Oesophagus Parts
The oesophagus has three anatomical constrictions where foreign bodies lodge and carcinomas preferentially develop. Their distances from the incisors are clinically essential for endoscopy and surgical planning.
✦ The Mnemonic
"Careful Arterial Diaphragms Create Constrictions"
Three physiological constrictions: Cricopharyngeal (15 cm) · Aortic arch (25 cm) · Diaphragmatic (40 cm)
Clinical Breakdown
The oesophagus is 25 cm long (in the patient) and runs from C6 (cricopharyngeus) to T11 (gastro-oesophageal junction). It has four anatomical parts: cervical, thoracic, abdominal. The three constrictions are where swallowed foreign bodies most commonly lodge and where oesophageal carcinoma most commonly arises.
Oesophageal carcinoma: squamous cell carcinoma (SCC) is most common in the upper and middle thirds (risk factors: smoking, alcohol, achalasia, Plummer-Vinson syndrome); adenocarcinoma is most common in the lower third (risk factor: Barrett's oesophagus from GORD). Adenocarcinoma has surpassed SCC in incidence in the Western world.
Zenker's diverticulum (pharyngeal pouch): pulsion diverticulum through Killian's dehiscence (between the thyropharyngeal and cricopharyngeal parts of inferior pharyngeal constrictor). Causes regurgitation of undigested food, halitosis, and a neck swelling. Treat endoscopically (Dohlman's procedure) or surgically.
⭐ Clinical Pearl
Barrett's oesophagus: metaplasia of squamous epithelium to columnar (intestinal) epithelium in the distal oesophagus — a consequence of chronic GORD. Carries a 0.5% per year risk of progression to adenocarcinoma. Surveillance endoscopy every 2–5 years depending on grade. High-grade dysplasia is treated with radiofrequency ablation or endoscopic mucosal resection.