SHORTENING OF THE ESOPHAGUS IN RESPONSE TO SWALLOWING

Esophageal shortening accompanies peristalsis in laboratory animals and is attributed to longitudinally oriented fibers in esophageal muscle layers. To evaluate this phenomenon in humans, esophageal shortening during suspended respiration in response to swallows was measured in five normal volunteers (median age, 23 yr). Metal mucosal clips were endoscopically placed at and 10 cm above the gastroesophageal junction, and their movement was recorded by videotaped fluoroscopy. All subjects demonstrated esophageal shortening with each swallow in a characteristic pattern with small interswallow variance. Early, minimal shortening of the proximal segment (6.0 +/- 2.4 mm) was followed by delayed, prominent distal segment shortening (18.9 +/- 9.3 mm) that principally accounted for overall change in total esophageal length (18.0 +/- 8.1 mm). The degree of esophageal shortening did not correlate with circular muscle contraction wave parameters that were obtained with intraluminal manometrics in a separate study (P > 0.2 for each correlation), and distal segment shortening uniformly preceded the onset of contraction waves in the same region. These findings indicate that patterned esophageal shortening with swallows occurs in humans, most prominently in the distal esophagus. The technique may be useful in determining the participation of axial esophageal movement in esophageal motility disorders.