Vascular graft healing. II. FTIR analysis of polyester graft samples from implanted bi-grafts

FTIR-ATR analysis has shown that the 4-step process for preclotting polyest er vascular grafts results in a uniform and reproducible fibrin coating of the polyester fibers. Western blot analyses have shown that FN and VEGF are also present in this fibrin coating. PTIR-ATR analyses of explanted grafts indicate that, while the in vivo healing of these preclotted polyester gra fts proceed through the inflammation, proliferation, and remodeling phases of normal wound healing, these phases are modified. Because the fibrin coat ing provides a nonporous barrier between peri-graft tissue and the flowing blood, these molecular changes are controlled by the interactions of blood- borne constituents with the lumenal surface of the preclotted graft. Also, a well prepared preclotted polyester graft shows a minimal inflammatory res ponse. After implantation, the fibrin preclot is more than 90% gone by the fifth day. However, the proliferation phase, involving synthesis of new pro tein and polysaccharide materials to replace the fibrin, appears to have be gun by the third day. Detection of collagen I in the 5-day explants suggest s that the overlapping remodeling phase of healing has begun. Protein and s accharide materials continue to be synthesized and remodeled, and, by the t enth day, collagen IV is detected. By 14-days post-implantation, there is a n increase in collagen IV and cellular membrane lipids. Because collagen IV is an indicator of the presence of endothelial cells, some of these cellul ar membranes must be of endothelial origin. Thus, it appears that FTIR-ATR can be a useful tool in the study of vascular healing. (C) 2001 John Wiley & Sons. Inc.