Prune Belly (Triad) Syndrome

Prune Belly (Triad) Syndrome


Triad syndrome—the clinical association of a thin flaccid abdominal wall, undescended testes, and bladder hypertrophy with hydroureters—was originally described in 1895 by Parker (1). Shortly thereafter, Osler (2) presented a similar constellation of findings in a child he described as having the appearance of “a wrinkled prune.” From that point, “prune belly” has unfortunately become synonymous with this syndrome. This clinical manifestation is also known as the Eagle-Barrett syndrome and the abdominal muscular deficiency syndrome. By classic description, the triad syndrome occurs in boys. However, 5% of patients are girls presenting with similar physical findings, with the obvious exception of the gonadal abnormality. The incidence of triad syndrome in the United States is approximately 1/26,000 live births of which 50% are white, 31% African American, and 10% Hispanic (3). Most cases are sporadic, although a familial occurrence has been described and might be influenced by the HNF1β gene (4,5).

Approximately three quarters of children with classic triad syndrome will have other associated anomalies. Urethral abnormalities, including atresia and megalourethra, have been reported but are not required as part of the triad. Urethral atresia is usually associated with a patent urachus. The most common skeletal abnormality is a thoracic deformity resulting in a protruded upper sternum, depressed lower sternum, and splayed ribs. Other less frequent skeletal deformities include talipes equinovarus, congenital hip dislocation, calcaneus valgus, polydactyly, syndactyly, arthrogryposis, scoliosis, and lordosis. Intestinal malformations are noted in approximately
one-third of children and most often are due to defective fixation or malrotation of the midgut. Cardiac atrial or ventricular septal defects, patent ductus, and teratology of Fallot have been reported in approximately 15% of children (4). Oral manifestations that included enamel hypoplasia and jaw bone abnormalities have become recently appreciated and possibly due to chronic renal insufficiency (6). The perinatal mortality remains substantial most often due to prematurity and pulmonary complications (3).


Each child presents with a unique constellation of problems resulting in its own set of considerations and requires individualized care (8). Therefore, no one treatment plan is appropriate for all children. In general, operative management can be divided into three broad areas: reconstruction of the urinary system, reconstruction of the abdominal wall, and transfer of the intra-abdominal testes to the scrotum.

Urinary Tract Reconstruction

Controversy surrounds the need for aggressive urinary tract reconstruction. Early aggressive operative intervention for all children is countered by the fact that renal dysplasia may be inherent, thus preventing any intervention from improving the functional status. In addition, imaging studies depicting significant hydroureteronephrosis do not always correlate with obstruction or the potential for symptoms, and hydroureteronephrosis by itself does not mandate reconstruction. Urinary tract reconstruction is beneficial in a child who has a component of obstructive uropathy and has been shown to have improved renal function with decompression of the urinary system. Reconstruction is also of benefit in the child who has progressive hydroureteronephrosis associated with increasing renal compromise and in the child who has recurrent symptomatic UTIs due to stagnant urine flow.

Urinary diversion plays an initial temporary role in the management of acute renal failure or sepsis. Often, children with urethral atresia or obstruction will present with a patent urachus, effectively emptying their lower tract. Infants with associated posterior urethral abnormalities resulting in obstruction or poor bladder decompression, who are not candidates for intermittent catheterization, benefit from a vesicostomy. A vesicostomy, however, may not adequately drain the upper urinary tract due to a relative obstruction of the ureter at the level of the bladder or poor urinary transport secondary to a highly compliant, adynamic ureter. Vesicostomy should be undertaken only when bladder catheterization has been shown to provide effective decompression of the upper urinary tract. Otherwise, temporary diversion of the upper urinary tract will be required. Nephrostomy tube drainage is helpful to stabilize an acute problem but long-term effectiveness is limited, resulting in a need for a more formal upper urinary tract diversion. There is a theoretical advantage in performing upper tract diversion as proximal as possible. This should maximally relieve stress to the kidney and limit stagnation of urine in a dilated tortuous ureter. However, there is often a disproportionate degree of distal versus proximal ureteral dilation that can prevent easy access of the proximal ureter.

It is compelling to perform a reduction cystoplasty during urinary reconstruction in a child with triad syndrome. However, long-term follow-up has been mixed regarding identifiable objective advantages (9,10,11). With time, the bladder will often regain its large size and lose its tone, resulting in inadequate emptying. For these reasons, it is not practical to proceed with reductive cystoplasty as the primary indication for urinary reconstruction. If a large, poorly contracting bladder results in inadequate urinary emptying, intermittent catheterization would be a more appropriate form of initial management. However, when undertaking formal urinary reconstruction with upper tract ureteral tailoring, reductive cystoplasty is practical and may provide limited improved bladder emptying (11).

Reconstruction of the Abdominal Wall

Several techniques have been devised to maximize the cosmetic benefits of abdominal wall reconstruction in children with triad syndrome. There is evidence indicating that the muscular defect is more pronounced centrally and caudally. Initial reconstructive efforts were based on removal of this abnormal tissue. While the appearance of the abdomen was improved, it was not ideal and resulted in a transverse incision and loss of the umbilicus. Monfort described preservation of the umbilicus, and others have added various modifications (12,13,14,15,16,17). Based on these approaches, abdominal wall reconstruction now allows for an excellent cosmetic and functional outcome (15,16,17,18). The benefit of abdominal wall reconstruction is dependent on the degree of abdominal wall laxity. The timing for this procedure should be based on the need for other operative intervention. If it is obvious that the child will not require upper urinary tract reconstruction, abdominal wall reconstruction can be undertaken at any time. If, however, there is the potential for upper urinary tract reconstruction, abdominal wall reconstruction should be deferred until the time of that intervention.

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Apr 24, 2020 | Posted by in UROLOGY | Comments Off on Prune Belly (Triad) Syndrome
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