[Experimental and clinical studies on the lower esophageal sphincter in reference to its asymmetry and to the effects of respiration, posture and gastric contents].

The present study was designed to investigate basic and clinical problems of intraluminal lower esophageal sphincter (LES) manometry. As for the basic study, manometry apparatuses, measuring conditions and methods were revalued. For clinical study, effects of gastric contents and gastrin were studied with special reference to the asymmetry of the LES. The results obtained may be summarized as follows: Occlusion test performed in a LES model and dogs showed that the rate of pressure increase was greater in proportion to the greater perfusion rate as well as to smaller calibre of the manometry tube. The lower esophageal sphincter pressure (LESP) became greatest when the perfusion rate was increased up to a certain level and also when the withdrawal speed of a manometry tube was slowed down to a certain speed. Analysis of LES from the point of respiratory reversal disclosed that the pressure was greatest at the direction of 8 o'clock followed by those at 0 and 4 o'clock. The length of LES was longest at 4 o'clock followed by those at 0 and 8 o'clock. These differences in length of LES was mostly in accordance with the length of LES caudal to the point of respiratory reversal. LESP measured in different postures was greatest in the prone position suggesting the effect of intraabdominal pressure. Intragastric instillation of saline resulted in increase of intragastric pressure and LESP. Asymmetry of the LES in patients with sliding hiatal hernia, esophageal varices and achalasia showed profiles specific to the individual lesion.