Modifications in gastroduodenal motility induced by the extramucosal section of circular duodenal musculature in dogs.

The effect induced on the gastroduodenal motility by the extramucosal section of the circular layer of the first two parts of the duodenum, excluding the pylorus, was studied in a series of 5 dogs. The myoelectric and manometric activities of the antrum, pylorus, and duodenum were recorded by using special devices surgically implanted in the gut wall. The recordings were made 3 mo after operation, both during basal conditions and after stimulation with neostigmine. The results were statistically compared with those obtained in a control group of 4 dogs in which the electromanometric devices had been implanted 3 mo before. The gastric emptying time of a food-barium meal was determined radiologically before the operations, and 3 and 9 mo after. The results demonstrate that extramucosal duodenal myotomy: (a) significantly decreases the basal and stimulated motor activity of the duodenum, without noteworthy alterations of the gastroduodenal myoelectrical activity and coordination of motor waves; and (b) significantly shortens the gastric emptying time.