Pediatric Posterior Urethral Valve

What causes posterior urethral valves?

PUV is thought to develop in the early stages of fetal development. The abnormality affects only males and occurs in about one in 8,000 births. This disorder usually occurs by chance. However, some cases have been seen in twins and siblings, suggesting a genetic component.

What are the symptoms of posterior urethral valves?

The syndrome may occur in varying degrees from mild to severe. The following are the most common symptoms of posterior urethral valves. However, each child may experience symptoms differently. Symptoms may include:

• An enlarged bladder that may be detectable through the abdomen as a large mass
• Urinary tract infection (usually uncommon in children younger than age 5 and unlikely in boys at any age, unless an obstruction is present)
• Painful urination
• Weak urine stream
• Urinary frequency
• Bedwetting or wetting pants after the child has been toilet trained
• Poor weight gain
• Difficulty with urination

The symptoms of PUV may resemble other conditions or medical problems. Always consult your child's doctor for a diagnosis.

How are posterior urethral valves diagnosed?

The severity of the obstruction often determines how a diagnosis is made. Often, PUV is diagnosed by fetal ultrasound while a woman is still pregnant. Children who are diagnosed later often have developed urinary tract infections that require evaluation by a doctor. This may prompt your doctor to perform further diagnostic tests, which may include:

• Abdominal ultrasound. A diagnostic imaging technique that uses high-frequency sound waves and a computer to create images of blood vessels, tissues, and organs. Ultrasounds are used to view internal organs as they function, and to assess blood flow through various vessels.
• Voiding cystourethrogram (VCUG). A specific X-ray that examines the urinary tract. A catheter (hollow tube) is placed in the urethra (tube that drains urine from the bladder to the outside of the body) and the bladder is filled with a liquid dye. X-ray images will be taken as the bladder fills and empties. The images will show if there is any reverse flow of urine into the ureters and kidneys.
• Endoscopy. A test that uses an instrument called a cystoscope which has a light and a camera lens at the end to examine the inside of part of the urinary tract. The cystoscope can also be used to treat the posterior urethral valve by cutting it.
• Blood test. A blood test may be ordered to assess your child's electrolytes and to determine kidney function.

What is the treatment for posterior urethral valves?

Specific treatment for PUV will be determined by your child's doctor based on:

• Your child's age, overall health, and medical history

• The extent of the abnormality

• Your child's tolerance for specific medications, procedures, or therapies

• Expectations for the course of the abnormality

• Your opinion or preference

Treatment for PUV depends on the severity of the condition. Treatment may include the following:

• Supportive care. Initially, treatment may focus on relieving your child's symptoms. If your child has a urinary tract infection, is dehydrated, and/or has electrolyte irregularities, these conditions will be treated first. Your child may have a catheter placed in his bladder (a small hollow tube that is inserted into the penis through the urethra and is threaded up into the bladder). Your child may also receive antibiotic therapy and intravenous (IV) fluids.

• Endoscopic ablation. After the initial management, a urologist (a doctor who specializes in the disorders and care of the urinary tract and the male genital tract) may see your child. The urologist may perform a procedure called an endoscopic ablation or endoscopic incision of valve. During this procedure, the urologist will insert an instrument called a cystoscope which has a light and a camera lens at the end to examine the inside of part of the urinary tract. The cystoscope can also be used to treat the posterior urethral valve by cutting it.

• Vesicostomy. In certain situations, a different procedure called a vesicostomy may be required. A vesicostomy is a small opening made in the bladder through the abdomen. Usually this opening is closed at a later time when the valves can be cut more safely.

Nearly 30 percent of boys with PUV may have some long-term kidney failure that may need to be addressed. The prognosis for PUV improves when detected early.