Posterior urethral valves?

Posterior urethral valves are most common obstructive anomaly of urethra. It represents a thin membranous flap that prevent normal urine flow from the bladder. It leads to renal dysplasia early in fetal life. Its incidence is in between 1 in 5000 and 1 in 8000 male births.


Most cases are detected prenatally by ultrasound, showing oligohydramnios(decrease in amniotic fluid) , hydronephrosis and/or a distended thick walled bladder. If the degree of obstruction is severe, fetus can have renal and respiratory failure from lung underdevelopment as result of low amniotic fluid volumes, requiring intensive care and close monitoring. Older boys may present with urinary tract infection (UTI) and voiding dysfunction.


The diagnosis of posterior urethral valves is made by radiographic imaging with ultrasound and voiding cystourethrogram. Ultrasound will usually show a dilated urethra, bladder, and kidneys; it is supportive of the diagnosis of posterior urethral valves, but not confirmatory. Voiding cystourethrogram is the most definitive study for diagnosis and will show a characteristic dilated and often elongated posterior urethra and abrupt transition to a narrower distal urethra, thickened bladder wall with trabeculations,bladder diverticulum and vesico-ureteric reflux. Occasionally, confirmation of valves with cystoscopy (small camera is inserted into the urethra for direct visualization of valves) is required.


Shortly after delivery a catheter will be placed into the urethra to continuously drain the urine from the bladder. Once your child is stable the posterior urethral valves are treated. This is done by cystoscopy,the valves are cut from the inside using electric current or LASER.,(endoscopic valve ablation). In case urethra is too small for the cystoscope to pass, the bladder is temporarily brought up to the skin on the belly (vesicostomy) so that the urine can directly drain into the diaper and not have to flow through the urethra.


Most boys will need to be monitored for kidney function and bladder function.