Congenital malformations - Edocr

218 PART VI GASTROINTESTINAL MALFORMATIONS
tracheoesophageal septum results in EA with or
without TEF. Recent studies have questioned the
presence of lateral tracheoesophageal folds and
have proposed that different types of EA and TEF
can be better explained by imbalance in the
growth of cranial and caudal folds in the area of
tracheoesophageal separation. 5,6 Localized alterations
in epithelial proliferation and apoptosis
have also been proposed to play a role. Isolated
esophageal atresia may result from failure of recanalization
of the esophagus during the eighth
week of development. These disruptions of normal
embryogenesis are associated with abnormal
development of enteric neural plexuses and abnormal
histopathology of surrounding esophageal
and tracheobronchial tissue and are responsible
for various structural and functional defects in the
trachea and esophagus following repair.
CLINICAL PRESENTATION
The diagnosis of EA/TEF requires a high degree
of suspicion. The earliest clinical signs are excessive
oral secretions and drooling of saliva.
Attempts at feeding result in choking, coughing,
regurgitation, and cyanosis. The abdomen will
be scaphoid in the absence of TEF but abdominal
distension is a common feature in infants
with a fistula between distal esophagus and the
respiratory tract. Respiratory symptoms such as
tachypnea, distress, cyanosis secondary to aspiration
of saliva and/or gastric contents with resultant
chemical pneumonitis will soon supervene if
diagnosis is delayed.
ASSOCIATED MALFORMATIONS
AND SYNDROMES
The incidence of associated malformations in
these infants is high and ranges from 50% to 70%.
As a group, infants with type A TEF have the
highest incidence of associated malformations
and infants with type E TEF are least likely to
have other malformations. Table 33-1 summarizes
commonly associated malformations in
these infants. The presence of associated malformations
particularly cardiac, skeletal, and chromosomal
abnormalities have significant negative
impact on survival and outcome. Infants with
Normal
EA + Distal
TEF 87%
Isolated EA
8%
EA + Proximal
TEF 1%
EA + Double
TEF 1%
Isolated
TEF 4%
Trachea
Esophagus
Stomach
Figure 33-1. Classification of esophageal atresia and tracheoesophageal fistulae. (Reprinted
from Brunner HG, van Bokhoven H. Genetic players in esophageal atresia and tracheoesophageal
fistula. Curr Opin Genet Dev. Jun 2005;15(3):341–7,with permission from Elsevier.)