Inflammation and neovascularization associated with clinically used vascular prosthetic materials

This study was designed to evaluate and compare healing characteristics, sp ecifically neovascularization and inflammation, of polymeric vascular graft materials commonly used in clinical applications. Our hypotheses were (i) polymeric materials used in vascular graft manufacture stimulate chronic in flammation and (ii) inflammation and neovascularization of polymeric materi als are related. Impra and Gore-Tex ePTFE, Meadox weavenit and woven Dacron , Hemashield microvel and woven Dacron, and Golaski microknit Dacron were i mplanted as 6-mm diameter disks within rat subcutaneous and adipose tissue. Following 5 weeks of implantation samples were evaluated by histological a nd immunocytochemical analysis. Sections were stained using hematoxylin and eosin or reacted with ED1 antibody and GSI lectin to quantify inflammation and neovascularization, respectively. The extent of inflammation and neova scularization were influenced by both tissue site of implantation and polym er characteristics. For subcutaneous implants, inflammation was graded as f ollows: Meadox weavenit > Hemashield woven > Meadox woven > Gore-Tex ePTFE > Hemashield microvel > Impra ePTFE > Golaski microknit, while only the Gol aski microknit neovascularized. Inflammation was graded as follows for adip ose implants: Hemashield woven > Hemashield microvel > Meadox weavenit > Me adox woven > Gore-Ter ePTFE > Golaski microknit > Impra ePTFE, while the fo llowing order of neovascularization was observed: Impra ePTFE > Gore-Tex eP TFE > Golaski microknit. The degree of inflammation following biomaterial i mplantation has a profound effect on implant neovascularization. These data suggest an inverse relationship exists between inflammation and neovascula rization. (C) 1999 by Elsevier Science Inc.