Absence of an upper esophageal sphincter response to acid reflux.

Manometric studies of the upper esophageal sphincter (UES) were done on 17 volunteer subjects and 16 patients with endoscopically evident esophagitis. Subjects entered one or both of two protocols designed to assess the effect of esophageal acid exposure on UES pressure. In protocol 1, continuous 3-h postprandial recordings were obtained; a modified sleeve sensor was used to measure UES pressure, and an intraluminal pH electrode was used to detect occurrences of spontaneous gastroesophageal acid reflux. In protocol 2, UES pressure was continuously monitored during a 10-min control period, followed by a 25-min period of esophageal perfusion with 0.1 N HCl. Our findings were that: 1) basal UES pressure measured during the 3-h recording was similar in the normal volunteers and in the group of patients with esophagitis, 2) episodes of spontaneous gastroesophageal acid reflux were not associated with a change in UES pressure in either the normal volunteers or in the patients with esophagitis, and 3) esophageal perfusion with HCl did not affect the UES pressure in either group, although severe heartburn occurred in most of the esophagitis patients. We conclude that the upper esophageal sphincter exhibits normal basal pressure in patients with esophagitis and that esophageal acid exposure, either spontaneous or experimental, does not affect UES pressure in normal volunteers or in patients with esophagitis.