A-rings are a type of distal oesophageal ring. They are above the B-ring and occur a few centimetres proximal to the gastro-oesophageal junction. They represent a physiological contraction of oesophageal smooth muscle covered by mucosa. A-rings are uncommonly symptomatic.
- oesophageal dysmotility
- oesophageal tumours
- benign oesophageal neoplasms
- malignant oesophageal neoplasms
- gastro-oesophageal reflux disease
- oesophageal stricture