Duodenal atresia (ORPHA:1203)
A rare, non-syndromic intestinal malformation characterized by a complete but short segment obliteration of the duodenal lumen.
Epidemiology
The prevalence at birth of duodenal atresia is estimated at 1/11,000 in Europe, with an approximately equal male to female ratio.
Clinical description
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 duodenal atresia) characterized by a short fibrous cord connecting the two ends or pouches of the 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. Clinical presentation is similar irrespective of the type of atresia with repeated vomiting after feeding during the first day first or second day of life. The vomit is often without bile stain, as most atresias are located above the papilla of Vater. Weight loss, dehydration, and hypochloremic metabolic alkalosis are the most common accompanying symptoms. In rare cases with a membranous atresia, there may by a small opening in the mucosal membrane and less severe obstructions may manifest several months, or even several years, after birth; intermittent vomiting without abdominal distention may be the only presentation.
Etiology
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.
Diagnostic methods
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 (bulb) and stomach. The membranous type with a small luminal opening is diagnosed by endoscopy.
Differential diagnosis
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. Other differential diagnoses include late appearing pyloric stenosis in cases of incomplete mucosal diaphragm, and other forms of intestinal atresia, small intestinal volvulus due to malrotation, duodenal duplication and duodenal stenosis.
Antenatal diagnosis
The malformation may be diagnosed at prenatal ultrasound from week 16-20 by the appearance of dilatated stomach and duodenal bulb associated with increased amounts of amniotic fluid.
Genetic counseling
Genetic counseling should be offered at prenatal diagnosis with special emphasis on the risk of trisomy 21. Whilst different mutations have been associated with duodenal atresia in a few instances, no specific genetic mapping in association with isolated duodenal atresia has been reported.
Management and treatment
Management involves neonatal resuscitation and surgical correction in the neonatal period. Post-operative complications are rare, but late complications (megaduodenum, blind loop syndrome, duodenogastric reflux, esophagitis, pancreatitis, cholecystitis and cholelithiasis) occur in very rare cases.
Prognosis
The prognosis with early surgical intervention is excellent.

                            Last update: 
                            April 2021


                            - Expert reviewer(s): 
                            Pr Niels QVIST | ERNICA*


                                * European Reference Network