Effect of proximal selective vagotomy on the canine lower esophageal sphincter

The effect of proximal selective vagotomy on the lower esophageal sphincter was studied in 13 dogs by manometry and cinefluorography. The studies, done under resting conditions and during abdominal compression, were repeated 8 weeks after proximal selective vagotomy in seven animals and after truncal vagotomy in six animals. Proximal selective vagotomy had no significant effect on the pressures in the lower esophageal sphincter; the resting pressures were 32.1 +/- 4.1 cm H2O before and 28.9 +/- 3.7 after operation, and the pressures on abdominal compression were 50.6 +/- 6.5 and 41.6 +/- 3.8 cm H2O, respectively (p < 0.05). Truncal vagotomy decreased the lower esophageal sphincter pressures at rest from 28.2 +/- 4.0 to 18.0 +/- 2.2 cm H2O (p = 0.1) and those during abdominal compression from 44.7 +/- 5.6 to 15.5 +/- 2.6 cm H2O (p < 0.01). Gastroesophageal reflux was not seen after proximal selective vagotomy but was seen in one animal in the truncal vagotomy group. Since proximal selective vagotomy does not decrease lower esophageal sphincter function, it offers an advantage over truncal vagotomy in the treatment of duodenal ulcer. The data also indicate that vagal afferents from the proximal stomach are not important in reflex control of lower esophageal sphincter activity.