Overview
Schatzki rings are fixed anatomic mucosal ring structures in the distal esophagus. They are distinct from lower esophageal muscular rings (A rings), which are transient, smooth, circumferential indentations in the esophagus. Lower esophageal rings were described first by Templeton in 1944. The vast majority of patients with lower esophageal rings are asymptomatic. In fact, lower esophageal rings are found during 6-14% of all routine upper gastrointestinal barium examinations. Lower esophageal rings that cause symptoms (true Schatzki rings) occur in only 0.5% of patients undergoing these examinations. Schatzki rings are a common cause of intermittent dysphagia. The association of intermittent dysphagia with lower esophageal rings was reported by Ingelfinger and Kramer and also by Schatzki and Gary in 1953.
Preferred examination
Barium esophagography is the preferred method of detection of Schatzki rings. Single-contrast esophagography performed with the patient drinking in the prone position is more sensitive in detecting lower esophageal mucosal rings than is erect double-contrast imaging of the esophagus.
Upper gastrointestinal endoscopy is commonly used for the evaluation of dysphagia. Upper endoscopy may not be as sensitive as barium esophagography in detecting lower esophageal rings.
In one study, endoscopy failed to depict more than one third of radiologically demonstrated lower esophageal rings, half of which had caused symptoms and dysphagia.
Esophageal rings may be missed during barium esophagography if distention of the distal esophagus is inadequate; therefore, adequate distention of the esophagus during barium esophagography is imperative. This distention is best achieved by using a single-contrast technique in the prone or right or left anterior oblique position with large boluses of barium. A modified Valsalva maneuver also may help in demonstrating the ring by distending the associated hiatal hernia.
(See the images below.)
Schatzki ring on an erect, double-contrast barium esophagogram. Image demonstrates a thin, ringlike narrowing (arrows) in the lower esophagus just above a hiatal hernia.
Schatzki ring. Prone, single-contrast barium esophagogram demonstrating a thin, ringlike narrowing (arrows) in the lower esophagus just above a hiatal hernia. This view is most sensitive for detecting lower esophageal rings, provided adequate esophageal distention is achieved.
Pathophysiology
The pathophysiology of Schatzki ring is not fully known. Various hypotheses include congenital origin, arising from a pleat of redundant mucosa, or as a result of gastroesophageal reflux or esophagitis.
Some investigators have demonstrated that Schatzki rings become narrowed during serial radiographic examinations and that they transform into actual peptic strictures. Even so, endoscopic biopsy and 24-hour esophageal pH monitoring have failed to show any symptoms or signs of gastroesophageal reflux or reflux esophagitis in more than one third of patients with Schatzki rings.
Schatzki ring is a common cause of intermittent dysphagia. In fact, in a large endoscopic series, it was the fourth most common endoscopic finding in endoscopic evaluation of dysphagia after esophageal stricture, normal endoscopy, and esophagitis/ulcer.
The main morbidity associated with lower esophageal rings is dysphagia, but many remain asymptomatic. Schatzki ring is a common cause of dysphagia. Typically, the dysphagia is intermittent or short-lived. Food may become stuck in the esophagus but can be forced down by drinking liquids or may be regurgitated. The dysphagia may not recur for months or years. Patients may have associated symptoms of gastroesophageal reflux.
There should be no direct mortality with this condition.
Differentials
Focal esophageal carcinoma