Thrombosis associated with a porcine bioprosthesis and ascending aortic graft in a patient with the Marfan syndrome.

A fatal thrombosis originating at the junction of an aortic bioprosthetic heart valve and a Dacron aortic graft was observed in a patient with the Marfan syndrome, who had had replacement of the ascending aorta with a valved conduit 29 months previously. This unique complication raises the question of whether patients with such prostheses should be on a program of full anticoagulation.