Anatomy of the oesophagus

The oesophagus measures approximately 25 cm in length and is divided into cervical, thoracic and intra-abdominal parts. It extends from the pharynx, at the level of vertebra C6, to the cardia of the stomach after traversing the diaphragm at T10 level. The usual surgical approach to the length of the oesophagus is through the right chest, where it is only crossed by the termination of the azygos vein. The oesophagus is lined throughout by a stratified squamous mucosa. It has a rich blood supply from the inferior thyroid artery, multiple branches directly from the aorta and from the oesophageal branch of the left gastric artery. At the lower end there is an important porto-systemic anastomosis between the oesophageal branch of the left gastric vein and the tributaries of the azygos vein, which accounts for the development of oesophageal varices in portal hypertension. Although there is no anatomical sphincter to be demonstrated at the lower end of the oesophagus in man, a multifactorial ‘physiological’ sphincter mechanism is present, which relaxes in belching and vomiting.