VIII. INTESTINAL ATRESIAS
The most common cause of neonatal intestinal obstruction is intestinal atresias
and stenosis. Atresia is complete obstruction of lumen of the intestine, and stenosis
referes to incomplete obstruction of the lumen. The most common intestinal atresia (in
decreasing order of frequency) are duodenal, ileal, jejunal. Colonic atresia is very rare.
Incidence 1 in 2710 live births (equal sex distribution)
Clinical Presentation
Infants with intestinal atresias are often diagnosed prenatally. After birth, they
can have abdominal distention and vomiting. Babies with colonic atresia can present
with perforation and/or such significant abdominal distension to require ventilatory
support.
The differential diagnosis of babies with a bilious vomiting include causes of
intestinal obstruction such as malrotation with or without volvulus, intestinal duplication,
meconium ileus, Hirschprung disease.
Radiological Presentation
On prenatal ultrasound, finings may include polyhydramnios or dilated,
“echogenic” bowel. Postnatally, duodenal atresias often show a double bubble sign (air
in the stomach and in the proximal duodenum). Small bowel atresias show dilated (air
filled proximal intestine). If a distal contrast enema is done, there is often a microcolon.
If peritoneal calcifications are seen, there is likely an in utero perforation.