Double bubble (radiology)

Double Bubble (Radiology)

The double bubble sign is a radiological finding typically observed in abdominal X-rays and ultrasounds. It is characterized by the presence of two distinct air-filled spaces in the upper abdomen, which resemble two bubbles. This sign is most commonly associated with duodenal atresia, a congenital condition where the duodenum is closed or absent, preventing the normal passage of stomach contents into the small intestine.

Diagram of duodenal atresia showing the double bubble sign

Pathophysiology

The double bubble sign occurs due to the accumulation of air in the stomach and the proximal duodenum. In normal circumstances, air and fluid pass from the stomach into the duodenum and then into the rest of the intestine. However, in conditions like duodenal atresia, this passage is blocked, leading to the characteristic appearance on imaging studies.

Causes

While duodenal atresia is the most common cause of the double bubble sign, other conditions can also produce a similar radiological appearance. These include:

• Annular pancreas
• Duodenal stenosis
• Malrotation with midgut volvulus
• Preduodenal portal vein

Clinical Presentation

Infants with duodenal atresia typically present with bilious vomiting shortly after birth. They may also exhibit signs of abdominal distension and failure to pass meconium. The condition is often associated with other congenital anomalies, such as Down syndrome.

Diagnosis

The diagnosis of duodenal atresia is primarily made through imaging studies. An abdominal X-ray will reveal the double bubble sign, while an ultrasound can provide additional information about the anatomy of the gastrointestinal tract. In some cases, a contrast study may be performed to confirm the diagnosis.

Treatment

The definitive treatment for duodenal atresia is surgical intervention. The procedure typically involves creating a connection between the stomach and the distal duodenum or jejunum to bypass the atretic segment. This surgery is usually performed shortly after birth to prevent complications such as dehydration and electrolyte imbalance.

Prognosis

With prompt surgical treatment, the prognosis for infants with duodenal atresia is generally excellent. Most infants recover fully and go on to lead normal lives. However, the presence of associated anomalies can affect the overall outcome.

Related Pages

• Duodenal atresia
• Congenital disorders
• Pediatric surgery
• Radiology