Prune belly syndrome (Eagle-Barrett syndrome)

What is prune belly syndrome?

Prune belly syndrome (Eagle-Barrett syndrome) is a condition present from birth with three main features:

1. Weak or missing abdominal wall muscles. The skin of the belly is wrinkled and looks like a prune, which gives the condition its name.
2. Both testicles stay inside the abdomen and do not come down into the scrotum. More details: undescended testicle.
3. Urinary tract differences: widening of the kidneys and their collecting systems (hydronephrosis), wide and twisting ureters (megaureter), a large bladder, and widening of the first part of the urethra next to the bladder. Urine often flows backward from the bladder toward the kidneys (vesicoureteral reflux). In some children the kidney tissue does not develop fully in the womb (kidney dysplasia).

Severity varies a great deal from child to child: from mild forms to severe forms in which the lungs and kidneys are seriously affected. A child’s outlook depends mainly on the lungs and kidneys.

How common is it?

Prune belly syndrome is rare and occurs almost only in boys. Partial forms are seen very rarely in girls.

How is it found?

During pregnancy

A prenatal ultrasound may show:

• a very large bladder,
• widening of the kidneys and ureters,
• a reduced amount of amniotic fluid.

A similar picture can be seen in other conditions, such as posterior urethral valves, so the exact diagnosis is usually made after birth. When the amniotic fluid is very low, the baby’s lungs may not develop fully. Such a pregnancy should be managed by a team that includes a maternal-fetal medicine specialist, a neonatologist, a pediatric nephrologist and a pediatric urologist, and delivery should be planned at an experienced center.

After birth

The diagnosis is usually made by appearance: a wrinkled, soft belly that spreads out to the sides, and an empty scrotum. Sometimes a full bladder and widened urinary tract can be felt through the belly.

Tests

• Ultrasound: kidney structure, widening of the collecting systems and ureters, bladder size and emptying.
• Blood tests: creatinine and electrolytes. In the first 1–2 days, the baby’s creatinine reflects the mother’s level, so kidney function is judged by how creatinine changes after the first days of life.
• Voiding cystourethrogram (VCUG): done in selected children rather than in every child; it shows reflux and the shape of the urethra. Protecting the child from infection during the test is especially important.
• Kidney scan: when needed, to assess how each kidney works and how urine drains.
• The lungs, heart, bones and joints are also checked.

Treatment

Treatment is planned individually and carried out by an experienced team: a neonatologist, pediatric nephrologist and pediatric urologist, and when needed a pulmonologist and an orthopedic surgeon.

The first weeks

• Monitoring of breathing, kidney function and urine output.
• Because of the widened urinary tract and reflux, antibiotic prophylaxis is commonly given.
• With any fever, a urinary tract infection should be checked for and treated right away.

Urinary tract

Despite the widening, urine drains well enough in many children, and no surgery is needed. Surgery is considered for repeated infections, poor drainage or worsening kidney function. Possible options:

• in infants, a temporary opening of the bladder onto the skin of the belly (vesicostomy),
• narrowing of the ureters and reattaching them to the bladder (ureteral reimplantation),
• making a very large bladder smaller.

Some children cannot empty the bladder completely. In these cases, the family can be taught to empty it regularly with a catheter.

Testicles

Because the testicles are inside the abdomen, they need to be brought down into the scrotum (orchiopexy). The operation is usually done in the first year of life, often laparoscopically, sometimes in two stages. In some children it is done at the same time as the abdominal wall repair. More details: orchiopexy.

Abdominal wall

Abdominal wall reconstruction (abdominoplasty) improves appearance and in some children may also help with coughing and with emptying the bladder and bowels. Whether and when to do it is discussed together with the family.

Long-term follow-up: what to expect

• Kidneys: a substantial share of children develop chronic kidney disease over time. Some may need dialysis or a kidney transplant years later. Regular ultrasounds, blood and urine tests and blood pressure checks are done together with a pediatric nephrologist.
• Infections: the tendency to urinary tract infections remains, so every fever should be taken seriously.
• Having children: fathering a child naturally is usually difficult. Most boys go through puberty on their own. Men who became fathers with assisted reproduction have been reported.
• Other issues: constipation, frequent respiratory infections, and foot and hip problems are possible.
• Transition: follow-up is lifelong. During adolescence, care is handed over in a planned way to an adult urologist and nephrologist.

When to see a doctor

Seek care urgently if:

• there is a fever, especially with vomiting, poor feeding or unusual sleepiness,
• there is very little urine, or the child has not urinated for a long time,
• a baby has trouble breathing.

Do not skip scheduled follow-up visits, even if the child feels well. Worsening kidney function may cause no symptoms for a long time.