Prenatal diagnosis of annular pancreas: reliability of the double bubble sign with periduodenal hyperechogenic band
Abstract
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 (N-1 = 3, N-2 = 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