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KEY POINTS
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Key Points

  • Arises from maldevelopment of the cloacal membrane, which prevents migration of mesenchymal tissue and impedes normal development of the lower abdominal wall.

  • Consists of exstrophy of the urinary bladder, exstrophy of the small or large intestine, anal atresia, hypoplasia of the colon, omphalocele, and malformed genitalia.

  • Incidence 1 in 200,000 to 400,000 livebirths.

  • Associated sonographic signs may include: large infraumbilical anterior midline defect with a protruding omphalocele, absent bladder, narrowed thorax, distorted spine, sacral myelomeningocele, and bilateral clubfeet. However, a correct prenatal diagnosis is rarely made.

  • Differential diagnosis includes bladder exstrophy, omphalocele, gastroschisis, amniotic band syndrome, myelomeningocele, and the limb–body wall deformity.

  • Management of pregnancy should include MRI, karyotype, and multidisciplinary consultation with surgery, urology, endocrinology, and genetics.

  • Delivery should occur in a tertiary center.

  • If the fetus is genetically male, the parents should be counseled about the potential need to reassign gender.

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CONDITION
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Cloacal exstrophy represents a spectrum of rare congenital anomalies that are thought to arise from maldevelopment of the cloacal membrane, which prevents migration of mesenchymal tissue and impedes normal development of the lower abdominal wall. The cloacal membrane separates the coelomic cavity from the amniotic space during the early embryogenic period. The position and the timing of the disruption of the cloacal membrane will determine the variant of the exstrophy that results. For example, inferior perforation results in epispadias; midperforation results in classic exstrophy; and the superior perforation results in superior-vesicle fissure (Jeffs, 1987). When cloacal exstrophy is present in its classic form, the constellation of severe abnormalities is among the most difficult for the pediatric surgeon to reconstruct. It consists of exstrophy of the urinary bladder, exstrophy of the small or large intestine, anal atresia, hypoplasia of the colon, omphalocele, and malformed genitalia, and associated neural tube defects in 50% of cases (Figure 64-1) (Fujiyoshi et al., 1987).

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Figure 64-1

Appearance of a newborn genetic male infant with classic cloacal exstrophy. The infraumbilical omphalocele can be seen at the superior aspect of the defect. There is a prominent elephant-trunk deformity prolapsed throughout the midline intestinal zone. The widely splayed bifid penis can be seen at the lateral aspect of the defect.

Graphic Jump Location
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The anatomy in cloacal exstrophy is complex, with a ventral abdominal wall defect consisting of an omphalocele at the superior margin of the defect and exposed bowel and bladder at the inferior extent (Figure 64-2). The hemibladders are separated in the midline by a zone of intestinal mucosa. Each hemibladder may have a ureteral orifice and the intestinal zone separating the hemibladders may have the orifices of the proximal gut superiorly and the distal gut inferiorly, with one or two appendiceal orifices in between (Warner and Zeigler, 1993). The proximal bowel orifice often prolapses in the characteristic ...

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