AN ELECTROMYOGRAPHICAL STUDY OF THE ESOPHAGUS WITH CHRONICALLY IMPLANTED ELECTRODES

The electromyogram of the esophagus has been studied by means of intramuscularly implanted electrodes to investigate pathophysiological changes seen in experimentally produced achalasia-like condition in dogs. These studies have been attempted to elucidate the functional mechanism of the esophagogastric junction.Electrodes are implanted into the esophageal muscle at 4 different points; the upper, middle, lower parts of the esophagus and the esophagogastric junction respectively and the electrodes have been kept chronically. In dogs, the electromyogram is taken during spontaneous swallowing without anesthesia or restraint while the studies are done.After the electrodes have been connected with the multi-channel amplifier, the electromyogram can be easily recorded until 3 weeks postoperatively.One day after the operation, dogs can eat and the electromyographical bursts move down to the lower part of the esophagus, judging from the electromyographical patterns at the 4 different points. The bursts are high in the maximum amplitude and long in the duration at the lower part of the esophagus as compared with the one from the upper part. Changes are slight in amplitude at the esophagogastric junction.