Use of bovine collagen for collagen arterial grafts raises the problem of possible contamination with the agents causing subacute spongiform encephalopathy. The safety of these products is the confirmed by the manufacturers and the risk of contamination is practically zero. A prospective non-randomized study conducted from January 1991 to December 1992 compared non-impregnated arterial stents with collagen arterial stents. Among the parameters studied, only the amount of blood transfused was significantly different. Collagen arterial grafts generated less blood loss.