Thromboplastic and fibrinolytic activity of autogenous-free vein grafts used as abdominal aorta replacements in dogs.

In the intima of a vein grafted into the aorta, the thromboplastic activity during the first 4 months after the operations is higher than in the artery and vein. At the same time, the plasminogen activator activity of the venous graft is also higher than that of the artery but lower than that of the vein. In the later post-operative period, both activities of the intima of the venous graft closely approaches those of the intima of the normal vein. In the media the thromboplastic activity is lower in the graft and the plasminogen activator content is higher than in the artery and vein. However, the thromboplastic and fibrinolytic activity in the adventitia of the venous graft, artery, and vein did not change significantly during the 36-month observation period of the experiment.