Upper oesophageal sphincter yield pressure in normal subjects and in patients with gastro-oesophageal reflux.

, , 459-462. Upper oesophageal sphincter yield pressure was measured in 26 normal subjects and in 69 patients with gastro-oesophageal reflux, using a system of continuously perfused catheters. There was no significant difference between the two groups. Perfusion of the oesophagus with hydrochloric acid produced no change in sphincter pressure. The resting sphincter pressure was not related to the degree of oesophagitis nor to the severity of reflux as measured by 15-hour pH recordings. There were significant differences in sphincter pressure recorded by the three catheters either when their orifices were set 5 cm apart longitudinally or when they were at the same level, equidistant around the circumference of a circle. This indicates that spatial orientation of catheter tips influences the pressure recorded from a sphincter.