What are the other Names for this Condition? (Also known as/Synonyms)

• Duodenal Stenosis

What is Duodenal Atresia? (Definition/Background Information)

• Duodenal Atresia is an embryopathy of the cranial intestine that leads to a complete absence of the duodenal lumen. 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
• 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 a Duodenal Atresia) characterized by a short fibrous cord connecting the two ends of the atresic duodenum
  • 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 depends on the degree of atresia. Important obstructions manifest during the first days of life with bilious vomiting if the obstacle is infra-vaterian, which starts in the hours after birth, and with feeding intolerance
• Weight loss, dehydration, and hypochloremic metabolic alkalosis are the most common symptoms. Less severe obstructions may manifest several months, or even several years, after birth with bilious vomiting without abdominal distention (major sign); however, failure to thrive may be the only presentation

(Source: Duodenal Atresia; Orphanet, National Institute of Health and Medical Research (INSERM), Paris.)

Who gets Duodenal Atresia? (Age and Sex Distribution)

• The prevalence of Duodenal Atresia is between 1 in 6,000 to 10,000 live births
• It is known to affect both girls and boys in equal proportion
• There is no racial, ethnic, or geographic predilection noted

What are the Risk Factors for Duodenal Atresia? (Predisposing Factors)

The following factors may be associated with Duodenal Atresia:

• Family history of the condition can increase the risk
• Certain congenital abnormalities
• Down syndrome
• Heart abnormalities
• Digestive system defects

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Duodenal Atresia? (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
• In most cases, Duodenal Atresia is sporadic, although an autosomal recessive pattern has been suggested in some families

(Source: Duodenal Atresia; Orphanet, National Institute of Health and Medical Research (INSERM), Paris.)

Autosomal recessive: Autosomal recessive conditions are traits or disorders that occur when two copies of an abnormal gene have been inherited on a non-sex chromosome. If both parents have an autosomal recessive condition, there is a 100% likelihood of passing on the mutated genes to their children. If, however, only one mutant copy of the gene is inherited, the individual will be a carrier of the condition, but will not be present with any symptoms. Children born to two carriers, have a 25% chance of being homozygous dominant (unaffected), a 50% chance of being heterozygous (carrier), and a 25% chance of being homozygous recessive (affected).

What are the Signs and Symptoms of Duodenal Atresia?

Common signs and symptoms of Duodenal Atresia may include:

• Feeding intolerance
• Weight loss
• Dehydration
• Hypochloremic metabolic alkalosis

Other symptoms seen after months or years, after birth may include:

• Bilious vomiting without abdominal distention

Based on the frequency of symptoms observed, the following information may be noted:

Very frequently present symptoms in 80-99% of Duodenal Atresia cases: 

• Polyhydramnios

Occasional symptoms in 5-29% of Duodenal Atresia cases:

• Abnormality of the pulmonary artery
• Annular pancreas

(Source: Duodenal Atresia; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

How is Duodenal Atresia Diagnosed?

• 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 and stomach due to the simultaneous distension of the stomach and first portion of the duodenum (above the stenosis)
• Differential diagnoses include late appearing pyloric stenosis in cases of incomplete diaphragm, and other forms of intestinal atresia, common mesenteric intestinal volvulus, and duodenal duplication
• Diagnosis is prenatal in 80-90% of cases (by ultrasound in the seventh month or before that reveals the characteristic “double bubble” image)

(Source: Duodenal Atresia; Orphanet, National Institute of Health and Medical Research (INSERM), Paris.)

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Duodenal Atresia?

The complications of Duodenal Atresia may include:

• Severe weight loss; malnutrition 
• Low birth weight 
• Premature baby; complications associated with prematurity
• Failure to thrive
• Small bowel obstruction
• Bowel perforation
• Sepsis: Generalized infection of the bloodstream 

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Duodenal Atresia Treated?

• Management of Duodenal Atresia 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

(Source: Duodenal Atresia; Orphanet, National Institute of Health and Medical Research (INSERM), Paris.)

• Surgery to repair the blockage, in which the damaged portion of intestine is resected and healthy parts are joined back together
• Feeding the baby through a vein or a tube directly in the stomach (parenteral nutrition) is undertaken after surgery, till such a time that the baby can resume normal eating
• Other supportive care, as needed, is provided by the healthcare provider

How can Duodenal Atresia be Prevented?

Currently, there are no known effective measures to prevent the formation of Duodenal Atresia.

• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• In order to prevent complications, a close monitoring of the developing fetus may be recommended by the healthcare provider

What is the Prognosis of Duodenal Atresia? (Outcomes/Resolutions)

The prognosis of Duodenal Atresia with early surgical intervention is excellent.

(Source: Duodenal Atresia; Orphanet, National Institute of Health and Medical Research (INSERM), Paris.)

• With recent advances in surgical techniques, the prognosis of the condition has significantly improved, such that a majority of the babies thrive after surgery
• Newborns surviving the surgery and post-surgical complications are able to lead normal and healthy lives

Additional and Relevant Useful Information for Duodenal Atresia:

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/