What is prune belly syndrome?
Prune belly syndrome, also known as Eagle-Barrett Sydrome, is a complicated defect that occurs during gestation and involves the development of the kidneys, bladder, abdominal wall and testes. It is virtually exclusively seen in boys. There is a spectrum of severity with which this problem presents. At one end of the spectrum, very little intervention is necessary, and at the other end there is poor kidney and lung function so that survival is not possible.
What are the typical findings of prune belly syndrome?
The kidneys usually are hydronephrotic meaning that the central part of the kidneys is dilated and abnormally holds urine. Also, the kidney tissue which makes urine may be poorly developed (dysplasia). Usually, the tubes leading from the kidneys to the bladder, called the ureters, are dilated and not uncommonly vesicoureteral reflux or partial blockage (obstruction) is present.
Vesicoureteral reflux means a regurgitation of urine from the bladder back up to the kidneys. The bladder likewise is usually stretched and dilated and may not empty well. Characteristically, the testes are present but undescended and are found within the abdomen. The abdominal wall has poor muscle tone particularly in the lower regions and may appear lax and wrinkled which gives rise to the name of this syndrome.
This uncommon problem occurs with an incidence of approximately one in 40,000 live births. Although there have been associations with genetic defects, most children have normal genetic studies and the cause for prune belly syndrome has not been determined.
What are the associated findings of prune belly syndrome?
There are several additional problems that may or may not be present in children with prune belly syndrome. Orthopedic related problems occur in approximately 45 percent of children and include chest wall deformities, scoliosus, hip dislocation and club foot. Pulmonary and respiratory problems occur in approximately 50 percent and heart defects are present in 10 percent.
How is prune belly syndrome diagnosed?
The condition is apparent at birth due to the appearance of the abdominal wall. Prenatal diagnosis of prune belly syndrome is possible during maternal fetal ultrasound imaging. In fact, most patients are now diagnosed by this means.
How is prune belly syndrome treated?
At birth, stabilization of the lung function and heart function is the first step. Thereafter, evaluation of the urinary tract by blood tests and imaging and orthopedic consultation follow. Renal bladder ultrasound, which uses high frequency sound waves to create images of the kidneys and bladder, is performed.
A voiding cystourethrogram (VCUG) is used to evaluate the bladder and to determine if vesicoureteral reflux is present. Other studies such as a renal scan or MR urography may be use to gather further information about kidney function and drainage. From these studies the urologist will gain and understanding of the anatomy and function of the urinary tract which will be the basis for ongoing management.
Each child with prune belly syndrome is unique and care must be individualized. In addition, expert care from multiple specialities is essential and initially may include neonatology, cardiology, pulmonology, orthopedics and nephrology, as well as urology. The overriding goals of urology management are to eliminate obstruction if present, improve kidney and bladder drainage and reduce the risk of urinary tract infection. Children are usually started on low dose, once-a-day antibiotics (prophylaxis) to prevent infection. Some children will require only surgery to correct the position of the testes which is done in infancy, while others may require reconstruction of the urinary tract and abdominal wall. Occasionally, urinary diversion procedures during early infancy to allow for better urinary tract drainage during the first few years of life.
A temporary vesicostomy is performed if the bladder cannot empty on its own. This involves bringing the bladder to a small opening on the lower abdominal wall so that the urine can freely drain to the outside and can be easily captured in a diaper. Blockages in the ureter are corrected and vesicoureteral reflux may require surgery which reconnects the ureters to the bladder wall in an antirefluxing fashion. Abdominal wall reconstruction can be performed to eliminate the lax redundant appearance and provide a smooth contour.
Regular follow-up with a urologist is required throughout life to monitor kidney function, drainage of the urinary tract and prevention of infections. Infections are the main cause of sudden loss of kidney function, but if renal dysplasia is present there may be a slow deterioration in the level of kidney function over time. Some children may need kidney transplants but generally do well if this is necessary.
There have been many advances in medical science in the last few decades that have allowed for much better care of children with prune belly syndrome and much better outcomes. Our urologists are committed to providing longterm care for children with prune belly syndrome. With the exception of those children most severely affected, most children not only survive, but go on to lead active, productive lives.