The experimental replacement of a cervical esophageal segment with an artificial prosthesis with the use of collagen matrix and a silicone stent

Objective: Attempts have been made to replace esophageal defects with a variety of artificial materials. However, because of the artificial nature of the materials, problems such as infection, leakage, stricture, or dislocation could not he avoided. Therefore we have designed a new type of artificial esophagus that is gradually replaced by host tissue. Methods: Our artificial esophagus was a two-layered tube consisting of a collagen sponge matrix and an inner silicone stent. We used it to replace 5 cm esophageal segmental defects in 43 dogs, and the inner silicone stent was removed endoscopically at weekly intervals from 2 to 4 weeks. Results: In the 27 dogs from which the silicone stent was removed at 2 or 3 weeks, constriction of the regenerated esophagus progressed and the dogs became unable to swallow within 6 months. in the 16 dogs from which the silicone stent was removed at 4 weeks, highly regenerated esophageal tissue successfully replaced the defect, leaving no foreign body in the host. Moreover, the regenerated esophagi had stratified flattened epithelia, striated muscle tissue composed of an inner circular and an outer longitudinal muscle layer, and esophageal glands. Conclusions: Even in mature adult higher mammals, esophageal high-order structures cars be regenerated provided that an adequate three-dimensional extracellular structure is put in place for a sufficient period.