Thrombosis of an aortic porcine xenobioprosthesis associated with familial antithrombin III deficiency.

Thrombosis of a porcine xenobioprosthesis in the aortic position associated with antithrombin III deficiency has not been reported. Admittedly a rare coagulation abnormality, it should be suspected in patients with previous tendencies or family history toward spontaneous thrombosis, especially in those with Scandinavian ancestry. Special precautions should be taken if a cardiac operation becomes necessary.