EXCESSIVE COMPETENCE OF THE LOWER OESOYPHAGEAL SPHINCTER AFTER NISSENFUNDOPLICATION - EVALUATION BY 3-DIMENSIONAL COMPUTERIZED IMAGING

Objective: To compare the competence of the lower oesophageal sphincte r after Nissen fundoplication with that in a control group of healthy volunteers using a new computerized manometric device that integrates the pressure and length of the entire sphincter into one measurement, called the vector volume. Design: Open study. Setting: University hosp ital, Italy. Subjects: 18 patients, 6-52 months (mean 10 months) after they had undergone Nissen fundoplication for gastro-oesophageal reflu x, and 14 healthy volunteers.Interventions: Oesophageal computerised m anometric system comprising a catheter with eight side holes radially oriented to each other at 45 degrees on one level and 24-hour oesophag eal pH monitoring. Main outcome measures: Differences in percentage ti me of oesophageal acid exposure, number of episodes of gastro-oesophag eal reflux, and lower oesophageal sphincter vector volume. Results: Th e pH of the oesophagus was returned to the normal range in all patient s after the Nissen fundoplication. There was a significant reduction i n both the percentage time of acid exposure and the number of episodes of gastro-oesophageal reflux compared with the control group (p < 0.0 01). The vector volume of the intra-abdominal part of the lower oesoph ageal sphincter was significantly increased compared with the control group (p < 0.04). Lower oesophageal sphincter pressure measured at the respiratory inversion point, and lower oesophageal length, both incre ased after fundoplication to become similar to control values. When sp hincter pressure was measured as a mean of the sphincter pressure curv e there was a clear difference postoperatively compared with controls (p < 0.02). Conclusions: Nissen fundoplication corrects abnormal gastr o-oesophageal reflux but abolishes normal physiological postprandial r eflux; this is caused by the gastric fundus that encircling the intra- abdominal oesophagus restores sphincter pressure and length, and modif ies its shape.