Posterior urethral valves (PUV) are obstructive membranes that develop in the urethra (tube that drains urine from the bladder), close to the bladder. The valve can obstruct or block
Valves Illustration the outflow of urine through the urethra. When this occurs, the bladder, ureters and kidneys become progressively dilated, which can lead to damage. The degree of urinary-outflow obstruction will determine the severity of the urinary tract problems.
PUV are thought to develop in the early stages of fetal development. The abnormality affects only male infants and occurs in about 1 in 8,000 births. This disorder is usually sporadic (occurs by chance). However, some cases have been seen in twins and siblings, suggesting a genetic component.
PUV occur in varying degrees from mild to severe. Due to increased use of prenatal imaging, PUV may be identified before any symptoms are present. If any dilation (hydronephrosis) is identified, the baby will be monitored throughout the pregnancy and after birth. Once the baby is born, further imaging studies will confirm the diagnosis.
Children who are diagnosed later may have the following signs or symptoms that require treatment:
We use voiding cystourethrogram (VCUG) to diagnose PUV. During this test, a catheter (tube) is placed through your child’s urethra into the bladder. The tube will be used to slowly fill the bladder with a solution called contrast. While the bladder is being filled, a special machine (fluoroscopy) is used to take pictures. The radiologist looks to see if any of the contrast goes back up into the kidneys. This study is used to diagnose vesicoureteral reflux (VUR). Additional pictures are taken while your child is urinating. The radiologist will look at the urethra while urine is passing to identify the blockage (PUV).
We will also look at your child’s kidneys and bladder with a renal bladder ultrasound (RBUS). This procedure uses sound waves to outline the kidneys and bladder. It will enable us to see the degree of hydronephrosis and the shape of the bladder.
We may also order blood tests to check how well the kidneys are functioning.
Treatment for PUV depends on the severity of the condition, your child’s age, bladder and kidney status. The surgical goal is to preserve kidney and bladder function.
After successful bladder drainage, either by the valve abilation or vesicostomy, we will continue to monitor your child's condition throughout his childhood and adolescence. We will need to assess the kidney function, watch for kidney growth and see how your child does through toilet training. Some children need ultrasounds every year while others may benefit from medications and additional surgeries. Our team will work with you and your family to tailor a plan based on your child's condition.
Visit the Center for Fetal Diagnosis and Treatment (CFDT) to learn more about lower urinary tract obstruction (LUTO) and watch our LUTO video on how our Urology and CFDT teams collaborate to provide accurate diagnosis before birth and expert evaluation and treatment after birth.
Reviewed by: Division of Urology
Date: May 2011