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.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
270
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.
Department of Urology, Al-Hussein and Sayed Galal University Hospitals, Al-Azhar University
Cairo, Egypt
RECRUITINGStone-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
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