Congenital hernia of the abdominal wall: a differential diagnosis of fetal abdominal wall defects

First Trimester Diagnosis of Omphalocele

Normal physiologic herniation of the fetal bowel is often seen on first trimester sonogram. An omphalocele is an abdominal wall defect that occurs as a result of herniation into the umbilical cord and is often associated with chromosomal anomalies. This case report presents an omphalocele seen in the first trimester and discusses how to differentiate this finding from normal physiologic bowel herniation.

Genetic analysis of Hedgehog signaling in ventral body wall development and the onset of omphalocele formation

Background

An omphalocele is one of the major ventral body wall malformations and is characterized by abnormally herniated viscera from the body trunk. It has been frequently found to be associated with other structural malformations, such as genitourinary malformations and digit abnormalities. In spite of its clinical importance, the etiology of omphalocele formation is still controversial. Hedgehog (Hh) signaling is one of the essential growth factor signaling pathways involved in the formation of the limbs and urogenital system. However, the relationship between Hh signaling and ventral body wall formation remains unclear.

Methodology/Principal Findings

To gain insight into the roles of Hh signaling in ventral body wall formation and its malformation, we analyzed phenotypes of mouse mutants of Sonic hedgehog (Shh), GLI-Kruppel family member 3 (Gli3) and Aristaless-like homeobox 4 (Alx4). Introduction of additional Alx4^Lst mutations into the Gli3^Xt/Xt background resulted in various degrees of severe omphalocele and pubic diastasis. In addition, loss of a single Shh allele restored the omphalocele and pubic symphysis of Gli3^Xt/+; Alx4^Lst/Lst embryos. We also observed ectopic Hh activity in the ventral body wall region of Gli3^Xt/Xt embryos. Moreover, tamoxifen-inducible gain-of-function experiments to induce ectopic Hh signaling revealed Hh signal dose-dependent formation of omphaloceles.

Conclusions/Significance

We suggest that one of the possible causes of omphalocele and pubic diastasis is ectopically-induced Hh signaling. To our knowledge, this would be the first demonstration of the involvement of Hh signaling in ventral body wall malformation and the genetic rescue of omphalocele phenotypes.

Prenatal diagnosis of a fetal abdominal eventration: a rare congenital abdominal wall defect

We report a case of abdominal eventration associated with cystic fibrosis, diagnosed by mid-trimester ultrasonography. The defect concerned the abdominal muscles and their aponevrotic sheath, but respected the skin. There was no associated malformation. The outcome was favorable after surgery, and the infant is well at the age of 6 months.

Body wall dysplasia: a rare case of abdominal hernia

Malformations of the fetal abdominal wall include a broad spectrum of anomalies, and prenatal sonography provides the possibility of detecting most of them. Omphalocele and gastroschisis are the most common conditions, but there are other rare forms. We describe here a rare case of body wall dysplasia that we called abdominal hernia that appeared upon prenatal sonography as an omphalocele-like defect.