Chitosan tubular stent combined with muscle flaps for repair of partial defects of the cervical esophagus / 中国组织工程研究

ABSTRACT

BACKGROUND:Over the years, muscle, skin, skeletal muscle flaps and luminal tissues, such as stomach and intestines, are used as an artificial esophagus to repair esophagus defects, but the results are not good. OBJECTIVE:To investigate the feasibility of chitosan tube stent combined with muscle flaps to repair partial defects of the cervical esophagus. METHODS:Thirty white rabbits were used to make animal models of partial cervical esophageal defects, and randomly divided into experimental group (n=20) and control group (n=10). Esophagus defect in rabbits of experimental group was repaired using autologous muscle flap with a chitosan tube stent, and esophagus defect in the control group was repaired only with muscle flap. Gross and histological appearance was observed at weeks 2, 4 and 8 after operation, and barium sulphate X-ray screen was performed at week 10 after operation. RESULTS AND CONCLUSION:After 2 weeks, muscle tissue structure, cellswel ing, and inflammatory cellinfiltration could be seen in the experiment and control groups, exhibiting an acute inflammatory reaction. After 4 weeks, the experimental group showed clear muscle flaps, reduced inflammatory reaction, and no obvious fibrosis;while in the control group, muscle tissue could be seen at defect site, with growth of fibrous tissue cells and a few of inflammatory cells. After 8 weeks, in the experimental group, squamous metaplasia could be seen on the gross surface of the muscle flaps,esophageal mucosa could be seen, accompanied by chronic inflammatory reaction under the mucosas that had a clear abate than that at 4 weeks after implantation;in the control group, chronic inflammatory reaction could be found, accompanied by clear fibrosis but no squamous metaplasia and mucosal regeneration. Barium sulphate examination found that the esophagus was smooth with a slight motility in the experimental group, but there was a part of stricture in the esophagus without motility. These findings suggest that the chitosan tube stent combined with muscle flaps could better repair partial defects of the cervical esophagus.