We hypothesize that overnight catheter drainage (OCD) of the urinary bladder might improve bladder dynamics and subsequently lead to improvement or resolution of hydronephrosis (HN) and renal function in boys who underwent PUV ablation.

Patients who have persistent HN and bladder dysfunction at least one year after PUV ablation will be randomly allocated into two groups: the first group (control group): 55 patients, their parents will be taught the timed voiding regimen every 2 hours, while the second group (OCD group): 55 patients, their parents will be taught the timed voiding regimen every 2 hours, in addition to placing an overnight catheter to drain the urinary bladder during night.

We will study the effect of OCD of the urinary bladder on the improvement or resolution of HN and urinary bladder function within a year of starting this regimen.

Posterior urethral valve (PUV) is the most common cause of bladder outlet obstruction (BOO) in boys. PUV induces damage to the smooth muscles of the bladder and ureter with subsequent damage to the renal parenchyma. All these sequelae begin antenatally and persist even after successful valve ablation.

The standard management of these sequelae includes timed voiding, double voiding, clean intermittent catheterization (CIC) to facilitate bladder emptying and anticholinergic drugs to improve poor bladder compliance. However, in some polyuric cases even voiding or catheterization as frequently as every 2 hours is not effective to maintain safe bladder volumes especially at night.

Overnight catheter drainage (OCD) of the urinary bladder has been increasingly suggested to be beneficial in protecting the upper tracts of patients with high urine output, defective and poorly compliant bladders, thus resulting in improvement of the renal function, hydronephrosis (HN) and the urodynamic changes as well.

Therefore, we hypothesize that OCD of the urinary bladder might improve bladder dynamics and subsequently lead to improvement or resolution of HN and renal function in boys who underwent PUV ablation.

Patients who have persistent HN and bladder dysfunction at least one year after PUV ablation will be randomly allocated into two groups: the first group (control group): 55 patients, their parents will be taught the timed voiding regimen every 2 hours, while the second group (OCD group): 55 patients, their parents will be taught the timed voiding regimen every 2 hours, in addition to placing an overnight catheter to drain the urinary bladder during night.

We will study the effect of OCD of the urinary bladder on the improvement or resolution of HN and urinary bladder function within a year of starting this regimen by laboratory tests, renal and bladder ultrasonography (US), voiding cystourethrogram (VCUG) and dimercaptosuccinic acid (DMSA) scan. The bladder dynamics will also be examined by urodynamic study (UDS).

Inclusion Criteria: Patients who have;

• Persistent hydronephrosis and
• Unfavorable bladder dynamics on urodynamic study performed at least one year after posterior urethral valve ablation will be included in the study. The unfavorable bladder dynamics will be defined as poor compliance or detrusor overactivity.

Exclusion Criteria: Patients who;

• Underwent urinary diversion (e.g. vesicostomy or ureterostomy),
• Have other conditions that could affect lower urinary tract function,
• Have infravesical obstruction or
• Those who will refuse to participate in the study will be excluded.