Effect of fundoplication on the lower esophageal sphincter

The lower esophageal sphincter of 26 patients was studied by infusion manometry before and after a modified Nissen fundoplication. Of these patients, 24 have remained asymptomatic (mean follow up, 21 months). The mean time for a positive acid infusion test increased from 267 seconds before, to 617 seconds after operation. The common cavity test was positive in 22 of the 26 patients before operation but positive in only the 2 symptomatic patients after operation. Mean lower esophageal sphincter pressure (cm H₂O) increased from 12.6 ± 2.0 to 16.5 ± 1.5 (x ± SEM). However, in only 15 of the 26 patients was an increase in lower esophageal sphincter pressure demonstrated, and in 7 a decrease in pressure was noted. One patient's symptoms recurred at 3 months in spite of an increase in lower esophageal sphincter resting pressure of 8 cm H₂O. The other symptomatic patient demonstrated a rise in lower esophageal sphincter pressure at 3 months of 8 cm H₂O, though this decreased to preoperative levels at 26 months, the time of symptom recurrence. Intraluminal pressure of the human cadaver esophagus after removal from the body was studied by means of an infusion manometric technique. Narrowing the esophageal lumen with extrinsic weight of as little as 50 g resulted in a zone of elevated pressure. The amplitude of the elevated pressure zone was directly related to the infusion rate. Elevations in lower esophageal pressure following fundoplication are probably secondary to extrinsic compression and are not necessary for a good clinical result.