This is a study of the use of an antibacterial solution, Hypochlorous acid, to prevent infection in vascular surgery bypass grafts. The solution will be used at the end of operations to insert a prosthetic vascular surgery bypass graft, to wash the wound and the vascular bypass graft before the wound is closed. The patients in this study will be undergoing surgery for problems with narrowed and or blocked arteries. The presence or absence of a graft infection will be followed for 12 months following the surgery. Prosthetic vascular graft infections have significant implications for patients with high rates of death and amputation, hence preventing them will have significant benefits for patients and the health care system.