Renal Calculi
Conditions
Brief summary
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.
Detailed description
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.
Interventions
PROCEDUREPreoperative double-J ureteral stenting followed by retrograde intrarenal surgery
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.
PROCEDUREDirect retrograde intrarenal surgery without planned preoperative ureteral stenting
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.
Sponsors
Al-Azhar University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
Two-arm, parallel-group randomized controlled trial
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
* Participants must meet all of the following criteria: * Adults aged 18-70 years. * Unilateral renal calculi. * Maximum total renal stone burden of 10-20 mm. * Planned treatment with RIRS. * Suitable candidate for elective endoscopic stone treatment. * Negative or appropriately treated preoperative urine culture. * Ability to provide written informed consent. * Ability and willingness to comply with postoperative follow-up, including non-contrast CT at 4 weeks after the final RIRS procedure.
Exclusion criteria
* Participants will be excluded for any of the following: * Bilateral renal calculi requiring simultaneous surgical treatment. * Active urinary tract infection, sepsis, or infected obstruction requiring urgent drainage. * Solitary kidney when randomization is considered clinically unsafe. * Known ureteral stricture or congenital ureteral abnormality likely to interfere with ureteroscopic access. * Previous failed ipsilateral ureteroscopic access requiring clinically indicated pre-stenting. * Existing ipsilateral ureteral stent or nephrostomy. * Previous ureteral reconstruction or urinary diversion. * Total renal stone burden greater than 20 mm. * Staghorn calculi. * Uncorrected coagulopathy. * Pregnancy. * Severe uncorrected cardiopulmonary disease precluding anesthesia. * Inability or unwillingness to provide informed consent. * Inability or unwillingness to comply with follow-up. * Any other condition judged by the treating surgeon to make randomization or RIRS clinically inappropriate or unsafe.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Stone-free rate | Four weeks after the final RIRS procedure | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Successful renal access | During the initial RIRS procedure | Successful access is defined as passage of the flexible ureteroscope into the renal collecting system without unsafe resistance, significant ureteral injury, or procedure abandonment. |
| Need for active ureteral dilation | During the initial RIRS procedure | Proportion of participants requiring active ureteral dilation to facilitate safe ureteroscope or access-sheath passage. |
| Intraoperative ureteral injury | During each RIRS procedure | Ureteral injury, including mucosal abrasion, submucosal injury, perforation, false passage, significant edema, or ureteral avulsion, documented according to a predefined injury classification. |
| Postoperative complications | From the initial RIRS procedure through 30 days after the final RIRS procedure | 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. |
Countries
Egypt
Contacts
CONTACTAbul-fotouh Ahmed, MD
PRINCIPAL_INVESTIGATORAbul-fotouh Ahmed, MD
Department of Urology, Faculty of Medicine, Al-Azhar University, Cairo, Egypt
Outcome results
None listed