Inferior Esophageal Ring Formation
The inferior esophageal ring, eponymously known as a Schatzki ring, is a round and regular mucosal web circumferentially indenting the esophageal lumen that forms at the squamocolumnar junction at the gastroesophageal junction. It is a commonly acquired ring typically occurring in middle age and associated with gastroesophageal reflux, though this has never been well proven. More recent data have further demonstrated similar rings in patients with eosinophilic esophagitis, suggesting that the ring may be a response to a chronic inflammatory process other than reflux at the gastroesophageal junction.
Further diagnostic difficulties stem from differentiating this ring from an annular peptic stricture. Using strict definitions, the ring contains only mucosa, whereas a stricture is an abnormality of deeper esophageal wall layers with fibrotic changes. The visual appearance may be helpful because a ring seen by radiographic or endoscopic means is a relatively thin membranous structure, in contrast to a stricture, which appears thicker. The cardinal symptoms of an inferior esophageal ring are intermittent dysphagia and/or food impaction with solid food. It is the most common cause of solidfood dysphagia in adults. Because symptoms result from the mechanical process in which a bolus of food that is too large tries to pass through a lumen that is too small, foods that cause symptoms are typically chunky hard solids, such as meats, bread, and raw vegetables. Earlier data suggested that the diameter of the ring dictates the chance of a food bolus sticking, but other factors, such as types of food, attention to bolus mastication, and use of fluids with the meal, further affect the likelihood of food bolus obstruction. Treatment of an inferior esophageal ring is mechanical disruption, which may be accomplished through biopsy or balloon or Savary dilation. For more recalcitrant rings, endoscopic incision may also be used. Recurrence is common, and pharmacologic antireflux therapy is often used to prevent ring formation, though no data are available to support this recommendation.