[Experimental and clinical studies on lower esophageal sphincter motor function with special reference to the influence of vagal denervation].

Dysmotility of lower esophageal sphincter (LES) is common following gastric surgery. This may result in gastroesophageal reflux which frequently seen following gastric surgery. The aim of this study was to determine the effect of various surgical procedures on esophagogastric motility in dog and human. Esophago-gastric motility was investigated by strain gauge transducers during fasted and fed state in conscious dogs. Motility recordings were performed in three groups of dogs; 1) control dogs, 2) with truncal vagotomized dogs (TV), 3) with selective proximal vagotomized dogs (SPV). In human, manometric recordings were performed before and after gastric surgery (SPV or distal partial gastrectomy). In control animals, lower esophagus and LES contracted simultaneously with each contractions of the stomach during interdigestive motor contractions in fasted state. In fed state, LES showed tonic contractions, while gastric body showed receptive relaxation. These motility pattern of LES was considered to prevent gastroesophageal reflux in both fasted and fed states. These coordinated LES contractions disappeared following SPV or TV. In human, the amplitude and velocity of esophageal propagating contractions deceased after SPV or distal partial gastrectomy. In conclusion, gastric surgeries such as SPV, TV and/or distal partial gastrectomy caused LES dysmotility. These phenomena explain frequent gastroesophageal reflux following gastric surgery. Supplementation of anti-reflux procedure for gastric surgery should be required in the prevention of gastroesophageal reflux following gastric surgery.