As the two vagal nerves descend with the oesophagus through the thorax they rotate with the oesophagus so that the left vagus comes to lie on the anterior surface of the oesophagus, forming the anterior vagal trunk. This trunk passes through the oesophageal hiatus of the diaphragm and distributes to the anterior stomach, the liver via the hepatic branches, and the upper small intestine. It carries parasympathetic motor fibres that stimulate gastric acid secretion and gastrointestinal motility.
The anterior vagal trunk and its hepatic branches are identified and selectively preserved or divided during laparoscopic and open hiatal hernia repair, fundoplication, and Heller myotomy. Division of the hepatic branches of the anterior vagal trunk (as in highly selective vagotomy) reduces gastric acid secretion while preserving antral and pyloric motility. Inadvertent division of the anterior vagal trunk during Nissen fundoplication causes delayed gastric emptying and bloating. The anterior trunk is the target for truncal vagotomy with drainage procedures for peptic ulcer disease.
Inadvertent injury or excessive traction on the anterior vagal trunk during laparoscopic Nissen fundoplication causes delayed gastric emptying, early satiety, and post-prandial bloating, requiring prokinetic therapy and occasionally balloon dilation of the pylorus if gastroparesis is severe.
Division of the anterior vagal branches supplying the acid-secreting fundus and body while preserving the hepatic and antral branches reduces basal and stimulated acid secretion for peptic ulcer treatment without requiring a drainage procedure, as antral and pyloric innervation remains intact.
