The effect of vagotomy on human gastroesophageal sphincter pressure in the resting state and following increases in intra-abdominal pressure.

The effect of surgical isolation and extrinsic denervation of the distal 5 to 7 cm of the human esophagus on resting gastroesophageal sphincter pressure and its response to graded increases of external abdominal compression was determined in 89 patients with duodenal ulcer. Fasting serum gastrin concentration also was measured. No significant changes in resting sphincter pressure were obtained before and after vagotomy of various types: parietal cell vagotomy, selective gastric vagotomy plus drainage, and selective gastric vagotomy plus precise antrectomy. No correlation between resting sphincter pressure and fasting serum gastrin concentration was found in any of the groups studied. The increase in gastroesophageal sphincter pressure was similar to the increase in intragastric pressure after 10, 20, and 30 mm Hg of external abdominal compression and was unchanged after all types of vagotomies. These results suggest that (1) extrinsic innervation of the lower esophageal sphincter in humans does not regulate the resting tone of the sphincter; (2) extrinsic "mechanical" influence does not play any role in the maintenance of resting pressure; (3) the effect of increased abdominal pressure is a pure mechanical effect, is unchanged after vagotomy, and therefore is not regulated by external neural reflex.