This prospective randomized pilot study will compare vacuum-assisted mini-percutaneous cystolithotripsy with standard transurethral cystolithotripsy for the treatment of bladder stones in children. Forty children aged 2 to 14 years with bladder stone(s) measuring 10 -30 mm will be randomly assigned to one of two surgical approaches. The vacuum-assisted mini-percutaneous group will undergo suprapubic percutaneous access using a mini sheath with suction-assisted fragment evacuation, while the transurethral group will undergo standard transurethral cystolithotripsy. The primary outcome will be total operative time. Secondary outcomes will include stone-free rate ,lithotripsy time and fragment clearance time, urethral mucosal injury, postoperative hematuria, fever, urinary tract infection, sepsis, urinary retention, urinary leakage from the suprapubic tract, catheterization time, hospital stay, postoperative pain, analgesic requirement, need for auxiliary procedures or conversion, and recurrence or urethral stricture-related symptoms during follow-up.

Bladder stones in children remain a relevant urological condition, particularly in settings where nutritional, metabolic, infectious, or hydration-related factors may contribute to stone formation. Minimally invasive endoscopic management has largely replaced open cystolithotomy in many centers. Transurethral cystolithotripsy is commonly used, but in young children the small urethral caliber may make repeated instrumentation and fragment extraction technically challenging and may raise concern about urethral mucosal trauma. Percutaneous cystolithotripsy provides an alternative route that may reduce repeated transurethral fragment extraction.

Vacuum-assisted mini-percutaneous cystolithotripsy uses a suprapubic percutaneous access tract and a suction-assisted sheath to maintain visibility and facilitate evacuation of stone dust and fragments during laser lithotripsy. However, pediatric comparative evidence remains limited.

This study is designed as a prospective randomized controlled pilot study including 40 children with bladder stone(s) measuring 10-30 mm. Eligible patients will be randomized in a 1:1 ratio to vacuum-assisted mini-percutaneous cystolithotripsy or transurethral cystolithotripsy. Both procedures will be performed under general anesthesia using Ho:YAG laser lithotripsy. Patients will be followed postoperatively to assess operative, perioperative, and follow-up outcomes. The study aims to generate preliminary comparative data on operative time, safety, stone clearance, postoperative recovery, and follow-up urinary outcomes to inform future adequately powered trials.

Inclusion Criteria:

• Children aged 2 to 14 years.
• Diagnosis of bladder stone or stones measuring 10-30 mm in maximum cumulative diameter, confirmed by ultrasound.
• Normal upper urinary tract.
• Fit for general anesthesia.
• Written informed consent obtained from parents or legal guardians.

Exclusion Criteria:

• Known urethral stricture or posterior urethral valves.
• Active urinary tract infection at the time of surgery.
• Coagulopathy or uncorrected bleeding disorder.
• Previous open bladder surgery.
• Any anatomical or clinical condition that, in the investigator's judgment, precludes safe endoscopic or percutaneous cystolithotripsy.

Individual participant data will not be shared because the study involves pediatric participants and individual-level clinical data. 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.

The operating surgeon and patients' guardians will not be masked because of the surgical nature of the interventions. Postoperative imaging assessment for stone-free status will be performed by a radiologist or outcomes assessor masked to treatment allocation.