Duodenal Atresia

INTRODUCTION:

• It is thought to represent a failure of recanalisation of the bowel lumen that is a solid tube early in fetal life (~11-12 weeks).
• Approximately 20–40 percent of all infants with duodenal atresia have Down syndrome.
• During pregnancy, duodenal atresia is associated with increased amniotic fluid in the uterus, which is called polyhydramnios.
• After birth, duodenal atresia may cause abdominal distension, especially of the upper abdomen.
• Bilious vomiting commonly occurs within the first day of life.
• Duodenal atresia (DA) is thought to occur as a result of failure of vacuolization of the duodenum from its solid cord stage. 
• The range of anatomic variants includes duodenal stenosis causing constipation , mucosal web with intact muscular wall (so-called windsock deformity); two ends separated by a fibrous cord, or complete separation with a gap within the duodenum.
• In most cases, the duodenal obstruction is distal to the ampulla of Vater, and infants present with bilious emesis in the neonatal period. In patients with a mucosal web, the symptoms of postprandial emesis may occur later in life.

ASSOCIATED ANOMALIES:

• Prematurity
• Down syndrome
• Maternal polyhydramnios
• Malrotation
• Annular pancreas
• Biliary atresia.
• Other  anomalies, such as cardiac, renal, esophageal, and anorectal anomalies, are also common. 

DIAGNOSIS:

• The diagnosis of duodenal atresia is usually confirmed by radiography.
• An X-ray of the abdomen shows two large air filled spaces, the so-called “double bubble” sign. 
• The air is trapped in the stomach and proximal duodenum, which are separated by the pyloric sphincter, creating the appearance of two bubbles visible on x-ray.

TREATMENT:

• Early treatment includes removing fluids from the stomach via a nasogastric tube, and providing fluids intravenously. 
• The definitive treatment for duodenal atresia is surgery (duodenoduodenostomy), which may be performed openly or laparoscopically