Is abdominal compression a useful stimulation test for analysis of lower esophageal sphincter function?

The change in pressure of competent and incompetent lower esophageal sphincter (LES) due to abdominal compression is still a controversial subject. Therefore, we studied the effect of sustained (SAC) and intermittent (IAC) abdominal compression on lower esophageal sphincter pressure (LESP) in normals (N), patients with hiatus hernia (HH), and patients with scleroderma (S). When resting lower esophageal sphincter pressure exceeded 15 mm Hg, response to SAC and IAC was similar in patients with HH and in normals. On the other hand when basal LESP was below 15 mm Hg, stimulated sphincter pressure during IAC was significantly lower than during SAC. Values recorded during SAC were also falsely high in patients with scleroderma. Values obtained during either SAC or IAC did not depend on presence or absence of reflux symptoms in any group. LES stimulation with IAC gives valid results which correlate closely with LESP. Stress tests with IAC therefore seem to be a useful stimulation test for the analysis of LES function.