ATTENUATION OF ESOPHAGEAL SHORTENING DURING PERISTALSIS WITH HIATUS-HERNIA

Background & Aims: Minimal quantitative information exists on esophage al shortening during peristalsis in the human esophagus. The aim of th is study was to ascertain the effect of hiatus hernia on longitudinal muscle-mediated peristaltic esophageal shortening, Methods: Seven volu nteers and 11 patients with hiatal hernia had metal clips endoscopical ly affixed at the squamocolumnar junction and 3-5 cm proximal to it (n = 11). Location of the lower esophageal sphincter and axial clip move ment were assessed using concurrent manometry and videofluoroscopy dur ing barium swallows in a supine and upright posture with and without a bdominal compression. Results: Three subject groups were defined by th e proximity of the squamocolumnar junction to the diaphragmatic hiatus : group 1, less than or equal to 0 cm; group 2, between 0 and 2 cm; an d group 3, greater than or equal to 2 cm. Peristaltic esophageal short ening was progressively diminished, re-elongation progressively prolon ged, and the degree of contraction observed in the distal esophageal s egment reduced with progressive degree of hiatus hernia, There was min imal mobility of the squamocolumnar junction relative to the hiatus wi th posture or abdominal compression. Conclusions: Longitudinal muscle contraction during peristalsis normally causes transient elevation of the squamocolumnar junction above the diaphragm. Esophageal shortening during primary peristalsis is reduced with increasing degree of hiatu s hernia, suggesting that there is diminished opposition of longitudin al muscle contraction from the phrenoesophageal attachments.