Subtle lower esophageal sphincter relaxation abnormalities in patients with unexplained esophageal dysphagia.

Background: Esophageal dysphagia is a relatively common symptom. We aimed to evaluate whether subtle, presently not acknowledged forms of dysfunction of the lower esophageal sphincter (LES) could explain dysphagia in a subset of patients with normal findings at high-resolution manometry (HRM) according to the Chicago classification v3.0. Methods: We used HRM to compare LES relaxation characteristics in 97 patients with unexplained dysphagia with those in 44 healthy subjects. In addition, normative values for time to LES relaxation and completeness of LES relaxation were calculated. Patients with delayed or incomplete LES relaxation were compared with patients with normal relaxation. Key Results: Dysphagia patients had a higher nadir LES pressure (P=.001) and a longer time to LES relaxation (P=.012) than healthy subjects. Based on the findings in healthy subjects, normal values of LES relaxation were defined as: >= 50% of swallows with normal LES relaxation time (<5 seconds) and <= 20% of swallows with incomplete LES relaxation (not reaching a value below 10 mm Hg). Dysphagia patients had significantly more often >50% swallows with delayed and/or incomplete LES relaxation than healthy controls (25% vs 4.5%; P=.004). Dysphagia patients with >50% delayed and/or incomplete LES relaxation had a significantly higher LES resting pressure (P<.001) and a significantly higher intrabolus pressure (P<.001) than dysphagia patients who did not fulfill the criteria. Conclusions and Inferences: Subtle LES relaxation abnormalities, such as a delayed relaxation of the LES and/or incomplete LES relaxation, could be a cause of dysphagia in approximately one quarter of the patients with otherwise unexplained esophageal dysphagia.