FRESH VEIN ALLOGRAFT SURVIVAL IN DOGS AFTER CYCLOSPORINE TREATMENT

Synthetic grafts are widely used for peripheral arterial reconstructio ns when autologous veins are not available, but their results have not been satisfactory, Venous allograft may be used as an alternative to synthetic prostheses, The aim of the study was to explore the immunosu ppressive efficacy of Cyclosporine A (CyA) as a means of preventing ve nous allograft failures and rejection. We utilized 56 mongrel dogs, Im munological incompatibility was checked with the skin graft method. Do nor inferior vena cava was transplated into the infrarenal abdominal a orta of recipient animals. One group (group 1, 10 dogs) served as a co ntrol and three groups received CyA treatment regimens, Group 2 (10 do gs) received postoperative oral CyA treatment for 30 days. Group 3 (12 dogs) received a vein graft pretreated with a CS A solution without p ostoperative immunosuppressive therapy. Group 4 (9 dogs) received a ve in graft pretreated with a CyA solution and postoperative CyA treatmen t for 30 days. Allografts were examined at 30 days for patency, aneury smal dilatation, gross structural changes, inflammatory response, and lymphocytic infiltration. Sex chromatine assessment determined the ori gin (donor or recipient) of the endothelial cells. The allografts hom groups 1 and 3 showed significant aneurysmal dilatation and perivenous inflammation when compared to dogs treated with oral CyA therapy (P < 0.0002). Moreover allografts treated with CyA therapy had a better-de veloped venous neointima (P < 0.009) with less fibrin (P < 0.02), and thinner medial (P < 0.0009) and adventitial layers (P < 0.02). No sign ificant differences were observed in neointimal thickness among the fo ur groups. Lymphocytic infiltration was greater in the group of animal s who did not receive oral CyA therapy (P < 0.0004), Barr bodies statu s showed significant differences between oral CyA treated groups and n ontreated groups (P < 0.0003). Oral CyA therapy reduced aneurysmal dil atation and immunological response, promoted the development of a neoe ndothelium, and preserved the structure of the venous layers. Graft pr etreatment with CyA flushing did not have a significant immunosuppress ive effect. (C) 1996 Academic Press, Inc.