To evaluate the role of both primary and deferred URS in the management of calculus anuria concerning the feasibility, clinical outcome, and cost-effectiveness in children in a comparative study

Thirty group B (30) patients will be admitted to do urinary drainage through the insertion of a JJ stent or percutaneous nephrostomy (PCN) at first , then a deferred URS will be done children will undergo primary URS( group A ) and in. Ureteral dilatation will be done when the stone size exceeds 10 mm to facilitate the extraction of the fragments. Ureteroscopic lithotripsy will be done using a 6.5:7.5 Fr semi-rigid ureteroscope and holmium laser. The ureteric stent will last for one week after lithotripsy. Postoperatively, the patients in both groups will monitored for post obstructive diuresis, fever, hematuria, and extent of renal function improvement.

Inclusion Criteria:

• Children ˂12 years with calculus anuria.
• Clinically stable (serum creatinine < 3.5 mg/dl, blood urea < 100 mg/dl,serum potassium level < 7 milliequivalent /L and /or ph of blood > 7.1)
• All the patients free of sepsis.

Exclusion Criteria:

• Unstable children (serum creatinine ≥ 3.5 mg/dl, blood urea ≥ 100 mg/dl, serum potassium ≥ 7 milliequivalent/l, and/or blood pH ≤ 7.1, signs of acidosis, sepsis, or fluid retention).
• Children with underlying urological structural abnormalities