Recent clinical studies showed an association between Peripheral Artery Disease (PAD) and circulating levels of Matrix Metalloproteinases (MMPs), especially MMP-2, MMP-9, MMP-8 and MMP-10, compared with healthy controls. A recent study showed the association between MMP-10 serum levels and severity and poor outcome in patients affected by Critical Limb Ischemia (CLI).~Also, MMPs seems to be involved in intimal hyperplasia and constrictive remodeling, both responsible of restenosis after surgical treatment of atherosclerotic lesions.~Intimal hyperplasia is a thickening of the tunica intima resulting in narrowing of the vessel lumen.~Elevated tissue levels of MMP-2 and MMP-9 have been identified in pig models of vein bypass grafts, temporally coinciding with the period of Smooth Muscle Cells (SMC) migration and neointimal formation.~In the present study the investigators want to evaluate MMP-1; MMP-2, MMP-9, MMP-8 and MMP-10 serum levels variations in patients affected CLI, before and after lower limb surgical revascularization through venous or prosthetic bypass in order to assess their role in predicting the surgical outcome of these procedures.~Patients with CLI will be randomized to receive lower limb surgical revascularization through autogenous venous (Group I) or prosthetic bypass (using synthetic polytetrafluoroethylene - PTFE- ) (Group II).~Patients enrolled in the present study will be followed through clinical and ultrasonographic examination at 1, 3, 6, 12 and 24 months. At the same time points MMPs plasma levels (by means of blood sampling through venipuncture) will be evaluated. Clinical, Instrumental and Laboratory data then will be matched.
In the present study the investigators will evaluate MMPs. serum levels variations in patients affected by critical limb ischemia, before and after lower limb surgical revascularization through venous or prosthetic bypass.