[Computer-assisted analysis of the pressure behavior of the esophagogastric junction during increase in intragastric pressure].

Two factors are to determine increasing lower esophageal sphincter pressure during intragastric pressure rising mainly: 1. the active intrinsic muscle tone and 2. the efficiency of the law by La Place. The purpose of the study was to estimate the part of both of them in this measurable phenomenon. We investigated 15 healthy volunteers and 5 patients post Nissen fundoplication. A simultaneous manometric examination of gaster and LES was carried out during gradual compression of abdominal wall. Analysis of dependence of LES-pressure on intragastric pressure, based on computer usage, was established. A linear equation described this dependence with the best correlation coefficient (r = 0.98) followed by potential and exponential equation. Fundoplication caused a steeper ascent without any changing of linear character of function. Considering linear equation is compatible with the law by La Place out not with a simultaneous pressure depending change of intrinsic muscle tone, these results indicate that the law by La Place has major importance in the measurable rising of high pressure zone during intragastric pressure increasing.