Oesophageal Ring

A circumferential, thin or thick band of tissue that narrows the oesophageal lumen, either at the lower end (the A ring and the B ring) or in the body (multiple fixed rings of eosinophilic oesophagitis), causing intermittent solid food dysphagia.

• Types:
  • B ring (mucosal ring, also called Schatzki ring): a thin 2 to 4 mm mucosal fold at the squamocolumnar junction; found in about 6 to 14% of barium swallows.
  • A ring (muscular ring): a thicker (4 to 5 mm) circumferential muscular band 2 cm or so above the squamocolumnar junction, at the upper end of the lower oesophageal sphincter, covered by squamous mucosa; rare and less often symptomatic.
  • Multiple fixed concentric rings of eosinophilic oesophagitis (a "ringed" or "trachealised" oesophagus), up to the whole length.
  • Rings after reflux, radiation, graft-versus-host disease, caustic injury or surgery.
• Symptoms usually appear when the lumen is less than 13 mm; most rings are asymptomatic and found incidentally.
• Mechanism: fibrosis and submucosal inflammation (reflux, eosinophilic infiltration) with contraction of a muscular or mucosal fold.

Intermittent dysphagia for solids (meat and bread), episodes of food bolus impaction and sudden onset chest discomfort, usually without weight loss; liquids pass easily.

• Heartburn and regurgitation; atopic disease and young male in eosinophilic oesophagitis.
• Differential diagnosis: peptic stricture, oesophageal web, achalasia, oesophageal cancer, extrinsic compression, motility disorders, hiatus hernia.
• Complications: food impaction, aspiration, mucosal tear, perforation (rare), and malnutrition in rings that cause progressive narrowing.

Barium swallow with distension and a solid bolus (a 13 mm tablet) shows the ring and its relation to a hiatus hernia; the A ring appears as a stable, thick constriction above the hernia, the B ring as a thin shelf at the hernia margin.

• Upper endoscopy: ring in the distal oesophagus, rings and furrows in the whole oesophagus in eosinophilic disease; mucosa is often fragile ("crepe paper").
• Biopsies: at least six from two levels for eosinophilic oesophagitis (15 or more eosinophils per high-power field), biopsies of the junction for Barrett oesophagus and of any lesion.
• High-resolution manometry for suspected achalasia or a muscular A ring with a tight sphincter; pH monitoring for reflux; CT or endoscopic ultrasound when the ring is thick, to exclude infiltrative disease.

Choose treatment by ring type, correct reflux or eosinophilic inflammation, and dilate for symptoms.

• Dietary and behavioural advice: small bites, chewing well, drinking with meals, and avoiding alcohol with meals.
• Acid suppression: omeprazole 20 to 40 mg daily (40 mg twice daily for suspected eosinophilic oesophagitis or severe reflux) for 8 weeks, then the lowest effective maintenance dose.
• B ring: bougie or balloon dilatation to 18 to 20 mm (relief in over 90%, recurrence in 30 to 70% in a year), or incision or cold forceps disruption for recurrence.
• A ring: dilatation to 18 to 20 mm; for a thick muscular ring, pneumatic dilatation to 30 mm or botulinum toxin 50 to 100 units injected in four quadrants (evidence limited), or surgical myotomy for resistant cases; check for achalasia.
• Rings of eosinophilic oesophagitis: fluticasone propionate 880 micrograms twice daily swallowed or budesonide orodispersible tablet 1 mg twice daily for 8 to 12 weeks, then maintenance; or an elimination diet (milk, wheat, egg, soy, nuts, fish and shellfish); dupilumab 300 mg SC weekly for refractory disease; gentle dilatation (balloon to 15 to 18 mm, with small increments) only after medical therapy, because the oesophagus is fragile and can tear.
• Acute food impaction: sit upright, nil by mouth, glucagon 1 mg IV (may relax the sphincter), endoscopic removal within 24 hours (emergency if saliva cannot be swallowed or the airway is threatened), then biopsy and treat the ring.
• Post-radiation or caustic rings: balloon dilatation with steroid injection (triamcinolone 10 mg/mL, 4 quadrants) in refractory cases.
• Special groups: children (eosinophilic oesophagitis most likely; fluticasone dose weight-based, dilatation by an experienced operator); pregnancy (omeprazole 20 mg daily; endoscopy only for impaction); elderly (check for cancer and dentures); renal impairment (no change); anticoagulated patients (careful with incision).
• Red flags: inability to swallow saliva, chest pain after dilatation, fever, neck or chest crepitus, progressive dysphagia, weight loss, anaemia.
• Follow-up: review at 4 to 8 weeks; repeat endoscopy with biopsies after 8 to 12 weeks of treatment for eosinophilic oesophagitis; repeat dilatation when symptoms recur; maintenance proton pump inhibitor.