Prune Belly Syndrome

What is prune belly syndrome?

Prune belly syndrome is also known as triad syndrome or Eagle-Barrett syndrome. It is characterized by the presence of three abnormalities that include the following:

• Absence of abdominal muscles
• Undescended testicles (a condition seen in newborns whereby one [or both] of the male testes has not passed down into the scrotal sac).
• An abnormal, expanded bladder and problems in the upper urinary tract, which may include the bladder, ureters, and kidneys

Because of the substantial involvement of the urinary tract, children with prune belly syndrome are usually unable to completely empty their bladders and have serious bladder, ureter and kidney impairment.

A child with prune belly syndrome may also have other birth defects. Most commonly, these defects involve the skeletal system, intestines and heart. Girls may have defects in their external genitalia, as well.

Prune belly is classified into three categories, I, II and III with category I patients being most severally symptomatic.

What causes prune belly syndrome?

Prune belly syndrome is an uncommon birth defect occurring in about one in 30,000 to 40,000 births. In 95 percent of the cases, it occurs in males. It may occur if there is a urethral obstruction during fetal development preventing any urine from flowing through the urinary tract. The urethra is the tube that drains urine from the bladder to the outside of the body for elimination. If there is obstruction, urine can reverse flow and cause an expanded bladder.

The cause of prune belly syndrome is unknown; however, some cases have been reported in siblings, suggesting a genetic component.

What are the symptoms of prune belly syndrome?

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

• The abdomen may have a wrinkly appearance with multiple folds of skin.
• An abdominal mass may sit above the pubic bones—this is a result of an expanded bladder.
• The urinary tract organs may be easy to feel through the abdominal area.
• An outline of the intestines may be visualized through the abdomen including visualization of peristalsis (the worm-like movements of the intestines shifting food forward).
• Absence of testes in the scrotum may be present in males.
• There may be underdeveloped muscles of the abdomen preventing a child from sitting upright.
• A child may experience frequent urinary tract infections

The symptoms of prune belly syndrome may resemble other conditions and medical problems. The specialists at the CHOC Urology Center carefully work with each patient to ensure a proper diagnosis and appropriate treatment plan.

How is prune belly syndrome diagnosed?

The severity of the defects often determines how a diagnosis is made. Typically, prune belly syndrome is diagnosed by fetal ultrasound while a woman is still pregnant. Because of the distinct abnormalities of prune belly syndrome, a physician is usually able to make a diagnosis after initial examination during the newborn period. A child who may not have the outward signs of prune belly syndrome may experience a urinary tract infection, which will prompt further testing by one of our specialists. Additional diagnostic procedures may include the following:

Renal 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 are taken as the bladder fills and empties. The images show if there is any reverse flow of urine into the ureters and kidneys.

Want to know more about the tests used by the CHOC Urology Center? Read our Common Diagnostic Procedures Guide for in-depth information on the tests we use.

What is the treatment for prune belly syndrome?

Specific treatment for prune belly syndrome will be determined by your child’s physician based on:

• The child’s age, overall health, and medical history.
• The extent of the disease.
• The child’s tolerance for specific medications, procedures or therapies.
• Expectations for the course of the disease.
• The family’s opinion or preference.

Treatment for the syndrome depends on the severity of symptoms. If the child has mild prune belly syndrome, he or she may be maintained on precautionary antibiotic therapy to prevent upper and lower urinary tract infections.

Some children may require a vesicostomy (a small opening made in the bladder through the abdomen) to facilitate emptying the bladder of urine. Other children may need to undergo an extensive surgery to reconstruct the abdominal wall and urinary tract. In boys, a surgical procedure to advance the testes into the scrotum may be performed, called an orchiopexy.