Duodenal atresia

Other Names: Duodenal stenosis

Duodenal atresia is an embryopathy of the cranial intestine that leads to a complete absence of the duodenal lumen. Many infants with duodenal atresia also have Down syndrome. Duodenal atresia is often associated with other birth defects.

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Epidemiology

The incidence of duodenal atresia is between 1/10,000 and 1/6,000 live births, with an approximately equal male to female ratio.

Cause

The cause of duodenal atresia is not known. It is thought to result from problems during an embryo's development. The duodenum does not change from a solid to a tube-like structure, as it normally would. Vascular anomalies, abnormalities in neural cell migration and failure of recanalization of the duodenal lumen may play a causative role, although the exact cause remains unknown.

Inheritance

In most cases, duodenal atresia is sporadic, although an autosomal recessive pattern has been suggested in some families.

Types

Duodenal atresia is classified into three types: type I (duodenal diaphragm) is linked to the presence of a mucosal diaphragmatic membrane with an intact muscle wall; type II (complete a duodenal atresia) characterized by a short fibrous cord connecting the two ends of the atresic duodenum; and type III (also complete duodenal atresia) which corresponds to a complete separation of the two ends of the duodenum, sometimes together with annular pancreas.

Signs and symptoms

In 30-52% of infants it is an isolated anomaly, but it is often associated with other congenital abnormalities. Approximately 20 to 30% of infants with duodenal atresia are carriers of trisomy 21, and about 20 to 25% have cardiac anomalies.

Other frequently described associated malformations include duodenal growth failure, annular pancreas , which are particular clinical forms of duodenal atresia, and anomalies of the biliopancreatic tract or choledochal cysts.

Clinical presentation depends on the degree of atresia. Important obstructions manifest during the first days of life with bilious vomiting if the obstacle is infra-vaterian, which starts in the hours after birth, and with feeding intolerance. Weight loss, dehydration, and hypochloremic metabolic alkalosis are the most common symptoms. Less severe obstructions may manifest several months, or even several years, after birth with bilious vomiting without abdominal distention (major sign); however, failure to thrive may be the only presentation.

Symptoms of duodenal atresia include:

• Upper abdominal swelling (sometimes)
• Early vomiting of large amounts, which may be greenish (containing bile)
• Continued vomiting even when infant has not been fed for several hours
• No bowel movements after first few meconium stools

Diagnosis

The clinical diagnosis is confirmed by abdominal radiography that shows a characteristic 'double bubble appearance with air trapped in the first portion of the duodenum and stomach due to the simultaneous distension of the stomach and first portion of the duodenum (above the stenosis).

Differential diagnosis Differential diagnoses include late appearing pyloric stenosis in cases of incomplete diaphragm, and other forms of intestinal atresia, common mesenteric intestinal volvulus, and duodenal duplication.

Diagnosis is prenatal in 80-90% of cases (by ultrasound in the seventh month or before that reveals the characteristic ``double bubble image).

Treatment

A tube is placed to decompress the stomach. Dehydration and electrolyte imbalances are corrected by providing fluids through an intravenous tube (IV, into a vein). Checking for other congenital anomalies should be done.

Surgery to correct the duodenal blockage is necessary, but not an emergency. The exact surgery will depend on the nature of the abnormality. Other problems (such as those related to Down syndrome) must be treated as appropriate.

Prognosis

The prognosis with early surgical intervention is excellent. If not treated, the condition is deadly.

Possible Complications These complications may occur:

• Other birth defects
• Dehydration

After surgery, there may be complications such as:

• Swelling of the first part of the small bowel
• Problems with movement through the intestines
• Gastroesophageal reflux

NIH genetic and rare disease info

• NIH info on Duodenal atresia

Duodenal atresia is a rare disease.

Duodenal atresia Resources
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