Alloplastic replacement of canine trachea with Dacron.

Two by two centimeter fenestrations were created in the cervical tracheae of 2 groups of 9 mongrels each during intubation anesthesia. In one group the defect was closed with a Dacron patch of 25 to 50 micron pore-size, while in the other group a Dacron patch of pore-size 125 to 150 micron was inserted. The implant was sealed with 1 ml of fibrin adhesive. Seven dogs of each group were evaluated. Implants made of low-porosity Dacron were not incorporated in any animal, but sloughed into the tracheal lumen. Contrarywise large-pore Dacron underwent connective tissue incorporation in all but one case. As early as 90, and even more so at 270, days granulation tissue rich in fibroblasts and histiocytes had grown into the implant. On the implant, a stroma formed which was epithelialized from the margin already after 90 days. After 200 and 270 days the implant was covered with a respiratory epithelium, however, scattered undifferentiated cells still could be found in its center. Porous prosthetic fabrics when used for partial tracheal replacement can be incorporated by connective tissue and can be epithelialized if the polymer is tissue-compatible, the pore-size of the implant ranges between 120 and 150 micron, the implant is sufficiently stable, and if infection is prevented by fibrin seal.