Prevention of Autogenous Vein Graft Failure in Peripheral Artery Bypass Procedures

PATIENTS MUST: * Be scheduled to undergo infra-inguinal bypass grafting surgery using excised autogenous vein for Chronic Critical Limb Ischemia (i.e., rest pain, non-healing ulceration or gangrene). For patients presenting with rest pain as the only manifestation of CCLI, must have the diagnosis confirmed by at least one of the following,: i.) an ankle pressure of \< 50 mmHg (or ABI \<0.4), ii.) a toe pressure \< 30 mmHg, iii.) a reduced TCPO2 \< 30 mmHg, or iv.) a severely ischemic or flat line transtarsal pulse volume recording (i.e., Category V). * Be males or females of at least 18 years old. * Have agreed to participate voluntarily and signed and dated an IRB-approved, Patient Informed Consent form. * Have a documented negative serum pregnancy test for all women of childbearing potential. * Be using an acceptable method of birth control if of reproductive potential. * Note: Patients undergoing operations to replace previously occluded grafts that involve placement of an entirely new bypass graft ARE eligible for this study.