2017 Volume 25 Issue 1 Pages 30-37
Background and study aims: Benign esophageal stricture has major deleterious effects on a patient’s quality of life and is often refractory. This study aims were to prepare the animal model and to investigate the mechanism of esophageal stricture in the view point of histological and biomechanical evaluation.
Material and method: Nine beagle dogs were enrolled in this study. Under general anesthesia, circumferential endoscopic submucosal dissection was carried out 5 cm length in thoracic esophagus for preparing stricture models. The process of stricture formation was evaluated by the endoscopic observation and histological findings. Immunohistochemical staining was performed for collagen I or collagen III. In the biomechanical evaluation, rectangular-shaped specimens were obtained from the esophageal samples. The failure load and linear stiffness were measured using a tensile tester and compared healed tissue with normal.
Results: The dogs developed severe stricture. The macroscopic appearance showed a deep ulcer formation and severe mucosal constriction. No esophageal glands or muscularis mucosae were evident, and instead, they were replaced with condensed granulation tissue that were composed type I and III collagen fibers. The inner circular muscular layer of the muscularis propria showed partial atrophy and fibrosis in the center of the lesion. The failure load and linear stiffness were significantly decreased in the healed tissue.
Conclusion: The cause of benign esophageal stricture might have been the biomechanical deterioration that was caused the change of the collagen components in the submucosal layers or atrophic changes of inner circular muscles.
