 3. Vascular disease infrapopliteal atherosclerotic of severe degree Patients with category Rutherford-Becker 4, pretty or bilateral. The critical ischemia of the foot is defined as a persistent persistent pain that needs analgesia and or not healing present sores 4 weeks, without evidence of improvement with conventional therapies and or walking test between 1-6 minutes in two ergometries separated at least for 2 weeks and or index ankle - arm in rest 0,8. 