A novel piglet model of esophageal stricture following variable segmental esophageal resection and re-anastomosis.

Background: Esophageal strictures following esophageal atresia repair are a source of significant morbidity. To test new therapeutic approaches, we designed a piglet model of esophageal stricture by resecting variable lengths of esophagus with subsequent re-anastomosis. This study describes the model and validates its physiologic impact by blinded analysis of the weight gains of the piglets.

Methods: A total of 24 two-week old Pietrain piglets had esophageal resections performed, ranging from 0 to 5 cm, with the goal of inducing postoperative esophageal strictures. Postoperative body-weights were evaluated by repeated analysis of variance followed by pairwise group-comparisons based on estimated marginal means. In addition, body weight was modeled by linear-mixed model regression. Different resection lengths were compared. The esophagi were evaluated postmortem for stricture.

Results: Of 24 operated piglets, 23 reached the endpoint, and 90% developed an esophageal stricture that was radiologically visible in a contrast study, as well as appreciable macroscopically in the necropsy. We found differences in pre- and postoperative body weights for all piglets (F (1, 18) = 298.54, p < 0.001), but no differences between resection lengths (F (4, 18) = 0.36, p = 0.837).

Conclusion: Our model of postoperative esophageal stricture offers the opportunity to investigate potential treatments for strictures associated with esophageal atresia, since it reliably induces strictures and results in minimal loss of animals. The similar body weight gain in all groups indicates that stricture is mainly the result of esophageal resection and re-anastomosis, regardless of the length of the resected segment.