Silver Graft

Warp-knitted, double-velour vascular prosthesis of polyester

Silver Graft protheses are warp-knitted, double-velour vascular prostheses made of polyethylene terephthalate (polyester) for reconstructive procedures on the aorta and arteries in the peripheral area. They are impregnated with absorbable modified bovine gelatin for temporary sealing. The outer surfaces of the prostheses are coated by a metallic silver layer to inhibit microbial adhesion. Temporary sealing and inhibition of microbial adhesion are confirmed by product tests as well as preclinical in vivo and in vitro tests. Silver Graft prostheses are available in different lengths and diameters.

Mode of action

The functional properties of 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. This modified bovine gelatin impregnation reduces the initial porosity of the textile prosthesis at the time of implantation of approximately to 0 ml/min/cm². From outside the impregnation of the prosthesis is enzymatically degraded and absorbed within 4-6 weeks after implantation, as shown in a publication by Ueberueck et al. in 2005. During this time endogenous tissue incorporates the prosthesis into the surrounding tissue and takes over the sealing function. On the inner side of the prosthesis a cell layer is formed, referred to as pseudo neointima. 
Silver Graft Helix is wrapped with an external polypropylene thread around the outside of the prosthetic wall to protect the prosthesis against mechanical pressure from outside and increase the kink-stability.

Intended use

• Reconstructive procedures on the aorta and in the peripheral area requiring a prosthesis with at least 6 mm in diameter. Axillofemoral and –bifemoral reconstructions are also indicated.
• Silver Graft can be implanted prophylactically as a protection against vascular graft infection. It is designed for long-term protection avoiding adhesion of microbes to the surface of the textile prosthesis.

MRI Safety and Compatibility

 Magnetic resonance Imaging (MRI) can be safely done in patients with implanted Silver Graft vascular prostheses under the following conditions:

• Static magnetic field: 1.5 T and 3 T
• Maximum spatial field gradient: 6.6 T/m
• Whole body averaged specific absorption rate (SAR): 2 W/kg

Indication

Silver Graft is intended for use as vascular prosthesis for replacement or bypass of diseased vessels in patients suffering from aneurysmal or occlusive disease. The supported helix variant is particularly intended for use in locations that are exerted to increased mechanical stress. E.g. this is the case for bypasses that are located directly under the skin or for above the knee.