[Allogenic and xenogenic aortic segmental transplants in inbred rats angiographically demonstrable vascular changes...

In order to make a systematic study of the significance of immunological reactions in vascular grafts, segments of abdominal aorta (4-5 mm long) were grafted into inbred rats. Four experimental combinations were used: I. syngeneic (CDF leads to CDF), II. weakly allogeneic (LEW leads to CDF), III. strongly allogeneic (BD 5 leads to CDF), IV. xenogeneic (guinea pig leads to CDF). After 100 days the gaft was macroscopically evaluated, angiographed and measured. Whereas no alterations of the vascular wall were found in group I, the degree of aneurysm formation increased significantly corresponding to the degree of histoincompatibility in the other groups: group II showed little aneurysm formation (medicum size 1.27 fold), group III more pronounced (1.71 fold) and group IV very pronounced (3.9 fold) with partial thrombosis in 3/5 of the cases. These findings are interpreted, as functional and morphological consequences of the immunogenicity of the aorta tissue. The conclusion was reached that the degree of histoincompatibility should be more carefully considered, also in vascular grafting.