Cryopreserved Venous Allografts Pretreated with Cyclosporine Revisited

In 1983 Bandlien et al reported that pretreatment of cryopreserved jugular allografts with cyclosporine (CsA) reduced immunogenicity and increased the patency of these grafts in the canine carotid artery. The purpose of this study was to determine whether CsA pretreatment of nonreversed cephalic venous allografts modifies the histologic events or increases patency in the canine femoral artery. The authors also wished to document the histologic events in the nonreversed cryopreserved cephalic autograft and allograft over a five-month period. Thirty-six nonreserved cephalic grafts were interposed in the canine femoral artery. Right venoarterial grafts were cryopreserved with CsA and the left grafts were cryopreserved without CsA. There were 28 allografts and 8 autografts so treated. Cryopreserved autograft endothelial cells (ECs) were quite well pre served on preoperative biopsies and rapidly repopulated the intima in one to three weeks like fresh autografts. All autografts remained patent. In contrast, allograft ECs disappeared early and were very slowly replaced with host ECs in the midgraft after five months. The allograft patency was more than 70 % in weighted analysis for the early periods studied without significant difference between CsA and control groups. Pretreatment with CsA did not appear to spare endothelium or influence the immune process significantly.