Purpose: To investigate the neointimal response to poly(organo)phosphazene- and amphiphilic polyurethane-coated, oversized, stainless steel stents implanted in porcine peripheral arteries.
Methods: Nonarticulated, stainless steel, slotted-tube stents were coated with 1) a biodegradable poly-(organo)phosphazene with aminoacid ester side groups and 2) a biostable polyurethane prepared from an amphiphilic polyether, diphenyl methane-4,4'-diisocyanate and butane diol as chain extender. The stents were deployed in porcine peripheral arteries using an oversized balloon.
Results: The neonintimal response to amphiphilic polyurethane-coated stents was similar to the uncoated metallic stents. Poly(organo)phosphazene-coated stents, however, induced a severe histiolymphocytic and fibromuscular reaction resembling a foreign body reaction.
Conclusions: Amphiphilic polyurethane is very promising as a biocompatible stent coating. Poly-(organo)phosphazene, however, appears unsuitable for this purpose.