External cricoid pressure is increasingly used to augment the upper esophageal sphincter (UES).
Objective
To determine the effect of: 1) pressures applied to cricoid, supra-cricoid and sub-cricoid regions on the length and amplitude of UES high-pressure zone (UESHPZ). 2) external cricoid pressure on LES tone.
Study Design
case-control study.
Methods
We studied 11 patients with supraesophageal reflux (58 ± 12 yr) and 10 healthy volunteers (47 ± 19 yr). We tested 20, 30, 40 mmHg pressures to cricoid, 1 cm proximal and 1 cm distal to cricoid. In an additional 15 healthy volunteers (46 ± 23 yr), we studied the effect of external cricoid pressure on LES tone. UES and LES pressures were determined using high-resolution manometry.
Results
There was significant increase of UESHPZ length with application of pressure at all sites. The increase of UESHPZ length was relatively symmetric, more orad and more caudad when the pressure was applied at the cricoid, supra-cricoid and sub-cricoid levels, respectively. The magnitude of pressure increase was greatest at the middle and orad part of the UESHPZ when the pressure was applied at the cricoid and supra-cricoid levels, respectively. The corresponding magnitude of increase in the caudad part of the UESHPZ was not observed with pressure at sub-cricoid level. There was no change of the LES pressure with application of cricoid pressure.
Conclusions
Effect of external pressure on UESHPZ is site dependent. Sub-cricoid pressure has the least effect on UESHPZ. External cricoid pressure at 20–40mmHg has no effect on the LES pressure.