Vascular supply

The arterial supply of the oesophagus tends to form a plexus which runs longitudinally within its wall. It arises from different sources as the oesophagus descends:

• upper third of oesophagus - cricoid cartilage down to arch of aorta:
  • inferior thyroid arteries of thyrocervical trunk
  • upper intercostal arteries
• from aorta for middle section via:
  • bronchial branches, particularly in the region of the tracheal bifurcation
  • oesophageal branches, slightly inferior to the bronchial arteries
• for lower section from:
  • ascending left gastric branch of coeliac artery
  • inferior phrenic branch of abdominal aorta

The venous system comprises, roughly:

• upper third: via inferior thyroid veins to brachiocephalic veins
• middle third:
  • azygous vein
  • hemiazygous system
• lower third:
  • inferior end of azygous and hemiazygous system
  • left gastric vein tributary of the portal vein

The venous link of the lower oesophagus to the portal vein and the draining of the superior oesophagus into the superior vena cava means that there exists a portosystemic anastomosis. This occurs above the oesophageal aperture within the submucosa. Consequently, when the portal venous pressure is raised e.g. in cirrhosis, the veins in this region can dilate into varicosities which are prone to catastrophic haemorrhage - oesophageal varices.