II. The Anti-reflux Mechanism: Manometric and Radiological Studies

This paper does not pretend to be a comprehensive review of the contributions made by pressure measurements to the study of the gastrooesophageal junction region, since this has been admirably achieved by Ingelfinger (1958); but it attempts to provide (1) an anatomical and physiological background to some of the changes in the shape of the barium shadow seen during a barium swallow examination and (2) a mechanical explanation of the anti-reflux mechanism. It is largely a record of personal observations but includes a review of experimental work and currently held views which are relevant to the suggestions put forward. Vantrappen, Texter, Barborka and Vandenbroucke (1960) have reviewed the anatomical and physiological aspects of the closing mechanism at the gastro-oesophageal junction. There must be few areas of the body where method and approach have so much influence on the results obtained. Until recently, for example, the existence of a cardiac sphincter was denied because the anatomist could not demonstrate one; and because the technique of the barium swallow examination minimised the effect of an intrinsic sphincter and emphasised the action of the diaphragm. It is important, therefore, to discuss briefly some of the contributions made by different methods and the limitations of these methods.