An interventional study of Preoperative double-J ureteral stenting followed by retrograde intrarenal surgery and Direct retrograde intrarenal surgery without planned preoperative ureteral stenting in Renal Calculi, sponsored by Al-Azhar University. Recruiting at 1 site in Egypt. Open to participants aged 18 Years to 70 Years. Per ClinicalTrials.gov, last updated 2026-08-21.
Sponsored by Al-Azhar University · Not applicable, Interventional, and Treatment
Among 56 studies in Kidney Calculi with a site in Egypt — 20 open to participants now, 22 under way, none of them phase 3. Kidney Calculi · Egypt.
Among the 56 studies in Kidney Calculi with a site in Egypt, this one is the 3rd largest by planned enrollment of the 51 interventional ones, is one of 12 that started in 2026, is one of 48 with no phase, reaches primary completion later than 21 of the 21 other live ones, and was the 53rd registered.
509 studies on the registry are indexed under Kidney Calculi; 146 are open to participants now.
This study's planned enrollment of 270 is above the median of 86 across 391 interventional studies indexed under Kidney Calculi.
Browse Kidney Calculi studies →20 of the 56 studies in Kidney Calculi with a site in Egypt are open now, in 1 country. Each count lists the studies.
Of the 88 Kidney Calculi studies recruiting now, 48 (55%) set no upper age limit and 23 (26%) stop at 75 or younger; 6 take children under 18; 11 take healthy volunteers.
This study: 18 Years to 70 Years · all sexes · no healthy volunteers.
The full table on the hub →56 studies; the count open now beside each. This study's row is marked.
First in 2011; this study’s year is marked. 12 started in 2026.
Median enrollment 100 across the 51 interventional studies, 100 across the 5 observational. Of the 24 that completed or were terminated, 0 (0%) have results posted.
1 of 56 have an industry lead sponsor. The 10 most frequent:
Al-Azhar University is the lead sponsor of 531 studies on the registry; 172 are open to participants now.
Of its 5 completed or terminated interventional studies of FDA-regulated products, 0 (0%) have results posted.
Al-Azhar University has 4 studies filed under Kidney Calculi — fewer than ten, so there is no comparison to draw.
6 of the studies in Kidney Calculi with a site in Egypt that are under way reach primary completion within a year, 0 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT05738304Al-Azhar UniversityUreteral Stenting After Retrograde Intrarenal Surgery for Renal Stones | 2026-11-01 |
| NCT07295860Mansoura UniversityFANS-FURS vs Suction Mini-PCNL for 2-3 cm Renal Stones: A Multicenter Randomized Trial | 2027-01-01 |
| NCT07749807Benha UniversityNebulized Glubran 2-Assisted Tubeless PCNL Versus Conventional PCNL | 2027-02-01 |
| NCT07516535Ain Shams UniversityDISS vs FANS in Suction-Assisted RIRS for Medium-Sized Renal Stones | 2027-04-30 |
| NCT07689565Tanta UniversityStandard Versus Flexible and Navigable Suction Ureteral Access Sheath in Pediatric Flexible Ureterorenoscopy for Renal Stones < 2 cm | 2027-06-01 |
Among the 56 studies in Kidney Calculi with a site in Egypt, from their registry updates:
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.
Retrograde intrarenal surgery is widely used for the treatment of selected renal calculi. Miniaturized flexible ureteroscopes may facilitate direct ureteral and renal access, potentially reducing the need for routine preoperative ureteral stenting. However, pre-stenting may improve passive ureteral dilation, facilitate access, reduce failed access, and decrease the need for staged treatment.
Participants will be randomly assigned in a 1:1 ratio to either preoperative double-J ureteral stenting for 7-14 days followed by RIRS or direct RIRS without planned preoperative ureteral stenting. All procedures will use a standardized miniaturized digital flexible ureteroscope and holmium:YAG laser lithotripsy technique. If safe access cannot be obtained in the direct-RIRS group, rescue ureteral stenting will be performed, and definitive RIRS will be delayed for approximately 7-14 days.
The primary outcome will be the stone-free rate assessed by non-contrast computed tomography 4 weeks after the final RIRS procedure. Secondary outcomes will include successful ureteroscopic access, need for active dilation, procedure abandonment, staged RIRS, operative time, laser parameters, ureteral injury, postoperative complications, hospital stay, pain, stent-related symptoms, readmission, and auxiliary procedures.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Participants must meet all of the following criteria:
Exclusion Criteria:
Participants will be excluded for any of the following:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Procedure: Preoperative double-J ureteral stenting followed by retrograde intrarenal surgery
Procedure: Direct retrograde intrarenal surgery without planned preoperative ureteral stenting
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.
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.
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.
Time frame: Four weeks after the final RIRS procedure
Successful renal access
Successful access is defined as passage of the flexible ureteroscope into the renal collecting system without unsafe resistance, significant ureteral injury, or procedure abandonment.
Time frame: During the initial RIRS procedure
Need for active ureteral dilation
Proportion of participants requiring active ureteral dilation to facilitate safe ureteroscope or access-sheath passage.
Time frame: During the initial RIRS procedure
Intraoperative ureteral injury
Ureteral injury, including mucosal abrasion, submucosal injury, perforation, false passage, significant edema, or ureteral avulsion, documented according to a predefined injury classification.
Time frame: During each RIRS procedure
Postoperative complications
Postoperative complications will include fever, urinary tract infection, sepsis, hematuria, renal colic, urinary retention, ureteral obstruction, stent migration, stent encrustation, ureteral stricture, emergency-department visits, readmission, and the need for emergency or auxiliary treatment. Complications will be graded using the Clavien-Dindo classification.
Time frame: From the initial RIRS procedure through 30 days after the final RIRS procedure
Plan to share: No — Individual participant data will not be shared because the study involves clinical data collected from a single institutional population, and the informed-consent and ethical-approval framework does not include public release of participant-level data. De-identified aggregate results may be shared in publications or presentations.
No publications or documents are linked to this record.
Started Aug 2026 (actual). Primary completion is estimated for Aug 2028, 23 months after the start.
Of 183 non-industry interventional studies with no phase under Kidney Calculi, half reached primary completion within 31 months of starting (the median), counting those still running; a quarter within 13 and three quarters within 54. This study's planned 23 months is below that.
Counting every sponsor, half of 199 studies reached it within 26 months; a quarter within 12 and three quarters within 51.
How these figures are worked out, and which studies are left out of them.
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