Aminophylline: Aminophylline will be administered intravesically at a dose of 0.5 mg/kg, diluted in 0.9% normal saline to a fixed total volume of 50 mL. The solution will be instilled through a urethral catheter, retained in the bladder for approximately 5 minutes, then drained before a second gentle semi-rigid ureteroscopic access attempt.
Normal Saline Placebo: A 50 mL volume of 0.9% normal saline placebo will be instilled intravesically through a urethral catheter, retained in the bladder for approximately 5 minutes, then drained before a second gentle semi-rigid ureteroscopic access attempt.
Study summary
This study will evaluate whether intravesical aminophylline can facilitate semi-rigid ureteroscopic access in children with distal ureteral stones when the first gentle attempt to enter the ureter is unsuccessful.
Children scheduled for semi-rigid ureteroscopy for distal ureteral stones will first undergo the standard gentle attempt to pass the ureteroscope through the ureteric orifice and intramural ureter. If access is achieved, the child will continue standard treatment and will not be randomized. If access is not achieved, the child will be randomized during the operation to receive either intravesical aminophylline or intravesical normal saline placebo.
The study solution will be instilled into the bladder for approximately 5 minutes, then drained, and a second gentle ureteroscopic access attempt will be made. The main outcome is successful same-session passage of the intended semi-rigid ureteroscope without balloon dilation. The study will also assess the need for JJ stenting and deferred ureteroscopy, same-session stone treatment, operative outcomes, complications, and early aminophylline-related safety.
Eligibility
Sex
ALL
Min age
2 Years
Max age
18 Years
Healthy volunteers
No
Inclusion Criteria:
* Children older than 2 years and younger than 18 years.
* Single unilateral lower/distal ureteral stone confirmed by low-dose non-contrast computed tomography according to local policy.
* Stone size 5 to 15 mm.
* Candidate for definitive treatment by semi-rigid ureteroscopy.
* Sterile urine culture before surgery, or previously positive urine culture that has been properly treated before intervention.
* Intraoperative failed initial gentle negotiation of the ureteric orifice/intramural ureter according to the study definition.
* Written informed consent from the parent or legal guardian, with child assent when appropriate.
Exclusion Criteria:
* Known hypersensitivity to aminophylline, theophylline, or ethylenediamine.
* Use of oral or intravenous aminophylline or theophylline within the previous 24 hours.
* Pre-existing ipsilateral JJ ureteral stent.
* Stone peeping at the ureteric orifice.
* Congenital or acquired abnormality that may affect distal ureteric access, such as ureterocele, obstructive megaureter, distal ureteric stricture, previous ureteric reimplantation, or previous ipsilateral ureteral reconstruction.
* Known bladder dysfunction or conditions likely to affect normal bladder capacity.
* Multiple ipsilateral ureteral stones or associated renal stones requiring flexible ureteroscopy or a ureteral access sheath strategy.
* Febrile urinary tract infection, pyonephrosis, sepsis, or any case requiring urgent decompression instead of definitive ureteroscopy.
* Cardiac disease, arrhythmia, uncontrolled hypertension, hyperthyroidism, epilepsy or seizure disorder, or significant hepatic impairment.
* Inability to complete follow-up.
Primary outcome measure(s)
Proportion of Participants With Successful Same-Session Semi-Rigid Ureteroscopic Access Without Balloon Dilation — Intraoperative, immediately after 5-minute intravesical study solution instillation during the index ureteroscopy procedure. Successful access is defined as passage of the intended semi-rigid ureteroscope through the ureteric orifice and intramural ureter after study solution instillation, without the need for balloon dilation. The outcome will be reported as the proportion of randomized participants achieving successful access in each study arm.
Trial sites (1)
Facility
City
Region
Status
Department of Urology- Beni-Suef University Hospitals
This page summarises publicly available registry data for informational purposes — not medical advice. Eligibility is determined by each study team; patients should discuss participation with their clinician.
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