Endoscopic findings in hypertrophic pyloric stenosis: appearance in classic and evolving disease.

BACKGROUND: Hypertrophic pyloric stenosis (HPS) is the most common abdominal surgical disorder in infants. Although the majority of cases are diagnosed by ultrasound, equivocal cases may require endoscopy. This study was performed to assess the various endoscopic appearances of HPS in infants.

METHODS: A prospective study comparing the endoscopic appearance of the antrum and pylorus of 18 children with HPS to 21 children in a normal control group.

RESULTS: Antral or pyloric mucosal hypertrophy was visualized endoscopically in all 18 study patients. The degree of mucosal thickening varied depending on the age of presentation and duration of symptoms. Antral fold hypertrophy was first noted at 10 days of age, and in the oldest patient (4 months of age) a pyloric mass was noted. By comparison, 21 control infants had no evidence of antral or pyloric narrowing or mucosal thickening.

CONCLUSIONS: Upper endoscopy can be a valuable adjunctive diagnostic tool in select cases of HPS when imaging tests are inconclusive or when infants present with clinical symptoms outside the typical age-time frame for HPS. Because HPS may evolve over time, it is important that the endoscopist recognize the different appearances of HPS.