Prenatal Diagnosis of Annular Pancreas: Reliability of the Double Bubble Sign with Periduodenal Hyperechogenic Band

Abstract

Objective: To evaluate the power of prenatal 2-D ultrasound examination in the 2nd trimester as a method of choice for accurate diagnosis of annular pancreas. Methods: Co-incidence of the double bubble sign (often accompanying gastroduodenal dilatation) together with a hyperechogenic band around the duodenum (corresponding with the tissue of annular pancreas) was used as a diagnostic criterion. Findings from postnatal surgery served for verification. Results: From 7,897 screened pregnancies, annular pancreas was proven in the cases where both signs were present, but never without the hyperechogenic band (N₁ = 3, N₂ = 3, p ≤ 0.05). Sensitivity and specificity were 100%. Conclusions: More multicentric studies are required to test this approach. The following diagnostic strategy is reasonable at the present time: when the double bubble sign is discovered, always suspect annular pancreas and look for the second sign: hyperechogenic bands around the duodenum. Also look for known associated anomalies, and vice versa, if any of associated anomalies are noted, also search specifically for the signs of annular pancreas.

Clinical significance of the prenatal double bubble sign - single institution experience

“…Careful ultrasonographic examination can sometimes lead to the identification of the anatomic cause of double bubble. Annular pancreas can be diagnosed by visualizing a hyperechoic band around the duodenum . In proximal jejunal atresia, three instead of two bubbles are present.…”

Annular pancreas: the failure of side-to-side gastrojejunostomy anastomosis and the success of repair with Roux-en-Y gastrojejunostomy

“…12 The diagnosis of annular pancreas can be suspected prenatally with the findings of doublebubble signs accompanied with hyperechogenic band around the duodenum during ultrasound examination. 13 After birth, simple radiograph of the abdomen may signify the presence of duodenal obstruction. These signs, however, are also commonly observed in other conditions such as duodenal web, duodenal atresia, and midgut volvulus.…”

Antenatally detected cystic biliary atresia: differential diagnoses of a double bubble

“…In this case, an upper GI contrast was performed to assess for the commonest causes - duodenal atresia, stenosis or obstruction due to malrotation or annular pancreas. The latter may be suggested by identifying a hyperechogenic band around the duodenum in addition to the double bubble (Dankovcik et al 2008). Gastrointestinal duplication cysts can be identified on ultrasonography as an anechoic cystic lesion that is separate from normal hollow structures, typically with a double wall.…”