Evaluation of a polyester collagen-coated heparin bonded vascular graft.

This animal study was designed to compare a collagen coated heparin bonded vascular graft (CHG) versus a collagen coated vascular graft (CG) regarding intraoperative blood loss and healing process. 24 polyester vascular grafts (12 CHG and 12 CG) of 6 mm in diameter and 5 mm in length were implanted between the common iliac and external iliac artery in 12 adult dogs. The grafts were explanted between the first and the sixth months which followed the implantations. The healing process was observed by gross examination, microscopic and scanning electron microscopic examination. Prostaglandin PGE2, TXB2, 6 keto PGF1 alpha and PGF2 alpha were measured by radioimmunologic assay from samples retrieved from the medium part of the graft. During implantation, there was no notable difference in blood loss through the graft. At the time of explantation, 20 grafts were patent (10 CHG, 10 CG). In both grafts, the healing process developed progressively between 2 and 6 months and 90% of the internal surface of the grafts were covered with endothelial like cells. At 6 months, the internal layer was thinner in heparinized graft. PGI2 secretion was found with the two types of grafts. In conclusion, the present study showed no difference in the blood loss or healing characteristic of CHG and CG except for a potentially thinner internal layer with CHG. Comparative studies in humans are necessary to evaluate the potential benefit of heparin bonded graft in clinical practice.