Neurovascular supply and lymphatic drainage of the esophagus

Anatomy

The oesophagus is divisible into three parts:

• a cervical part between the level of 6th cervical vertebra and upper border of 1st thoracic vertebra
• a thoracic part between the level of 1st thoracic vertebra to the diaphragm
• an abdominal part, which commences as it crosses the diaphragm and runs a short course of about 1 - 2.5 cm before reaching the stomach

Although the oesophagus is generally vertical in its course, it has two shallow curves, and also bends in an anteroposterior plane to follow the cervicothoracic curvatures of the vertebral column. It can also bend slightly to the right as it is pushed by the aorta before bending to the left to reach the esophageal hiatus.

Blood supply

The cervical oesophagus is supplied by the inferior thyroid artery.

The thoracic oesophagus is supplied by the brachial and oesophageal branches of the thoracic aorta. Four or five oesophageal branches arise from the anterior surface of the aorta and descend obliquely to the oesophagus. Here, they form a vascular chain that anastomoses above with the oesophageal branches of the inferior thyroid arteries, and below with the ascending branches from the left phrenic and left gastric arteries.

The abdominal oesophagus is supplied by arteries from the left gastric artery, a branch of the celiac trunk and the left inferior phrenic artery. 

Venous drainage

The oesophagus is drained by oesophageal veins which arise from the peri-oesophageal venous plexus. Blood from the oesophagus drains into a submucous plexus and then into a peri-oesophageal venous plexus which gives rise to the oesophageal veins. Veins of the abdominal oesophagus return blood through plexuses to the left gastric and upper short gastric veins. The left gastric vein meets the lower oesophageal veins at the oesophageal opening in the lesser curvature and then drains into the portal vein .

Those from the thoracic oesophagus drain predominantly into the azygos veins and, to a lesser extent, the hemiazygous, intercostal and bronchial veins. Those from the cervical oesophagus drain into the inferior thyroid vein.

Innervation

Esophagus is innervated by the sympathetic and parasympathetic divisions of the autonomic nervous system. 

• Cervical part receives parasympathetic supply from the recurrent laryngeal nerve, while the sympathetic supply comes from the cervical sympathetic trunk.
• Thoracic part is innervated by the autonomic esophageal plexus. The sympathetic source for this plexus is the sympathetic trunk, while the parasympathetic input comes from the vagus nerve (CN X).
• Sympathetic supply of the abdominal part comes from the fifth to twelfth thoracic spinal nerves (T5-T12), while the parasympathetic source is the esophageal plexus.

Lymphatic drainage

The lymphatic drainage of the abdominal oesophagus occurs to the left gastric and left and right paracardial nodes. Lymph from the posterior surface is drained directly to the uppermost para-aortic nodes.

The cervical and thoracic oesophagus have an extensive, longitudinally continuous submucosal lymphatic system, which presumably explains remote para-oesophageal lymphadenopathy in oesophageal carcinoma. Efferent vessels from the cervical oesophagus drain to the deep cervical nodes either directly or through the para-tracheal nodes. Vessels from the thoracic oesophagus drain to the posterior mediastinal nodes and those from the abdominal oesophagus drain to the left gastric lymph nodes. Some may pass directly to the thoracic duct.