A truncal vagotomy involves division of the anterior and posterior vagal trunks close to the abdominal oesophagus and just below the diaphragm. This operation is very successful at reducing acid secretion and therefore it promotes ulcer healing.
However, the patency of the pyloric sphincter is dependent on vagal tone and hence denervation alone can lead to a functional outflow tract obstruction. Thus, a drainage procedure is employed at the same time as the truncal vagotomy to encourage emptying, e.g. a pyloroplasty or a gastro-jejunostomy.
Despite complications such as diarrhoea, truncal vagotomy remains a popular operation for chronic ulceration because of its simplicity. It is particularly indicated in the following situations:
- cirrhosis, where a stiff left liver lobe makes dissection of the hiatus impossible
- previous splenectomy: alternative vagotomy procedures may divide the left gastric artery resulting in a devascularized proximal stomach
- in emergency situations, e.g. bleeding gastroduodenal artery - simplicity permits rapidity