PAEA Surgery End Of Rotation (EOR) Practice Exam

What does a barium swallow reveal in cases of pyloric stenosis?

1. Single bubble sign

2. String sign

3. Double bubble sign

4. Triple bubble sign

The correct answer is: String sign

In cases of pyloric stenosis, a barium swallow study often reveals the "string sign." This sign is characterized by the appearance of a narrow, elongated channel of barium that outlines the hypertrophied pylorus. The hypertrophy of the pyloric muscle leads to a significantly narrowed pyloric channel, making it resemble a string. The "string sign" is an important diagnostic feature, as it provides visual confirmation of the obstruction caused by the muscular constriction at the pylorus. In the context of pyloric stenosis, this is a key finding seen on imaging. The other signs, such as the "double bubble sign," are typically related to duodenal atresia rather than pyloric stenosis. The double bubble sign indicates the presence of air in the stomach and proximal duodenum while the distal bowel is obstructed. The "single bubble sign" is not commonly associated with these conditions, and the "triple bubble sign" is indicative of other specific gastrointestinal obstructions. Thus, the "string sign" is what you would expect from a barium swallow in pyloric stenosis.