Since the 1950s, several investigators have published reports of patients with dysphagia who had associated lower esophageal ringlike constrictions, but each investigator had a different opinion as to the cause and nature of these rings. In 1953, Ingelfinger and Kramer believed that these rings occurred as a result of a contraction by an overactive band of esophageal muscle[1] ; however, Schatzki and Gary believed that these rings were fixed and not contractile.[2] Some of this controversy may be related to the confusion of categorizing muscular and mucosal rings under the same entity, as concluded by Goyal et al.[3, 4, 5, 6]
Endoscopic appearance of the distal esophagus illustrating a Schatzki ring.
Two rings have been identified in the distal esophagus. The muscular ring, or A ring, is a thickened symmetric band of muscle that forms the upper border of the esophageal vestibule and is located approximately 2 cm above the gastroesophageal junction. The A ring is rare; furthermore, it is even more rarely associated with dysphagia. On the other hand, the mucosal ring, or B ring, is quite common and is the subject of discussion in this article. The B ring is a diaphragmlike thin mucosal ring usually located at the squamocolumnar junction; it may be symptomatic or asymptomatic, depending on the luminal diameter.
The pathogenesis is not clear, and patients typically present with intermittent nonprogressive dysphagia for solids. Fortunately, most patients respond well to initial and repeat dilatation therapy. A small number of patients may have stubborn rings that require more aggressive endoscopic or surgical intervention.
Endoscopic appearance of the distal esophagus illustrating a Schatzki ring. Two rings have been identified in the distal esophagus. The muscular ring, or A ring, is a thickened symmetric band of muscle that forms the upper border of the esophageal vestibule and is located approximately 2 cm above the gastroesophageal junction. The A ring is rare; furthermore, it is even more rarely associated with dysphagia. On the other hand, the mucosal ring, or B ring, is quite common and is the subject of discussion in this article. The B ring is a diaphragmlike thin mucosal ring usually located at the squamocolumnar junction; it may be symptomatic or asymptomatic, depending on the luminal diameter.
The pathogenesis is not clear, and patients typically present with intermittent nonprogressive dysphagia for solids. Fortunately, most patients respond well to initial and repeat dilatation therapy. A small number of patients may have stubborn rings that require more aggressive endoscopic or surgical intervention.
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