Intestinal Atresia and Stenosis

Intestinal atresia is a term used to describe a complete blockage or obstruction of any part of the  intestine.

Stenosis refers to a partial obstruction that results in a narrowing of the opening (lumen) of the intestine.

It may involve any part of gastrointestinal tract, but broadly it involves- duodenum, jejunum and ileum. Most atresias occur in distal ileum (36%), 13% occurs in proximal ileum. 31% occur in proximal jejunum and 20% occur inthe distal jejunum.

Duodenal Stenosis and Atresia


Type-1-(92%) there is obstructing web formed from mucosa and submucosa. Outwardly there is no muscular and mesentry defect.
Type-2-(1%)Two blind ends of the duodenum are connected with small fibrous baqnd and there is no mesenteric defect
Type-3-(7%)there is no connection between two blind ends of the duodenum. V-shaped defect is present in the mesentry

Approximately 50% of patients with duodenal atresias have some form of anomaly (eg, cardiac, anorectal, or genitourinary), and as many as 40% have trisomy 21. Hence, all neonates with duodenal atresia should be assessed for concomitant malformations. Growth retardation and polyhydramnios are often present prenatally.



Ultrasonography may indicate  a dilated stomach and proximal duodenum. Polyhydramnios is present as the fetus is unable to swallow the amniotic fluid.

Common associated anomalies and chromosomal defects may be assessed by screening maternal serum and amniotic fluid.

In the Newborn:

  • Clear or bilious emesis is evident within hours of birth, with or without abdominal distention.
  • An aspirate of more than 20 mL of gastric contents should raise the
  • Dehydration or failure to thrive should raise suspicion of stenosis or partial obstruction.
  • X Ray abdomen: reveal the classic double-bubble sign, representing air in the stomach and proximal duodenum, which is associated with complete or near-complete duodenal obstruction.  Contrast radiography using air or contrast may confirm the diagnosis

Initial resuscitation in terms of gastric decompression, fluid resuscitation and thermoregulation should be done. Unless malrotation with volvulus remains a concern, preoperative assessment of other associated anomalies should be performed. The definative tratment is surgery:

  • Duodenoduodenostomy
  • Duodenotomy with excision of the web

Jejunoileal Stenosis and Atresia


Type I : The mucosa and submucosa form a web or intraluminal diaphragm, resulting in windsock obstruction. A mesenteric defect is not present, and the bowel length is not affected.

Type II : The mesentery is intact; however, the bowel is not joined. The proximal dilated and blind end is connected to distal collapsed end with a fibrous .The overall length of the small bowel is not usually shortened.

Type IIIa : is similar to that in type II atresias,but no bridging fibrous cord is present, and a V-shaped mesenteric defect is present. The proximal blind end is usually markedly dilated and aperistaltic. The bowel length is shortened.

Type IIIb: A large mesenteric defect with significant bowel shortening is noted. This lesion is also known as a Christmas tree or apple-peel deformity, because of the bowel’s appearance as it wraps around a single perfusing vessel. with

Type IV : It involves multiple small-bowel atresias of any combination of types I to III. This defect often takes on the appearance of a string of sausages because of the multiple lesions.


Prenatal : Ultrasonography and prenatal screening , the reported accuracy of prenatal ultrasonography is widely variable,

After birth:

Clinically, neonates with a proximal atresia develop bilious emesis within hours, whereas patients with more distal lesions may take longer to begin vomiting. Abdominal distention is more pronounced with distal lesions.

X Ray Abdomen

It is helpful for confirming the diagnosis. With more proximal atresias, few air-fluid levels are evident with no apparent gas in the lower part of the abdomen. The more distal lesions demonstrate more air-fluid levels, though the distal intestine remains gasless.

Once the diagnosis is made, the patient should be fully resuscitated before surgical correction is attempted, unless a perforation or volvulus is suspected. Gastric decompression, fluid resuscitation, and thermoregulation are essential. Preoperative antibiotics should be administered.