The Pyloric Sphincteric Cylinder in Health and Disease

Focusing on the movement and physiology of the pyloric region, this study develops the concept of a sphincteric cylinder whose cyclical activity may open and close the aperture. Emphasis is placed on pathology which affects the structure or function of the cylinder.

---

Many divergent views of the anatomy and motility of the pylorus are compared in this special treatise on the subject. The anatomical findings of Cunningham, Forssell and Torgersen are discussed and integrated with radiological forms of movement. It appears that the pyloric ring is not a "sphincter", but that it forms part of a more intricate sphincteric mechanism. Evidence for a sphincteric cylinder is presented. Its cyclical activity may open and close the aperture and result in propulsion and retropulsion. The roles of gastroscopy, manometry, ultrasonography and radionuclides in pyloric motility and gastric emptying are discussed. Anatomical and functional alterations of the sphincteric mechanism in pathological conditions, such as gastritis, gastric ulceration and pyloric carcinoma, are described. This may help to clarify the pathogenesis of these ailments.