[Chronic arterial rejection and immunogenicity of the extracellular matrix in iso-, allo- and xenograft in rats].

Both allografts and xenografts chronic arterial injection results in arterial wall dilation and rupture, making them unsuitable for long term-arterial replacement in vascular surgery. Cells in the arterial wall carry major antigenic determinants and can be removed by detergent treatment to produce a graftable proteic matrix tube. We compared the patency and the macroscopic and microscopic morphological changes that occurred in sodium dodecyl sulfate (SDS)-treated and untreated arterial iso-, allo- and xenografts, two months after implantation in 63 rats. We quantified elastin, collagen and nuclear density in the three layers of the grafts by morphometric methods. SDS treatment removed endothelial and smooth muscle cells, but preserved elastin and collagen extracellular matrix. All arterial xenografts, whether SDS-treated or untreated, were aneurysmal two months after grafting, with loss of the medial cellular and extracellular components. In allografts, SDS treatment prevented dilation, reduced aventitial inflammatory infiltration and preserved medial elastin. SDS-treated allografts had an evenly distributed, non-inflammatory intimal thickness that was richer in elastin fibers than untreated allografts. These results suggest an interspecies, but not an intraspecies, graft antigenicity of arterial extracellular matrix. SDS treatment prevented chronic rejection of the arterial allograft and led to the proliferation of an elastin-rich and adapted intima.