Abstract
A small caliber vascular graft was newly developed. We already developed 3mm in internal diameter biological vascular graft with heparin slow release (A. S. A. I. O., 1985). The graft lost pliability and produced yellow because of glutaraldehyde crosslinking. These disadvantages were overcome and a new graft with natural tissue compliance was developed using new crosslinking reagent Polyepoxy Compounds (PC). The graft of 2.5-3.0mm in internal diameter showed 96% patency in animal study. For the basic material of the graft, carotid arteries from dogs were used. It was soaked in distilled water to destroy the endothelial cells, then the graft lument was contacted with 2% protamine solution. Protamine penetrated into the wall was crosslinked to collagen with PC. After washing, the graft was soaked in 1% heparin, then washed with distilled water. The grafts were implanted into carotid arteries of 40 dogs at a length of 6cm (80 grafts). Sixteen non-heparinized control grafts were implanted in 8 dogs.
Seventy-seven heparinized grafts were patent during the observation up to 389 days after the surgery. On the other hand, all the control grafts were occluded within 1 week. Microscopic observations revealed that the inner surface of the heparinized grafts had no thrombus nor platelets aggregations. Complete endothelialization on the graft surface was observed in the long term specimens. This graft with natural tissue compliance and heparin slow release was very useful for the small caliber vascular graft.
