Functional neointima characterization of vascular prostheses in human

Background. The purpose of this study was to evaluate neointimal functionality of synthetic vascular grafts repopulated by host cells after implantation. Methods. We obtained reseeded inflow and outflow cannulas of 2 patients undergoing orthotopic heart transplantation after left ventricular assist device implantation 9 and 10 months before. After cell isolation we examined cellular function of reseeded cells and their capability to form a functional endothelial layer applying immunohistologic markers and quantitative Western blot for endothelial nitric oxide synthase activity. Results. Neointima formation in inflow and outflow cannulas differs macroscopically and by histologic appearance. The neointima formation on the surface of the polyethylene terephthalate fiber (Dacron) grafts differs substantially from native aortic vessel wall with respect to cellular and extracellular matrix composition and cellular function. Conclusions. The neointima of Dacron prostheses is composed of cells with rudimentary physiologic endothelial function. We conclude that synthetic matrices are not suitable scaffolds for generating functional cardiovascular implants.