Is all ineffective esophageal motility the same? A clinical and high-frequency intraluminal US study

BackgroundIneffective esophageal motility (IEM) is characterized by frequent hypotensive or failed peristaltic contractions; its pathophysiology is controversial.ObjectiveTo evaluate whether patients with IEM because of GERD would differ from patients with other etiologies of IEM on the basis of esophageal-muscle thickness measured by high-frequency intraluminal US (HFIUS).DesignSingle-center prospective study.SettingAcademic medical center; from January 2004 to June 2005.SubjectsA total of 46 patients who were newly diagnosed with IEM were classified into 2 groups: GERD-related IEM (group I, n = 26) and non-GERD–related IEM (group II, n = 20) on the basis of the presence of reflux esophagitis and/or pathologic acid exposure by 24-hour esophageal pH monitoring. In addition, 16 asymptomatic healthy volunteers with no reflux esophagitis, normal manometric finding, and normal level of acid exposure were included as controls.Main Outcome MeasurementsWe compared the clinical characteristics, including a predominant principal esophageal symptom and the results from HFIUS among the control, GERD-related IEM (group I), and non-GERD–related IEM (group II) groups.ResultsThe proportion of typical reflux symptom as a predominant symptom was higher in group I (66%) than in group II (25%). Muscle thickness was greater in group II than in group I and the control group during both the baseline rest period and the peak of contraction period at all levels of the middle of the lower esophageal sphincter (LES), and 3 cm and 9 cm above the LES (respectively) (P < .05).LimitationThe limitation was the small sample size.ConclusionsPatients with non-GERD–related IEM had increased muscle thickness on HFIUS compared with patients with GERD-related IEM and the controls. Based on this study, IEM is not necessarily indicative of GERD.