Long-term evaluation of a growable graft

The safety of a vascular graft that can grow with the growth of its recipients was evaluated during long-term implantation in experimental animals. An acellular matrix made of human saphenous vein was cross-linked with a polyepoxy compound to give controlled biodegradability, hydrophilicity, and antithrombogenic properties. Four millimeter internal diameter (ID) grafts, enveloped with a polyester mesh tube of 10 mm ID were implanted in 15 puppies. The diameter of the graft grew to 9.5 mm after 1 year from the original 4 mm, and remained stable for 2 years and 7 months of observation. The newly formed neointima reinforced with polyester mesh was composed of smooth muscle cells covered with endothelial cells. The original vein graft was completely absorbed, and there were no degenerative changes such as calcification or aneurysmal dilatation. The graft maintained the expected size.