Epidemiology Clinical Presentation: Associations
Epidemiology Clinical Presentation: Associations
Epidemiology Clinical Presentation: Associations
neonatal period. It is considered to be one of the commonest causes of a fetal bowel obstruction.
Epidemiology
The prevalence of duodenal atresia is ~1 in 5,000-10,000 newborns, and there is no sex-associated difference in
prevalence.
Clinical presentation
Patients present in early life with duodenal obstruction and associated symptoms of abdominal distension, vomiting
and absent bowel movements. In complete atresia, duodenum ends blindly with no communication with the distal
bowel (and therefore no aeration distally). The atretic segment is usually just distal to the ampulla of Vater 1 and the
child has bilious vomiting. If the atresia is proximal to the ampulla, the vomiting is non-bilious.
The vomiting usually occur within the first 24 to 38 hours of neonatal life, typically following the first oral feeding
and progressively worsens if not treated.
Pathology
Although more distal small bowel atresia is believed to be secondary to an ischemic episode, duodenal atresia is
thought to represent a failure of recanalization of the bowel lumen that is a solid tube early in fetal life (~11-12
weeks).
In duodenal atresia, there is complete obstruction of the duodenal lumen, while in duodenal stenosis there is an
incomplete obstruction of the duodenum lumen
Recognition that these structures are not continuous with the stomach will aid in the correct interpretation. This may
occur in cases of choledochal cysts or renal, hepatic, omental, duplication or ovarian cysts. Likewise, a "double
bubble" may be seen in cases of Ladd's bands, annular pancreas or volvulus, in which there is no duodenal atresia.
Associations
Associated conditions are common and include:
Down syndrome: ~30% of duodenal atresia cases may have Down syndrome while ~3% of Down syndrome
cases may have duodenal atresia
VACTERL association
annular pancreas
other intestinal atresias
o jejunal atresia
o ileal atresia
o anal atresia
Radiographic features
Plain radiograph
Abdominal radiographs may classically show a double bubble sign with gas filled distended stomach and duodenum
with an absence of distal gas. A similar appearance (either filled with fluid or gas) can be seen in other modalities.
A double-bubble sign on an abdominal x-ray is a reliable indicator of duodenal atresia with even higher positive
predictive value in patients with Down syndrome.
The presence of distal bowel gas, although more classically associated with duodenal stenosis, can be seen in
duodenal atresia via anomalous bile duct anatomy 4.
Barium study
Barium contrast can be administered sometimes via an orogastric or nasogastric tube under fluoroscopy to evaluate
the upper gastrointestinal tract. Only a controlled amount of barium is placed to confirm obstruction. It is then
removed by nasogastric tube to prevent reflux and potential aspiration.
Ultrasound
May also show a dilated stomach and duodenum giving a double bubble type appearance. This, however, may not be
sonographically detectable until the mid to late second trimester. May also show evidence of polyhydramnios as an
ancillary sonographic feature.
If a double-bubble sign is seen on antenatal ultrasound, then it is important to demonstrate a connection between the
two fluid-filled structures because foregut duplication cyst, as well as other abdominal cysts, may simulate the
appearance of a double-bubble sign
Differential diagnosis
For plain radiograph appearances consider:
duodenal stenosis
duodenal web
intestinal malrotation and midgut volvulus
All three of these will show distal gas: