- Clinical science
Duodenal atresia is a complete occlusion or absence of the duodenal lumen, whereas duodenal stenosis refers to an incomplete obstruction caused by narrowing. Both conditions present with signs of obstruction, including a distended upper abdomen, delayed meconium passage, and vomiting. If the defect is located proximal to the major duodenal papilla, nonbilious vomiting occurs, whereas a defect occurring distal to the papilla causes bilious vomiting. Evidence of polyhydramnios on prenatal ultrasonography may lead to an early diagnosis of duodenal obstruction. An abdominal x-ray typically shows the double bubble sign. Duodenal atresia and stenosis generally have a favorable prognosis and may be surgically treated through duodenoduodenostomy.
Duodenal atresia occurs when recanalization of the closed duodenum fails to occur or occurs only partially during the embryonic period (usually between the 8th–10th week of gestation). Because the development of the duodenum is connected to the growth of the pancreas and the hepatobiliary system, duodenal atresia is commonly associated with anomalies of these organs as well.
Vomiting, that is typically bilious if the stenosis is distal to the major duodenal papilla
- Atresia or high-grade stenosis: vomiting few hours after birth
- Mild stenosis: vomiting after a few days
- Distended upper abdomen and scaphoid lower abdomen
- Delayed meconium passage
X-ray of the abdomen
- Double bubble sign
- Gasless distal bowel
- Associated anomalies may also be investigated with the following methods:
- Definition: absence of the jejunal lumen
- Epidemiology: less common than duodenal atresia
Clinical features: similar to duodenal atresia
- Polyhydramnios (intrauterine)
- Bilious vomiting and upper abdominal distension (postpartum)
- Diagnosis: abdominal x-ray shows a triple bubble sign and gasless colon
- Treatment: surgical correction with bypass of the occluded part of bowel is always required
The differential diagnoses listed here are not exhaustive.
- Preoperative management
Surgery: bypass the atresia or stenosis
- The exact procedure depends on the anatomic findings and associated anomalies
- Common procedure: duodenoduodenostomy or duodenojejunostomy with a proximal transverse-to-distal longitudinal (diamond-shaped) anastomosis
- If diagnosis and treatment occur quickly, the survival rate of isolated duodenal atresia (without further anomalies) is 95%.
- The presence of other anomalies worsens the prognosis.