Duodenal atresia is a congenital closure of the lumen of the duodenum, which is the first portion of the small intestine and is separated from the stomach by the pyloric sphincter. During fetal development, the duodenum develops from the posterior portion of the foregut and the anterior portion of the midgut. The liver and pancreas originate from the diverticulum arising from the ventral part of the duodenum, and the bile duct runs along the ventral free side of the duodenum. Rotation and cavitation result in the duodenum forming a loop shape. Duodenal atresia can be a result of an annular pancreas, which presses on the duodenum, or abnormalities of the bile duct.
Duodenal atresia is usually suspected during prenatal care when the mother has polyhydramnios, or excess amniotic fluid. Newborns present with a distended abdomen and clear intestinal obstruction. Radiography in newborns generally shows a distended stomach and duodenum, called the double bubble effect. In some cases, infants may have duodenal stenosis, which is a narrowing of the lumen of the duodenum that can develop into complete atresia as the child grows. Diagnosis of duodenal atresia is commonly seen in pediatric patients with other abnormalities, such as cardiac and skeletal disorders and trisomy 21.
Treatment of duodenal atresia is ultimately surgical repair of the small intestine. Early treatment in newborns includes providing intravenous fluids and suctioning of free fluids in the abdomen until the patient is stable for surgery. The procedure is called a duodenoduodenostomy, which means to create a new opening of the duodenum and bypass the obstruction. Prognosis of post-operative patients is good; however, complications tend to arise when the patient has other congenital abnormalities.
Image Caption: Scheme of digestive tract, with duodenum marked. Credit: Olek Remesz/Wikipedia (CC BY-SA 2.5)