MANOMETRIC STUDIES ON ASYMMETRY OF LOWER ESOPHAGEAL SPHINCTER IN DOGS

Abstract

Manometric pressure profile of the lower esophageal sphincter (LES) was measured with perfused 3-lumen tube (Sherwood Type I, Fr.10) at 3 different directions at the same level in dogs.
1. Measurement in 8 mongrel dogs disclosed that LES pressure was significantly high at right anterior (2 o'clock) and left anterior (10 o'clock) directions compared with pressure at dorsal direction (6 o'clock). There was no statistically significant difference of LES length 3 different directions.
2. LES pressures and lengths were signfiicantly increased and difference of LES pressures among 3 different directions was amplified by intravenous administration of 4μg/kg/hr of Tetragastrin.
3. LES pressures and lengths were not affected by intravenous administration of 0.5mg/kg/hr of Atropine sulfate.
4. LES pressures were preserved, but LES lengths were shortened by division of the phrenicoesophageal ligament. Difference of LES pressures among 3 different directions disappeared of ter this procedure. Division of the phrenico-esophageal ligament produced the “second” high pressure zone at directions of 2 and 10 o'clock.
The present studies suggest that difference of LES pressures, or lengths in different directions is a product of anatomical structures of the hiatal muscle, and not of LES itself.