Histological study of the elongated esophagus in a rat model.

BACKGROUND

Esophageal elongation by traction suture is used in pediatric patients to manage long-gap esophageal atresia (EA). There was no histological evidence of the esophageal elongation. Here, we sought to clarify the histologic effects of traction on the esophagus by using a rat EA model simulating Foker's method.

MATERIALS AND METHODS

Rats were randomly assigned into three groups (n = 5 each). The traction group underwent daily stretching of the distal segment of the esophagus. The nontraction group underwent a sham operation, and the normal group served as controls. Seven days after the operation, the distal segments of the esophagus were removed. The length and thickness were measured, and samples were stained with Ki-67, nNOS, and S-100.

RESULTS

The whole length of the esophagus in the traction group was significantly longer than that in the nontraction group (P < 0.01). The thickness of esophageal mucosa and muscle tended to become thin by traction, but not significantly. The Ki-67-positive ratio of mucosa and muscle was significantly higher in the traction group (P < 0.05). There were no significant differences in Ki-67 between two segments (cardia-middle and middle-stump) in any group. Auerbach's plexus was identified at all sites of elongated esophagus by nNOS and S-100 staining.

CONCLUSIONS

By traction, the esophagus was elongated uniformly and cell proliferation activity was promoted in all parts of the elongated esophagus in the rat EA model.