Ultrasonography and gastric emptying in children: validation of a sonographic method and determination of physiological and pathological patterns

Background: The association between gastric emptying and gastro-esophageal reflux (GER) has been widely recognised from scintigraphic studies. Objective: A prospective study to (a) validate US as a means of measuring gastric emptying, (b) determine physiological patterns of gastric emptying and (c) measure gastric emptying in symptomatic refluxers. Materials and methods: Three cohorts were studied: (a) Ten babies in whom gastric emptying was measured by US and scintigraphy; (b) gastric emptying in 330 asymptomatic children aged between 15 days and 10 years to determine physiological variations; and (c) gastric emptying in 552 children with GER, manifesting as vomiting or cardiorespiratory problems. Results: US and scintigraphic techniques showed general concordance in 90% of cases. In the remaining 10%, discordant results were related to overlapping of duodenum and stomach during scintigraphy and shadowing of the gastric antrum by air during US. Tremendous variations were induced by change of feed volume or type of formula, underlining the need for a standardised procedure. Twenty-two percent of cases showed a peculiar 'plateau' which differed significantly from the physiological patterns. Most of these babies had esophagitis or acute life-threatening events. Conclusions: Investigation of gastric emptying seems to be a key element in the assessment of children with 'pathological' GER. US is a safe and cheap alternative to scintigraphy for the assessment of gastric emptying.