The Impact of Gastric Distension on the Lower Esophageal Sphincter and Its Exposure to Acid Gastric Juice
- 1 July 2010
- journal article
- research article
- Published by Ovid Technologies (Wolters Kluwer Health) in Annals of Surgery
- Vol. 252 (1), 57-62
- https://doi.org/10.1097/sla.0b013e3181e3e411
Abstract
Background and Aims: The lower esophageal sphincter (LES) in patients with gastroesophageal reflux disease often has a low resting pressure and a short abdominal length. The mechanism by which this occurs is unknown. We hypothesize that gastric distension causes progressive effacement of the abdominal portion of the LES, exposing it to acid injury resulting in mucosal and sphincter damage. Our aim was to assess in normal subjects the effect of gastric distension on the LES length and pressure and its exposure to acid gastric juice. Methods: Eleven asymptomatic volunteers had their LES length and pressure measured before and during gastric distension. The location of the pH step-up point (shift from gastric pH to a pH >4) was also measured before and after distension. Results: Progressive gastric distension with air resulted in progressive shortening of LES (R2 = 0.89, P < 0.0001). After infusion of 750 cc of air there was a significant reduction in the median LES length from 4 to 2.6 cm (P = 0.001). This change occurred in the abdominal length of the LES (2.6–1.4 cm [P = 0.001]) and not in the thoracic length. At rest the pH step-up point was 0.5 cm above the lower border of the LES and with distension moved a median of 1 cm cephalad within the LES. Simultaneously with the loss of length there was a reduction in LES pressure (27.4–23.4 mm Hg, P = 0.02). Conclusions: Gastric distension causes progressive shortening of the abdominal length of the LES and a reduction in its pressure. The process exposes the effaced mucosa and sphincter to acid gastric juice.Keywords
This publication has 30 references indexed in Scilit:
- Obesity and Gastroesophageal Reflux: Quantifying the Association Between Body Mass Index, Esophageal Acid Exposure, and Lower Esophageal Sphincter Status in a Large Series of Patients with Reflux SymptomsJournal of Gastrointestinal Surgery, 2009
- Bravo Catheter-Free pH Monitoring: Normal Values, Concordance, Optimal Diagnostic Thresholds, and AccuracyClinical Gastroenterology and Hepatology, 2009
- Manometry of the lower esophageal sphincter: inter- and intraindividual variability of slow motorized pull-through versus station pull-through manometry.Digestive Diseases and Sciences, 2003
- Evolving concepts of reflux: the ups and downs of the LES.Canadian Journal of Gastroenterology, 2002
- Increased frequency of transient lower esophageal sphincter relaxation induced by gastric distention in reflux patients with hiatal herniaGastroenterology, 2000
- Transient lower esophageal sphincter relaxationGastroenterology, 1995
- The lower esophageal sphincter in health and diseaseThe American Journal of Surgery, 1988
- Gastric distention: A mechanism for postprandial gastroesophageal refluxGastroenterology, 1985
- Mechanisms of Gastroesophageal Reflux in Patients with Reflux EsophagitisThe New England Journal of Medicine, 1982
- Mechanism of gastroesophageal reflux in recumbent asymptomatic human subjects.JCI Insight, 1980