[The relationship between lower esophageal sphincter motility and function with gastroesophageal reflux disease].

SUBJECTIVE: To evaluate the motor pattern and function of lower esophageal sphincter (LES) and esophageal acidification episodes before and after intragastric load in the patients with gastroesophageal reflux disease (GERD) and in controls, and identify the relationship between transient LES relaxations (TLESR), and low LES pressure and acid reflux episodes. METHODS: All of them undergone a pH/manometric monitoring during fasting and for 3 h after meal. RESULTS: 68 episodes of acid reflux were detected totally, and 43% (29/68) occurred during transient LES relaxation, 31% (21/68) occurred after down drifts (<1 mmHg/s) in basal LES pressure or in persisting low basal LES pressure. There were more patients with acid reflux episodes compared TLESR in patients with GERD than in volunteers (P <0.05). More acid reflux episodes in patients with GERD than in controls (P <0.001). But ingestion of the meal induced a significant increase in the TLESR frequency during the first and second postprandial hours. CONCLUSIONS: The pathophysiology of gastroesophageal reflux disease is multifactorial. It is established that impaired lower esophageal sphincter function play an important role in GERD. Transient LES relaxation could probably be considered one of the pathophysiologic mechanisms of gastroesophageal reflux, but it is not a necessary prerequisite for the acidification events. Some reflux episodes result from low resting LES pressure rather than from transient LES relaxations alone.