Intravesical Aminophylline for Urgent Ureteral Stenting in Acute Calculous Anuria

Intravesical Aminophylline-Assisted Urgent Retrograde Ureteral Stenting for Acute Calculous Anuria: A Prospective Randomized Controlled Trial

Acute calculous anuria is a urological emergency caused by ureteral stone obstruction in a solitary functioning kidney or bilateral ureteral obstruction. Urgent decompression of the upper urinary tract is required to restore urine drainage and prevent further renal impairment.

This prospective randomized double-blind controlled trial will evaluate whether intravesical aminophylline can facilitate urgent retrograde ureteral stenting in adult patients with acute calculous anuria due to ureteral stones. Eligible patients will be randomly assigned to receive either intravesical aminophylline diluted in normal saline or placebo saline before attempted retrograde Double-J ureteral stent placement.

The primary outcome is technical success, defined as successful placement of a Double-J ureteral stent across the obstructing stone without the need for percutaneous nephrostomy. Secondary outcomes include stenting time, intraoperative complications, renal function recovery, postoperative pain, analgesic requirement, and the need for alternative drainage.

Study Overview

• Status: Recruiting
• Conditions: Acute Kidney Injury; Ureteral Calculi; Obstructive Uropathy; Acute Calculous Anuria
• Intervention / Treatment: Drug: Intravesical Aminophylline; Drug: Placebo Saline

Detailed Description

This is a prospective, randomized, double-blind, controlled trial conducted at the Department of Urology, Beni-Suef University Hospital.

The study will include adult patients aged 18 years or older presenting with acute calculous anuria due to ureteral stone obstruction in a solitary functioning kidney or bilateral ureteral obstruction. Obstruction will be confirmed by pelvi-abdominal ultrasound and computed tomography of the urinary tract. Eligible patients will have clinical and laboratory evidence of acute renal impairment, including oliguria or anuria and elevated serum creatinine.

After eligibility assessment and informed consent, participants will be randomly allocated in a 1:1 ratio to one of two groups.

Participants in the aminophylline group will receive intravesical instillation of 250 mg aminophylline diluted in normal saline to a total volume of 160 mL. Participants in the control group will receive placebo intravesical instillation using normal saline with the same total volume. The study solution will be prepared by a nurse who is not involved in the operation to maintain blinding of the patient and the operating surgeon.

Under general or spinal anesthesia, the patient will be placed in the lithotomy position. A cystoscope will be introduced and the bladder will be emptied. The assigned intravesical solution will then be instilled into the bladder and retained for 5 minutes before proceeding with retrograde ureteral stenting. Under fluoroscopic guidance, a guidewire will be advanced through the ureteric orifice in an attempt to bypass the obstructing ureteral stone. If successful, a Double-J ureteral stent will be advanced over the guidewire and positioned across the obstruction.

The primary endpoint is technical success of retrograde ureteral stenting, defined as successful placement of the Double-J stent across the obstructing stone without the need for percutaneous nephrostomy. Secondary endpoints include time required for successful stent placement, intraoperative complications, serum creatinine changes at 24, 48, and 72 hours after decompression, postoperative pain score, analgesic requirement, and the need for alternative drainage after failed retrograde stenting.

• Study Type: Interventional
• Enrollment (Estimated): 72
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Hany F Badawy, MD; Phone Number: +201149525028; Email: HANYFATHY86@GMAIL.COM
• Study Contact Backup: Name: Mahmoud Abdallah, MD; Phone Number: +201211874080; Email: Drhanyfathy86@GMAIL.COM

Study Locations

• Egypt
  • Beni Suweif Governorate
    • Banī Suwayf, Beni Suweif Governorate, Egypt
      • Recruiting
      • Department of Urology- Beni-Suef University Hospitals
      • Contact: Hany F Badawy, MD; Phone Number: +201149525028; Email: HANYFATHY86@GMAIL.COM
      • Contact: Mahmoud Abdallah, MD; Phone Number: +201211874080; Email: Drhanyfathy86@GMAIL.COM
      • Principal Investigator: Hany F Badawy, MD

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Patients aged 18 years or older.
2. Diagnosis of acute calculous anuria due to ureteral stone obstruction in a solitary functioning kidney.
3. Obstruction confirmed by pelvi-abdominal ultrasound and computed tomography of the urinary tract.
4. Clinical and laboratory evidence of acute renal impairment, including oliguria or anuria and serum creatinine >2 mg/dL.
5. Ability to provide written informed consent.

Exclusion Criteria:

1. Known hypersensitivity to aminophylline, theophylline, or other methylxanthines.
2. Evidence of active urinary tract infection or urosepsis.
3. Previous history of ureteral stricture or major urinary tract reconstructive surgery.
4. Hemodynamic instability requiring immediate life-saving measures before urological intervention.
5. Pregnancy.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Intravesical Aminophylline; Participants will receive intravesical instillation of 250 mg aminophylline diluted with normal saline to a total volume of 160 mL. The solution will be retained in the bladder for 5 minutes before attempted urgent retrograde Double-J ureteral stent placement.	Drug: Intravesical Aminophylline; Aminophylline 250 mg diluted with normal saline to a total intravesical instillation volume of 160 mL. The solution will be retained in the bladder for 5 minutes before urgent retrograde Double-J ureteral stent placement.
Placebo Comparator: Placebo Saline; Participants will receive intravesical placebo instillation using normal saline to a total volume of 160 mL. The solution will be retained in the bladder for 5 minutes before attempted urgent retrograde Double-J ureteral stent placement.	Drug: Placebo Saline; Placebo intravesical instillation using normal saline to a total volume of 160 mL. The solution will be retained in the bladder for 5 minutes before urgent retrograde Double-J ureteral stent placement.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Technical Success of Retrograde Double-J Ureteral Stent Placement	Technical success will be defined as successful placement of a Double-J ureteral stent across the obstructing ureteral stone during the initial urgent retrograde stenting procedure without the need for percutaneous nephrostomy.	During the index urgent retrograde stenting procedure

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Retrograde Stenting Attempt Time	Time will be measured in minutes from the start of the retrograde stenting attempt after the 5-minute intravesical dwell time until successful final Double-J stent positioning or the decision to stop the retrograde attempt because of technical failure.	During the index urgent retrograde stenting procedure
Intraoperative Complication Rate	Proportion of participants who experience intraoperative procedure-related complications, including ureteral mucosal injury, ureteral perforation, bleeding, guidewire false passage, or other procedure-related adverse events.	During the index urgent retrograde stenting procedure
Serum Creatinine Change During the First 72 Hours After Decompression	Serum creatinine will be measured before decompression and at 24, 48, and 72 hours after the procedure to assess early renal function recovery.	Baseline, 24 hours, 48 hours, and 72 hours after decompression
Postoperative Pain Score During the First 24 Hours	Postoperative pain will be assessed using a 10-point Visual Analog Scale, where 0 indicates no pain and 10 indicates the worst imaginable pain. Scores will be recorded every 4 hours during the first 24 hours after recovery from anesthesia.	Every 4 hours during the first 24 hours postoperatively

Collaborators and Investigators

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

Study record dates

Study Major Dates

• Study Start (Actual): April 8, 2026
• Primary Completion (Estimated): March 1, 2027
• Study Completion (Estimated): April 1, 2027

Study Registration Dates

• First Submitted: May 25, 2026
• First Submitted That Met QC Criteria: May 25, 2026
• First Posted (Actual): June 1, 2026

Study Record Updates

• Last Update Posted (Actual): June 2, 2026
• Last Update Submitted That Met QC Criteria: May 29, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Double-J stent; Intravesical aminophylline; Retrograde ureteral stenting; Acute calculous anuria; Emergency urinary drainage
• Additional Relevant MeSH Terms: Urogenital Diseases; Male Urogenital Diseases; Calculi; Pathological Conditions, Anatomical; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urolithiasis; Urinary Calculi; Renal Insufficiency; Ureteral Diseases; Pathological Conditions, Signs and Symptoms; Ureterolithiasis; Acute Kidney Injury; Ureteral Calculi
• Other Study ID Numbers: FMBSUREC07042026Ahmed

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared. Only aggregated, de-identified study results will be reported. Individual-level data will remain confidential and will be accessible only to the study investigators and authorized regulatory or ethics committee representatives if required.

Drug and device information, study documents

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