Vagotomy Involves the Vagus Nerve (Cranial Nerve X)
A vagotomy is a surgical procedure that involves sectioning or cutting the vagus nerve (cranial nerve X), which is the tenth cranial nerve. This nerve has the longest course of any cranial nerve in the body, extending from the brainstem through the neck, thorax, and into the abdomen 1, 2.
Anatomical Course and Function
The vagus nerve originates in the medulla and travels through multiple regions:
- Intracranial portion: Exits the brainstem and passes through the posterior fossa
- Cervical portion: Descends in the posterior carotid sheath through the neck
- Thoracic portion: Continues into the chest, where the recurrent laryngeal branches arise
- Right recurrent laryngeal nerve: Loops under the subclavian artery
- Left recurrent laryngeal nerve: Loops under the aortic arch in the aortopulmonary window
- Abdominal portion: Extends to provide parasympathetic innervation to thoracic and abdominal viscera 2
Functional Branches Affected by Vagotomy
The vagus nerve provides:
- Branchial motor innervation: To pharyngeal and laryngeal muscles via pharyngeal branches and superior/recurrent laryngeal nerves
- Visceral motor (parasympathetic) innervation: Predominant parasympathetic supply to thorax and abdomen 1
- Sensory innervation: Visceral sensation to pharynx, larynx, and viscera 1
Clinical Context in Gastric Surgery
In gastric surgery, vagotomy specifically targets the vagal branches to reduce gastric acid secretion. The Japanese gastric cancer treatment guidelines note that preservation of specific vagal branches can improve postoperative quality of life:
- Hepatic branch of anterior vagus: Preservation reduces gallstone formation
- Celiac branch of posterior vagus: Preservation reduces diarrhea and weight loss 3
When performing pylorus-preserving gastrectomy, the hepatic branch should be preserved to maintain pyloric function 3.
Important Clinical Considerations
The extensive course of the vagus nerve makes it vulnerable to injury at multiple anatomical levels. Vagotomy can be:
- Intentional: As in gastric surgery for acid reduction
- Iatrogenic: From surgical procedures, intubation, or trauma along its course 2
The most clinically significant complication of vagal injury is vocal cord paralysis, which can result from damage anywhere along the nerve's path from skull base to mid-chest 1, 2.