Effect of fundoplication on transient lower oesophageal sphincter relaxation and gas reflux

BACKGROUND: Fundoplication is used widely to treat severe gastro-oesophageal reflux disease. Difficulty in belching and increased flatulence are common side-effects. Transient lower oesophageal sphincter (LOS) relaxation is important to help vent gas from the stomach. The effect of fundoplication on LOS function and gas reflux was therefore investigated. METHODS: Oesophageal manometry was performed before operation and 3-15 months after fundoplication in 14 patients with reflux disease who had a total (360 degrees) fundoplication. Five patients also had highly selective vagotomy. Gastric distension was induced by 750 ml carbon dioxide. RESULTS: Fundoplication reduced the median number of episodes of gas reflux during 10 min of gastric distension from 5 (interquartile range (i.q.r.) 3-7) to 0 (i.q.r. 0), and the median number of transient LOS relaxations from 4 (i.q.r. 2-6) to 0 (i.q.r. 0-1). Fundoplication did not affect basal LOS pressure but significantly increased nadir pressure during swallow-induced relaxation. CONCLUSION: Fundoplication controls reflux by inhibiting the triggering of transient LOS relaxation and by preventing the complete ablation of pressure at the gastro-oesophageal junction during LOS relaxation. These effects may also contribute to the side-effects of the operation.