Abstract
Polyester mesh tube was subcutaneously implanted into adlut dogs for 20 days to prepare fibrocollanous tissue tube enforced with the mesh. The tube was treated over night with 0.01% ficin at pH 7.0 to remove non-collagenous substances, then washed with saline. A solution of protamin sulphate was pored into the prepared collagen tube. The protamin was crossl inked to the collagen by glutaraldehyde, then the protamin crosslinked collagen tube was dipped into a heparin solution. By this procedure, the heparinized collagen vascular graft was prepared. The grafts were implanted into the thoracic descending aortae of 40 dogs. Non-heparinized collagen grafts were also implanted in 16 dogs as a control experiment. The grafts were taken out for macroscopic and microscopic observations at various periods of time up to 183 days post implantation. All of the tested grafts were patent through the experimental period. There was no thrombus formation on the heparinized graft. In the case of the control experiment, red thrombus layer was formed on the surface. Capillary blood vessels and fibroblasts penetrated into the net work of both the heparinized and non-heparinized collagen from the out side of the grafts. In the case of the heparinized collagen graft, thrombus formation was completely protected during the healing process, however, the endothelialization was delayed compared with the case of the non-heparinized collagen graft.
