Vesalius18 in 1542 began the quest for synthetic arterial substitutes by inserting reeds in the femoral arteries of animals, and this search has by no means ended.1,4,14,16,17 The reported high incidence of thromboses in synthetic grafts less than 8 mm2,10,19 testifies eloquently to the need of further refinements. Although many factors influence patency, in the present study "wettability" of the graft was reduced with silicone in an attempt to decrease the thickness of the pseudointima and thus the incidence of thrombosis. It is well known that the degree of tissue reaction incited by a fabric graft directly determines the thickness and healing time of the neointima, and that the degree of tissue reaction incited is directly proportional among other things to the degree to which the fabric absorbs tissue fluids.6,11 The limited "wettability" of Teflon resulting in a virtual absence of acute inflammatory changes and chronic