Abstract
We have developed a small-caliber vascular graft with an ID of 2.5 to 3.0mm by chemical modification of canine acellar carotid artery using a hydrophilic crosslinker, polyepoxy compound (PC). For the control, glutaraldehyde (GA) treated grafts were prepared. Sixteen dogs were used, 11 for the new graft and the other 5 for the control. A segment of the graft, 6cm in length, was implanted in the carotid artery. Sodium heparin was given during the surgery, but no anticoagulant was used there after. The compliance of the new graft was similar to that of the native artery. No excessive bleeding was noticed at the anastomotic sites. The patency rate was 77% during the longest observation period of 71 days whereas in the control, it was 10%. Microscopic observation revealed that on the inner surface of the new graft on the 7th P. O. D., endothelial like cells had appeared near the anastomotic lines. And at the same time, fibroblast infiltration in the graft wall was observed. These findings suggest that the reduction in initial bleeding is due to the high flexibility of the PC-treated graft and that the improved patency is caused by the blood element-repelling effect of the poly (ethylene glycol) chains of PC. Furthermore, the healing process is considered to be significantly enhanced by the accummulation of adhesive proteins such as fibronectin in the hydrogel layer on the surface of the graft. From these results, there is a high possibility for this new graft, with its many advantages, to be used clinically, as for example, a coronary bypass graft.
