Renal CalculiNCT07559214
FANS VS DISS in Treatment of Renal Stone < 2cm
A study testing Flexible ureteroscopy in people with Renal Calculi, run by Assiut University.
Trial summary
To compare between FANS \& DISS in : Operative time Stone free rate Complications Amount of fluid irrigation Read more about this study
- Who is it for?
- Ages 18 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Renal Calculi
- What is being tested?
- Flexible ureteroscopy
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 100 participants
- Where
- No sites listed yet
- Study dates
- Jun 2026to Sep 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- All patients < 18 years old presented with renal stone > 2cm whatever the site of the stone (pelvic or calyceal)
Who cannot join
- Inaccessibility to introduce access sheath or FURS
- Previous Inserted JJ stent
- Active UTI
- Patients refuse to participate in the protocol
About this study
Official title: Flexible and Navigable Access Sheath (FANS) VS Direct in Scope Suction (DISS) in Treatment of Renal Stone > 2 cm , Controlled Randomized Trial
To compare between FANS \& DISS in :
- Operative time
- Stone free rate
- Complications
- Amount of fluid irrigation
Read the detailed description
Retrograde intrarenal surgery (RIRS) has revolutionized the management of renal stones, yet achieving high stone-free rates (SFR) while maintaining low intrarenal pressure (IRP) remains a challenge. Elevated IRP during irrigation is linked to post-operative complications, including systemic inflammatory response syndrome and renal parenchymal damage. To mitigate these risks, suction-assisted technologies have emerged as vital adjuncts to traditional flexible ureteroscopy (FURS).The Flexible and Navigable Access Sheath (FANS) represents a significant evolution in this field. Unlike traditional rigid sheaths, FANS features a deflectable tip that can be guided into specific calyces, allowing for synchronized suction and active fragment evacuation. Conversely, Direct In-Scope Suction (DISS) utilizes a sheathless approach, where suction is integrated directly into the ureteroscope. While DISS avoids potential ureteral trauma associated with access sheaths, FANS is often associated with shorter operative times due to its superior irrigation-aspiration efficiency.For renal stones measuring less than 2 cm, both techniques aim to optimize the "perfusion-absorption" balance, effectively clearing stone dust and debris while preventing pyelovenous reflux. However, comparative data specifically for smaller stones remains limited. This study evaluates the clinical efficacy, safety profiles, and operative outcomes of FANS versus DISS in the treatment of renal calculi < 2 cm, aiming to determine which suction modality provides the most favorable balance of procedural efficiency and patient safety.
- Conditions
- Renal Calculi
- Being tested
- Flexible ureteroscopy
- Medical subject headings
- Kidney Calculi
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Flexible ureteroscopyProcedure or surgery
Also called FURS
Unlike traditional rigid sheaths, FANS features a deflectable tip that can be guided into specific calyces, allowing for synchronized suction and active fragment evacuation. Conversely, Direct In-Scope Suction (DISS) utilizes a sheathless approach, where suction is integrated directly into the ureteroscope. While DISS avoids potential ureteral trauma associated with access sheaths, FANS is often associated with shorter operative times due to its superior irrigation-aspiration efficiency
| Study group | Role | What they receive |
|---|---|---|
| Flexible and navigable access sheath (FANS) | Experimental | In patients undergoing the FANS procedure , an access sheath with a bendable tip and aspiration feature will be placed into the relevant ureter up to the renal pelvis over the guidewire. The single-use flexible scope will be passed through the access sheath, and the renal collecting system. After this maneuver, the tip of the placed access sheath will be pushed into the renal calyces or pelvis under the guidance of the flexible URS and a holmium fiber will be used to pulverize the stones with a 273-µm fiber. In this group, stones were disintegrated (fragmented) into an adequate size (< 3 mm) to allow an efficient extraction with the help of active aspiration, finished by insertion of JJ in all patients. Receives: Procedure: Flexible ureteroscopy |
| Direct in scope suction (DISS) | Experimental | In the DISS group, a single-use flexible URS with a direct in-scope suction system will be introduced over the placed guidewire and navigated into the renal pelvis without the use of an access sheath. The suctioning port on the ureteroscope and the laser fiber operates via the same port. In this group, the dusting preset of the same laser device will be used to disintegrate the stones. While continuous irrigation was applied to ensure optimum visualization, finished by insertion of JJ in all patients Receives: Procedure: Flexible ureteroscopy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Operative time
The operative time is the duration of surgical procedure
Measured: <60 minutes
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Apr 2026
- Study startJun 2026 (estimated)
- Primary completionJun 2027 (estimated)
- Study completionSep 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Renal CalculiStudies of the same condition, open and under way.
- More trials run by Assiut 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
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Assiut University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Armia Ezzat Thabet Azer, Assiut University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07559214
- Sponsor's protocol ID
- FANS VS DISS
- Status last verified
- Apr 2026
- First submitted
- 10 Apr 2026
- Last updated
- 30 Apr 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 30 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Flexible and Navigable Access Sheath (FANS) VS Direct in Scope Suction (DISS) in Treatment of Renal Stone > 2 cm , Controlled Randomized Trial
- ClinicalTrials.gov ID
- NCT07559214
- Acronym / sponsor ID
- FANS VS DISS
- Conditions
- Renal Calculi
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- Assiut UniversityUniversity, hospital or other
- Study start
- Jun 2026 (estimated)
- Primary completion
- Jun 2027 (estimated)
- Study completion
- Sep 2027 (estimated)
- First posted
- 30 Apr 2026 (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.
To compare between FANS \& DISS in :
- Operative time
- Stone free rate
- Complications
- Amount of fluid irrigation
Detailed description
Retrograde intrarenal surgery (RIRS) has revolutionized the management of renal stones, yet achieving high stone-free rates (SFR) while maintaining low intrarenal pressure (IRP) remains a challenge. Elevated IRP during irrigation is linked to post-operative complications, including systemic inflammatory response syndrome and renal parenchymal damage. To mitigate these risks, suction-assisted technologies have emerged as vital adjuncts to traditional flexible ureteroscopy (FURS).The Flexible and Navigable Access Sheath (FANS) represents a significant evolution in this field. Unlike traditional rigid sheaths, FANS features a deflectable tip that can be guided into specific calyces, allowing for synchronized suction and active fragment evacuation. Conversely, Direct In-Scope Suction (DISS) utilizes a sheathless approach, where suction is integrated directly into the ureteroscope. While DISS avoids potential ureteral trauma associated with access sheaths, FANS is often associated with shorter operative times due to its superior irrigation-aspiration efficiency.For renal stones measuring less than 2 cm, both techniques aim to optimize the "perfusion-absorption" balance, effectively clearing stone dust and debris while preventing pyelovenous reflux. However, comparative data specifically for smaller stones remains limited. This study evaluates the clinical efficacy, safety profiles, and operative outcomes of FANS versus DISS in the treatment of renal calculi < 2 cm, aiming to determine which suction modality provides the most favorable balance of procedural efficiency and patient safety.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Flexible and navigable access sheath (FANS) | Experimental | Procedure: Flexible ureteroscopyIn patients undergoing the FANS procedure , an access sheath with a bendable tip and aspiration feature will be placed into the relevant ureter up to the renal pelvis over the guidewire. The single-use flexible scope will be passed through the access sheath, and the renal collecting system. After this maneuver, the tip of the placed access sheath will be pushed into the renal calyces or pelvis under the guidance of the flexible URS and a holmium fiber will be used to pulverize the stones with a 273-µm fiber. In this group, stones were disintegrated (fragmented) into an adequate size (< 3 mm) to allow an efficient extraction with the help of active aspiration, finished by insertion of JJ in all patients. |
| Direct in scope suction (DISS) | Experimental | Procedure: Flexible ureteroscopyIn the DISS group, a single-use flexible URS with a direct in-scope suction system will be introduced over the placed guidewire and navigated into the renal pelvis without the use of an access sheath. The suctioning port on the ureteroscope and the laser fiber operates via the same port. In this group, the dusting preset of the same laser device will be used to disintegrate the stones. While continuous irrigation was applied to ensure optimum visualization, finished by insertion of JJ in all patients |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- All patients < 18 years old presented with renal stone > 2cm whatever the site of the stone (pelvic or calyceal)
Key exclusion criteria (4 listed)
- Inaccessibility to introduce access sheath or FURS
- Previous Inserted JJ stent
- Active UTI
- Patients refuse to participate in the protocol
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 |
|---|---|---|
| Flexible ureteroscopyAlso: FURSUnlike traditional rigid sheaths, FANS features a deflectable tip that can be guided into specific calyces, allowing for synchronized suction and active fragment evacuation. Conversely, Direct In-Scope Suction (DISS) utilizes a sheathless approach, where suction is integrated directly into the ureteroscope. While DISS avoids potential ureteral trauma associated with access sheaths, FANS is often associated with shorter operative times due to its superior irrigation-aspiration efficiency | Procedure or surgery | Direct in scope suction (DISS), Flexible and navigable access sheath (FANS) |
Primary outcome
Operative time
Time frame: <60 minutes
The operative time is the duration of surgical procedure
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 Apr 2026.
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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.
The record lists no contact. Use the official record to reach the sponsor.
Questions about this trial
What is this clinical trial studying?
A study testing Flexible ureteroscopy in people with Renal Calculi, run by Assiut University.
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 1 inclusion and 4 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: opening soon, as of the sponsor's last update on 30 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
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?
This study is still under way. Results are not available in the source record yet.
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?
Operative time (time frame: <60 minutes). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 30 Apr 2026.