A Phase 2 interventional study of Tamsulosin and Placebo Capsule in Renal Stones, Retrograde Intrarenal Surgery and Ureteral Access Sheath Placement, sponsored by Beni-Suef University. Recruiting at 3 sites in Egypt. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-06-03.
Sponsored by Beni-Suef University · Phase 2, Interventional, and Treatment
This multicenter randomized controlled trial will evaluate whether preoperative tamsulosin, intraureteral aminophylline, or their combination can improve ureteral access during primary retrograde intrarenal surgery for renal stones. Adult patients with unilateral renal stones measuring 2 cm or less and planned placement of a 10/12 Fr ureteral access sheath will be randomly assigned to one of four groups in a 2x2 factorial design. Participants will receive either tamsulosin or placebo for 7 days before surgery and either intraureteral aminophylline or intraureteral placebo during the procedure. The main outcome will be successful first-attempt placement of the planned 10/12 Fr ureteral access sheath after study solution instillation, without active ureteral dilatation, sheath downsizing, prestenting with deferred surgery, or abandonment of the procedure due to access failure.
Retrograde intrarenal surgery is a commonly used minimally invasive procedure for the treatment of renal stones. Successful completion of the procedure may require placement of a ureteral access sheath. However, ureteral access sheath insertion can be difficult in some patients because of ureteral resistance or spasm, which may lead to ureteral trauma, active ureteral dilatation, prestenting with delayed surgery, or inability to complete the planned procedure.
This study is designed to compare systemic, local, and combined pharmacologic strategies for facilitating ureteral access during primary retrograde intrarenal surgery. Tamsulosin is an alpha-1 adrenergic receptor blocker that may reduce ureteral tone when given before surgery. Aminophylline is a smooth-muscle relaxant that may reduce ureteral spasm when administered locally into the ureter during the procedure.
This is a prospective, multicenter, randomized, double-blind, placebo-controlled, parallel-group trial with a 2x2 factorial design. Eligible adult patients with unilateral renal stones measuring 2 cm or less who are scheduled for primary retrograde intrarenal surgery with planned 10/12 Fr ureteral access sheath placement will be randomized in a 1:1:1:1 ratio. The four treatment combinations are: placebo capsule plus intraureteral placebo, tamsulosin capsule plus intraureteral placebo, placebo capsule plus intraureteral aminophylline, and tamsulosin capsule plus intraureteral aminophylline.
Patients assigned to tamsulosin will receive tamsulosin 0.4 mg once daily for 7 days before surgery, while patients assigned to placebo will receive a matching placebo capsule. During surgery, the assigned intraureteral solution will be instilled through an open-end ureteric catheter positioned in the distal ureter on the study side. After a standardized 5-minute waiting period, one controlled attempt will be made to place the planned 10/12 Fr ureteral access sheath.
The primary endpoint is successful first-attempt placement of the planned 10/12 Fr ureteral access sheath after study solution instillation, without active ureteral dilatation, sheath downsizing, prestenting with deferred retrograde intrarenal surgery, or abandonment of the procedure due to access failure. If the planned sheath cannot be inserted safely, management will proceed according to a predefined rescue pathway, including active ureteral dilatation if considered safe or ureteral stenting with deferred surgery. Forced sheath advancement against marked resistance will be avoided.
Secondary outcomes will assess flexible ureteroscope advancement, need for rescue maneuvers, access-related ureteral injury, operative outcomes, postoperative pain, complications, hospital stay, and stone-free status during follow-up.
324 studies on the registry are indexed under Nephrolithiasis; 90 are open to participants now.
This study's planned enrollment of 322 is above the median of 92 across 257 interventional studies indexed under Nephrolithiasis.
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Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
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Contraindication
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Participants will receive a matching placebo capsule once daily for 7 days before retrograde intrarenal surgery and intraureteral placebo using normal saline 0.9% during the procedure before attempted placement of the planned 10/12 Fr ureteral access sheath.
Drug: Placebo Capsule · Drug: Intraureteral Placebo
Participants will receive tamsulosin 0.4 mg capsule once daily for 7 days before retrograde intrarenal surgery and intraureteral placebo using normal saline 0.9% during the procedure before attempted placement of the planned 10/12 Fr ureteral access sheath.
Drug: Tamsulosin · Drug: Intraureteral Placebo
Participants will receive a matching placebo capsule once daily for 7 days before retrograde intrarenal surgery and intraureteral aminophylline solution during the procedure before attempted placement of the planned 10/12 Fr ureteral access sheath.
Drug: Placebo Capsule · Drug: Intraureteral Aminophylline
Participants will receive tamsulosin 0.4 mg capsule once daily for 7 days before retrograde intrarenal surgery and intraureteral aminophylline solution during the procedure before attempted placement of the planned 10/12 Fr ureteral access sheath.
Drug: Tamsulosin · Drug: Intraureteral Aminophylline
Tamsulosin 0.4 mg capsule once daily for 7 days before retrograde intrarenal surgery.
Matching placebo capsule for tamsulosin, taken once daily for 7 days before retrograde intrarenal surgery.
Aminophylline 250 mg/10 mL will be diluted with 10 mL normal saline 0.9% to a total volume of 20 mL. The solution will be instilled intraureterally through an open-end ureteric catheter positioned in the distal ureter on the study side. After a standardized 5-minute waiting period, one controlled attempt will be made to place the planned 10/12 Fr ureteral access sheath.
Normal saline 0.9% to a total volume of 20 mL will be instilled intraureterally through an open-end ureteric catheter positioned in the distal ureter on the study side. After a standardized 5-minute waiting period, one controlled attempt will be made to place the planned 10/12 Fr ureteral access sheath.
Successful First-Attempt 10/12 Fr Ureteral Access Sheath Placement
Successful placement of the planned 10/12 Fr ureteral access sheath at the first standardized post-instillation attempt during primary retrograde intrarenal surgery, without active ureteral dilatation, sheath downsizing, prestenting with deferred retrograde intrarenal surgery, or abandonment of the procedure due to access failure.
Time frame: During the index retrograde intrarenal surgery procedure
Requirement for Active Ureteral Dilatation
Proportion of participants requiring active ureteral dilatation after unsuccessful first standardized post-instillation placement of the planned 10/12 Fr ureteral access sheath.
Time frame: During the index retrograde intrarenal surgery procedure
Requirement for Prestenting and Staged RIRS
Proportion of participants requiring ureteral stenting with deferred retrograde intrarenal surgery because of unsuccessful or unsafe ureteral access during the index procedure.
Time frame: During the index retrograde intrarenal surgery procedure
Access-Related Ureteral Injury
Occurrence of access-related ureteral injury during ureteral access sheath insertion, graded endoscopically where feasible.
Time frame: During the index retrograde intrarenal surgery procedure
Postoperative Pain Score
Postoperative pain intensity assessed after the index procedure using the study pain assessment method.
Time frame: Within 24 hours after the index procedure
Plan to share: No — Individual participant data will not be shared because the study involves individual-level clinical and operative data from a multicenter interventional trial. Only aggregated, de-identified study results will be reported in publications. Any future data sharing request will require approval from the Research Ethics Committee, Faculty of Medicine, Beni-Suef University, and the participating study centers.
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Studies of the drug tested here: Tamsulosin