment.

Conditions

Renal Calculi

Outcome Measures

Primary Outcomes (1)

• Stone-free rate

  Stone-free status will be assessed using postoperative non-contrast computed tomography. The primary analysis will define stone-free status as absence of any residual renal stone fragment greater than 2 mm.

  Four weeks after the final RIRS procedure

Secondary Outcomes (4)

• Successful renal access

  During the initial RIRS procedure

• Need for active ureteral dilation

  During the initial RIRS procedure

• Intraoperative ureteral injury

  During each RIRS procedure

• Postoperative complications

  From the initial RIRS procedure through 30 days after the final RIRS procedure

Study Arms (2)

Pre-stenting group

EXPERIMENTAL

Procedure: Preoperative double-J ureteral stenting followed by retrograde intrarenal surgery

No-pre-stenting group

ACTIVE COMPARATOR

Procedure: Direct retrograde intrarenal surgery without planned preoperative ureteral stenting

Interventions

Preoperative double-J ureteral stenting followed by retrograde intrarenal surgery PROCEDURE

Participants randomized to this group will undergo insertion of a 4.8-6 French double-J ureteral stent approximately 7-14 days before definitive RIRS. The stent will be used to provide passive ureteral dilation. Definitive RIRS will then be performed using a miniaturized digital flexible ureteroscope and holmium:YAG laser lithotripsy. The stent size, length, date of insertion, dwell time, technical success, complications, urinary tract infection, and stent-related symptoms will be recorded.

Pre-stenting group

Direct retrograde intrarenal surgery without planned preoperative ureteral stenting PROCEDURE

Participants randomized to this group will undergo direct RIRS without planned preoperative ureteral stenting. No routine active ureteral dilation will be performed before initial access. Gentle dilation may be performed when clinically necessary and will be documented. If safe access cannot be achieved, the procedure will be discontinued and a double-J ureteral stent will be inserted for passive dilation. Repeat RIRS will be scheduled approximately 7-14 days later.

No-pre-stenting group

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Participants must meet all of the following criteria:
• Adults aged 18-70 years.
• Unilateral renal calculi.
• Maximum total renal stone burden of 10-20 mm.
• Planned treatment with RIRS.
• Suitable candidate for elective endoscopic stone treatment.
• Negative or appropriately treated preoperative urine culture.
• Ability to provide written informed consent.
• Ability and willingness to comply with postoperative follow-up, including non-contrast CT at 4 weeks after the final RIRS procedure.

You may not qualify if:

• Participants will be excluded for any of the following:
• Bilateral renal calculi requiring simultaneous surgical treatment.
• Active urinary tract infection, sepsis, or infected obstruction requiring urgent drainage.
• Solitary kidney when randomization is considered clinically unsafe.
• Known ureteral stricture or congenital ureteral abnormality likely to interfere with ureteroscopic access.
• Previous failed ipsilateral ureteroscopic access requiring clinically indicated pre-stenting.
• Existing ipsilateral ureteral stent or nephrostomy.
• Previous ureteral reconstruction or urinary diversion.
• Total renal stone burden greater than 20 mm.
• Staghorn calculi.
• Uncorrected coagulopathy.
• Pregnancy.
• Severe uncorrected cardiopulmonary disease precluding anesthesia.
• Inability or unwillingness to provide informed consent.
• Inability or unwillingness to comply with follow-up.

Sponsors & Collaborators

• Al-Azhar University: lead

Study Sites (1)

Department of Urology, Al-Hussein and Sayed Galal University Hospitals, Al-Azhar University

Cairo, Egypt

RECRUITING

MeSH Terms

Conditions

Kidney Calculi

Condition Hierarchy (Ancestors)

Nephrolithiasis; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Urolithiasis; Urinary Calculi; Male Urogenital Diseases; Calculi; Pathological Conditions, Anatomical; Pathological Conditions, Signs and Symptoms

Study Officials

• Abul-fotouh Ahmed, MD

  Department of Urology, Faculty of Medicine, Al-Azhar University, Cairo, Egypt

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Abul-fotouh Ahmed, MD

CONTACT

00201001066756; abulfotouhahmed@yahoo.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Model Details: Two-arm, parallel-group randomized controlled trial

Study Record Dates

• First Submitted: August 16, 2026
• First Posted: August 19, 2026
• Study Start: August 19, 2026
• Primary Completion (Estimated): August 14, 2028
• Study Completion (Estimated): November 1, 2028
• Last Updated: August 21, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will not share

Locations

EG (1)