Evolution in the recognition of infantile hypertrophic pyloric stenosis.

PURPOSE: To analyze changes in the clinical condition at presentation and methods of establishing the diagnosis of infantile hypertrophic pyloric stenosis (IHPS). METHODS: Retrospective review of patients who underwent pyloromyotomy (PM) for suspected IHPS at two institutions from 1969 through 1994 was performed. For the purposes of comparison, the population was divided into five equal time periods. RESULTS: Over the 25-year period, 901 infants underwent PM. Patients presented at a younger age, weighed more, and had a shorter length of illness in the most recent time period. Hypochloremic alkalosis was found half as frequently in the most recent time period compared to the earliest group. A palpable pyloric tumor was present in 79% of patients in the earliest time period compared with 23% in the most recent time period. Sixty-one percent of patients in the earliest group and 96% in the latest group underwent an imaging study, reflecting the referring physician's evaluation before referral to the surgeon. CONCLUSIONS: Currently, patients with IHPS less frequently present with the clinical hallmarks of the disease. The use of imaging studies to establish the diagnosis has become common practice. The result has been the diagnosis of IHPS before alkalosis has developed, a shorter clinical course, less morbidity, and a shorter postoperative hospital stay.