Alcohol-preserved homologous connective tissue tubes containing polyester mesh within their walls were evaluated as arterial prostheses in the thoracic aortae of 20 dogs. As the control, 146 knitted Dacron prostheses were used.
Silicone rubber tubes covered with polyester mesh were implanted in dogs' subcutaneous layers. Two to three weeks after implantation, the tubes and the surrounding connective tissue were removed en bloc as little excess tissue as possible and were dipped and preserved into 70% solution of ethanol. Before the implantation as an arterial substitute, the silicone tube was pulled out and the connective tissue with polyester mesh was immersed into saline solution. Therefore preparation of the grafts of desired size and shape was easily performed.
All the dogs were held for sacrifice from 1 to 43 weeks after operation except 4 for long-term observation. All the grafts were patent at the time of removal. The luminal surface was shiny and smooth. Microscopic examination revealed that the fibers of the polyester mesh were enveloped by matured connective tissue. It took 15 weeks after implantation to covered the surface of the neointima completely with endothelium, while in the cases of the control specimens, it took more than 20 weeks. Both gross and microscopic examinations showed no aneurysmal dilatation, nor other degenerative changes such as calcification, ulceration, hyalin degeneration and thrombus deposition.
These results indicate that the alcohol-preserved homologous connective tissue tube is superior to the control specimen of the knitted Dacron prosthesis and is acceptable as an arterial substitute.