[An experimental study on temporal changes of post-operative anti-reflux effect by modified Mark IV operation for...

This study was intended to elucidate possible temporal changes of the valve and fundoplication which are formed by modified Mark IV operation as a surgical treatment of esophageal achalasia. Heller's procedure was also studied in terms of its comparison with the above operation. Adult mongrel dogs were operated on as follows and studied at the following postoperative points: Heller's procedure at the forth postoperative week, Modified Mark IV operation at the forth postoperative week, Modified Mark IV operation at the third postoperative month. Postoperative comparative studies were made on temporal changes of the anti-reflux effect by intraesophagogastric pressure and withdrawal pH examinations, measurements of intragastric pressure at reflux through simultaneous evaluation of intraesophageal pH and inner pressures at 3 points, i.e. the esophagus, the high pressure zone and the stomach, and histological and morphological examination. From the above the following conclusion was drawn: The valve formed by modified Mark IV operation showed temporally a shortening tendency, and a significant shortening of the length of valve was observed also in comparisons of values between the forth postoperative week and the third postoperative month. Also in terms of the measurement of inner pressures, a significant decrease was observed in the length and the force of high pressure zone. However, comparisons of the intragastric pressure values at reflux revealed no significant difference in values between the forth week and the third month after the modified Mark IV operation and almost similar anti-reflux effects between both in spite of a shortening of the valve. The above results suggested that more reliable and long-term sustaining of the anti-reflux effect needed more extensive formation of the fundoplication.