The aim of this study is to assess the efficacy and safety of autologous transplantation of bone-marrow cells for therapeutic angiogenesis and vasculogenesis in diabetic patients with non-revascularizable critical limb ischemia.

Phase I/II, prospective, single-center study, with consecutive inclusion of 20 diabetic patients with critical limb ischemia due to bellow-the-knee extensive arterial disease.

After the inclusion, patients are submitted to a bone-marrow aspiration (30 ml) under sedation. Autologous bone-marrow mononuclear cells (minimum 80 millions mononuclear cells) are infused intraarterially at popliteal artery by blocking antegrade perfusion during 3 minutes.

Clinical and angiographic follow-up will be performed at 3 months after the infusion to assess the efficacy of autologous mononuclear cells transplantation in terms of:

• Changes in below-the-knee angiography from baseline to 3 months follow-up.
• Changes in Ankle-Brachial pressure Index, transcutaneous oxygen pressure, and size of main ischemic ulcer will be also assessed at target limb.

Inclusion Criteria:

• Diabetic patients under treatment (type I or II)
• Critical limb ischemia (rest pain and/or non-healing ischemic ulcers lasting more than 4 weeks, and/or Ankle-Brachial Index < 0,8)
• Not suitable to be revascularized (surgical and interventional consensus)

Exclusion Criteria:

• Neoplastic disease and/or hematologic disease during the last 2 years
• Diabetic retinopathy
• Ischemic ulcer greater than 10 cm2
• Major amputation at target limb
• Life expectancy > 2 years