Evaluation of the antireflux mechanism following laparoscopic fundoplication

Background Laparoscopic Nissen fundoplication is an effective procedure for the treatment of gastrooesophageal reflux disease (GORD), but the underlying motility mechanisms that explain the success of this operation remain unclear. Methods Twenty patients with a history of GORD underwent stationary oesophageal manometry and prolonged ambulatory pH monitoring, both before and 3 months after fundoplication. Results Eighteen patients were completely cured of reflux symptoms and stopped all antireflux medication after operation. After fundoplication there was a significant increase (P < 0.01) in median resting lower oesophageal sphincter (LOS) pressure and length. Median residual LOS pressure during swallow-induced LOS relaxation also increased significantly after operation (P < 0.01). The number of reflux episodes decreased from a median of 48 to 3 after fundoplication (P < 0.01). The time at pH less than 4 decreased from 5.7 to 0 per cent in the supine position (P < 0.01), and from 9.8 to 0.2 per cent while upright (P < 0.001). Conclusion Early subjective results at 3 months following laparoscopic antireflux surgery show improved symptoms. One of the mechanisms underlying the antireflux action of fundoplication is an increase in median residual LOS pressure at the gastro-oesophageal junction. This may be a purely mechanical effect of the fundic wrap extrinsic to the LOS.