Relationship between stenting time and regeneration of neoesophageal submucosal tissue.

The authors developed a new type of artificial esophagus consisting of an inner silicone tube and an outer non antigenic collagen tube. The novel feature of this artificial esophagus is that the main part of the prosthesis is replaced by host tissue. In a previous study, the authors found that no stenosis of the artificial esophagus developed when the replacement part was stented for more than 4 weeks. It was considered that this stenosis was caused mainly by poor regeneration of submucosal tissue, rather than by the grade of reepithelialization. In this study, it was found that, in cases in which the stent dropped out within 3 weeks, fibrous tissue was noted beneath the neoesophageal epithelium. In such cases, neither muscle layers nor submucosal glands regenerated beneath the neoesophageal epithelium after replacement. However, in cases in which the stent dropped out more than 4 weeks after surgery, the neoesophagus was covered with a polylayer of squamous epithelium and had normal esophageal glands and a muscle layer. Therefore, it was concluded that muscle tissue and esophageal glands were able to regrow in the neoesophagus when the portion replaced by the artificial esophagus was stented for at least 4 weeks.