Kidney CalculiNCT05269108
Safety and Efficacy of Fluoroscopy-free Technique During Retrograde Intrarenal Surgery for Renal Stones
A study testing Fluoroscopy-free RIRS and Standard RIRS in people with Kidney Calculi and Radiation Exposure, run by Al-Azhar University at 1 site in Egypt.
Trial summary
Aiming to reduce radiation exposure to patients and physicians, the investigators conduct this study protocol to evaluate the possibility of performing retrograde intrarenal surgery (RIRS) under direct visualization without fluoroscopy. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Kidney Calculi, Radiation Exposure, Retrograde Intrarenal Surgery
- What is being tested?
- Fluoroscopy-free RIRS and Standard RIRS
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 503 participants
- Where
- 1 siteEgypt
- Study dates
- 25 Feb 2022to 4 Apr 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Renal stone.
- Stone size: ≥10 mm.
Who cannot join
- Partial and complete staghorn stones.
- Pregnant women.
- Morbid obesity.
- Uncorrectable coagulation disorders.
- Active urinary tract infection (UTI).
- Stone in a calyceal diverticulum.
- Urinary tract obstruction distal to the stone.
- Concomitant pathology that needs intervention in the same setting.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Safety and Efficacy of Fluoroscopy-free Technique During Retrograde Intrarenal Surgery for Renal Stones: A Prospective, Randomized, Non-inferiority Trial
Aiming to reduce radiation exposure to patients and physicians, the investigators conduct this study protocol to evaluate the possibility of performing retrograde intrarenal surgery (RIRS) under direct visualization without fluoroscopy. the investigators will prospectively evaluate the outcome of fluoroscopy-free RIRS for renal stones in comparison with the standard technique. The investigators expected that the fluoroscopy-free technique has high safety and efficacy even in complicated cases.
Read the detailed description
With improved flexible URS instrumentation and lithotripsy technology, retrograde intrarenal surgery (RIRS) became an alternative and excellent option for renal stones. Fluoroscopy imaging may be necessary during various steps of RIRS, such as insertion of a guidewire and stent, access sheath insertion, detection of stone location and size, and assessment of collecting system anatomy.
In an effort to decrease radiation exposure, several studies were conducted to evaluate the possibility of performing RIRS under direct visualization without fluoroscopy. Most studies concluded that fluoroscopy-free RIRS is a feasible, effective, and safe technique. The reported stone-free rate ranged from 83.8% to 95.7%. No major complications were observed.
Despite the reported high safety and efficacy of the fluoroscopy-free RIRS technique, most of the studies were retrospective and included only uncomplicated cases, and none of the studies address its results against control.
In the present study, the investigators will prospectively evaluate the efficacy and safety of fluoroscopy-free RIRS for renal stones in comparison with fluoroscopy-guided technique as standard control. The study will include all patients with renal stones amenable to RIRS. The investigators expected that the fluoroscopy-free technique can deal with large stones and complex situations with high safety and success rate. The study hypothesis is that "the fluoroscopy-free technique has efficacy and safety similar to the fluoroscopy-guided technique".
The investigators also aim to determine the patients and surgical characteristics impacting the need for fluoroscopy. The intra-operative fluoroscopy imaging is expected to be necessary during RIRS, especially in complicated cases. In the fluoroscopic-free group, the fluoroscopic equipment will be available in the operating room and will be used if needed.
- Being tested
- Fluoroscopy-free RIRS, Standard RIRS
- Medical subject headings
- Kidney Calculi
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Fluoroscopy-free RIRSProcedure or surgery
RIRS for renal stone under direct visualization, without fluoroscopy
Standard RIRSProcedure or surgery
RIRS for renal stone under fluoroscopy-guidance
| Study group | Role | What they receive |
|---|---|---|
| Fluoroscopy-free RIRS | Experimental | Patients will be treated by RIRS without fluoroscopy Receives: Procedure: Fluoroscopy-free RIRS |
| Standard RIRS | Active comparator | Standard RIRS under fluoroscopy-guidance will be performed Receives: Procedure: Standard RIRS |
What is being measured
The primary outcome is the main question the study is designed to answer.
stone-free rate
defined as no residual stone or residual fragment(s) less than 4 mm (as confirmed by CT-UT).
Measured: 3-months after the intervention.
complication rate
intraoperative and postoperative complications
Measured: intraoperative till 3-months postoperative complications
Secondary outcomes (3)
fluoroscopy time
intraoperative fluoroscopy imaging
Measured: intraoperative
Operative time
Time from induction of anesthesia till the end of the procedure
Measured: The procedure time
the need for fluoroscopy
The need for fluoroscopy imaging in a fluoroscopy-free group
Measured: Intraoperative
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Mar 2022
- Study start25 Feb 2022
- Primary completion4 Feb 2024
- Study completion4 Apr 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Kidney CalculiStudies of the same condition, open and under way.
- More trials run by Al-Azhar UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- The 1st group: Fluoroscopy-free RIRS. The 2nd group: Fluoroscopy-guided RIRS.
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 503 participants (actual)
Sponsor and investigators
- Lead sponsor
- Al-Azhar University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Abul-fotouh Ahmed, Al-Azhar University
- Investigators
- Abul-fotouh Ahmed, MD, Principal investigator, Al-Azhar University Hospitals, Cairo, Egypt
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05269108
- Sponsor's protocol ID
- Uro_Azhar_2_022
- Status last verified
- Apr 2023
- First submitted
- 25 Feb 2022
- Last updated
- 14 Aug 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Ahmed AF, ElShazly A, Daoud A, Abdelazim H, AlGammal M. Safety and Efficacy of Fluoroscopy-Free Technique During Retrograde Intrarenal Surgery for Renal Stones: A Prospective, Randomized, Controlled, Noninferiority Trial. J Endourol. 2025 Jul;39(7):636-645. doi: 10.1089/end.2025.0120. Epub 2025 May 14.
PubMed 40364776
Study at a glance
From the registry record, last updated by the sponsor on 14 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Safety and Efficacy of Fluoroscopy-free Technique During Retrograde Intrarenal Surgery for Renal Stones: A Prospective, Randomized, Non-inferiority Trial
- ClinicalTrials.gov ID
- NCT05269108
- Acronym / sponsor ID
- Uro_Azhar_2_022
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 503 participants (actual)
- Lead sponsor
- Al-Azhar UniversityUniversity, hospital or other
- Study start
- 25 Feb 2022 (actual)
- Primary completion
- 4 Feb 2024 (actual)
- Study completion
- 4 Apr 2024 (actual)
- First posted
- 7 Mar 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Aiming to reduce radiation exposure to patients and physicians, the investigators conduct this study protocol to evaluate the possibility of performing retrograde intrarenal surgery (RIRS) under direct visualization without fluoroscopy. the investigators will prospectively evaluate the outcome of fluoroscopy-free RIRS for renal stones in comparison with the standard technique. The investigators expected that the fluoroscopy-free technique has high safety and efficacy even in complicated cases.
Detailed description
With improved flexible URS instrumentation and lithotripsy technology, retrograde intrarenal surgery (RIRS) became an alternative and excellent option for renal stones. Fluoroscopy imaging may be necessary during various steps of RIRS, such as insertion of a guidewire and stent, access sheath insertion, detection of stone location and size, and assessment of collecting system anatomy.
In an effort to decrease radiation exposure, several studies were conducted to evaluate the possibility of performing RIRS under direct visualization without fluoroscopy. Most studies concluded that fluoroscopy-free RIRS is a feasible, effective, and safe technique. The reported stone-free rate ranged from 83.8% to 95.7%. No major complications were observed.
Despite the reported high safety and efficacy of the fluoroscopy-free RIRS technique, most of the studies were retrospective and included only uncomplicated cases, and none of the studies address its results against control.
In the present study, the investigators will prospectively evaluate the efficacy and safety of fluoroscopy-free RIRS for renal stones in comparison with fluoroscopy-guided technique as standard control. The study will include all patients with renal stones amenable to RIRS. The investigators expected that the fluoroscopy-free technique can deal with large stones and complex situations with high safety and success rate. The study hypothesis is that "the fluoroscopy-free technique has efficacy and safety similar to the fluoroscopy-guided technique".
The investigators also aim to determine the patients and surgical characteristics impacting the need for fluoroscopy. The intra-operative fluoroscopy imaging is expected to be necessary during RIRS, especially in complicated cases. In the fluoroscopic-free group, the fluoroscopic equipment will be available in the operating room and will be used if needed.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
- Model description
- The 1st group: Fluoroscopy-free RIRS. The 2nd group: Fluoroscopy-guided RIRS.
| Arm | Type | Receives |
|---|---|---|
| Fluoroscopy-free RIRS | Experimental | Procedure: Fluoroscopy-free RIRSPatients will be treated by RIRS without fluoroscopy |
| Standard RIRS | Active comparator | Procedure: Standard RIRSStandard RIRS under fluoroscopy-guidance will be performed |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Renal stone.
- Stone size: ≥10 mm.
Key exclusion criteria (8 listed)
- Partial and complete staghorn stones.
- Pregnant women.
- Morbid obesity.
- Uncorrectable coagulation disorders.
- Active urinary tract infection (UTI).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Fluoroscopy-free RIRSRIRS for renal stone under direct visualization, without fluoroscopy | Procedure or surgery | Fluoroscopy-free RIRS |
| Standard RIRSRIRS for renal stone under fluoroscopy-guidance | Procedure or surgery | Standard RIRS |
Primary outcome
stone-free rate
Time frame: 3-months after the intervention.
defined as no residual stone or residual fragment(s) less than 4 mm (as confirmed by CT-UT).
complication rate
Time frame: intraoperative till 3-months postoperative complications
intraoperative and postoperative complications
3 secondary outcomes
fluoroscopy time
Time frame: intraoperative
Operative time
Time frame: The procedure time
the need for fluoroscopy
Time frame: Intraoperative
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Aug 2026.
- Background: PubMed 40364776Ahmed AF, ElShazly A, Daoud A, Abdelazim H, AlGammal M. Safety and Efficacy of Fluoroscopy-Free Technique During Retrograde Intrarenal Surgery for Renal Stones: A Prospective, Randomized, Controlled, Noninferiority Trial. J Endourol. 2025 Jul;39(7):636-645. doi: 10.1089/end.2025.0120. Epub 2025 May 14.
- "Safety and Efficacy of Fluoroscopy-Free Technique During Retrograde Intrarenal Surgery for Renal Stones: A Prospective, Randomized, Controlled, Noninferiority Trial."Link provided by the sponsor.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Abul-fotouh Ahmed, MD principal investigator
Al-Azhar University Hospitals, Cairo, Egypt
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Fluoroscopy-free RIRS and Standard RIRS in people with Kidney Calculi and Radiation Exposure, run by Al-Azhar University at 1 site in Egypt.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 14 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Egypt. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
stone-free rate (time frame: 3-months after the intervention.). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05269108, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Aug 2026.