Tamsulosin and Intraureteral Aminophylline for Ureteral Access During RIRS (TAM-AMIN-UAS)

Comparative Efficacy of Tamsulosin, Intraureteral Aminophylline, and Their Combination in Facilitating Ureteral Access During Retrograde Intrarenal Surgery: A Multicenter Randomized Controlled Trial.

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.

Study Overview

• Status: Recruiting
• Conditions: Renal Stones; Retrograde Intrarenal Surgery; Ureteral Access Sheath Placement
• Intervention / Treatment: Drug: Placebo Capsule; Drug: Intraureteral Placebo; Drug: Tamsulosin; Drug: Intraureteral Aminophylline

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Estimated): 322
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Hany F Badawy, MD; Phone Number: +201149525028; Email: Hanyfathy86@gmail.com@GMAIL.COM

Study Locations

• Egypt
  • Aswan Governorate
    • Aswān, Aswan Governorate, Egypt
      • Recruiting
      • Department of Urology- Aswan University Hospitals
      • Contact: Ahmed
      • Contact: Ahmed Ahmed, MD; Phone Number: +20 11 00299002; Email: ahmed.salaheldien@aswu.edu.eg
      • Principal Investigator: Ahmed S Ahmed, MD
  • Beni Suweif Governorate
    • Banī Suwayf, Beni Suweif Governorate, Egypt
      • Recruiting
      • Department of Urology- Beni-Suef University Hospitals
      • Principal Investigator: Hany F Badawy, MD
      • Contact: Hany F Badawy, MD; Phone Number: +2; Email: Hanyfathy86@gmail.com
  • Sohag Governorate
    • Sohag, Sohag Governorate, Egypt
      • Recruiting
      • Urology Department- Sohag university Hospital
      • Contact: Ahmed M Elsherif, MD; Phone Number: +20 10 07385302; Email: Ahmed-mahmoud@med.sohag.edu.eg
      • Principal Investigator: Ahmed M Elsherif, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age 18 years or older.
• Unilateral renal stone 2 cm or less in maximal diameter on preoperative imaging.
• Scheduled for primary retrograde intrarenal surgery.
• Ability to provide written informed consent.

Exclusion Criteria:

• Prior ureteral stenting on the study side.
• Bilateral same-session retrograde intrarenal surgery.
• Concomitant ureteral stone requiring primary semirigid ureteroscopy as the main procedure.
• Known ureteral stricture or prior ureteral reconstructive surgery on the study side.
• Active urinary tract infection or untreated positive urine culture.
• Pregnancy.
• Known allergy or contraindication to tamsulosin or aminophylline.
• Significant cardiac arrhythmia, uncontrolled ischemic heart disease, seizure disorder, or hyperthyroidism.
• Severe hepatic impairment.
• Inability to comply with the 7-day preoperative medication protocol.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Factorial Assignment
• Masking: Quadruple

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo Capsule Plus Intraureteral Placebo; 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; Matching placebo capsule for tamsulosin, taken once daily for 7 days before retrograde intrarenal surgery.; Drug: Intraureteral Placebo; 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.
Experimental: Tamsulosin Plus 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: Intraureteral Placebo; 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.; Drug: Tamsulosin; Tamsulosin 0.4 mg capsule once daily for 7 days before retrograde intrarenal surgery.
Experimental: Placebo Capsule Plus Intraureteral Aminophylline; 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; Matching placebo capsule for tamsulosin, taken once daily for 7 days before retrograde intrarenal surgery.; Drug: Intraureteral Aminophylline; 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.
Experimental: Tamsulosin Plus 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; Tamsulosin 0.4 mg capsule once daily for 7 days before retrograde intrarenal surgery.; Drug: Intraureteral Aminophylline; 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	During the index retrograde intrarenal surgery procedure

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	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.	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.	During the index retrograde intrarenal surgery procedure
Postoperative Pain Score	Postoperative pain intensity assessed after the index procedure using the study pain assessment method.	Within 24 hours after the index procedure

Collaborators and Investigators

• Sponsor: Beni-Suef University
• Investigators: Principal Investigator: Hany F Badawy, MD, Faculty of Medicine, Beni-Suef University

Study record dates

Study Major Dates

• Study Start (Actual): May 6, 2026
• Primary Completion (Estimated): April 1, 2027
• Study Completion (Estimated): May 1, 2027

Study Registration Dates

• First Submitted: May 28, 2026
• First Submitted That Met QC Criteria: May 28, 2026
• First Posted (Actual): June 3, 2026

Study Record Updates

• Last Update Posted (Actual): June 3, 2026
• Last Update Submitted That Met QC Criteria: May 28, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Tamsulosin; ureteral access sheath; Retrograde intrarenal surgery; Intraureteral aminophylline
• Additional Relevant MeSH Terms: Urogenital Diseases; Male Urogenital Diseases; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urolithiasis; Nephrolithiasis; Sulfur Compounds; Organic Chemicals; Hydrocarbons; Hydrocarbons, Cyclic; Hydrocarbons, Aromatic; Amides; Benzene Derivatives; Benzenesulfonamides; Sulfonamides; Sulfones; Tamsulosin
• Other Study ID Numbers: FMBS050526BadawyTAMAMINUAS; FMBSUREC/05052026/Badawy (Other Identifier: FM-BSU REC)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: 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.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No