What is Prune Belly Syndrome?
Prune belly syndrome is a triad of conditions composed of cryptorchidism, urinary tract abnormalities, and abnormalities in the musculature of the abdomen. The skin in surrounding the anterior abdominal wall appears thin, wrinkled and lax, hence the term “prune belly”. The presence of three abnormalities and its evident physical manifestation defines this clinical condition.
How Prevalent is Prune Belly Syndrome?
It is estimated that at least 1 in every50, 000 live births have this condition and almost 95% are males. Most of the cases occur sporadically, and rarely familial cases occur.
Prune Belly Syndrome Characteristics
Three conditions are encompassed by this syndrome, because of this characteristic; prune belly syndrome is also called a triad syndrome. Specifically, the three conditions are as follows:
- An abdominal wall musculature that is deficient
- Urinary tract anomalies accompanied by megaureters and megacystis
Deficient abdominal wall musculature
In prune belly syndrome, the child is born with a deficient abdominal wall musculature. This is one of the characteristics of prune belly syndrome which results from poor development of muscles in the abdominal area. It is usually the muscles in the ventral and lateral area that are most affected.
Without proper musculature of the abdominal wall, there is no support provided to the abdominal organs inside. The following conditions may happen as a result of the deficient musculature:
- Vital organs such as kidneys, stomach and liver can be easily palpated
- There is increased risk of damage to the abdominal organs even form a slight injury
- Possible rupture of abdominal organs such as the spleen
- Possible protrusion of the organs outside the body
- Increased risk for hemorrhage and infection
A characteristic of the disease is the wrinkled appearance of the belly as a result of the poor musculature in the abdomen. The deficient musculature is attributed to the following:
- Absence of muscles in the abdominal wall
- Replacement of the muscles by collagenous dense tissue
- Presence of hypoplastic atrophic or hypertrophic muscle fibers
- Immature muscle fibers
This condition affects the infant’s growth and development; an impaired abdominal wall musculature can have the following effects:
- Prevalence of respiratory infections
- Delay in walking due to the severe protruding abdomen
- Difficulty sitting up from a supine position
- Constipation that becomes chronic
Anomalies in the urinary system
Another characteristic of this syndrome is the genitourinary tract abnormalities that accompany it. These include the following:
- Renal hypoplasia
- Prostatic hypoplasia
- Dilated prostatic urethra
- Ureteral dilatation
Renal Hypoplasia. Renal hypoplasia involves the changes in the cellular structure and morphology of the kidneys. When cellular changes happen, it also alters the function of the whole organ itself. In this case, the kidney’s normal function is altered due to the changes in its normal cellular make-up.
Megacystis. Megacystis or enlarged bladder is also seen in this syndrome, because the bladder is grossly enlarged, it gives an hour glass shape or configuration. The gross enlargement is again attributed to the abnormal ration of connective tissues against the normal bladder tissues.
Prostatic Hypoplasia. In this syndrome characteristic, the prostate cells lacks epithelial cells, organs such as the prostate gland is normally composed of layers of epithelial cells, but in this syndrome, there is significant lack in the development of epithelial cells.
Dilated Prostatic Urethra. In this syndrome, the urethra near the prostate gland is found to be dilated.
Ureteral Dilatation. In prune belly syndrome, the ureters are found to be elongated, dilated and tortuous; it is usually the lower part of the ureters that are affected.
The abnormalities in the structure and cellular makeup of the kidneys and urinary system bring significant effects to the infant, these may include the following:
- Urinary stasis and eventually urinary tract infection
- Future infertility as a result of prostatic abnormalities
- Improper drainage of urine
- Possible kidney damage from infection and urinary stasis
Individuals with prune belly syndrome have undescended testes or cryptorchidism. in majority of the cases, the testes are found within the abdomen. An undescended testis increases the risk of forming testicular malignancies in later life. This risk increases by about 30-50 times among males with prune belly syndrome.
Signs and Symptoms
Muscular and Gastrointestinal
- Absence of abdominal wall muscles
- Wrinkled appearance of the abdomen
- Wandering spleen
- Chronic constipation
- Bladder distention
- Urinary stasis
- Urine backflow
- Recurrent urinary tract infections
- Difficulty urinating
Reproductive (in later life)
- Discomfort post ejaculatory
- Bladder spasms
What causes prune belly syndrome is generally unknown, but certain factors are thought to lead to the condition.
- Chromosomal abnormalities
- Embryological defects
- Defects in the mesenchymal plate
- Imperfection in the urethra that are inherent
- An early obstruction of the urinary system
1. Ultrasound. Ultrasound studies can be done while the infant is still inside the mother’s womb; this is possible since one of the theories explaining the cause of include embrologic defects and inherent imperfections in the urinary tract system. These events can actually occur inside the womb. Ultrasound studies usually reveal large abdominal mass or enlarged kidneys.
2. Radiograph studies. This would further give the clinician a picture of the bladder and ureters, tortuous ureters and an enlarged bladder is usually seen in infants with prune belly syndrome. Radiographic studies such as this helps the clinician look for internal anomalies related to the syndrome.
3. Voiding cystourethrogram. This diagnostic test involves viewing the urethra and bladder while urinating to evaluate bladder, ureter or kidney abnormalities, this is usually done to patients who have chronic urinary tract infections.
Medications. Medications target the possible complications brought about by the abnormalities in the urinary tract, most common among these are urinary tract infections. To prevent or manage urinary tract infections, patients are given antibiotics.
When the infections begin to occur more frequently, the abnormalities are then surgically corrected.
Orchiopexy. This is the surgical treatment for undescended testes. It is performed by pediatric urologists and is done before 2 years of age. In orchiopexy, the undescended testes are moved into the scrotal sac and are fixed there permanently.
Reconstruction of the abdominal wall. The abdomen is reconstructed to help improve respiration, protect the underlying vital organs and also improve the child’s physical appearance. With advances in surgical science, complications from the abdominal wall reconstruction are now reduced, improving the child’s condition even greater. New approaches in surgical procedures even lead to the further improvement of the child’s physical appearance.
Percutaneous Nephrostomy. This is a surgical procedure done to patients with prune belly syndrome who are suspected to have ureteropelvic junction obstruction. Diagnosing this condition among prune belly patients can be difficult, and it can only be confirmed through a placement of a percutaneous nephrostomy.
Pyeloplasty. This surgical treatment involves the dissection of the upper ureters, which is seen generally normal in most patients.
Vesicostomy. This is a surgical procedure employed to patients with recurrent urinary tract infections who are also suspected to have kidney affectation. In this procedure an opening is made in the urinary bladder and a stoma or an opening is made externally or through the skin, this allows the drainage of urine from the bladder itself.
The prognosis for this condition is highly variable. Prognosis usually depends on the extent of abdominal wall impairment, recurrent urinary tract infections and kidney affectation.
With proper medical attention and treatment, infants with prune belly syndrome can survive to adulthood.
- Testicular cancer. If the undescended testes are not treated early, it can predispose the individual to developing malignancies in later life. A primary risk factor to developing such malignancies is this condtion.
- Infertility. Due to the abnormalities in the testes and the genitourinary tract, sperm production becomes compromised and this leads to infertility.
- Kidney disease. Kidney disease is a result of the recurrent urinary tract infections seen in prune belly syndrome, du to the stasis of urine and its poor flow, bacteria and other microorganism proliferate and infect the ureters and the kidneys eventually.
Pictures of Prune Belly Syndrome
Here are the some images of Prune Belly Syndrome
Prune Belly Syndrome infant with deficient abdominal wall
Image Source - documentingreality.com
Image Source - georgetown.edu
Image Source - medscape
Image Source – Medscape