A child presented with intermittent episodes of left sided flank pain. Ultrasonography reveals a large hydronephrosis with dilated renal pelvis and coical thinning with a normal ureter. Kidney differential function was observed to be 19% which of the following is the best management:: (A) Nephrectomy, (B) Pyeloplasty, (C) External Drainage, (D) Endopylostomy
Answer is B. Pyeloplasty