Prosthetic vascular conduit in contaminated fields: a new technology to decrease ePTFE infections

Vascular reconstruction using prosthetic materials in contaminated fields can lead to infection, graft loss, and subsequent amputation. We hypothesized that minocycline and rifampin bound to an ePTFE graft using a unique methacrylate technology would provide for resistance from infection and controlled antibiotic elution. Kirby Bauer susceptibility testing was performed on plates overlaid with Staph aureus (SA) and Staph epidermidis (SE) using 6 mm diameter discs of uncoated graft or antibiotic coated graft (ABX). Zones of inhibition (ZIH) were determined after 24 hours. ABX grafts were then placed in a continuous water bath and a recirculating, pulsatile flow device. Susceptibility testing and high performance liquid chromatography with mass spectroscopy was performed to determine graft performance and antibiotic elution rate. ABX grafts had an average ZIH of 35 mm for SA and 44 mm for SE (each P < 0.0001). After the 1 week water bath, the ZIH of the ABX grafts was 23 mm on both the SA and SE plates. The high performance liquid chromatography with mass spectroscopy revealed that after 24 hours, 50 per cent of the antibiotics remained on the graft, and there was a sustained elution for 7 days. Minocycline and rifampin can be bound to ePTFE vascular grafts using a unique methacrylate method. In vitro, the grafts provide a slow elution of antibiotics that provide resistance from infection by SA and SE for up to 2 weeks after graft insertion.