Safety and Efficacy of Fluoroscopy-free Technique During Retrograde Intrarenal Surgery for Renal Stones

Study Overview
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Brief Summary
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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
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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.

Official Title
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Safety and Efficacy of Fluoroscopy-free Technique During Retrograde Intrarenal Surgery for Renal Stones: A Prospective, Randomized, Non-inferiority Trial

Conditions
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Kidney Calculi, Radiation Exposure, Retrograde Intrarenal Surgery

Intervention / Treatment
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* Procedure: Fluoroscopy-free RIRS
* Procedure: Standard RIRS


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Renal stone. Stone size: ≥10 mm. Exclusion Criteria: 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.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: The 1st group: Fluoroscopy-free RIRS. The 2nd group: Fluoroscopy-guided RIRS.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Fluoroscopy-free RIRS<br>Patients will be treated by RIRS without fluoroscopy | Procedure: Fluoroscopy-free RIRS<br>* RIRS for renal stone under direct visualization, without fluoroscopy<br>|
| Active Comparator: Standard RIRS<br>Standard RIRS under fluoroscopy-guidance will be performed | Procedure: Standard RIRS<br>* RIRS for renal stone under fluoroscopy-guidance<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| stone-free rate | defined as no residual stone or residual fragment(s) less than 4 mm (as confirmed by CT-UT). | 3-months after the intervention. | 
| complication rate | intraoperative and postoperative complications | intraoperative till 3-months postoperative complications | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| fluoroscopy time | intraoperative fluoroscopy imaging | intraoperative | 
| Operative time | Time from induction of anesthesia till the end of the procedure | The procedure time | 
| the need for fluoroscopy | The need for fluoroscopy imaging in a fluoroscopy-free group | Intraoperative |