Intrathoracic esophageal replacement in the dog with the use of an artificial esophagus composed of a collagen sponge with a double-layered silicone tube

Objectives: Intrathoracic esophageal replacement with an artificial esophag us is considered difficult. We attempted to replace the intrathoracic esoph agus,vith an artificial esophagus composed of a collagen sponge with a doub le-layered silicone tube and examined the state of host tissue regeneration . Methods: A 5-cm long gap was created in the intrathoracic esophagus in 9 dogs and repaired by interposition of our prosthesis. The dogs were fed onl y by intravenous hyperalimentation for 28 days, The silicone tube was remov ed at 29 days after the operation, and oral feeding was reintroduced, Resul ts: One dog was put to death at each of the following times: 1, 2, 3, 3, 6, 12, and 24 months after the operation, One dog is still surviving without problems after more than 26 months. One dog died of malnutrition at 10 mont hs. In all dogs, the host regenerated tissue had replaced the resulting gap at the time of silicone tube removal. The mucosa had fully regenerated wit hin 3 months and the glands within 12 months. The process of stenosis and s hrinkage was complete within 3 months and did not advance thereafter. The l amina muscularis mucosae were observed as islets of smooth muscle within 12 months. Although the skeletal muscle regenerated close to the anastomoses, it did not extend to the middle of the regenerated esophagus even after 24 months. Conclusions: Use of a collagen sponge,vith a double-layered silico ne tube was shown to be feasible even in the thorax and to allow the regene rated host tissue, consisting of the mucosa, glands, and lamina muscularis mucosae, to replace the esophageal gap.