A New Antithrombogenic Coating Material — Fluorine-Acryl-Styrene-Urethane Silicone Graft-Block Copolymer — for a Circulatory Assist Device

Summary

To assess the effectiveness of a fluorine-acryl-styrene-urethane-silicone (FASUS) graft-block copolymer (DIA Medical Supply, Chiba, Japan) as a new antithrombogenic coating material, we evaluated it in a veno-arterial bypass (VAB) circuit in a canine model. Twelve dogs, divided into two groups, underwent femoro-femoral VAB without an oxygenator for 6 h at a mean flow of 500ml/min. In the control group (control, n = 6), non-coated polyvinyl chloride tubes and nylon cannulas were used. In the FASUS-coating group (coated, n = 6), all tubing materials and cannulas were coated with a FASUS copolymer. Heparin (0.5 mg/kg) was administered only initially. After the VAB was completed we examined macroscopic clots on the material surfaces, and we examined microthrombus formation and platelet morphology by, using a scanning electron microscope (SEM), to evaluate thrombogenicity. Both macroscopic and microscopic examinations, showed that all tubing materials in the control group had major clots. By contrast, no clots were observed in any portions of the entire circuits of the coated group. SEM examinations revealed thick layers of platelet aggregation and fibrin sheets that had firmly adhered to the uncoated surfaces, whereas in the coated group, morphologic platelet changes were slight. These data suggest that a FASUS polymer coating over the entire VAB circuit is effective for preventing thrombus formation.