PRUNE BELLY SYNDROME

- EAGLE-BARRETT SYNDROME

The prune belly syndrome is the association of distended abdominal wall, large hypotonic bladder and cryptorchidism.

It occurs in 1:35,000 to 1: 50,000 live births. The vast majority occurs in males (1) with a normal karyotype.

ETIOLOGY

• The syndrome may result from either a mesodermal defect, affecting the abdominal wall musculature, gubernaculum and urinary tract musculature (2). Histological studies support Pagon's theory (3) that the primary defect is bladder obstruction and that abdominal muscle deficiency occurs secondary to this defect (4,5).
• The syndrome has also been described in fetuses with abdominal wall over-distention (secondary to renal tract obstruction) resulting from a number of different etiologies (6). However relief of the megacystis in the second trimester may not prevent the development of this syndrome

ULTRASOUND

• Megacystis (the bladder may be huge and occupy the entire fetal abdomen)
• Abdominal muscle deficiency giving it a wrinkled appearance.
• Marked dilatation of both ureters (due to shortening of the anterior wall of the prostatic urethra resulting in some kinking and obstruction)
• Cryptorchidism.
• Fetal ascites has been reported (7).

DIFFERENTIAL DIAGNOSIS

• Posterior urethral valves.
• Urethral atresia.

REFERENCES

1. Sanders RC, Nussbaum AR, Solez K. Renal dysplasia: sonographic findings. Radiology 1988;167:623-626.
2. Workman SJ, Kogan BA. Fetal bladder histology in posterior urethral valves and the prune belly syndrome. J Urol 1990;144:337-339.
3. Pagon RA, Smith DW, Shepard TH. Urethral obstruction malformation complex: a cause of abdominal muscle deficiency and the "prune-belly". J Pediatr 1979;94:900-906.
4. Moerman P, Fryns JP, Godderies P et.al. Pathogenesis of the prune-belly syndrome: a functional urethral obstruction caused by prostatic hypoplasia. Pediatrics 1984;73:470-475.
5. Nakayama DK, Harrison MR, Chinn DH et.al. The pathogenesis of prune belly. Am J Dis CHILD 1984;138:834-836.
6. Finley BE, Bennett TL, Burlbaw J et.al. Development of the Eagle-Barrett (prune belly) syndrome and a thickened, poorly functional bladder wall after early second trimester decompression of fetal megacystis. Ultrasound Obstet Gynecol 1993;3:284-286.
7. Fried S, Appelman Z, Caspi B. The origin of ascites in prune belly syndrome - early sonographic evidence. Prenat Diagn 1995; :876-877.