Prune Belly Syndrome is a rare congenital disorder primarily affecting newborns, characterized by a wrinkled, “prune-like” appearance of the abdomen. This distinctive look results from underdeveloped abdominal muscles. The condition impacts multiple body systems, with significant effects on the urinary tract.
Core Characteristics
Prune Belly Syndrome is defined by a triad of features observed at birth. The most visible characteristic is the deficiency of the abdominal wall musculature. This absence or weakness of muscles causes the belly skin to appear thin, loose, and wrinkled, often allowing intestinal loops to be visible.
The second feature involves significant urinary tract abnormalities. The bladder is frequently enlarged (megacystis) and may not empty effectively. Ureters, the tubes connecting kidneys to the bladder, are often dilated and twisted (hydroureter), which can lead to urine backing up into the kidneys (hydronephrosis). Vesicoureteral reflux, the backward flow of urine from the bladder into the ureters and kidneys, is also common. The third characteristic, almost exclusively seen in males, is cryptorchidism, where one or both testicles fail to descend into the scrotum.
Underlying Factors
The precise cause of Prune Belly Syndrome remains largely unknown, with most cases occurring sporadically. However, several theories attempt to explain its development. One theory suggests an early obstruction in the fetal urinary tract, specifically the urethra, during development. This blockage could cause significant bladder distension, secondarily impairing abdominal muscle development and preventing testicle descent.
Another explanation is a primary mesodermal defect. This theory posits a problem in the development of the mesoderm, the embryonic tissue layer that gives rise to muscles, urinary tract structures, and testes. Such a defect would account for the simultaneous malformations across these systems. While most cases are not inherited, familial instances suggest a possible genetic component, though no single gene has been definitively identified.
Related Health Impacts
Beyond the defining triad, individuals with Prune Belly Syndrome often experience other health challenges. Kidney function is frequently compromised, with many patients developing chronic kidney disease or even kidney failure due to persistent urinary tract issues. Approximately one-third of affected individuals may eventually require a kidney transplant.
Lung development can also be affected, particularly in severe cases, leading to pulmonary hypoplasia. This occurs when the enlarged bladder restricts lung growth in the womb, potentially causing breathing difficulties at birth. Skeletal abnormalities, such as clubfoot or scoliosis, are observed in some individuals. Gastrointestinal issues like constipation or feeding difficulties can arise. Less commonly, some patients may also present with cardiovascular issues, including heart defects.
Identification and Treatment Approaches
Prune Belly Syndrome is often detected during prenatal ultrasound examinations, which can reveal an enlarged bladder, hydronephrosis, or underdeveloped abdominal muscles. After birth, diagnosis is confirmed through physical examination and imaging studies such as ultrasound, voiding cystourethrogram (VCUG), and renal scans.
Treatment involves a multidisciplinary approach tailored to the individual’s needs and the condition’s severity. Surgical interventions are frequently necessary to manage urinary tract issues, including procedures like vesicostomy (creating an opening from the bladder to the abdomen for drainage) or complex bladder reconstruction (cystoplasty) to improve urine flow and protect kidney function. Abdominal wall reconstruction (abdominoplasty) may be performed to improve muscle tone and appearance. For undescended testicles, orchidopexy surgically brings them into the scrotum. Ongoing supportive care, including respiratory support for lung issues and management of kidney disease (dialysis or transplant), is also provided.
Living with the Condition
The long-term outlook for individuals with Prune Belly Syndrome varies significantly, depending primarily on the severity of kidney and lung involvement. While some babies may face severe complications, many individuals can lead fulfilling lives with appropriate medical management. Lifelong follow-up with a team of specialists, including urologists and nephrologists, is important to monitor kidney function and maintain urinary tract health.
Ongoing care often includes preventative measures, such as antibiotic prophylaxis to reduce the risk of urinary tract infections, which are common due to incomplete bladder emptying. Physical therapy can help improve abdominal wall strength and mobility, supporting daily activities and posture. Psychological support and engagement with patient advocacy groups can also be beneficial in addressing the unique challenges associated with the syndrome.