Platelet avidity of cryopreserved veins: thrombogenicity of cryopreserved veins

Prior work has suggested that cryopreserved venous allografts may serve as an effective arterial substitute. To determine the relative thrombogenicity of this material, platelet uptake of cryopreserved canine jugular veins (CJV) before and after deendothelialization was compared to fresh CJV before and after deendothelialization, and to PTFE. CJV were frozen in Medium 199 (M199) with 10% dimethylsulfoxide to -70 degrees C. CJV were deendothelialized with collagenase (165 u/mg Worthington type II in phosphate-buffered saline) for 15 min at 37 degrees C. Canine platelets were harvested, labeled with indium-III-oxine, and suspended in 1 liter of M199. Labeled platelets were used to perfuse each graft in a nonpulsatile flow loop for 120 min. Deendothelialization led to a significant increase in platelet uptake (P less than 0.05). Frozen deendothelialized CJV showed the highest affinity for platelets. PTFE, cryopreserved, and fresh CJV showed similar affinity for platelets. Cryopreservation alone did not seem to inhibit the ability of endothelial cells to act as a nonthrombogenic surface and did not alter the histologic structure of the veins.