Reminiscences on the antireflux mechanism.
A common view is that the lower esophageal sphincter is the sole component of the antireflux mechanism. Other methods of investigation especially radiology, and the effects of surgery suggest that the position of the sphincter and the size and shape of the hiatus are at least as important as the sphincter in the control of reflux and recent appropriate manometric studies support this view. The development of some of the ideas about what is and what is not a significant component is reviewed. A unifying hypothesis is offered which proposes that the sphincter is of primary importance in resisting the challenge of intragastric pressure developed by contraction of the stomach wall which may lead to physiologic reflux; whereas the position of the sphincter and the size of the hiatus are concerned with resisting the challenge of intra-abdominal pressure. The physiologic component has a limited capability of resisting intra-abdominal pressure so that when the anatomic component fails, pathologic reflux occurs.
D004943:Esophagogastric Junction / Q000000981:diagnostic imaging / Q000502:physiology* / Q000503:physiopathology; D006551:Hernia, Hiatal / Q000503:physiopathology; D006801:Humans; D008365:Manometry; D011312:Pressure; D011859:Radiography; D013270:Stomach / Q000502:physiology