CELL-FREE ARTERIAL GRAFTS - MORPHOLOGIC CHARACTERISTICS OF AORTIC ISOGRAFTS, ALLOGRAFTS, AND XENOGRAFTS IN RATS

Purpose: Chronic rejection of arterial allografts and xenografts resul ts in arterial wall dilation and rupture, making them unsuitable for l ong-term arterial replacement in vascular surgery. In the arterial wal l, as in other organs, the cells probably carry major antigenic determ inants. Arterial wall cellular components can be removed by detergent treatment to produce a graftable matrix tube. Methods: We compared the patency and macroscopic and microscopic morphologic changes that occu rred in sodium dodecyl sulfate (SDS)-treated and untreated arterial is ografts, allografts, and xenografts 2 months after implantation in rat s. We quantified elastin, collagen, and nuclear density in the three l ayers of the graft wall (intima, media, and adventitia) by morphometri c methods. The SDS treatment removed endothelial and smooth muscle cel ls and cells in the adventitia but preserved elastin and collagen extr acellular matrix. Results: All arterial xenografts, whether SDS treate d or untreated, were aneurysmal 2 months after grafting, with loss of the medial cellular and extracellular components. In allografts, SDS t reatment prevented dilation, reduced adventitial inflammatory infiltra tion, and preserved medial elastin. The SDS-treated allografts had an evenly distributed, noninflammatory intimal thickening that was richer in elastin fibers than that in untreated allografts. Conclusions: The se results suggest an interspecies, but not an intraspecies, graft ant igenicity of arterial extracellular matrix. The SDS treatment prevente d chronic rejection of the arterial allograft and led to the prolifera tion of an elastin-rich and adapted intima.