Imaging findings in infants with recurrent vomiting after pyloromyotomy: a pictorial review.

Hypertrophic pyloric stenosis (HPS) is a common entity with an incidence of 2-4 per 1000 live births. Current definitive treatment is with pyloromyotomy, which is usually performed laparoscopically. The procedure is generally well tolerated with resolution of the patient's symptoms. In a small percentage of patients, however, there is recurrent vomiting which warrants further investigation. In this pictorial review, the expected post-operative appearance of the pylorus will be described, and the imaging findings and clinical course of two patients with recurrent vomiting after pyloromyotomy will be presented.