CASE 6898 Published on 03.11.2009

Triple bubble sign in Proximal Jejunal Atresia

Section

Paediatric radiology

Case Type

Clinical Cases

Authors

R Sathyanarayana1, A Paterson1, B Vasantha Rao2, S Shah2, WA McCallion2. Royal Belfast Hospital for Sick Children. 1Department of Radiology, 2Department of Paediatrics/Paediatric Surgery

Patient

1 days, male

Clinical History
A preterm male infant born at 33-weeks of gestation developed bilious vomiting on day 1.
Imaging Findings
A male neonate born preterm at 33 weeks of gestation developed bilious vomiting on day 1 after birth. On clinical examination, the abdomen was distended. A plain abdominal radiograph demonstrated three distinct gas bubbles with absence of distal gas. After fluid resuscitation and nasogastric aspiration the infant underwent a laparotomy on day 2. The laparotomy revealed a type II proximal jejunal atresia which was surgically repaired. The post-operative recovery was uneventful.
Discussion
Jejuno-ileal atresia occurs in 1 of 3000-5000 births. Intrauterine ischemic injury is believed to be the etiology. This may be a primary vascular insult or occur secondary to conditions such as small bowel volvulus, intussusception, maternal ingestion of vasoconstrictor drugs (such as cocaine) or constriction of the mesentery in tight abdominal wall defects. Associated anomalies are seen in up to 25%, and include small bowel malrotation, cystic fibrosis, gastroschisis and omphalocele.

Anatomically four types of jejuno-ileal atresia have been described: Type I (membranous), Type II (ends separated by a fibrous cord), Type IIIa (ends separated by a V-shaped mesenteric defect), Type IIIb (‘apple-peel’ deformity), and Type IV (Multiple atresias).

The clinical presentation is with bilious vomiting in the immediate post natal period. The majority of infants present within 24-48 hours of birth.

Early diagnosis and surgical management is essential, as progressive dilatation of the jejunum may compromise its blood supply, leading to perforation and meconium peritonitis .

A supine abdominal radiograph is the single most useful investigation in neonates who present with bilious vomiting, though an obstruction should not be diagnosed in the hours immediately after birth, as it can take up to 24 hours for air to pass through the non-obstructed GI tract. Correct interpretation of the bowel gas pattern is the key to making an early and accurate diagnosis. Generally speaking, the specificity of the plain abdominal radiograph declines with the number of dilated bowel loops.

The “double bubble” sign is typically associated with duodenal atresia. The same appearances, however, may be mimicked by duodenal stenosis or a duodenal web, and extrinsic causes of duodenal obstruction. However, the “triple bubble” sign has been quoted as a specific marker for proximal jejunal atresia. A more distal jejuno-ileal atresia will demonstrate multiple dilated bowel loops down to the level of the obstruction. The location of the obstruction can only be estimated by the number of dilated bowel loops seen, and it is important to remember, that in infants with multiple atresias the bowel will only be dilated down to the level of the most proximal one. Neonates do not have developed valvulae conniventes and haustra, meaning small and large bowel cannot be differentiated on a plain radiograph taken in the first few days of life, and the radiologist cannot therefore, always distinguish between a distal small bowel and a colonic obstruction. A contrast enema is required when multiple dilated bowel loops are visible, as there may be a distal ileal or large bowel obstruction, and the enema in such cases may be both diagnostic and therapeutic.

In summary, the “triple bubble” sign on a plain abdominal radiograph is produced by the dilated stomach, duodenal cap and proximal jejunum, and is a specific sign for proximal jejunal atresia.
Differential Diagnosis List
Proximal Jejunal atresia
Final Diagnosis
Proximal Jejunal atresia
Case information
URL: https://www.eurorad.org/case/6898
DOI: 10.1594/EURORAD/CASE.6898
ISSN: 1563-4086