Esophageal Arteries

The esophageal arteries are a group of small arteries that supply the thoracic portion of the esophagus. These arteries arise mainly from the descending thoracic aorta and form an important part of the longitudinal arterial network that ensures continuous blood supply along the length of the esophagus. They contribute to the vascular anastomoses between cervical, thoracic, and abdominal regions of the esophagus.

Origin

The esophageal arteries typically arise as 4 to 5 small branches from the anterior or right lateral aspect of the descending thoracic aorta. Their number and exact origin can vary between individuals.

• Primary source: Descending thoracic aorta (mid-esophageal region)

Additional contributions may come from:

• Inferior thyroid artery (cervical region)

• Left gastric artery (abdominal region)

• Bronchial arteries (occasionally)

Course

After branching from the thoracic aorta, the esophageal arteries pass obliquely forward to reach the esophagus. They travel in the connective tissue of the posterior mediastinum and enter the wall of the esophagus, forming longitudinal and transverse anastomoses within the submucosa and muscular layers.

These arteries may pierce the adventitia and muscularis of the esophagus and branch extensively within the submucosa. Their close association with lymphatics and veins forms a rich neurovascular network along the esophagus.

Distribution

The esophageal arteries primarily supply the:

• Thoracic portion of the esophageal wall

• Esophageal muscularis and mucosa

• Peri-esophageal connective tissue and surrounding lymph nodes

Anastomoses

The esophageal arteries form important anastomotic connections:

• Superiorly: With esophageal branches of the inferior thyroid artery (from the thyrocervical trunk)

• Inferiorly: With esophageal branches of the left gastric artery (from the celiac trunk)

• Laterally: With bronchial and intercostal arteries

These longitudinal anastomoses are critical in maintaining esophageal blood flow even when one region is compromised.

Venous Drainage

The venous return from the esophageal arteries is via the esophageal veins, which drain into:

• Azygos vein (right side)

• Hemiazygos and accessory hemiazygos veins (left side)

• Left gastric vein (which drains into the portal vein)

These connections between systemic and portal venous systems form the basis of the portosystemic anastomosis, which becomes clinically significant in portal hypertension.

Topographic Relationships

• Anterior: Trachea (superiorly), pericardium (centrally)

• Posterior: Vertebral column, descending aorta

• Right: Azygos vein, thoracic duct

• Left: Mediastinal pleura, descending aorta

Histological Features

Within the esophageal wall, the arteries form a submucosal plexus composed of arterioles and capillaries. These are tightly regulated by autonomic innervation and show a rich capillary density, especially in the muscularis layer.

Clinical Significance

• Esophageal Varices: Result from dilation of esophageal veins due to portal hypertension; the arterial supply may contribute to bleeding if varices rupture.

• Esophageal Ischemia: Rare, but may occur with severe aortic disease or systemic hypotension, especially in the elderly or post-surgical patients.

Topographic Summary

• Number: 4–5 variable branches

• Origin: Descending thoracic aorta

• Supply: Middle third of esophagus

• Anastomoses: With inferior thyroid and left gastric arteries

• Drainage: Azygos system and left gastric vein