Orientation of lower esophageal sphincter pressure using three-dimensional high-resolution manometry in patients with achalasia: a pilot study.

BACKGROUND: This study was performed to evaluate the orientation of lower esophageal sphincter (LES) pressure in patients with untreated achalasia using three-dimensional high-resolutionmanometry (3D-HRM).

METHODS: The study involved 20 patients with untreated achalasia (10 men, 60 [47-74] years of age). The 3D-HRM assembly had 32 standard channels and 12 3D channels. During basal LES pressure measurements, the orientations of the LES high- and low-pressure zones were evaluated at end-expiration. The directional relationships between the orientation of the LES high- and low-pressure zones were also evaluated.

RESULTS: The LES high-pressure zones were located on the greater curvature side in nine (45%) patients, from the greater curvature to posterior wall side in six (30%), and from the greater curvature to anterior wall side in five (25%). The LES high-pressure zones were located mainly on the greater curvature side, but there were some variations of the orientation among the patients. The LES low-pressure zones were most frequently located from the lesser curvature to the posterior wall side in 11 (55%) patients, from the lesser curvature to anterior wall side in 6 (30%), on the posterior wall side in 2 (10%), and on the anterior wall side in 1 (5%). Significant differences were found in the directional relationships between the orientation of the LES high- and low-pressure zones (P = 0.0053).

CONCLUSIONS: This is the first report from Japan focusing on the LES pressure orientation using 3D-HRM. Such evaluation may be useful for clarifying the pathophysiology of achalasia.