Neonatology - Bowel Atresia

Question 1

Definition

Answer 1

Congenital malformation characterised by the presence of a blind-ending duodenum, which is not patent

Question 2

Epidemiology

Answer 2

It is commonly associated with other conditions and genetic abnormalities, with 25-40% of cases having a concurrent diagnosis of Down’s Syndrome.

Question 3

Aetiology

Answer 3

Duodenal atresia occurs as a result of failed recanalization of the embryonic duodenum during the gestational period. Other associated conditions include:
- Other intestinal atresia’s
- VACTERL association (Vertebral defects, Anal atresia, Cardiac defects, Tracheo-oesophageal fistula, Renal anomalies, Limb abnormalities)

Question 4

Pathophysiology

Answer 4

Duodenal atresia typically arises during the early stages of embryonic development, specifically during the formation of the digestive tract. The duodenum normally forms by the fusion and recanalization (opening) of a solid tube. In cases of duodenal atresia, this recanalization process is disrupted. In individuals with duodenal atresia, there is a failure of the duodenal lumen to open properly. This can result in a complete closure of the duodenum, leading to a blind-ending pouch, or a partial narrowing of the duodenal passage. The exact cause of this developmental abnormality is not fully understood but may involve genetic and environmental factors. The primary consequence of duodenal atresia is the obstruction of the digestive flow from the stomach to the rest of the small intestine. Because the duodenum is the first segment of the small intestine, its blockage can prevent ingested food and digestive juices from reaching the rest of the intestines. During pregnancy, the blockage of the duodenum can lead to an accumulation of amniotic fluid in the amniotic sac, a condition called polyhydramnios. This is often detected during prenatal ultrasound examinations.

Question 5

Symptoms

Answer 5

Antenatally:
● Polyhydramnios
Postnatally:
● Abdomen distension
● Vomiting (may be bilious or non-bilious)

Question 6

Diagnosis

Answer 6

Abdominal X-rays,
● Characteristic ‘double bubble’ sign. This includes one gas bubble visible in the stomach, and another in the proximal, patent part of the duodenum prior to the atresia. This pattern occurs due to air from the stomach being trapped between the pyloric sphincter and the blind end of the duodenum.

Question 7

Treatment

Answer 7

• Surgical repair, specifically duodenoduodenostomy. This procedure involves reconnecting the closed proximal and distal segments of the duodenum to alleviate the
  obstruction.