A rational approach to the diagnosis of hypertrophic pyloric stenosis: do the results match the claims?

The currently accepted premise that the diagnosis of hypertrophic pyloric stenosis (HPS) should be made on clinical grounds, with ultrasound (US) and upper gastrointestinal series (UGIS) reserved for those with a negative clinical examination, was tested. Variable clinical skills of initial examiners, including pediatric surgeons, made abdominal palpation no more sensitive or specific than US or UGIS. For those with a negative clinical examination, proceeding directly to a UGIS will result in monetary savings, especially if good clinical performance decreases the probability of HPS among those without palpable pyloric "tumors." The benefits of a "US first" approach (no radiation, better patient and parent acceptance, no contrast medium) are less apparent but no less important and increase as clinical experience declines and performance of US improves. Criteria for the clinical or sonographic diagnosis of HPS should be kept strict to avoid false-positive results; false-negatives and other causes of vomiting should be identified by UGIS.