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Congenital intestinal atresias, stenosis, and webs typically present
early in neonatal life due to the associated obstructive symptoms.
The reported incidence varies from 1 to 2 in 5000 births in the United
States. These malformations can occur throughout the intestinal
tract, but are most commonly found in the duodenum (50%)
and the jejunum or ileum (35–40%). A colonic location
is identified in 5% to 10% of atresias, and rarely,
pyloric or gastric lesions are present (< 1%).1
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Pathophysiology
and Genetics
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The etiology most commonly accepted for jejunoileal and colonic
atresias involves intrauterine mesenteric ischemia from a variety
of vascular accidents, encompassing umbilical cord infarcts, volvulus,
internal hernias, fascial defects, intussusception, and intestinal perforation.
The affected segment is then reabsorbed. In contrast, duodenal atresia
is attributed to a failure of the recanalization process. Genetic
links and familial patterns of intestinal atresias (mostly autosomal
recessive) are also well described, although the specific genes or
mutations involved have yet to be identified. Duodenal atresia is
associated with anomalies including trisomy 21, congenital heart
disease, malrotation, esophageal atresia, imperforate anus, genitourinary
disorders, and gallbladder agenesis. Recently, an autosomal recessive
syndrome comprising neonatal diabetes mellitus, intestinal atresias,
and gallbladder agenesis has been described.2 An
autosomal recessive genetic disorder called Herlitz syndrome is
linked to some cases of pyloric atresia. Patients with this syndrome
suffer from epidermolysis bullosa lethalis, which results in severe
vesiculobullous lesions after minimal skin friction.
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Clinical Features, Diagnosis,
and Treatment
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The majority of infants with intestinal atresia present as newborns
with signs and symptoms of intestinal obstruction (see Chapter 389), including vomiting (which may be bilious), varying degrees
of abdominal distension, and often failure to pass meconium. Antenatal diagnosis
has been reported, facilitating prompt postnatal diagnosis and management
but without proven impact on long-term outcome.3
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Antral and Pyloric
Atresia and Webs
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Antral or pyloric atresias and webs are rare lesions that present
typically with nonbilious emesis and failure to thrive.4 Unlike
acquired hypertrophic pyloric stenosis, these neonates present with
polyhydramnios in utero and an enlarged stomach at the time of birth.
Partial antral and duodenal webs can also present with chronic vomiting,
often commencing upon the advent of solid feedings, due to intermittent
or partial obstruction.5 The most common abnormality
is a pyloric web, which is a membrane that can become redundant over
time and prolapse into the pyloric channel, creating a classic “windsock” finding.
Diagnosis of pyloric atresia typically requires an upper GI contrast
study and/or endoscopy. Following adequate fluid resuscitation
and gastric decompression, treatment includes laparotomy followed
by pyloroplasty, gastroduodenostomy, or primary anastomosis, depending on
the type and severity of the lesion. Endoscopic laser treatment of
an antral web has been reported.6
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Duodenal Atresia
and Webs
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Duodenal atresia and webs account for half of all intestinal
atresias. In contrast to jejunoileal atresias, duodenal ...