Prolonged endoscopic and manometric observations of the pylorus

Functional aspects of the antral-pyloric segment were evaluated in 30 patients without gastroduodenal disorders by means of prolonged endoscopic observations. Patients were examined in standardized conditions. Pressure measurements of the antrum, pylorus and duodenal bulb were assessed by means of water-perfused polyvinyl tubes in 7 patients of the same group a few days after the endoscopy. The pylorus appeared open in above 80% of the total endoscopic observation time. Pyloric closure was observed only for few seconds at the end of 30-40% of antral peristaltic waves. The antrum and pylorus appeared to contract in sequence. Antral peristaltic waves moved at a mean rate of 2.4 per minute and duodenal reflux was observed at a mean rate of 0.96 per minute usually in the form of bubbles. The manometric measurements by means of pull through in 7 patients and immediately after by means of prolonged registration carried out in a fixed position in 4 patients failed to show a high pressure zone in the gastroduodenal junction. In some cases it was possible to observe a peculiar phasic activity in the pyloric tract. The endoscopic and manometric observations suggest that human pylorus does not act as a true physiological sphincter. These findings confirm the functional aspects described by radiology and manometry in other studies. In this way, endoscopy appears to be a useful procedure to evaluate some functional aspect of the gastroduodenal tract.