Duodenal Atresia and Stenosis

Introduction Congenital duodenal obstruction may be due to intrinsic or extrinsic lesions. Intrinsic duodenal obstruction may be caused by duodenal atresia, stenosis, diaphragm with or without perforation, or by a wind-sock web or membrane that balloons distally. Extrinsic duodenal obstruction may be caused by malrotation with Ladd’s bands or a preduodenal portal vein or annular pancreas. The annular pancreas itself is not believed to be the cause of obstruction, as there is usually an associated atresia or stenosis in these patients. Duodenal obstructions usually occur in the second part of the duodenum. They are believed to result from a developmental error during early foetal life within the area of intense embryological activity involved in the creation of the biliary and pancreatic structures. Thus, the obstruction usually occurs at or below the ampulla of Vater. Duodenal obstruction is associated with prematurity (46%) and maternal polyhydramnios (33%).1 In addition, there is a high incidence of specific associated anomalies, including Down syndrome (>30%), malrotation (>20%), congenital heart diseases (20%), and other gastrointestinal tract (GIT) and renal anomalies. Along with prematurity and low birth weight, these associated anomalies are known to be significant risk factors contributing to mortality in patients with duodenal atresia. Of note, the presence of Down syndrome itself does not influence the outcome of these babies.