Effect of fVII and/or fXI ASO treatment on the time to catheter occlusion. Rabbits (n = 8-12 per group) were given a 4-week course of control ASO, fVII or fXI ASO, or fVII plus fXI ASO combination subcutaneously prior to insertion of a catheter into their jugular veins and treatment was continued. Catheter occlusion was assessed as described. The bars represent the mean of at least 8 separate experiments, whereas the lines above the bars reflect the SD. *P < .001 compared with the control.