Warp-knitted, double-velour vascular prosthesis of polyester
Silver Graft is a warp-knitted, double-velour vascular prosthesis of polyester (polyethylene terephthalate/pegoterate), which has been impregnated with absorbable modified bovine gelatine (Polygelin). To avoid microbial adhesion, the textile prosthesis is also coated with a layer of silver on its surface. The gelatine impregnation reduces the initial porosity of the textile prosthesis at the time of implantation from approximately 1900 ml/min/cm² at a pressure of 120 mm Hg to 0 ml/min/cm². Silver Graft is supplied in the form of straight tubes and bifurcations. Silver Graft contains per cm² prosthesis wall 3.4 - 6.5 mg modified bovine gelatin (Polygelin) prepared from bovine gelatin and hexamethylene diisocyanate. Silver is a component at a concentration of 0.07 - 0.16 mg/cm². Other ingredients are glycerol, polyester (polyethylene terephthalate/pegoterate), water, titanium, palladium and carbon, which forms part of the orienting thread.
The functional properties of the vascular prosthesis Silver Graft are based on the principle that a highly porous textile construction is temporarily sealed by a biologically degradable mass, which does not possess any independent pharmacological properties. The gelatine impregnation of the prosthesis is enzymatically degraded and absorbed within 4-6 weeks after implantation. During this time endogenous tissue takes on the sealing function of the modified gelatin and a cell layer, referred to as a neointima, forms on the inside surface of the prosthesis.