The degree of HUN was graded as mild, moderate or severe. Of 71 patients with a posterior urethral valve evaluated after valve ablation 20 (28.2%) had persistent HUN in a total of 32 renal units (RUs). We determined the association of HUN with urodynamic abnormalities, the effect on HUN of treating these abnormalities and when persistent HUN could be considered residual stretching.
Persistent hydroureteronephrosis (HUN) is often seen in boys with a history of a posterior urethral valve even years after valve ablation and it is often assumed to represent residual stretching.
