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.