Nerve Supply of the Thoracic Oesophagus
Overview
The thoracic oesophagus receives both autonomic (parasympathetic and sympathetic) innervation. The principal nerve supply is from the vagus nerves via the oesophageal plexus, which surrounds the oesophagus in the posterior mediastinum.
Oesophageal Plexus
The oesophageal plexus is a network of nerve fibres that surrounds the oesophagus in the posterior mediastinum.
Formation:
- Formed by the branches of both right and left vagus nerves after they leave the pulmonary plexuses posterior to the respective bronchi
- Also receives sympathetic fibres from the greater splanchnic nerve
Position: Surrounds the oesophagus from approximately T4 downward, forming an irregular network on its surface
Supplies:
- Oesophagus (motor + secretomotor + sensory)
- Adjacent pericardium
- Adjacent mediastinal pleura
Termination: As the oesophageal plexus descends, the nerve fibres reconverge into two trunks:
- Anterior vagal trunk (predominantly from left vagus)
- Posterior vagal trunk (predominantly from right vagus)
These trunks descend on the oesophagus and pass through the oesophageal hiatus with it, becoming the anterior and posterior gastric nerves on the stomach.
Note: Each vagal trunk contains fibres from both vagi (not exclusively from one side) because of the rotation of the gut tube during development. The left vagus (initially anterior) becomes the anterior gastric nerve; the right vagus (initially posterior) becomes the posterior gastric nerve.
Vagus Nerves — Thoracic Course
Right Vagus
- Enters the thorax posteromedial to the right brachiocephalic vein
- Descends on the right side of the trachea, giving a right recurrent laryngeal nerve in the neck (not the thorax)
- Passes posterior to the right bronchus → forms the posterior part of the right pulmonary plexus
- Continues to oesophageal plexus
Left Vagus
- Descends between the left common carotid and subclavian arteries
- Crosses the left side of the aortic arch
- At the inferior border of the aortic arch: gives off the left recurrent laryngeal nerve, which curves under the arch (posterior to the ligamentum arteriosum) and ascends in the tracheo-oesophageal groove
- Forms the left pulmonary plexus → continues to oesophageal plexus
Sympathetic Supply
| Source | Route | Function |
|---|---|---|
| Greater splanchnic nerve (T5–T9 thoracic ganglia) | Joins oesophageal plexus | Vasomotor; pain from lower thoracic oesophagus |
| Thoracic sympathetic ganglia (T1–T4) | Via rami communicantes | Supply upper thoracic oesophagus |
Pain fibres from the oesophagus travel with the sympathetic nerves — oesophageal pain (e.g., spasm, reflux) is referred to the same dermatomes as cardiac pain (T1–T5), which explains why oesophageal spasm can mimic angina pectoris.
Functional Nerve Supply Summary
| Function | Nerve |
|---|---|
| Motor to smooth muscle (lower 2/3 of oesophagus) | Vagus (parasympathetic — via oesophageal plexus) |
| Motor to skeletal muscle (upper 1/3) | Vagus (somatic — via recurrent laryngeal nerves) |
| Secretomotor | Vagus |
| Vasomotor | Sympathetic |
| Pain (visceral afferent) | Sympathetic (greater splanchnic — T5–T9) |
| Reflex afferent (peristalsis trigger) | Vagus |
Left Recurrent Laryngeal Nerve — Thoracic Relations
The left recurrent laryngeal nerve is the most surgically important nerve in relation to the oesophagus:
- Curves under the aortic arch, posterior to the ligamentum arteriosum
- Ascends in the left tracheo-oesophageal groove
- At risk in: oesophageal surgery, aortic arch surgery, left lung malignancy, and mediastinal lymph node enlargement (e.g., bronchogenic carcinoma — gives hoarseness)