Congenital malformations - Edocr

242 PART VI GASTROINTESTINAL MALFORMATIONS
of abdominal folds or if the lack of fusion of abdominal
folds leads to herniation of intestine and
abdominal viscera. A predominant disorder of
cephalic fold leads to associated defects of the
sternum, diaphragm, pericardium, and heart as
seen in pentalogy of Cantrell. Similarly, a predominantly
abnormal development of caudal fold
would lead to associated cloacal and bladder
exstrophy.
CLINICAL PRESENTATION
Most cases of omphalocele are being diagnosed
on prenatal ultrasound and appear as a round
mass in the midline with the umbilical vessels inserting
into the mass. In an infant without a prenatal
diagnosis, omphalocele is easily diagnosed
at birth by a congenital defect of the anterior
abdominal wall with absent abdominal muscles,
fascia, and skin. As a result, abdominal viscera
herniate into a sac at the base of the umbilical
cord and are covered by a membrane. The umbilical
vessels are on the surface of the sac and
umbilical cord is attached at the apex of the sac
(Fig. 37-1).
ASSOCIATED MALFORMATIONS
AND SYNDROMES
Associated congenital malformations are frequently
seen in infants with omphalocele and
their incidence varies widely from 40% to 90%
in different reports. A higher incidence has been
reported in studies which included abortions
and stillbirths. A defect is considered isolated if
no other congenital malformations are noted
Figure 37-1. An infant with omphalocele with umbilical cord attached at the apex of the sac.
(Used with permission from Drs. Marleta Reynolds and Anthony Chin, Department of Pediatric Surgery,
Children’s Memorial Hospital, Chicago, IL)