If problems with your veins prevents you from having an AV fistula, you may need an AV graft instead. To create an AV graft, your surgeon uses a man-made tube to connect an artery to a vein. you can use AV graft for dialysis soon after surgery. However, you are more likely to have problems with infection and blood clots. Repeated blood clots can block the flow of blood through the graft and make it hard or impossible to have dialysis.