IN-VITRO AND IN-VIVO CALCIFICATION OF VASCULAR BIOPROSTHESES

Efficacy of different chemical treatments on calcification of vascular graft in vitro and in vivo was studied. Culture medium-filled rat aor tas were separately treated in 0.2% glutaraldehyde and epoxy compound, and photooxidized in 0.01% methylene blue for a shorter period (group 1). Another group of rat aortas were separately treated in the same c hemicals for a longer period (group 2). All fresh and treated aortas o f both groups were cultured for 21 days in an organ culture medium and implanted (except for group 1) in weanling rats for five months. Hist ology and immunohistochemistry revealed that differently treated aorta s of group 1 grow and calcify, and the smooth muscle cells between ela stin fibers are the primary site of calcium deposition. In contrast, d ifferently treated aortas of group 2 neither grew, nor did calcify in the medium except the epoxy compound cross-linked aorta of group 2 whi ch did not grow but did calcify. Untreated aorta did not calcify. All fresh and differently treated aortic homografts calcified severely in rats. Our whole arterial segment-calcification system would be useful for analyzing the molecular and cellular mechanisms of both bioprosthe tic and atherosclerotic calcification of vascular graft. New anticalci fication technique is the only hope for better outcome of future vascu lar bioprostheses. (C) 1998 Published by Elsevier Science Ltd. All rig hts reserved.