Posterior urethral valves are a rare congenital (born with) malformation that affects the urinary tract of only male infants. Abnormal folds of tissue begin to grow early in fetal development in the posterior urethra (a tube that drains urine from the baby’s bladder and carries it outside his body) and block or partially block the flow of urine.
This condition may be inherited but the cause is not currently known.
How are posterior urethral valves diagnosed?
One-third of all cases are diagnosed by ultrasound during pregnancy. Early diagnosis and intervention are crucial for the best outcome. Treatment before birth happens only when the condition is very severe, and complications occur.
No matter when PUV is diagnosed, treatment requires the collaboration of a multidisciplinary team including perinatologists (if diagnosed before birth), neonatologists (if diagnosed before or shortly after birth), urologists, and nephrologists.
What are the indicators of PUV detected in utero?
- Kidney swelling
- Bladder stretching
- Low levels of amniotic fluid leading to pulmonary hypoplasia (underdeveloped lungs)
What are the symptoms after birth?
Mild to moderate PUV may not be diagnosed until the child is older and symptoms become more pronounced, such as:
- Abdominal or lower back pain
- Difficult or painful urination
- Distended bladder
- Frequent urinary tract infections
- Bedwetting past the age of seven
- Difficulty toilet training
How is PUV diagnosed?
Renal (kidney) and bladder ultrasound uses sound waves to observe the child’s kidney size, any swelling, and the shape of the bladder.
Voiding cystourethrogram employs X-rays to see the shape and size of the bladder and urethra, how much urine is backed up to the kidneys, and the bladder’s ability to empty.
Blood tests can determine how well the kidneys are functioning
How is PUV treated?
The primary goal postnatally is to relieve any pressure on the kidneys, typically by placing a catheter (tube) to drain the bladder.
Surgical interventions can be performed to prevent further damage to the kidneys and bladder and include:
Valve ablation wherein a surgeon cuts the valve so that it no longer blocks the flow of urine.
Vesicostomy is a surgical procedure that offers a temporary solution if the obstruction is severe, or the baby is too small to perform an ablation (above). A vesicostomy creates an opening in the lower belly to allow continual draining of urine. The opening is typically closed in the future.
Ureterostomy is a surgical procedure where the ureter (which connects the kidney to the bladder) is disconnected from the bladder and is instead connected to an opening in the belly. This takes pressure off the kidneys and reduces the risk of urinary tract infections. This is less commonly performed.
Learn more
Cincinnati Children’s https://www.youtube.com/watch?v=ZGoq8AVwxXs
Reviewed by: Foong-Yen Lim, MD
