Enhanced graft healing of high-porosity expanded polytetrafluoroethylene grafts by covalent bonding of fibronectin

The effect of covalent bonding of fibronectin on the patency and graft heal ing of high-porosity expanded polytetrafluoroethylene (ePTFE) grafts was ev aluated. Bilateral carotid grafting was performed in ten mongrel dogs using high-porosity (60 mu m) ePTFE grafts, 4cm in length and 4mm in internal di ameter, that either had been pretreated by the covalent bonding of fibronec tin (fibronectin grafts) or were untreated (control grafts). The grafts wer e harvested 4 to 6 weeks after surgery and subjected to macroscopic and lig ht-microscopic observations. There was no significant difference in patency between the fibronectin grafts and the control grafts with rates of 80% an d 70%, respectively. The thrombus-free area score was significantly greater in the fibronectin grafts than in the control grafts, at 86.9% vs 34.0%, F urthermore, the pseudointima was better replaced by fibrous tissue in the f ibronectin grafts than in the control grafts, being lined with a Layer of e ndothelial-Like cells, More transmural tissue ingrowth was evident in the f ibronectin grafts than in the control grafts. The covalent bonding of fibro nectin improves graft healing by stimulating transmural tissue ingrowth in high-porosity ePTFE grafts.